[kijin]

Every summer, I see a couple of posts on HN about some supposedly groundbreaking scheme to cool a building by a few degrees without using an traditional A/C. Usually it's a combination of ventilation and evaporation, resulting in somewhat cooler but much more humid air.

I guess it might work in the Bay Area. But as someone who lives where I regularly see temperatures higher than the human body temperature with humidity higher than the human body's water content, that kind of scheme is an absolute non-starter. This article does a great job explaining why.

The fact that blowing air over blocks of ice didn't work 100 years ago should remind today's inventors that damp air is unlikely to be a good solution, either, in most parts the world that currently rely on compressor-based air conditioners.

[seanmcdirmid]

Most people in the Bay Area don't need AC.

Swamp coolers don't work in the tropics, obviously. They are great in the desert though (except during monsoon season). In the tropics, you cool by extracting humidity, not injecting it. And extracting humidity might not work very well in a very dry desert...so...

The ice block thing worked perfectly fine in Iran, at least.

[kijin]

> In the tropics, you cool by extracting humidity, not injecting it. And extracting humidity might not work very well in a very dry desert...so...

You seem to be saying that an air conditioner requires significant ambient humidity in order to be effective. That doesn't make sense, as anyone from Phoenix, Arizona can testify.

A typical air conditioner does not cool the air by extracting humidity. It extracts humidity by cooling the air and so bringing it below its condensation point. Extracting humidity is a welcome side effect, since it helps us feel more comfortable, but it is not the primary function of a modern air conditioner.

[tunap]

Fellow Zoni here, and a moon-lighting HVAC service tech. To clarify a common misconception, A/C refrigerant does not cool air even though that is the net result. It actually absorbs heat and releases it outside the strucure. Sorry for the pedantry, but if we come here to learn, may as well learn the technicals.

http://web.mit.edu/2.972/www/reports/compression_refrigerati...

[dpark]

This is a distinction without a difference. Removing heat from the interior air is the same thing as cooling the interior air.

If you mean that the air conditioner doesn't produce a magical substance called "cool", that's true, but no one claimed that it does. The mechanism transfers heat with the effect of cooling the interior.

[tunap]

Just thought I would try to illuminate a prevalent technical misconception.

[dpark]

I get that, but he didn't make an incorrect or misleading claim. And honestly, most people on HN probably understand that air conditioners move heat.

[jogjayr]

> Most people in the Bay Area don't need AC.

I second that. The Bay Area has this gloriously perfect climate where you need nothing more than a table or ceiling fan in the summer, a small electric space heater in the winter and nothing at all most of the time. With the right architecture and insulation you could spend almost nothing on heating or cooling.