We Need to Say “Yes!” to Air Conditioning


Guest Essay by Kip Hansen


Contrary to the common mantra that we must turn the thermostat up on our air conditioners to cut down on electrical energy usage — in order to save the planet from sure destruction — a recent article in the New York Times offered a different perspective.

If You Fix This, You Fix a Big Piece of the Climate Puzzle”  by Lisa Friedman (July 13, 2017) offered us a little one-question quiz:

“There’s no single solution for climate change, but there is one that would be more effective than others. What do you think it is?”

The multiple choice answers were:

Build more wind farms

Eat less meat worldwide

Improve air conditioners

Switch to mass transit

If you picked “Improve air-conditioners” you were rewarded with a cheery message (and the rest of the article, hidden until this point):

“You’re right! Curbing 87 percent of the climate change pollutants found in air-conditioners by 2050 could eliminate 89.7 gigatons of emissions.”

“New research from the Lawrence Berkeley National Laboratory in California indicates that adding improved efficiency in refrigeration and phasing out fluorinated gases used for cooling, as mandated by international agreement, could eliminate a full degree Celsius of warming by 2100.”

The new research is this paper: “Opportunities for Simultaneous Efficiency Improvement and Refrigerant Transition in Air Conditioning” by N.K. Shah and others.  [The 108-page paper is available for viewing online or as a free  downloadable .pdf].

The thrust of the paper is that if we do two things, we will save a lot of energy and emit fewer GHGs.  And if we do, these actions alone could eliminate a full degree Celsius of warming in 2100.  That is of course great news, since it is believed by many now that the temperature rise from a doubling of CO2  would be somewhere around 1 to 1.5 degrees total, a figure which, if we start our counting in 1880, we have already reached, we could totally forestall all global warming by fixing the air conditioner problem!

Despite my somewhat lighthearted description, there is actually something important here — one of those rare opportunities for policy action that is Win-Win, No-Regrets, and helpful to both the developed world and the developing nations —  sensible pragmatic choice that doesn’t cost much — maybe nothing if actual savings cover increased cost.

The solution is to accomplish two things:

1.  Transitioning to low-global warming potential (GWP) refrigerants

According to the Wiki , the refrigerants currently in use are: “chlorofluorocarbon (CFC), hydrochlorofluorocarbon (HCFC), or hydrofluorocarbon (HFC) refrigerant. The refrigerant names include a number indicating the molecular composition (e.g., R-11, R-12, R-22, R-134A). The blend most used in direct-expansion home and building comfort cooling is an HCFC known as chlorodifluoromethane (R-22).

Dichlorodifluoromethane (R-12) was the most common blend used in automobiles in the US until 1994, when most designs changed to R-134A due to the ozone-depleting potential of R-12. R-11 and R-12 are no longer manufactured in the US for this type of application, so the only source for air-conditioning repair purposes is the cleaned and purified gas recovered from other air conditioner systems. Several non-ozone-depleting refrigerants have been developed as alternatives, including R-410A. “

The problem with most of these is two-fold:  CFCs and HCFCs are believed to “deplete the ozone layer” of the atmosphere and are thus being phased out for that reason.  The second is that the newer refrigerants are said to have high Global Warming Potentials — their action as Greenhouse Gases when they eventually end up in the atmosphere.

There are newer alternatives until consideration,  each with lower GWPs but individual problems.  For instance, the “Greenfreeze” refrigerant developed by Greenpeace is a mixture of propane and butane.  Highly flammable, potentially explosive, and only approved in the USA is very small charge loads — ruling it out for air conditioners of  5kW or less.  Similar is R-290 (straight propane).

The paper contains a detailed discussion of current and future refrigerants.

However, the outlook is good that suitable materials will be developed that are not harmful to the environment, not flammable nor explosive, not toxic (like ammonia) and which will have substantially lower GWPs.

These alternatives, if they come without too much of a cost penalty,  will replace existing refrigerants, probably through a combination of social pressure for consumers and corporations to produce and buy “greener” air conditioners, and through international environmental agreements.

2. Efficiency Improvements for Air Conditioners

The major change will be to inverter air conditioners.  The benefits of inverter units are claimed to be:

“At least 30% – 50% cheaper to run as it consumes less power

Far quicker to achieve desired temperature

The start up time is reduced by 30%

Much quieter

No temperature fluctuations, maximising comfort level

No voltage peaks from compressor”

Inverter air conditioners run at variable speeds, depending on the degree of cooling necessary to reach the desired room temperature.   In addition to being variable speed, many inverter air conditions are in effect heat pumps (as are all air conditioners, strictly speaking) but in this case, they can be run “backwards”, pumping heat from the outside air into the room, thus act as heaters as well as coolers.     The heating ability of these inverter/heat-[pump ACs is limited to outside temperatures with a lower limit of 40 degrees F — below that, they don’t function efficiently.  However, this is a great benefit in many applications where HVAC (heating, ventilation, air conditioning) systems need to maintain a narrow room temperature in temperate climates, such as Los Angeles, California, where air conditioning can be needed nearly every day, and heating only occasionally when temperatures drop below 50 degrees.

We Could All Use a Break

We could all use a little break from our energy bills.  But where this really matters is everywhere else — what we call The Rest of the World, ROW.

To quote the New York Times —  “That’s because from India to the Philippines to South Africa, air-conditioners are increasingly a must-have item. Less than 10 percent of homes in India have units, but air-conditioning makes up 40 percent to 60 percent of the country’s electricity demand in major cities like New Delhi. Businesses and homeowners in Asia and Africa are expected to buy an estimated 700 million air-conditioners by 2030, and 1.6 billion by midcentury.”

As energy access increasing in the developing world, the world in which most humans live, the demand for air conditioning will increase — and efficiency will matter a very great deal as their developing electrical grids ramp up to meet the needs and desired of the people.

This is One Useful Thing

Switching refrigerants to less-harmful options and improving the efficiency of air conditioners is a sensible pragmatic action that can be supported and taken now, without having to wait for climate science to get its head straight and policy makers to find the right PC correct political yoga-pose that will get them re-elected.

What’s not to like?

# # # # #


Author’s Comment Policy:

I am always anxious to read your ideas, opinions, and to answer your questions about the subject of the essay, which in this case is how improvements in air conditioning equipment and refrigerants can be a win-win action that has a perceived positive effect on potential global warming.

As regular visitors know, I do not respond to Climate Warrior comments from either side of the Great Climate Divide — feel free to leave your mandatory talking points but do not expect a response from me.

If we have HVAC professional, building engineers or architects  reading here, I’d love to read your take on the suggestions made in the  LBNL paper.

# # # # #

207 thoughts on “We Need to Say “Yes!” to Air Conditioning

  1. The other solution is to have less children. Unless your religion tells you to have more.

    • Jimmy ==> While “have less children” is another popular mantra, history has shown that the only thing — other than war and devastating plague — that reduces population growth dependably is raising the standard of living in rapidly growing populations to near that of developed western countries, many of which now have negative growth rates due to births (total populations in EU grow due to immigration).

      • Kip, haven’t you come to the realization yet that the “have fewer children” mantra has now shifted to the forefront since climate crisis appears to have lost its political power? Of course, population reduction has ALWAYS been the reason behind climate crisis, but you have to understand that if you can’t get people to willingly die through killing the energy generation system, then you have to find another reason for world government. Nations, nor people, will go into population reduction without an overriding world government to force the issue. Having less children can be forced by the government, as was the results of the Chinese experiment. But to get that done world wide will require the world government that was going to come about by climate crisis. If only Mother Nature had cooperated, but no! The Beatles got it partly right, “Here comes the Sun,” but it came without enough heat too early to make everyone fall in line and give up cheap energy, even though the brainwashing was ferocious!
        Don’t worry, Jimmy, alternative sexual orientation will most surely help push down the number of those babies you don’t want!

    • Fewer children is the equivalent of cultural suicide. In extreme forms it is xenocidal.
      It is a fool’s way to deal with problems of environment and resources and has never been shown to be necessary, much less effective.

      • Agree hunter. It is cultural (and I think civilization’s suicide). All in the name of global warming which has been shown over and over to not exist to any measurable level (except by changing the historical data).
        Those who want population control never seem to lead by example. Less population of you and your kind, not for me or my kind.

      • The racist core of environmentalism is the belief that there are too many brown babies. The fact is that nowhere in Europe or North America are white populations increasing by reason of births.

    • What if we just ate our children instead? Does this offset the “eat less meat” thingie..?

    • Jimmy, I read somewhere that the ideal family would have one and a quarter children (Paul Ehrlich maybe). Now I would like to see that.

      • Nevermind, my editor is mis-red squiggling.
        Few people I know have an air conditioner in their home.
        I rely on an air conditioned (cooled) Starbucks during my daily summer bike rides, that often include 3 to 4 hours of bike riding to reach.

      • Beer. I want a beer.
        “Up to one degree by 2100” is almost certaily some deep fable. It is a stretch to get one degree more. And there is a Paris agreement which limits warming to 1.5 C. It all depends on Trump now. Should Trump say we’ll gonna do that, and go to negative emissions by 2030, the climatariat would be happily waiting for their money.
        (may contain traces of sarcasm)

    • Garymount ==> Yes — and No. Refrigerators are on the top five first-buy modern products when the poor finally are hooked up to a dependable 24/7 electrical grid — but they do not suck power like A/C. Frigs in EU have nearly all switched to the new propane-based refrigerants.

