Sustainable air conditioning — The Economist

[mblakele]

This week The Economist published a leader and a main article on sustainable air conditioning.

leader: https://www.economist.com/leaders/2018/08/25/how-to-make-air-conditioning-more-sustainable

WHAT is the single most effective way to reduce greenhouse-gas emissions? Go vegetarian? Replant the Amazon? Cycle to work? None of the above. The answer is: make air-conditioners radically better. On one calculation, replacing refrigerants that damage the atmosphere would reduce total greenhouse gases by the equivalent of 90bn tonnes of CO2 by 2050. Making the units more energy-efficient could double that. By contrast, if half the world’s population were to give up meat, it would save 66bn tonnes of CO2. Replanting two-thirds of degraded tropical forests would save 61bn tonnes. A one-third increase in global bicycle journeys would save just 2.3bn tonnes.​

main article: https://www.economist.com/internati...o-great-good-but-at-a-high-environmental-cost

At the moment, only 8% of the 3bn people in the tropics have air-conditioning, compared with over 90% of households in America and Japan. But eventually, it will be near universal because so many trends are converging behind its spread: ageing, since old people are more vulnerable to heat stroke; urbanisation, since fields cannot be air-conditioned but offices and factories must be; and economic growth, since, after mobile phones, the middle class in emerging markets want fans or air-conditioners next.​

Note that the GHG impact is mostly about refrigerant gases, not electricity. But electricity plays a role too.

At the moment, according to the IEA, it takes about 2,000 TWhs (terawatt hours) of electricity to run all the world’s cooling machines for a year. This produces 4bn tons of CO2, 12% of the total. Without drastic improvements in air-conditioners’ efficiency, the IEA reckons, they will be burning up 6,000 TWhs by 2050.​

 

[nwdiver]

This week The Economist published a leader and a main article on sustainable air conditioning.

leader: https://www.economist.com/leaders/2018/08/25/how-to-make-air-conditioning-more-sustainable

WHAT is the single most effective way to reduce greenhouse-gas emissions? Go vegetarian? Replant the Amazon? Cycle to work? None of the above. The answer is: make air-conditioners radically better. On one calculation, replacing refrigerants that damage the atmosphere would reduce total greenhouse gases by the equivalent of 90bn tonnes of CO2 by 2050. Making the units more energy-efficient could double that. By contrast, if half the world’s population were to give up meat, it would save 66bn tonnes of CO2. Replanting two-thirds of degraded tropical forests would save 61bn tonnes. A one-third increase in global bicycle journeys would save just 2.3bn tonnes.​

main article: https://www.economist.com/internati...o-great-good-but-at-a-high-environmental-cost

At the moment, only 8% of the 3bn people in the tropics have air-conditioning, compared with over 90% of households in America and Japan. But eventually, it will be near universal because so many trends are converging behind its spread: ageing, since old people are more vulnerable to heat stroke; urbanisation, since fields cannot be air-conditioned but offices and factories must be; and economic growth, since, after mobile phones, the middle class in emerging markets want fans or air-conditioners next.​

Note that the GHG impact is mostly about refrigerant gases, not electricity. But electricity plays a role too.

At the moment, according to the IEA, it takes about 2,000 TWhs (terawatt hours) of electricity to run all the world’s cooling machines for a year. This produces 4bn tons of CO2, 12% of the total. Without drastic improvements in air-conditioners’ efficiency, the IEA reckons, they will be burning up 6,000 TWhs by 2050.​

Ironically CO2 aka R744 is the refrigerant we should be using... but it operates at much higher pressures that R410A.

 

[SageBrush]

I am all for efficiency but a magazine that calls itself the 'economist' should realize that for something like AC as the costs drop consumption rises.

 

[miimura]

Reducing electricity use from air conditioning is not really about improving the efficiency of the cooling system itself, but rather improving the envelope that the system is trying to keep cool. Improving insulation and air leakage of most buildings is far easier than improving the SEER by the same magnitude.

 

[SageBrush]

Reducing electricity use from air conditioning is not really about improving the efficiency of the cooling system itself, but rather improving the envelope that the system is trying to keep cool. Improving insulation and air leakage of most buildings is far easier than improving the SEER by the same magnitude.

Fair sentiment, but a 15 y/o AC unit is going to have a SEER way below a modern unit.

 

[nwdiver]

Reducing electricity use from air conditioning is not really about improving the efficiency of the cooling system itself, but rather improving the envelope that the system is trying to keep cool. Improving insulation and air leakage of most buildings is far easier than improving the SEER by the same magnitude.

It's frustrating that Americans can't seem to grasp the concept of zoned AC (Lots of things Americans fail to grasp .... ) I installed a split system in my home and even put a curtain up separating the hallway to the bedrooms from the kitchen / living room. It's amazing the effect a simple curtain can have to slow the flow of air. In the summer the half of the house I'm actually in stays a comfortable ~74F while the other side of the curtain is usually ~85F. In the winter it drops to ~50F. So I'm only heating or cooling the half of the house I'm actually in... just makes sense... which is probably why this is unpopular in the US

 

[mblakele]

I am all for efficiency but a magazine that calls itself the 'economist' should realize that for something like AC as the costs drop consumption rises.

Hmm, are you sure you read either article? They weren't really about efficiency. The GHG emissions are more due to refrigerant gas than electricity usage.

These articles cite projections that GHG emissions due to AC will triple by 2050, primarily because more people worldwide will be able to afford AC. According to the articles, more AC is good because access to AC makes people healthier and more productive — but bad because of increased GHG emissions.

