Improving air conditioner efficiency could reduce worldwide temps • Hacker News Board

Re: Improving air conditioner efficiency could reduce worldwide temps

#161

Post by jonknee » Thu, Jul 13, 2017, 9:07 PM UTC

erikpukinskis wrote: post #141

toomuchtodo wrote: post #96

Earlier quoted context omitted.

My bedroom in Tampa, FL reaches 90F at night without air conditioning. There is no way I could live without AC here.

That's because your house is designed with active cooling as a presumption. If your house was designed to utilize passive cooling effects (thermal mass, green roof, evaporative cooling, overhangs, shades, airflow compression, etc) your bedroom wouldn't get that hot.

The greenest building you can imagine would still be uncomfortably hot in Tampa during the Summer without A/C. It's a hot and humid place.

Re: Improving air conditioner efficiency could reduce worldwide temps

#162

Post by amluto » Thu, Jul 13, 2017, 9:08 PM UTC

rb808 wrote: post #7

Half the article wasn't about a/c efficiency it was that HFC is more of a greenhouse gas than CO2, and was agreed to be phased out. Is there really an HFC replacement - what is it? I wasnt aware.

One of the nicest refrigerant choices is, perhaps ironically, CO2. It has negligible warming potential in the quantities that would be used as refrigerant, it's very safe, and it's dirt cheap. The main downside is that the whole system has to be operated at higher pressure that it does for HFC refrigerants.

Re: Improving air conditioner efficiency could reduce worldwide temps

#163

Post by maxerickson » Thu, Jul 13, 2017, 9:08 PM UTC

erikpukinskis wrote: post #134

djsumdog wrote: post #119

So we curb emissions by building a bunch of new A/C units? Sorry, that's silly. CO2 is just one of many many forms of pollution. Think you're doing your part by purchasing a hybrid or electric vehicle? There are barrels of oil that go into those tiers, the plastics, not to mention all the pollution that goes into battery production. If your car is fuel efficient, the best thing you can do for the environment is drive…

I think your thinking is a little short sighted. Yes, on a 20 year horizon replacing our existing inefficient stuff is wasteful. But on a 100 year time horizon, population will rise to 10 billion, and we'll turn over almost all of our climate systems. What I would propose is we start now thinking about what sustainable architecture looks like, and start trying to imagine more permanent cultural edifices. I.e. permacu…

What do you mean by efficient?

Re: Improving air conditioner efficiency could reduce worldwide temps

#164

Post by thomk » Thu, Jul 13, 2017, 9:08 PM UTC

Slightly offtopic but I just had a new HVAC system put in my house and one of the things the tech pointed out to me is that effective AC has a lot to do with effective dehumidifying.

I don't know why it never crossed my mind before but now when I transition from indoors to outdoors (and back) I notice the humidity delta as much as the temperature delta.

Re: Improving air conditioner efficiency could reduce worldwide temps

#165

Post by eppp » Thu, Jul 13, 2017, 9:09 PM UTC

Scramblejams wrote: post #36

bradlys wrote: post #18

> The Lawrence Berkeley study argues that even a 30 percent improvement in efficiency could avoid the peak load equivalent of about 1,500 power plants by 2030. Okay, but where is this 30% jump in efficiency going to come from? That seems like a pretty big leap!

It's been mentioned elsewhere in this thread, but if you run your refrigerant loop through the ground instead of cooling it using the hot ambient air, you can absolutely achieve that improvement in efficiency. The concept is described here: https://energy.gov/energysaver/geothermal-heat-pumps The amount of efficiency increase you get depends on the ground temp, which varies by latitude, but I've seen 70% reductions i…

The reason most people don't use it is that it costs a fortune to install initially and is dependent on local geology. The payback is longer than most people own their houses for and anecdotally the advertised payoffs have been reduced due to efficiencies standard systems. This further reduces the incentives.

Re: Improving air conditioner efficiency could reduce worldwide temps

#166

Post by swiley » Thu, Jul 13, 2017, 9:09 PM UTC

axelfontaine wrote: post #64

American air conditioners running at full power, chilling the interior and dripping on the sidewalk below on a hot day always deeply trouble me. Maybe it's my european view on things, but for contrast here in Munich we aren't just building out a city-wide heat network, but we also have a cold network! Cold river water flows through the pipe network that traverses the city and large office building can get connected t…

I might be wrong but I was under the impression that heat pollution is super bad for ecosystems and is one of the ways factories tend to legally damage the environment.