      • And people in the UK are having their kitchens explode. It is a huge mistake to populate a country with such potent bombs. As these products age and start to leak propane, this will become even more common.
        Getting down to the facts now. CFCs DO NOT break down ozone. That was a scam perpetrated by Dupont Chemical to get their out-of-patent refrigerant banned in favor of their new, more expensive refrigerant. Now, 20 years later, we have the admission from the scientist, who “discovered” and then claimed that CFCs broke down ozone, that he fabricated the results and the claims. Unfortunately, people still believe in this scam.
        We know now that it is solar radiation and nitrogen gas in the atmosphere that, at very cold temperatures, breaks down ozone. There is nothing we can do about that and it is not our fault.
        And, the whole concept of greenhouse gases is bogus, particularly as they are applied in climate models in which there is no night-time.
        First, no gas at any concentration in the atmosphere can warm the climate, particularly in sunlight.
        Second, these “radiative gases” (their real descriptor) are saturated in sunlight, converting IR to heat and heat to IR, having no net effect, zero effect, nada.
        Third, the upper tropical troposphere is supposed to be where these gases “trap” IR and send it back to Earth’s surface. Two problems here, (1) that part of the atmosphere, dubbed “the hotspot,” is not warm and, according to NASA, has been cooling for close to 40 years and (2) that part of the troposphere is -7 deg C and the surface is 15 deg C, such that the IR send down is reflected and not absorbed; no heating. It is thermodynamically impossible for a cool object to heat a warmer object.
        Fourth, CO2 and water vapor are by far the dominant radiative gases, with all others being pathetically small regardless of fantastic claims of their “power” as greenhouse gases. Methane may be 20 times the radiative gas compared to CO2 but it is in 1/400th of CO2’s concentration and, thus, it is dwarfed by its own scarcity in the atmosphere.
        Fifth, while CO2 and water vapor have no net effect in sunlight, it is during the night that these radiative gases are influential. With no solar energy input, they convert heat energy in the atmosphere to IR which is lost to space. That is why the air chills down so quickly after sunset and why small breezes kick up so quickly on a sunny day with scudding clouds as the air cools in the moving cloud shadows.
        Sixth and most important. Water vapor is part of the water cycle, in which huge amounts of heat energy go to breaking hydrogen bonds between water molecules to form water vapor. This gas makes air less dense and, on a sunny day, this now much less dense air, being warm as well as humid, rises. As it rises, the air cools via adiabatic cooling and eventually the water vapor condenses out at altitude, releasing the latent heat energy from the water vapor. The now-condensed water, then coalesces to droplets and the cool rain or snow falls back to the surface.
        The water cycle is known to all elementary school kids, but “climate scientists” prefer (or must) to ignore this huge, global, heat engine that exerts a powerful negative feedback on global warming. They simply cannot let it be part of their system (models) as their pathetic, non-existent CO2 “effects” would be laughable in the face of real world negative feedbacks, such as the water cycle.

      • To be fair, the Grenfall fridge was of a brand/model that had a known defect that the maker had publicized. Other models are less problematic. (Although they may leak as they age. I’ve just had two fridges wimp out on me—I was told that the tubing becomes permeable with age.)

      • I would like to have a link to “the admission from the scientist, who “discovered” and then claimed that CFCs broke down ozone, that he fabricated the results and the claims.”

      • higley7,
        Several points which don’t fit reality…
        The chlorine in CFC’s does break down ozone. The only point where Solomon and others were wrong is the speed of one of the reaction steps, which was far slower than expected. That means that other reactants in the real atmosphere (including natural chlorinated like meythylchloride – from fungi and algue) have at least as much or more influence. That also doesn’t exclude the role of Dupont to watch their profits with the new patented refrigerants…
        no gas at any concentration in the atmosphere can warm the climate, particularly in sunlight
        Reference? Water vapor does have absorption areas already in the visible spectrum…
        Second, these “radiative gases” (their real descriptor) are saturated in sunlight, converting IR to heat and heat to IR, having no net effect, zero effect, nada.
        Something called “conservation of energy” does contradict that: if the satellites measure less transport of IR in the CO2 bands to space, that energy is conserved somewhere else… Namely the atmosphere. See:
        Third, the upper tropical troposphere is supposed to be where these gases “trap” IR and send it back to Earth’s surface. Two problems here, (1) that part of the atmosphere, dubbed “the hotspot,” is not warm and, according to NASA, has been cooling for close to 40 years
        Less warming of the hot spot region than at the surface is not the same as cooling… See:
        (2) that part of the troposphere is -7 deg C and the surface is 15 deg C, such that the IR send down is reflected and not absorbed; no heating. It is thermodynamically impossible for a cool object to heat a warmer object.
        Sorry Highley, you are completely wrong on that point: it is perfectly possible to melt steel by a laser beam that comes from a CO2 laser cooled with water. A receiving object doesn’t know what the temperature of the sending object was. It simply absorbs the energy contained in it.
        What is right is that a warmer object emits more radiation energy per m2 than a cooler object. Thus overall, more energy is received by the cooler object than by the warmer if they are in each neighborhood. But still the warmer object will cool down less fast in space if a cooler object is near it.
        Thus please, check your facts before jumping to conclusions which are, to say the least, are a little biased…

      • they do not suck power like A/C

        That’s because a refrigerator is a closed system (while the door is closed) whereas an A/C system is anything but!
        Roger Knights comments

        I’ve just had two fridges wimp out on me—I was told that the tubing becomes permeable with age.

        That is probably correct. I have noted in recent years that there is a combination of aluminium and copper tubing in modern refrigerators. Copper and Aluminium set up an electrochemical cell, the result of which is corrosion. The wetter the condition of the cell the faster will be the corrosion. My cynical mind suggests that around 10 years might be a suitable period for “planned obsolescence”.

        • Gary Kerkin ==> The situation ismuch worse on boats like mine — the salt air eats nearly everything, including refrigeration tubing.

      • Ferdinand Englebeen writes: “Something called “conservation of energy” does contradict that: if the satellites measure less transport of IR in the CO2 bands to space, that energy is conserved somewhere else… Namely the atmosphere. “
        Let me guess; you an inorganic chemist? Engineer (not of the biological kind)?
        Ferdinand, is it your opinion that trees, dogs, people and other organic life on this planet simply “grow” magically without consuming any energy?

    • Perhaps we should ask the surviving former residents of the Grenfell Tower in London how mandating “green” refrigerants in domestic refrigerators have affected their lives.

  2. Air conditioning literally saves lives… From a Warmunist perspective, that’s bad for the climate.

      • But Scot, that means they won’t need any aircon up there!
        I’m pointing out you can’t live in 129 degree heat – and that there will be more heatwaves like this coming in the Middle East etc.
        (By the way, you do know why its so cold in Greenland and there’s snow falling right? That cold spot in the ocean from melting ice off S Greenland. Where did that come from??)

      • “you can’t live in 129 degree heat”
        Of course people can. I’ve worked in 140 F before (greenhouse during summer).

      • btw, that article is bogus. It got up to 134 F in parts of the western US in the 1930s.

      • How does meltwater from glaciers produce a temperature that is 33 degrees below freezing? I am not being sarcastic, but serious, since I know so little about this topic. For a non-scientist like me, it is confusing when both sides make contradictory arguments with great passion and conviction.

      • The local prediction is for temperatures above 100 degrees F for the next few days. Hidden in the article is that the record high local temperature was 107 in. . . .1937.

      • ICISIL – Don’t you know that NOAA adjusted those temperatures downwards due to [put lame reason here] and that the temperature in Death Valley was actually only 47 Deg F on that date? Get with the narrative, [snip]!! [/sarc]
        [Your sarcasm is noted, and is fine. “Skeptic” is the preferred tag here, though. -mod]

      • … efficient & renewable … renewable & efficient …
        That’s easy to type and easier to say. What does it mean?
        Efficient with respect to what?
        What is renewable? Hydro power?
        Is the Tonopah solar heater a good example of renewable? Is it a good example of efficient?
        It “just” needs to be … something that does not exist.

      • This is from Griff’s link

        Officially, Death Valley set the record for the hottest temperature ever recorded on Earth on 10 July 1913, soaring to 134F (57C). But Burt posted a devastating critique of that measurement in October 2016, concluding it was “essentially not possible from a meteorological perspective”, and that the weather observer committed errors

        Apparently the next trick of Climate Science DeJour is to make current high temperatures seem like records (the hottest Evah) simply by having the prior record discredited as “errors”

      • “I’m pointing out you can’t live in 129 degree heat”
        Telling porkies again, Grifter?
        Of course you can, you can work in it too.
        In fact, you can work in a lot hotter if the humidity isn’t high.

    • The things he is talking about, these better AC units, the air source heat pumps are great. I have 2 of them on my house in CT USA. I use them when the ambient air is above 35F or so as that’s the break even cost point for them supplying heat to my house versus my oil furnace. Natural gas lines are more than 3/4 a mile from my home, and thus not available. They have saved me 500 gallons of oil this past winter, since I can avoid using oil for most of the spring and fall, and even some winter days. Obviously they cool my home well, and are as quiet as one would want.
      The big thing for me is that using them has saved me hundreds of dollars this past winter in oil costs while cooling my house better than wall/window units. I am a huge fan.

      • Mike ==> Thank you for weighing in on the residential heat-pump HVAC units. Your situation is exactly where the most benefit is found — those spring and fall days where temps require just a bit of warming in the house — heat that is available from the ambient outside air which can be pumped into the house.
        In New York’s Central Hudson Valley, we often have chilly nights and hot days — heat pump/inverter a/c units handle the situation perfectly at reduced cost. Like your home, firing up our furnace to warm the ancient hot water radiators costs too much.

    • Health is what matters. We live in central Arkansas, quite hot & quite humid in summer. I maintain relative humidity at or just under 40% all year long. Maintaining this low humidity costs money but we spend on health care only for annual checkup.
      Besides saving lots of money there, it’s rather pleasant to feel good. I don’t even have flu shots, maybe have a cold once every 8 years. My HVAC is an in-ground geothermal, 3 speed heat pump, uses R-22, makes low cost or free hot water, has a dehumidification cycle, and I also have a sizable dehumidifier as well. Lastly, we also have some air change so the home air isn’t stale.
      Yes, we spend a little more on electricity, but I think we save lots & lots on health care.
      Science has just recently shown that refrigerants had little or nothing to do with the ozone hole, so those changes of refrigerants were a waste of money. I think that perhaps a subsidy for high quality dehumidification would save a lot of money spent on health costs.

