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%
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?
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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.
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