So the question is how to handle a tripling of AC usage without also tripling GHG emissions.

 

[SageBrush]

Hmm, are you sure you read either article

I read the snippets you posted. I am not going to pay for the full article.

The snippet says that consumption and refrigerant are about equal in GWP. Commenting on one is as equally relevant as the other.
The suggestion to replace refrigerant strikes me as a very bad idea given the likelihood that it would allowed to escape into the environment.

I do agree with new units having low GWP refrigerant and high SEER although I have no personal stake here. We open windows at night and use fans during the day in the summer.

BTW, what refrigerant is in our cars ?

 

[Joel Weber]

Do the refrigerants have any risk of causing ocean acidification and food chain collapse?

 

[mspohr]

The problem is that engineering more efficient AC and retooling to manufacture it depends on a lot of unknowns and may not even be possible.
OTOH, moving to a plant based diet requires no scientific or engineering breakthroughs, just some education on the deleterious effects of meat on human health, planet health and the animals themselves.
Framing this as an either/or question is a good way to convince people that they don't need to do anything now... just wait for science and engineering to solve the problem.

As usual, the question is not either/or but do both... and don't wait for some pie in the sky miracle.

 

[SageBrush]

OTOH, moving to a plant based diet requires no scientific or engineering breakthroughs

Completely off tangent, but Google bicycling in the Netherlands.

 

[mspohr]

Completely off tangent, but Google bicycling in the Netherlands.

Cycling is a common mode of transport in the Netherlands, with 36% of the people listing the bicycle as their most frequent mode of transport on a typical day as opposed to the car by 45% and public transport by 11%. Cycling has a modal share of 27% of all trips nationwide.More at Wikipedia
Low tech... easy adoption

 

[Joel Weber]

Getting safe bicycling infrastructure built is a huge political challenge, though.

 

[mblakele]

Do the refrigerants have any risk of causing ocean acidification and food chain collapse?

I don't see how refrigerants would lead to ocean acidification: that's specific to CO2. I understand that refrigerants are more like CH4 in this respect: potent GHG, more potent than CO2. But I wouldn't rule out food chain collapse through enough of any GHG, even without ocean acidification.

Wikipedia has some technical details: Refrigerant - Wikipedia

[ HFCs and PFCs ] still have global warming potentials thousands of times greater than CO2​

That article goes on to say that 2,3,3,3-Tetrafluoropropene - Wikipedia is a good contender, having global warming potential "much closer" to CO2. It can take decades for a new refrigerant to replace old ones: think of all the old AC units, fridges, and freezers scattered around the world. But reducing the GHG impact of new units is still a net good, because of that expected tripling of AC usage worldwide by 2050.

 

[Joel Weber]

Is it a viable replacement for R-410a in something like a Chiltrix CX-34 or Mitsubishi Mr Slim?

 

[SageBrush]

Cycling is a common mode of transport in the Netherlands, with 36% of the people listing the bicycle as their most frequent mode of transport on a typical day as opposed to the car by 45% and public transport by 11%. Cycling has a modal share of 27% of all trips nationwide.More at Wikipedia
Low tech... easy adoption

All true, but you have to watch a couple videos to enjoy the flavor.

I think it was the low hanging fruit aspect that prompted me to mention the Dutch experience.

 

[Xenoilphobe]

This is a population issue, not an AC issue, ever see the movie The Kingman?

Samuel L Jackson (Valentine) has some crazy ideas that kinda make some sense..

Quote from movie, "When you get a virus, you get a fever. That's the human body raising its core temperature to kill the virus. Planet Earth works the same way: Global warming is the fever, mankind is the virus. We're making our planet sick. A cull is our only hope. If we don't reduce our population ourselves, there's only one of two ways this can go: The host kills the virus, or the virus kills the host." (Valentine)

 

[nwdiver]

This is a population issue, not an AC issue

If you can solve the problem with a better refrigerant like CO2 its an AC issue...

 

[Xenoilphobe]

I couldn't actually read the article, but I know this.. I significantly reduced the load by using close and open cell foam in my home, changing the roof color from black to the lightest gray that our HOA Nazi's would allow, switching to LED lighting, timers and motion sensors, electric cars (X3), solar, and I still feel like my load could be reduced.... I still have an old 13 SEER AC X 2, but only one carries the whole 5000 SF load now... I am letting the old HVAC run until it burns up... then trying to figure out what to do next... a know a variable speed scroll compressor will help, but I have also looked a using my pool as a geothermal sink with this..Heat Recovery Pool Heater | Compare To Solar Pool Heater | HotSpot Energy LLC

 

[mspohr]

I couldn't actually read the article, but I know this.. I significantly reduced the load by using close and open cell foam in my home, changing the roof color from black to the lightest gray that our HOA Nazi's would allow, switching to LED lighting, timers and motion sensors, electric cars (X3), solar, and I still feel like my load could be reduced.... I still have an old 13 SEER AC X 2, but only one carries the whole 5000 SF load now... I am letting the old HVAC run until it burns up... then trying to figure out what to do next... a know a variable speed scroll compressor will help, but I have also looked a using my pool as a geothermal sink with this..Heat Recovery Pool Heater | Compare To Solar Pool Heater | HotSpot Energy LLC

I've installed the Chiltrix CX-34 from HotSpot Energy. I use it for heating only (no need for AC where I live). Works great. Variable speed DC fan and pump. Very efficient.