      • Exactly right. Mold spores are nasty things and propagate rapidly in living spaces with higher humidity levels.

  3. I think Jimmy Haigh must mean fewer children, rather than children of small stature. He should note that the birthrate Worldwide has been dropping for decades, with the significant exception of equatorial Africa. As the free market economy takes hold there, it will have the same effect of reducing the birthrate it has had in the rest of the developing World. The data suggest that religion does not enter the equation.

    • Right! The hottest place on the whole planet and they’re having the most kids! Don’t they know people can’t live in that kind of heat? Laughably ludicrous conclusions from laughably ludicrous AGW “science”!

    • Birth rates are falling in Africa as well. They just haven’t fallen as far as the rest of the world.

  4. There seem to me to be a range of ways of reducing air con energy use/impact…
    Solar power is often at its most effective at the times when aircon is in use. Solar on your roof means you power (at least in part) your aircon renewably. And perhaps the rest of the grid has solar farms attached.
    Insulated houses – like passivhaus designs – don’t need cooling anyway (or as much)
    The UK uses demand management, where central control over aircon/refrigeration/water pumping city wide allows the control of when aircon fires up and how many sytems fire up at once… massively reduces demand
    There are aircon designs I’ve seen where ice is produced and used in cooling

    • The UK uses demand management …
      Say what? References please, as I’ve never heard of such a thing.

      • Sounds like: if the UK says AC isn’t needed at a certain time, you can’t use yours or they’ll turn it off for you

    • The best way to reduce energy use is to use network analysis to identify all climate extremists and to have all their power cut off in all aspects of their lives. this way the Griffs of the world can demonstrate for us all the wonderful merits of a low carbon lifestyle.
      And if our climate extremists wish to live a negative carbon lifestyle, they can [ snipped — Author. Violates WUWT commenting policy. Please refrain yourself.]

    • Steve
      Well its a complicated subject… and in the time I have I’ve not found a particularly clear explanation to link to..
      But look here in section 2.3.3..
      I’m really referring to these 2 items under ‘automated devices’ section:
      Direct load control – involves installing devices on certain types of plant that
      enable the electricity supplier to (remotely) control consumption. This form of DSR
      is typically applied to loads that can be turned off or cycled for short periods
      without a noticeable loss of service (e.g. air conditioners, water heaters). Remote
      control of electric storage heaters is the most familiar example.
      Dynamic demand control – devices which can be used with any time-flexible
      electrical load (refrigeration, air conditioning, heating etc.). They can turn devices
      on and off in response to changes in the frequency of electricity supply.
      UK has firms which contract with firms using electricity and with National grid, to use devices described to reduce demand. The key is ‘is typically applied to loads that can be turned off or cycled for short periods
      without a noticeable loss of service (e.g. air conditioners, water heaters)’

      • So they shut off your electricity when it gets really hot. That’s what this means.
        The article is basically propaganda. Two speed compressors are almost as efficient as variable speed and much cheaper as they don’t need the inverter electronics. The problem is that home and light commercial A/C uses sealed body compressors that rely on returning refrigerant to cool the compressor windings and mechanical and entrained oil for lubrication. At reduced speed the compressors are much more prone to failure from poor oil return and insufficient cooling. Bottom line is, they aren’t used much in these applications because they are expensive and don’t work very well. pretty much defines Green devices in my experience.
        The amount of power saved never makes up for the extra cost and higher failure rate at lower capacity ratings. Pretty marginal even at 20 tons capacity.
        -Refrigeration and HVAC tech and system designer

    • Griff
      The only way anyone could shut off anything in my house is to cut the power lines. I won’t buy anything that can be controlled remotely. So those Demand Management people can go suck eggs.

    • Griff — You say: “Solar power is often at its most effective at the times when aircon is in use.”
      Not really true. Outside air temperature peaks several hours after peak sunlight due to thermal capacitance of the ground. Inside air temperature peaks later than outside air temperature due to the building’s thermal resistance and capacitance.
      So peak air conditioning loads often occur late afternoon and even early evening when there is little help from solar.
      You would have to get much fancier to have solar support air conditioning fully. Such systems exist — you can freeze water late morning and early afternoon, then melt it to cool the air later, but these are expensive and temperamental systems.

      • Beyond that, many homes are empty during the middle of the day. Peak energy use occurs closer to 5pm as people come home and start cooking dinner.
        This has been explained to Griff many times, but like the lies about German renewable generation and arctic ice, he prefers to tell untruths rather than deal with the world as it is.

      • “Not really true. Outside air temperature peaks several hours after peak sunlight due to thermal capacitance of the ground. Inside air temperature peaks later than outside air temperature due to the building’s thermal resistance and capacitance.”
        From my experience temperatures typically fall just before sunset and gradually fall all night long. I have only seen them go up due to change in wind direction or an increase in cloud cover. So the hour of peak temperature is strongly affected by the weather and location.
        Other factors are the amount of insulation, air infiltration rating of the exterior walls, and weather or not the roof is vented. If you have a well insulated home, low air infiltration and a vented roof you only need a couple of hours of cooling during the day to get the inside temperature down to a comfortable level. Once there the air conditioner can be turned off for most of the late evening or or night. Once the outside air temperature cools enough you can open your windows and night to provide additional cooling if needed. Solar power in this case can easily supply all of the air conditioning power needs.
        My home is 11970s construction and it was very drafty when I got it. I sealed all gaps in the interior walls doors and windows to stop the air leaks. Now if the interior air temperature is 70 in the morning on a very hot day the interior temperature typically reaches 78 by sunset. IF the outside air cools off fast enough i can use fans and open windows to cool it off to 73 by morning. Obviously I don’t need a lot of AC to maintain a comfortable temperature inside.

    • “Griff July 20, 2017 at 5:17 am
      There are aircon designs I’ve seen where ice is produced and used in cooling”
      That’s just a box with a fan on it that blows air across some ice, that’s NOT aircon being discussed. Does not address dehumidification either.

    • “Insulated houses – like passivhaus designs – don’t need cooling anyway”
      My house doesn’t need cooling either, and it isn’t any sort of “Green” design.
      Mind you, it is around 350 years old and the walls are a minimum of three feet thick.
      Plus, in the winter, once it warms up, it acts like a space heater, so doesn’t take a lot of heating.

  5. Better and safer refrigerants have been a form of Grail for a while. If you live in Ontario, the land of excess power to be sold cheap and at a loss to America, shouldn’t you want to use AC?

  6. You didn’t explain well the reason the inverter based system is more efficient. It has to do with duty-cycles. Say you need your A/C (or heat) to run 1/3rd of the time, the traditional approach is a thermostat with warm and cold set points a degree or two apart. The cycling on and off is very inefficient. The inverter approach allows variable drive motors to run at 1/3rd speed (etc.). Continuous operation is much more efficient.

    • Thank you! I was just about to throw the BS flag on energy savings via inverter based systems. However, can you explain why and/or how energy is wasted starting and stopping the A/C system? How much of these gains do you lose during very low load conditions (say, nighttime temperatures of 78 with the thermostat set to 76 degrees)?

      • I would assume the surge currents on the compressor and fan motors starting repeatedly is what makes them less efficient.

      • But what’s not being considered is that cycling a motor will increase its lifetime compared to running one constantly (assuming the winding insulation is adequate to handle repeated surge currents).

      • I Came I Saw I Left July 20, 2017 at 6:37 am
        But what’s not being considered is that cycling a motor will increase its lifetime compared to running one constantly (assuming the winding insulation is adequate to handle repeated surge currents).

        For airconditioners that’s exactly backwards. Running an airconditioner constantly is better for it than having it turn on and off all the time. The extreme of on-off is called short cycling and is very damaging to the airconditioner. link
        Lots of equipment does have a maximum duty cycle. If you run it too long it will overheat and, if you insist on pushing it, burn out. That’s not usually the case with airconditioners.

      • CB, that only applies to an improperly sized unit where the duty cycle is too high.

      • commie and I Came ==> My understanding is that the variable speed units do not necessarily run constantly .. when the room temperature is low enough, consistently, they can shut off altogether — like at night. When running, they vary the motor speed according to the temperature differential between the desired temp and the room air temp. This helps to eliminate the “freezing blast of really cold air” that plagues many a/c installations, one secretary positioned under a cooling vent forced to wear a sweater, while others complain it is still too hot.

      • Variable speed compressors save power because the compressor is more efficient at lower compression ratios ( low speed). Variations on that theme have been used on bigger systems for decades. The present “green mania” has manufacturers applying the principle to systems where it is not a good choice. Lots and lots of “Green” stuff is sold on the basis that it is reliable and cost effective when it is actually the opposite! Solar power, wind energy, etc.

      • ICISIW, the size of the winding doesn’t matter all that much. It’s the extra heat generated while the motor is starting up, plus the extra torque during startup that causes the wear and tear.

      • Ronald, I don’t know all the details, but the industry claim is about a 40% reduction in electricity usage. (I have no first hand knowledge).
        At my house my blower unit is in non-conditioned space, so whenever the unit turns off, the whole blower assembly starts warming up. The next time it is turned on, first the blower unit has to be cooled, then the ducts have to cooled and finally house gets its turn.
        And then it only runs for a few minutes and shuts down just to do it all over again another few minutes later.
        I _assume_ it is the whole blower/ductwork assembly being cycled like that which wastes so much energy.
        At night, I assume it must do some kind of duty cycle, but when it kicks on, it kicks on at some minimal power.
        FYI: Assuming the claim is true, an inverter based system is perfect to tie into a solar panel with battery backup. When an inverter system is pulling power from the mains, the first thing that happens is the mains power is converted to DC, then the inverter creates the appropriate frequency AC.

    • greg ==> Thank you for expanding the explanation. I kind of short-changed readers with “Inverter air conditioners run at variable speeds, depending on the degree of cooling necessary to reach the desired room temperature. ” hoping that those really interested would click through to the link.