Re: Improving air conditioner efficiency could reduce worldwide temps

#167

Post by eveningcoffee » Thu, Jul 13, 2017, 9:10 PM UTC

rplst8 wrote: post #61

Scramblejams wrote: post #36

Earlier quoted context omitted.

It's been mentioned elsewhere in this thread, but if you run your refrigerant loop through the ground instead of cooling it using the hot ambient air, you can absolutely achieve that improvement in efficiency. The concept is described here: https://energy.gov/energysaver/geothermal-heat-pumps The amount of efficiency increase you get depends on the ground temp, which varies by latitude, but I've seen 70% reductions i…

The challenge for these is the cost. First, you either have to drill wells that are ~500 feet deep or lay coils of tubing under your yard (if you have one) below the frost line. Doing either is expensive, though the wells are much more so. The downside of the cheaper option (the coils under yard) is that earth shifts, and the coils will too. I've had two separate friends install these (usually 4-6 separate coils) onl…

Would adding layer of concrete around the pipes mitigate the problem?

Re: Improving air conditioner efficiency could reduce worldwide temps

#168

Post by lfam » Thu, Jul 13, 2017, 9:10 PM UTC

erikpukinskis wrote: post #141

toomuchtodo wrote: post #96

Earlier quoted context omitted.

My bedroom in Tampa, FL reaches 90F at night without air conditioning. There is no way I could live without AC here.

That's because your house is designed with active cooling as a presumption. If your house was designed to utilize passive cooling effects (thermal mass, green roof, evaporative cooling, overhangs, shades, airflow compression, etc) your bedroom wouldn't get that hot.

Early Florida homes (19th and early 20th century) were built by people who understood passive cooling techniques.

But, the invention of AC and the development of super-strong residential building codes in response to destructive hurricanes has steered the last ~70 years of home construction towards sealed concrete boxes with air conditioning infrastructure built in.

Many of the classic passive cooling techniques of the old Florida homes are not even legal now. The benefit is your house doesn't collapse in a hurricane.

Re: Improving air conditioner efficiency could reduce worldwide temps

#169

Post by julianj » Thu, Jul 13, 2017, 9:11 PM UTC

hughw wrote: post #143

djsumdog wrote: post #119

So we curb emissions by building a bunch of new A/C units? Sorry, that's silly. CO2 is just one of many many forms of pollution. Think you're doing your part by purchasing a hybrid or electric vehicle? There are barrels of oil that go into those tiers, the plastics, not to mention all the pollution that goes into battery production. If your car is fuel efficient, the best thing you can do for the environment is drive…

Reducing the number of humans could be one approach. The idea causes rancorous response from religious people who believe God told us to be fruitful and multiply. To reduce births might require coercion, it's true, but it would not require killing people or making them suffer. I don't see how else we can continue to enjoy the benefits and power of technology while keeping the planet habitable and enjoyable.

Every time I see this suggested I am reminded of Idocracy. Only some people will choose not to reproduce. The genes of those who disagree with this idea will be the genes passed on to later generations. One could also assume that the opposing ideas regarding reproduction are also more likely to be passed on. I don't really see this as a viable voluntary solution.

If not voluntary, how could a place do this without instituting something like a 'one child' policy?

Re: Improving air conditioner efficiency could reduce worldwide temps

#170

Post by zabuni » Thu, Jul 13, 2017, 9:11 PM UTC

erikpukinskis wrote: post #141

toomuchtodo wrote: post #96

Earlier quoted context omitted.

My bedroom in Tampa, FL reaches 90F at night without air conditioning. There is no way I could live without AC here.

That's because your house is designed with active cooling as a presumption. If your house was designed to utilize passive cooling effects (thermal mass, green roof, evaporative cooling, overhangs, shades, airflow compression, etc) your bedroom wouldn't get that hot.

evaporative cooling? thermal mass? Did you not read the parent? How is a thermal mass going to help a place that has a low temperature of 90? And how will evaporative cooling work in a place with 80% humidity?