[TomK32]

Why did no one mention the Romans yet? They came up with the frigidarium where you could literally cool down with your friends and some private houses even had water running inside their walls to cool it down (or hot air in the colder months).

Temperature control in buildings is 100% architecture and technical add-ons like AC are a poor choice. Look at termites how they use architecture to cool their hives.

[Xylakant]

> Temperature control in buildings is 100% architecture and technical add-ons like AC are a poor choice.

AC is not only temperature control. Running water through the walls or evaporation cooling only work in moderately dry climates but will not help much in humid climates. Cooling the walls will just lead to condensation and wet walls. There's certainly a lot that can be done without AC, but humidity control is required in some regions of the world.

[ComputerGuru]

The article does mention the Romans, though:

> The eccentric Roman emperor Elagabulus sent slaves to bring snow down from the mountains and pile it in his garden, where breezes would carry the cooler air inside.

[_pmf_]

> Temperature control in buildings is 100% architecture and technical add-ons like AC are a poor choice. Look at termites how they use architecture to cool their hives.

Clay for the win. Even using a very thin clay based upper layer does incredible things to the room climate.

[bryanrasmussen]

is Clay also for the win in hot, humid climates?

[nf05papsjfVbc]

Yes, it works fairly well. You need to have a high ceiling for it to be effective though. I don't know why that is so, however.

[yxhuvud]

I wonder why central cooling hasn't taken off like central heating has. It seems to me that the economy of scale would work really well with cold just as it does with heat.

[VLM]

Compressed liquid refrigerant is very expensive compared to cheap water for heating. Long pipes full of liquid would be very expensive to initially fill not to mention after leaks. And there would be leaks...

Historically most refrigerants have had "issues" when leaked either environmental or being toxic or otherwise it minimizes danger to keep as little as possible. Even if we could afford to use 1000x as much refrigerant with a central compressor station, it would be bad for the environment to use it that way.

You can move a huge amount of heat with water pressurized to merely 14 psi or so, but I have a puron aka R-410A conditioner at home and that dude runs near 400 psi on a hot day and its difficult to run miles of high pressure pipe.

I'm not sure bigger compressors are that much more efficient than smaller compressors, taking into account the environmental and economic expense of the pipes.

From an engineering standpoint its cheaper safer and less environmentally destructive to push kilowatts thru copper wire than push high pressure expensive refrigerant thru long high pressure pipes if all other things were equal which they mostly are.

[pinot]

You do not have to distribute the compressor gasses- you just pump cold water/glycol around. Every factory everywhere does it this way for distributed cooling, as well as hospitals/colleges/corp campuses with central plants.

For a long while, Stanford had an underground reservoir of ice for even better cooling (freeze ice at night when electrical prices are low, melt off during the day) http://web.stanford.edu/dept/news/news/1999/april21/iceplant...

[Ajedi32]

Why would you need to use the refrigerant itself for heat transfer from end users? Couldn't you just use water for that; like they do for central heating? (E.g. Chill water using centralized AC, then pump the cold water through pipes to cool homes and businesses?)

[SAI_Peregrinus]

Why would you use long pipes of refrigerant? Move the air, not the refrigerant. Plenty of existing central heating systems do that (no radiators, just vents in each room). Systems like this already exist and work rather well.

[blackguardx]

In the US, centralized AC is the norm in the numerous suburban houses. Newer apartment buildings in cities have centralized AC and window units are usually only used in older buildings.

[yxhuvud]

You are speaking centralized as in having one central unit for the building, are you not? I am speaking about having a big company, usually city-run, making the cool in a huge plant and then pump it out (in insulated pipes) to the rest of the city/town.

The heat version of it is very common here in Sweden (for towns bigger than, say, 10k people) and it is a lot more efficient (and therefore, cheaper) than having heating units in the different buildings. We even have bigger data centers selling their spare heat from their cooling back to the heating systems.

[closeparen]

Universities often have one or more chiller plants that cool multiple buildings on campus (also boiler plants).

Very large building-sized boiler and chiller plants served each half of my campus (probably less than a square mile in total). I'm not sure it would work at city scale.

[pinot]

It's called District Cooling

https://en.wikipedia.org/wiki/District_cooling

[nerdshoe]

Deep lake cooling is used in Toronto, Canada, though not widespread, and is offered by a private company. http://enwavetoronto.com/district_cooling_system.html

[obstinate]

I live in a building that does use central cooling. I'm not quite sure how it works, but I believe that they pump chilled water through our radiators. The radiators are more like air conditioner radiators than traditional cast iron radiators, and they have fans attached that can be controlled by the renter.