  7. Kip:
    Not an HFAC professional, but have them in the family. (1) saying the “outlook is good” that better refrigerants will be developed is a long way from actually having them. And unless the new ones are lubricant- and seal-compatible with R134, they won’t be used to convert existing systems. Propane is a drop-in replacement for R12; R134 is not.
    (2) The variable-speed AC motor controllers have improved drastically in cost and power capacity in the past 15 years and will no doubt find their way into more AC compressors in the near future. I don’t think existing compressors can be retrofitted, so market penetration will be limited to new and replacement systems. Variable speed motors are widely used for furnace circulation fans already.

    • R-134A can be a “drop in replacement” for R-12. I have it running in 3 old Mercedes as a conversion.
      The “trick” is that you must flush the system and then replace the mineral oil with ester based oil. Oh, and change the filler valves with an adapter for the Schrader valve to match the R-134A valve. A little crew on thing with the two different thread sizes on opposite ends.
      I’ve also had 2 other cars converted over the years, but those cars have now gone to car heaven… I’ve used this conversion for many many years now 😉

  8. “New research from the Lawrence Berkeley National Laboratory in California indicates that adding improved efficiency in refrigeration and phasing out fluorinated gases used for cooling, as mandated by international agreement, could eliminate a full degree Celsius of model-based warming by 2100.”

      • I’m attacking the ridiculous notion that this could somehow “prevent” 1C of warming by 2100. It’s not based in reality, at all. Nowhere did I attack the continued improvement of refrigeration efficiency.

      • And it is much more complicated than you realize and decidedly not a common sense based proposal. It is leading edge and as much about marketing as it is about a viable technology. People could save easily twice as much money just by keeping their condensers clean!

    • deebodk ==> The real world point is that no matter how electricity is generated in the future, there will be only a set amount available on/to the grid and more demand means more generation base load needed.
      Any approach that reduces peak-time demand benefits society. Reducing electric bills benefits the end user. Reducing pollution from HCFCs and HFCs — suspected of “harming” the ozone layer (in my opinion, the science is still out on that) and both powerful GHGs can only be good, even if they have a negligible effect.
      All of these are things that have only positive effects — with no downsides.
      There is a small increase in the cost of inverter A/Cs, which might be off-set by the savings in electricity spread over the lifetime of the unit.

      • Again, where did I attack the continued efficiency improvement of these technologies or even the reduction of real pollution? It’s amazing how so many people have reading comprehension problems. I made one correction to a statement that improved its accuracy 100-fold, and that correction was about future warming abatement and that alone. Then I get folks all over my case about something else entirely. Strawman much?

      • If these changes save money, there is no need for them to be mandated by government. They will happen on their own.
        BTW, the jury came back on HCFCs and HFCs effect on the ozone a long time ago. There isn’t any.

  9. In 1917, there were no air conditioners at all. What are the chances that we will be making much more efficient air conditioners in 2117, even without a climate change incentive? I would put it around 100% (barring all out nuclear war or a leftist new world order).
    The future will be far better at dealing with the problems of the future than we are, especially if we don’t hog-tie the present with restrictive carbon mitigation taxes.

    • jclarke341 asked, “What are the chances that we will be making much more efficient air conditioners in 2117?”
      I don’t know but they’re more efficient today than they were 25 years ago.
      … new air conditioners today use about 50 percent less energy than they did in 1990.
      Energy for HVAC systems are a large expense for commercial and residential buildings. The supplier with the lowest energy cost (among several factors) will get the business.

      • And Richard it is why Germans don’t complain about electricity unit prices and use 35% less electricity per household than Us households -efficient appliances

      • Germany has moderate climate. Neither too hot nor too cold. Even so, living in a property, without air-conditioning, heater switching on at 10 pm and off at 6 am can test anyone’s manners. Naturally newer constructions are better equipped, but not everyone can afford them.

      • I installed a 2 ton unit in my house in 1984. The Rated Load Amps were mid 20’s. I installed a 2 ton unit in my ex-wife’s house last week and the Rated Load Amps were 27! Don’t believe everything you read!

      • I don’t think that your energy.gov link is lying, but there is NO support for a 50% better EFFICIENCY on that site. It says they use 50% less power. It may be like “let’s ban vacuum cleaners over 1600W” or arbitrary limitations on power for hair dryers or tea kettles.

      • @Curious George
        Exactly. If the cooling load is reduced by better insulation, low-E glass, vented roofs, etc, then sure, you can probably see a 50% reduction in power used to maintain the same interior conditions. At some point you wind up running into the thermodynamic law of diminishing returns. There is a minimum amount of work necessary to transport heat from point A to point B that’s set by the Carnot cycle.

      • “And Richard it is why Germans don’t complain about electricity unit prices”
        Making stuff up again, Grifter?
        I bet these 350,000 households complain very loudly indeed.
        The electricity was shut down around 350,000 households
        The social problems in the energy sector are increasing: last year the electricity has been disconnected as never before. The reason for this is the rising price of electricity.

        But hey, what does the comfort of 350,000 low-income households matter to you Climate Warriors when you’ve got the planet to save (and especially when you’re being paid to do it)?

  10. Let’s see:
    Step one; Support good “green” energy, and punish evil fossil fuel energy, raising electricity costs to exorbitant levels.
    Step two; Once electricity costs are sufficiently high, support expensive, energy-saving planet-saving technology by offering rebates, tax incentives, etc.
    Step three; ignore that steps one and two have already occurred, further ignoring that the higher initial cost of the new, energy-saving planet-saving technology will more than likely still outweigh the artificially increased cost of electricity.
    Step four; Crow loudly about your “accomplishment” and virtue-signal to your heart’s content.

  11. The biggest problem I have personally encountered with the newer refrigerants is that when the “old” refrigerants are made illegal (like R-12), what might normally be a relatively minor repair turns into a full system replacement.

  12. I think its all wrong:
    1. Refrigerants don’t cause any detectable global warming.
    2. The ozone hole is the same size it has always been. CFCs don’t make any difference to it.
    3. An inverter air conditioner is no more efficient than a good quality new non-inverter air conditioner.
    4. Nothing discussed in the article will make any difference to the world’s climate. Its just more green c**p.

    • Berniea ==> You should read the paper concerned. Inverter/variable speed a/c units are far more energy efficient.

      • Kip, sorry, I just clicked through that paper. It is thoroughly non-technical, repeating the mantra of “efficiency” hundreds of times. Nowhere does it offer a number, other than “we want to achieve a 30% efficiency improvement in 2030”, without a hint how to do it. A total waste of time.

      • BTW, how should I interpret Table 38, China, 2030 Efficiency Improvement, 118-277?

      • Curious ==> The paper, pdf here, is 108 pages of very technical detail about refrigerants, economies, market predictions, etc. The study is to try and predict the effects of a “from 30% efficiency improvement” in air conditioning technology, thus the phrase is repeated.
        Table 38. Range of estimated peak load reduction (GW) in 2030 and 2050 from 30% efficiency improvement and low-GWP refrigerant transition
        If you do not understand the table, I suggest actually reading the associated text — in this case “estimated peak load reduction (GW)” resulting from a 30% increase in efficiency of air conditioners is expected to reduce peak load by 118 –277 GW.
        Really though, you have asked me to do your homework for you while you sling nonsense complaints about a paper that you have not really read with the intention of understanding — a first requirement for learning anything.

    • Bernia
      All true except
      “3. An inverter air conditioner is no more efficient than a good quality new non-inverter air conditioner.”
      As the load increases evaporator temp goes down and condenser temp rises. Pumping continuously at a lower load up a lower temperature difference uses less power.

  13. Since the global warming and ozone depleting effects of CFCs are grossly exaggerated, the correct response is to use the one that is most efficient in cooling.
    Is there any significant difference in the efficiencies of the various refrigerants? You did not address that in the article.
    [Comment rescued. -mod]

    • scarletmacaw ==> The original paper under discussion is 108 pages long. It exhaustively discusses refrigerants, their Global Warming Potentials, and their efficiencies.
      The basic answer is that only refrigerants within a certain efficiency band are even considered commercially viable.
      A/C is a technology that has advanced to the point where the easy savings have already been achieved — but mostly in the motors and compressors. Switching to variable speed inverter air conditioners — already in use in many applications — moves the technology into a lower energy consumption band.
      Changing refrigerants is a matter of the cost of the refrigerant — the new propane and butane based refrigerants being very inexpensive — and the considerations of what happens when old a/cs are disposed of the the gases leak into the atmosphere.

  14. once again they steal 1st, 2nd and 3rd base with the implicit assumption that a tiny amount of a trace gas can raise the global temperature …

  15. Several years ago i had them install a new AC unit in a house i own in Texas, asked them to put in an huge oversized condenser with a variable speed fan, with extra large hoses, put in a lot more glass wool, double pane glass, and made sure everything was well sealed. The electric bill got cut in half. Today I’m sitting in my condo and I’m running two fans, we don’t even run the AC unless it’s above 28 degrees C. It’s nicer to hear the birds and the dogs than sitting in a closed house.

    • Our original thermostat did not have “circulation” as an option. Thus, we set the AC to come on at 25°C (77° F). Once it had cycled a time or two we let it go up a couple of degrees. A new thermostat has the option of the fan coming on a bit every hour. This reduces the stale/stuffiness. Windows are open during the night and closed when outside air reaches the lower inside temperature.

      • Hultquist ==> Sounds like you would benefit from a new “split” inverter a/c unit, maybe even one with heat-pump capabilities. consider it when replacement time comes around.

    • We replaced our old modified roof with a TPO membrane installed on 2″ of industrial insulation. My highest bill so far this summer, with my wife home full time, has been $66.35. Our house is 2496 sq ft. There are more tech fixes than simply AC. Our AC is a 22 year old builders grade system. If the heat doesn’t much get in it is cheap to get it out…..

  16. “However, the outlook is good that suitable materials will be developed …” Really? They’ve been looking for continuously and there isn’t one on the horizon.

    • Coach ==> On the contrary, the newer refrigerant gases are already in use in Europe in nearly 100% of refrigerators — R290a (basically propane). In the US, R290a and other propane/butane mixtures are approved for use in small units only because of the flammability of the gas itself — which is an issue if/when it leaks.
      There are other gases under consideration which are not flammable.
      The truth is most homes are at greater risk from their gas cook stoves and their BBQ grills than they would be from the tiny (2-3 ounces) of propane sealed in their A/C units.
      Regulation will come around on R290a and/or other hydrocarbon gases will be used.

      • Kip “The truth is most homes are at greater risk from their gas cook stoves and their BBQ grills than they would be from the tiny (2-3 ounces) of propane sealed in their A/C units.”
        Tell that to the people in that apartment building in London. The Propane/Butane refrigerator that exploded really warmed up their homes. 🙁

      • Matt ==> There is no evidence that UK refrigerators explode or did explode in this instance. There is a lot of anti-Green propaganda (which I like no better than the pro-Green propaganda).
        Note that there are literally millions of frigs in Eu using R290.
        If you find any official finding that flammable refrigerant caused Grenfell, please post a link, we’d be interested.

    • Actually, you’re both wrong. Next gen fluorocarbon refrigerants are now being sold which are non-ozone depleting and have lower GWP. 134a in automotive use is being replaced by 1234yf, and HFO blends including R449A, R454A and R513A are being sold to replace HFC blends such as R410A and R404A. Conversions of grocery store systems, some of which still use R22 are also accelerating. In grocery refrigerator applications these blends also reduce energy use 7-10%.
      And Kip the refrigerant charge for a home a/c system is not 2-3 oz.

  17. My take away from this is an old idea. If we don’t artificially hobble our economy, and allow technological innovation we will invent our way right out of this made up crisis. A hundred years from now homes will use a fraction of the current energy they now do, and we will have safe clean, and cheap, means of producing an abundance of that energy.
    Now if we can just stop throwing money at three hundred year old obsolete tech we might even do it sooner.

    • Peter ==> Do you work in an office building? Visit a friend in high-rise apartments? Can you imagine the air quality without modern HVAC units circulating, exchanging, and heating/cooling that air?
      Have you ever lived in the tropics? Lived where humidity and temperature (°F) both approach 100 daily? (I have, and it is not pleasant).

  18. “not toxic (like ammonia)”
    The amount of ammonia in a domestic refrigerant unit would be inconsequential. Refrigerators used to be cooled with ammonia.

    • I Came ==> Yes, absolutely right — and with propane. The circle has come around and propane and other hydrocarbons are being used.
      Ammonia has downsides when leaking into homes and office buildings — even small leaks into enclosed spaces unacceptable.

      • Sure it’s unacceptable, but it can be smelled at levels well below its toxicity level, and I doubt the type of leak that typically would develop in a domestic refrigerator would release gas a rate that would be dangerous. Propane is more dangerous and we use it all of the time indoors..

      • The problem with ammonia refrigeration is that it always leaks. I don’t know what it is about them, but if you’ve ever worked around industrial units based on ammonia you’d know that.

    • It is still used in camper fridges. It operates in solution with water for the most part so leaks are more messy than dangerous.

      • John ==> You refer to the RV and motorhome style Dometic electric/propane refrigerators. They do use a water/ammonia refrigerant mixture. These units all have the heating portion of the frig open to the outside, not the inside, so when they are left to rot (a sad but common occurrence), the mess goes outside too. .

  19. A chance to refer to Seichi Konzo …
    [ Seichi “Bud” Konzo (1905 – 1992) was a professor of engineering at the University of Illinois at Urbana-Champaign from 1929-71 and a pioneer in the field of home heating and cooling. He lived in the first air-conditioned house in North America in 1933.
    Konzo published more than 100 technical papers and books as author or co-author, including:
    Summer Air Conditioning, 1958.
    Winter Air Conditioning, 1958.
    The Quiet Indoor Revolution, 1992. ]

  20. Speaking of HVAC:
    Is space cold or hot? There are no molecules in space so our common definitions of hot/cold/heat/energy don’t apply.
    The temperatures of objects in space, e.g. the earth, moon, space station, mars, Venus, etc. are determined by the radiation flowing past them. In the case of the earth, the solar irradiance of 1,368 W/m^2 has a Stefan Boltzmann black body equivalent temperature of 394 K. That’s hot. Sort of.
    But an object’s albedo reflects away some of that energy and reduces that temperature.
    The earth’s albedo reflects away 30% of the sun’s 1,368 W/m^2 energy leaving 70% or 958 W/m^2 to “warm” the earth and at an S-B BB equivalent temperature of 361 K, 33 C colder than the earth with no atmosphere or albedo.
    The earth’s albedo/atmosphere doesn’t keep the earth warm, it keeps the earth cool.
    “The first design consideration for thermal control is insulation — to keep
    heat in for warmth and to keep it out for cooling.”
    “Here on Earth, environmental heat is transferred in the air primarily by
    conduction (collisions between individual air molecules) and convection
    (the circulation or bulk motion of air).”
    Oops! WHAT?! Did they forget to mention RGHE “theory?” Global warming? Climate change? Bad scientists!
    Oh, wait. These must be engineers who actually USE science
    “This is why you can insulate your house basically using the air trapped
    inside your insulation,” said Andrew Hong, an engineer and thermal
    control specialist at NASA’s Johnson Space Center. “Air is a poor
    conductor of heat, and the fibers of home insulation that hold the air still
    minimize convection.”
    “”In space there is no air for conduction or convection,” he added. Space
    is a radiation-dominated environment. Objects heat up by absorbing
    sunlight and they cool off by emitting infrared energy, a form of
    radiation which is invisible to the human eye.”
    Uhh, that’s SPACE NOT EARTH where radiation rules.
    “Without thermal controls, the temperature of the orbiting Space
    Station’s Sun-facing side would soar to 250 degrees F (121 C), while
    thermometers on the dark side would plunge to minus 250 degrees F
    (-157 C). There might be a comfortable spot somewhere in the middle of
    the Station, but searching for it wouldn’t be much fun!”
    121 C plus 273 C = 394 K Ta-dahhh!!!!!
    Shiny insulation keeps the ISS COOL!!!! Just like the earth’s albedo/atmosphere keeps the earth COOL!!! NOT hot like RGHE’s BOGUS “Theory.”

  21. In this vein, have many here read this article on how CFCs almost certainly could not account for any stratospheric ozone depletion?
    A ‘Duck Duck Go’ search for ‘ozone not depleted by cfcs’ puts it at second place in the search results. The data and evidence it presents seem sound.
    Any comments would be appreciated. I aim to convince ‘well educated’ family and friends of our need to be more critical of popular but false environment notions, and I think the CFC scare could lead the way.

    • Thank you. O3 is very reactive – it’s biggest enemy is another O3 molecule. CFCs are inert. UN Vienna Convention and Montreal protocol are based on false premises and should be dissolved.

      • Thanks jaakkokateenkorva. Specifically, the paper makes the claim that sea water evaporation, volcanoes and biomass burning produce chlorine and fluorine in amounts that far exceed those produced by humans with CFCs. So, human impacts here would be negligible, if any at all.
        The paper also underscores the theoretical underpinning of the concern, noting specifically that:
        1) CFCs are too heavy to reach the upper atmosphere, so any chlorine liberated due to UV light would if anything reside in the lower atmosphere, well away from stratospheric ozone
        2) the photochemical process put forward (CFC + UV light = Cl + other stuff) has never been observed in the upper atmosphere (at least at the time of writing, 1989), it was produced in a laboratory only
        3) a single chlorine atom could not destroy nearly countless O3 molecules, or the ozone layer could not exist since chlorine is in such high abundance
        Is the paper to which I refer a good tool to describe what appears to be a hoax?

  22. building homes with windows that open and that have verandahs to shade walls n precool air as well as greenery around the home is a FAR nicer cheaper and affective option over using power and sharing everyones bugs via aircon.
    a simple fan and a spray bottle of water for the 40C days suffices.

  23. Pretty much the same article could have been written substituting “refrigerator” for “air-conditioner”. I recall a number of home-economics articles on reducing costs that said you can replace all the regular light buldb with LED bulbs, and put in more insulation and upgrade your windows to triple-panes, but the best and fasted way to save energy expenses was to replace the 10 year-old fridge with a current model – you will save as much, or more, energy than all the other things combined.

    • Peter ==> Efficiency regulations have greatly reduced the costs of operating home appliances in the US and EU. In the Rest of the World, initial cost of homer-owner appliances is often more important — thus millions of inefficient but cheap a/c units (you can buy a one-room a/c at WalMart for less than a hundred bucks).
      New Refrigerators in EU are all running R290a (propane) refrigerants in units with strict (possibly insane) efficiency requirements. Efficiency requirements are not so strict in the US, but vastly improved over even 20 years ago. I recently attempted to buy a little chest freezer which was very efficient — but it turn out to be so efficient that it had to be run in a temperature controlled environment, like your pantry — it would not work in your garage where the temperature range would be too great — use in a garage voided the warranty.
      Working with regulators to require variable speed units (inverter a/cs) and expanding manufacturing will bring down initial costs, which are currently a little higher — no WalMart cheapies yet.

      • Thanks for a nice illustration. Build a freezer that can’t run anywhere – and you have achieved a 100% efficiency 🙂 Unfortunately, that’s where the world is going.

  24. Notice the article at the link is from Great Britain. Here in RI, where I live, the energy costs are not “spiraling”. I would have to have some very real financial incentive to replace my current central AC with a new, more expensive one.

    • Proud ==> Is your existing unit a heat pump? That is, can it heat and cool? Maine has a pretty low cooling demand compared to Arizona, South Texas, Florida, etc.
      When you current unit comes up for replacement (which it eventually will) you would be wise to consider the newer inverter/variable speed units. Probably not a heat pump capable unit though as your heating needs are greater, although the heat pump unit would keep the house evenly comfortable on those warm days with chilly nights (40-50°F).

  25. ““New research from the Lawrence Berkeley National Laboratory in California indicates that adding improved efficiency in refrigeration and phasing out fluorinated gases used for cooling, as mandated by international agreement, could eliminate a full degree Celsius of warming by 2100.”
    This is an interesting claim.
    I have not been able to find the claim of a 1 degree C temperature reduction by 2100 in the full paper.
    See Figure 1 from the paper.
    The paper states that current radiative forcing from HFC’s is 0.012 W/m^2. Basically zero.
    The paper states that under Business As Usual (BAU), direct radiative forcing from refrigeration could increase to 0.25 W/m^2 by 2050. Basically still zero.
    The paper states that current CO2e emissions (direct leaks and indirect fossil fuel power generation to run units) for stationary refrigeration units is 700 Mtons/year, compared with 36,000 Mtons/year total anthropogenic.
    The paper states in Table ES-4 that a 30% efficiency improvement results in almost 6 times bigger CO2e reductions than phasing out HFC for a lower CO2e (one-fourth the Global Warming Potential) refrigerant. If you replace a high efficiency HFC unit with a lower efficiency non-HFC unit, the overall effect may be an *increase* in CO2e emissions.

    • And don’t forget, the fact that it isn’t warming anymore pretty much dispels the notion that CO2 has any effect anyway! Here we are, twisting and turning and throwing things out to fight a ghost!

  26. Greenpeace did not invent R290 (aka R22a. propane). It has been around for years. The last I heard, the insurance industry has no problem with it.You use 2.5 times less than R22. The head pressure is lower ( less energy used), and the air is colder. Another EPA block. I have been using it for a few years now.

    • Ric Have you not read the news? The Greenfell tower fire is reportedly started by a refrigerator coolant leak.

      • Dave ==> To be fair, while they have identified the original source of the fire to be a particular model of Hotpoint fridge-freezer, they have not made the claim that a coolant leak was to blame. The coolant in that model was called “pentane” in the press (but was probably R290), which is flammable. A modern frig uses only a few ounces of refrigerant. It is possible that it was a leak which was then sparked off by something — but more probably that there was an electrical fault in the wiring inside or to the frig that started the blaze.

      • The guy in whos flat the fire started stated that the fridge “exploded”. An electrical fire won’t do that. Though very likely an official whitewash will ultimately find that R290 was not to blame (and nobody and nothing else either).

      • Greenpeace also pushed for the insulation to be ‘blown’ with flammable gasses instead of HCFCs, so the whole box is a pile of fuel, not just the refrigerant.

        Greenfreeze is insulated with cyclopentane blown polyurethane foam. This replaces the CFC- or HCFC-blown insulation foams currently used in refrigerators. Cyclopentane has no ozone depletion potential (ODP) and the effect of its components on global warming is negligible. The insulation value of cyclopentane blown foam compares favorably with that of CFC-11 blown foam, and is better than HCFC-141b blown foam. According to the UNEP “In the past two years cyclopentane has emerged as the most promising zero Ozone Depleting Potential (ODP) alternative to CFC-11 as a blowing agent for rigid insulation foam.”

        The idea that my fridge could burn, at all, is repugnant and a bit alien to the history here in the USA.
        Having one made with flammable gas in a sealed system is OK, if necessary. Having it coated in plastic blown with gasoline equivalent is, er, a bit daft….

      • “tty July 20, 2017 at 9:43 am
        The guy in whos flat the fire started stated that the fridge “exploded”.”
        I have seen many electrical appliances burn and go bang. To an untrained inexperienced lay person when one sees an appliance go bang with smoke and sparks and fire, that’s seen as an “explosion”.

    • Ric == R22 and 22a are HCFCs more exactly “Chlorodifluoromethane“.
      You are right, of course, propane was one of the original refrigerants many years ago along with ammonia.
      Greenpeace did fund research that developed a blend of propane and isobutane — “Greenfreeze” — for use in refrigerators. The product currently in use is R290 — straight propane. Nearly all new refrigerators in Eu use R290.

      • Please don’t propagate the propaganda that Greenpeace invented the propane / butane mix. I’ve used it since about 1984 or so. George Gobel was my source for the information, and he sold a branded version of something similar to it in the late ’80s / early ’90s (I bought some cans of it while in Texas).
        Has a posting by him from the ’90s listing mixes that work well.
        I converted my 1980 Honda Civic myself, using camping stove fuel iso-Butane and propane torch gas. IIRC, I used about 50 % propane to have the peak pressure be a bit lower than George’s 60/40 mix. I still have the kit I used (including the camp fuel vampire tap and R-12 gauge set) in the garage, though I sold the car in about 1994. Later, I converted my first Mercedes 240-D to the same mix. That was about 1996.
        All Greenpeace has done is taken a well established technology and try to claim they had something to do with it. It’s bogus PR stunts at best.
        George deserves the credit for making this mix known and was very active during the ’80s and ’90s on the old newsgroups. Searching news groups archives (particular sci.energy IIRC) will turn up lots of discussion.
        Tell Greenpeace to stop lying.

      • E.M. ==> Propane was used as a refrigerant back in the days of ammonia. It is not new in any case.
        However, Greenpeace did fund research and development of propane/isobutane mixtures , and the campaign to transition to propane-based refrigerants in Europe, where it is now used in nearly all new household refrigerators.
        They definitely didn’t invent propane.

      • Kip,
        I’m talking specifically about the propane iso-butane mix, not pure propane. Pure propane was one of the first refrigerants and is clearly ‘historical’. The use of propane iso-butane mix is what Greenpeace is claiming to have created, yet it was in use well before their first promotion date (about 1992).
        I had a Honda running on it about 1984 / 1985 and did so for many years. The use was discussed by George Gobel on the sce.energy news group IIRC.
        Any “research” Geenpeace may have done can only consist of trying it, testing it, and saying “Gee, it as good as everyone is saying”, not any invention.
        That they are responsible for promotion of it, I have no doubt. They are very good at self promotion.
        More details here:

      • E.M. ==> The latest R290 is just “HC — R-290 — Propane — C3H8 or CH3CH2CH3” — R290 is what is generally in use in EU refrigerators — not the mix of propane and iso-butane developed and promoted by Greenpeace.

      • Kip,
        AGAIN you address a point I did not raise and do not care about. I said nothing about R-290.
        Raising that as some kind of counter point to my only topic, that George Gobel published the iso-butane propane mix, and I was personally using it, long before Greenpeace found out about it, is at best a red herring.
        Greenpeace is presenting ISO-BUTANE PROPANE MIX as their creation. It is not.
        They quite likely did trial, test, and promote it, but they got the idea from netnews in the late 1980s.
        I was using it when I worked for Apple computers. I left there in 1992, so there is a hard date marker on when I was talking with George and first trialed the mix. Several years before I left. IIRC, it was about 1985 but could be as late as 1987. ALL of those well before the 1992 date that Greenpeace lists in their own article for when they stated promoting it.
        I’m saying zero about propane alone use. I’m saying zero about R-290.

      • E.M. ==> You are not the only reader here. I am not arguing with you about the Greenpeace/Greenfreeze issue. I have supplied links for those who want to know about that particular refrigerant.
        I answer questions in my own way and make comments containing additional information for the broader readership as well.
        It is interesting that you had an earlier experience with propane/butane mixes as an auto a/c refrigerant and have told all of us the story. I appreciate it, really, I do.
        I do want to the other readers to know that neither EU nor the US generally actually use the Greenpeace propane/butane mix, although there are some mixes on the very long list.
        R290, propane, is the Hydrocarbon (HC) refrigerant that has captured market share.

    • Ric, what appliance are you using that in? I was not aware that R-290 was being used in A/C. Home refrigerators use a much smaller charge and I know R-290 has been used in cars but I wouldn’t want it in my home or commercial A/C!

  27. The economic benefits of airconditioning are huge. link Prosperity is good for the environment. link The environmentalists should love airconditioning.

  28. About 1970 we bought an old chest freezer (~14 cu. feet) at a household goods auction. The only other bidder wanted it to hold fishing bait. We paid $15 and hoped it would work for several years until we could afford a new one. The old one still works.
    A 1982 model frig/freezer quit last month, so 35 years. 2 is not a large sample size, but makes me wonder about lifespan of such things.
    We have a 12 year old air-sourced heat pump with resistor heaters for very cold days.
    House is all electric. I bought and installed (saved $$$) a Pella sliding glass door with latest technology. The insulating character of the new one is very noticeable compared to the 1980s model I took out. New windows all around would be nice. When our check from “Big Oil” arrives new windows won’t be far behind.

    • One of the ways companies reduce the manufacturing costs of refrigeration and A/C compressors is to make them smaller and run them faster. This means smaller bearings, hotter running, smaller oil reserve and faster failure if anything goes wrong. the old refrigerators had big, clunky compressors with robust operating limit parameters. Nobody makes anything like that anymore. And nobody counts how much energy goes into manufacturing the newer, more sophisticated stuff. Usually, the price tells the story.

  29. In the northern midwest, I was frequently in fear of imminent death from freezing in winter and usually gloried in the few really hot days in summer (though the rare 1 or 2 hot nights per year were times of insomnia). In the SW, I found myself shivvering on 90+ degree F days from the dry cool breezes. “Swamp boxes” seem to work well there.
    In the deep south, have frequently advocated installation of those beach-side (and chem-lab) showers with the big rings you can find by feel when the salt is blinding — every other street corner should suffice, so you could dash from one to the next. Either that or “space suits” with portable A/C packs.
    A/C is necessary for life as we know it. Even prince Murat (Napoleon’s nephew), when he immigrated to St. Augustine, found it necessary to invent an arrengement of a net-shielded beach chair, mostly submerged, but within which he could read books, and write, spending hours each day thus protected from the hostile climate and ravening mosquitoes & no-see-ums.

  30. Obviously improved efficiency of any kind should be welcomed. Question is why has these efficient fridges an AC’s penetrated the market already. A cost analysis would make the article much more valuable.

    • Eric ==> Variable speed inverter a/cs are available, and you can buy them. They are not, however, the cheapie WalMart window units so ubiquitous. Google something like “buy split variable speed inverter air conditioner heat pump” and you will be inundated with offers.
      More efficient frigs are all the rage — for them it is the question of refrigerant used. UL is still worried about flammable refrigerants.

      • Split units are not as cheap on a BTU-for-BTU basis as central units and you need a minimum of one per floor. They are better than window units but that’s about all you can say for them. A Mitsubishi 31K cooling unit is $2,233 less installation. A coworker is having his central air unit replaced, with installation, for about $3,600.

  31. The desirable refrigerant for cooling systems is not toxic, not flammable, has no impact on ozone and has global warming potential of 1 or less. There are very few good candidates available to do that. As a result the industry has been moving to butane and propane which are flammable but otherwise is comparable with existing hardware making it a easy change for manufactures. However it appears the recent Grendfell tower fire was caused by refrigerator fire that involved butane. So use of flammable gases should be re thought.
    A better alternative is to use what the industry calls R-744. This gas is not flammable, not toxic, has no effect on the ozone layer, and has a global warming potential of 1. Its also cheep and there are no maintenance restrictions regarding releasing it into the air. R-744 systems are generally as efficient or more efficient as other commonly used refrigerants. The only down side is that it needs to be kept at a pressure 5 to 10 times higher than existing systems. So it is not a drop in replacement the industry wants.
    However many car manufactures have decided to use due to the flammability issues of other refrigerants. Also Coka-Cola recently made a new vending machine that uses it and boosted the efficiency 20% percent at the same time.
    Note R-744 is CO2.

    • It is being used in grocery store systems. Fairly substantial capacity. Hardware is expensive due to the pressure ratings.

      • Yeah, no kidding. It’s used in fire suppression systems, and you have class 600 fittings and schedule 80 pipe throughout.

  32. I am an auto dealer, car manufacturers are phasing out the R134A refrigerant and replacing it with 1234YF due to the enhanced greenhouse gas effect of R134A, which remains longer in the atmosphere. But this is not without challenges, the new refrigerant costs $85 per pound, the R134A is about $2 a pound. We must purchase a $9,000 machine to service vehicle air conditioners and it also requires substantially more time to evacuate and recharge a system. The new refrigerant is also under higher pressure and is combustible.
    Will this save the Earth, I doubt it, but it will raise the cost of new vehicles and the cost to service them.
    EPA did not mandate the use of this new material but they did coerce the manufacturers into using it, by reducing CAFE (fuel mileage) requirements when they use it in the vehicles they manufacture.

  33. hell I paid the price (permanently injured at age 20 in Army) to allow myself to be comfortable in my own house. I pay my bills. I’ll keep the temp set at what works best for me and others can shut up if they don’t like it.

  34. This is false attribution, at best:
    “There are newer alternatives until consideration, each with lower GWPs but individual problems. For instance, the “Greenfreeze” refrigerant developed by Greenpeace is a mixture of propane and butane. ”

    Greenfreeze Technology
    Greenfreeze uses a mixture of propane (R290) and isobutane (R60Oa), or isobutane as a pure gas for the refrigerant.

    The major household appliance manufacturers, who had already invested in HFC-134a refrigeration technology as the substitute for CFCs, at first claimed that the ‘Greenfreeze’ concept would not work. However, upon realizing that the first completely -CFC, HCFC and HFC-free refrigerator was about to come on the market, and recognizing the market appeal of a truly environmentally friendly refrigerator, the four biggest producers, Bosch, Siemens, Liebherr and Miele gave up their resistance to the hydrocarbon technology, and introduced their own line of ‘Greenfreeze’ models in the spring of 1993.

    This is roughly a decade after George Gobel made a posting on usenet news that caused me to trial a propane iso-butane mix in my 1980 Honda Civic (that was gone by 1994 after running about 1/2 a decade on this mix).

    George H. Goble is a staff member at the Purdue University Engineering Computer Network and a 1996 Ig Nobel Prize winner.
    Goble is commonly known as “ghg” since he has used that as a login id, and signature in digital communications, since the 1970s. He received his BS, MS, and PhD in Electrical Engineering at Purdue University.
    In 1981, he wired together the backplanes of two DEC VAX-11/780’s and made the first multi-CPU Unix computer, preceding DEC’s dual processor VAX-11/782. The operating system was based on the 4.2 BSD kernel, and the modifications thus made eventually made it into the 4.3 BSD Unix release. At the beginning of the 4.3 BSD user manuals, Bill Joy wrote a special note of thanks to GHG for being courageous enough to put the multi-CPU kernel into a production environment before anyone else did. (However, the frequent crashes for a while inspired the writing of many humorous text files by the Purdue University Electrical Engineering student body, such as “The VAX had a Blowout”, to be sung to the tune of London Bridge is Falling Down). The development of the Dual-CPU Unix system was the subject of Goble’s Master’s thesis.
    Around this time, Goble also developed a networking protocol for Unix, referred to as pnet, which was used at Purdue at the time before being displaced by TCP/IP. Pnet allowed remote logins, and remote execution of commands, among other capabilities.

    In the late 1980s, Goble started experimenting with refrigerants, due to increased danger and lower thermodynamic efficiency of the recently introduced R-134a
    compared to the older R-12 which was being phased out due to concerns about damage to the ozone layer, and the incompatibility of R-134a with the lubricating oil and other materials used in systems built for R-12. In 1987, he converted the beverage refrigerators in the Eta Kappa Nu lounge in the basement of the Purdue Electrical Engineering building to using a refrigerant of his own devising. This refrigerant is now recognized as R-406A by ASHRAE and is available commercially under the trade name AutoFrost. He later developed another refrigerant which is compatible with R134A lubricants, but which is superior in thermodynamic efficiency and lower system internal pressures called GHG-X8.

    He also published on usenet news a formula for using just propane / isobutane mixes. That was the mix I used for about a decade in the mid-80s to mid-90s before converting my newer cars to 134-A (change the mineral oil to ester based oil after a flush, put a screw on adapter on the Schroeder valves to match the funny R-134A hose fittings)
    Here’s a link to a later posting by him:
    That Greenpeace has come along later, taken what was public knowledge, and try to paint it as some kind of great leap forward they did is just propaganda of the worst kind.
    Credit where credit is due says to credit George Gobel.
    FWIW, I was very happy with the propane iso-butane mix. It worked better than R-12 by a tiny bit and significantly better than R-134a. I had zero issues with it. Since it is commercial flammable gas mixture, it contains odor chemicals, so in the very unlikely case of a cabin leak, you will smell it. Only real “issue” I had was to tell the mechanic it was in there and not to mess with the A/C.
    “Whenever” R-134a “goes away”, I’m just going to take the adapters off the valves and refill with that mix. George advocated 60% propane 40% iso-butane. I just dumped in the whole can of iso-butane then added propane to the full mark. IIRC it was about 50% propane and slightly lower pressure when the sight glass showed liquid.
    FWIW #2: I drive very old Mercedes and will likely keep driving them the rest of my life. No problem with air-bag recalls, no “fly by wire” and maybe you suddenly can’t steer problems, nice big and roomy, and the Diesel is old enough it doesn’t need a smog test ever. So keeping it until either it, or I, can’t be repaired anymore… I’ve got a ’79 and ’80, and an ’84 at the moment. Still works a champ.

  35. I’m doing my share… I had steak seven times in ten days 🙂 My vegan friend wasn’t very happy, hahaha

    • Termites in Zimbabwe build gigantic mounds inside of which they farm a fungus that is their primary food source. The fungus must be kept at exactly 87 degrees F, while the temperatures outside range from 35 degrees F at night to 104 degrees F during the day. The termites achieve this remarkable feat by constantly opening and closing a series of heating and cooling vents throughout the mound over the course of the day. With a system of carefully adjusted convection currents, air is sucked in at the lower part of the mound, down into enclosures with muddy walls, and up through a channel to the peak of the termite mound. The industrious termites constantly dig new vents and plug up old ones in order to regulate the temperature.

    • I wholeheartedly endorse house design that recognizes solar orientation and leverages passive heating/cooling. There are fairly simple design aspects that can greatly reduce energy demand.

  36. We put the AC on 26 ºC at night in its ‘DRY’ position. Humidity is the biggest enemy when you want to sleep when it is hot.. So every time it reaches a certain humidity the AC stops. When the outside air is dry we just put a ventilator.

  37. Health is what matters. We live in central Arkansas, quite hot & quite humid in summer. I maintain relative humidity at or just under 40% all year long. Maintaining this low humidity costs money but we spend on health care only for annual checkup.
    Besides saving lots of money there, it’s rather pleasant to feel good. I don’t even have flu shots, maybe have a cold once every 8 years. My HVAC is an in-ground geothermal, 3 speed heat pump, uses R-22, makes low cost or free hot water, has a dehumidification cycle, and I also have a sizable dehumidifier as well. Lastly, we also have some air change so the home air isn’t stale.
    Yes, we spend a little more on electricity, but I think we save lots & lots on health care.
    Science has just recently shown that refrigerants had little or nothing to do with the ozone hole, so those changes of refrigerants were a waste of money. I think that perhaps a subsidy for high quality dehumidification would save a lot of money spent on health costs.

  38. My skeptical nature blossoms on this refrigerant nonsense. First, it has the smell of a scam, like DDT, CO2, Ozone Hole, etc, etc, etc. I have natural gas piped directly to my water heater and furnace. What is the big deal over flammable refrigerants???

    • pochas94 ==> All boat owners know about propane which is basically the refrigerant under discussion. It is heavier than air — sinks to the floor and pools in low spots. on boats, that means that your propane cook stove in the is the biggest threat in your diesel engined sail boat. (If you have a gasoline powered motor boat, the gasoline is your biggest threat).
      I knew one couple that were enjoying a candlelight dinner in their cockpit when the leaking propane from the cook stove filled the boat to the level of the lowest candle. They survived but found themselves blown out of the boat into the mangroves — the boat was a total loss.
      Refrigerators normally have the compressor and their electrical connections in a compartment at the bottom of the frig in the back. If that little space fills with flammable refrigerant, leaking out, an electrical spark can ignite it and create a handy (though not huge) explosion. No one wants that.
      Frigs with R290 in home fires tend to firecracker when the flames get hot enough to release the propane refrigerant — like a small green can of propane gas that one uses in a camp stove or portable BBQ.

      • So, I guess sailboats no longer carry propane for cooking? And I guess people with propane refrigerators can survive the fire but not the refrigerator explosion? This whole thing smacks of wild exaggeration for fun and profit.

      • pochas94 ==> No, actually, many/most pleasure boats use propane but there are very stringent standards for installation and use. All propane tubing copper, the propane tanks are located in an outside propane locker that vents to the atmosphere and has no space to collect leaked propane (my propane locker has a three inch hole that goes directly outside, to the under-the-boat air space between the pontoons — it is a catamaran). The specialized propane cook stove has safety features that turn off the gas if the flame goes out — and uses no pilot lights. A propane detector rounds out the safety features. Most have an electric solenoid gas valve at the tank that must be turned on by a switch with a prominent indicator light so it is not left on when not actually cooking – the valve shuts the gas at the tank.
        More regulations here.

  39. ??? What century are these people in?
    Every European air conditioner unit I have seen, works in reverse as a heater during the winter. This is hardly rocket science.
    And the trouble with replacing CFC gasses in air conditioners, is that the cheaper manufacturers have been using methane as an alternative. It was a methane fridge that set light to the Grenfel tower block in London, killing more than a hundred people. (New fridges have been exploding, up and down the country recently….)
    Green technology and engineering is half baked nonsense. My sister changed her toilet to a water-saving model. So now you have to flush four times, and use twice as much water as before. This is Greenery in action – a fantasy world totally detached from reality.

    • Ralph ==> If you are familiar with the US, you will know that it is NOT common here for a/cs to be reversible and act as heating units. This is true in most of the Rest Of the World — where cheap air conditioners rule the roost in peoples windows.
      Even the newer variable-speed inverter a/c units in the US do not necessarily have heat pumps features.
      Google “buy variable-speed inverter air conditioner” and compare features.

  40. This may relate. It’s from this about daylight savings time.

    The result of the study showed that electricity use went up in the counties adopting daylight saving time in 2006, costing $8.6 million more in household electricity bills. The conclusion reached by Kotchen and Grant was that while the lighting costs were reduced in the afternoons by daylight saving, the greater heating costs in the mornings, and more use of air-conditioners on hot afternoons more than offset these savings. Kotchen said the results were more “clear and unambiguous” than results in any other paper he had presented.
    Read more at: https://phys.org/news/2010-03-daylight-energy.html#jCp

    • This could be achieved by comparing Arizona (no daylight savings) to a neighbor New Mexico.

  41. An issue with the air-source heat pumps is that they are being touted as replacements for furnaces in the RGGI states. Synapse Energy’s “The RGGI Opportunity 2.0” claims 9 million tons of CO2 could be avoided by shifting 1.3 million furnaces to heat pumps. They state “Heat pump technology has existed for decades, and these units are commonplace in Europe and Asia, but high-performing systems that function well in cold-weather climates as in many of the Northeast states have just recently begun to make inroads in the United States.”
    I don’t care how well high-performing systems function. Below 40 deg F there is dramatically less heat in the air to extract and when you get down to so cold that you really want heat, there isn’t enough heat in the air to keep your house warm. So you have to have auxiliary heat. Those added costs and the unintended consequences of having to deal with a larger winter peak with markedly less solar available are ignored.

    • Roger ==> You are quite right when discussing heat pump systems that rely on the outside air for heat. The generally accepted cut-off point is about 40 degrees F — under that they are not really appropriate. Their best use is in temperate climates and as three season room-temperature regulators — heating and cooling as necessary.
      While nothing in this essay is talking of them, Heat Pumps systems that use well water from two wells (one source and one sink), however, can be appropriate in many more areas as the water temperature of deep well water is around 52 degrees F.

  42. This article demonstrates what is wrong with the skeptic strategy of proving that the warming is less “severe” than claimed. WARMING IS GOOD. Warmer temperatures mean better health, longevity, and biodiversity.
    I asked the man at the US National Ice Core Lab in Denver what “Climate Optimum” meant. He thought it referred to extremes.
    Optimum is a high school word. It should not be misunderstood by college graduates, but it is.
    Before all the screaming began, warm periods were called “climate optimum” because the wos more human and wildlife well-being at those times.
    This fact is not just “cute.” It is most of the war.

  43. I have worked in the building automation management/ energy efficiency field directly since 1997. The number we used to use to calculate savings/usage in most commercial buildings and educational facilities was 40% lighting, 35% cooling, 25% plug loads. The easiest and quickest way to save energy costs was to replace lighting from T12 to T8 and add automated scheduling which resulted in about 30% reduction in the lighting portion of the bill and about a 2 year payoff. We used this saving to pay for HVAC upgrades and maintenance wish list items which had a 5 to 7 year payoff. For commercial buildings a large chunk of the savings came from reducing the peak demand charges. Starting about 2004, most of the industry had finished with the easy lighting upgrades. T5 lamps came out but the cost did not offer a quick payback so it wasn’t implemented widely. The same time HVAC started to be the largest single energy using item. Reversible Heat pumps and variable speed fans started to become popular. Most variable speed motors save energy because of the way the system is sized. Most systems are sized for the 97% Cooling day, a few are sized for 99% cooling day. Meaning 97% or 99% of temperature cooling degree days are below this point. No designer, engineer, or technician wants to be on the hook when a system is undersized. So the natural response is to oversize the system to largest the budget can provide. The variable speed motor is used to right size the motor for all those days when conditions are below design. The pump/ fan energy curve gives a 50% reduction in energy used with a 25% reduction in speed. But the pump / flow curve is not the same relationship and will vary depending on the construction and motor design, so the efficiency curve is more complicated. After the fan/pump motor efficiency is tackled, the next item in a cooling system to address is the compressor efficiency. This is best address by monitoring delta pressure and delta temperature within operational design across the compressor. Otherwise the flow can slow too much and you can slag your compressor, or push too much flow and the efficiency suffers and the compressor seals have issues.
    The different types of refrigerant offer differing levels of efficiency depending on the operational conditions of pressure and temperature. The earlier refrigerants used a lower pressure and a less extreme temperature range. It was easier to build and maintain the system. The newer refrigerants require more complex systems to maintain the same effectiveness of the previously used refrigerants. Ammonia as a refrigerant has a poor COE. An ammonia chiller is only worth using if you already have a significant amount of waste heat to try to recover, otherwise use an air-cooled or even better a water cooled chiller.
    Enough theory, my last house with 1400 sq ft had an central AC from 1973 and a compressor from 1992. I would guess it was close to a SEER 9 or 10 rating. I replaced the windows, installed a radiant barrier in the attic, and dropped my electrical costs from summertime bills of $200/month to $110/month. ( I kept my cooling setpoints between 78 and 82).
    I moved across town to a house built in 2003 with 2700 sq ft and two units with 20 SEER ratings. With better windows and more attic insulation, my summer electrical bill hasn’t exceeded $75 with cooling setpoints between 74 and 78. For a house the biggest difference is in insulation and proper fenestration management.
    For most of the US, the easy energy savings have been done. Now energy engineers have to use more creative and costly efforts to reduce a smaller pool of energy.
    I am skeptical that a future refrigerant will magically jump out of the periodic table and provide an amazing increase in refrigerant efficiency near standard temperature and pressure. I am highly skeptical that the effort to force more changes is about the environment and not money and control.
    Automation EIT Engineer

    • For most of the US, the easy energy savings have been done. Now energy engineers have to use more “creative and costly efforts to reduce a smaller pool of energy.”
      From my personal experience most existing homes leek too much air resulting in high heading and cooling cost. Yes most are insulated. However isolation doesn’t do a lot of good if air goes through the weeping holes in window and thorough seams in heating and cooling ducts in the ceiling. Most people treat it as fact that AC has to be on all the time to keep a home cool. In a well sealed home with insulation AC really only needs to be on for a few hours to keep the home cool for most of the day. In most cases you don’t need to spend a lot of money to block air leak in walls and duct work but most people don’t want to do the work. Instead most think installing new window is the best way to reduce heating and cooling cost. No window however at the most expensive step and may not help much.

  44. Ozone is a very important greenhouse gas. It is renown for absorbing very short wave incoming solar radiation, but it also absorbs outgoing long wave earth spectra.
    You can see that according to Modtran, compared to zero ozone background, ozone accounts for 7.85 W/m2 reduction in earth spectra radiation to space. That’s a lot.
    To be perfectly clear, I am not suggesting we sequester ozone.

    • Anything you place above the radiating zone (equivalent emissions height) that hinders outgoing infrared emissions, will raise the eeh and cause surface warming. This is an important influence that parallels TSI and amplifies this “too tiny to matter” effect. There are others as well.

      • Equivalent to what? EEH is a new label to me, seemingly similar to “effective radiative altitude”. Trouble is, each GHG has its own effective radiative altitude and is equivalent to no other.
        Whether hindering outgoing radiation will raise the surface (or more likely whatever radiative altitude) depends on saturation. If the bands were saturated at 280 ppm, all surface light is long since extinguished, and increasing concentration can only warm by broadening.
        I have not looked in to ozone broadening, but CO2 broadening is very slight in the current atmosphere, and posited broadening at higher concentrations has only been measured in jars.

Comments are closed.