Instead of buying a new airconditioner wouldnt that money be better spent on making your house cooler by putting in more windows and things likesky lights that let heat out through the roof or a whole house fan which uses a lot less electricity?

@majortom: If you are in a moderate climate and the heat that you want to transport out of the building is mainly coming from humans and appliances you are right. But if you are in a warm climate most heat is coming from the warm air outside and from the solar radiation heating up the roof and the interior via the windows. In the latter case it is better to have small windows, window shades and well insulated walls.

Tom, you've obviously never been to AZ.
...of course, my suggestion would be: Don't live where it's too hot to live.

What's the complaint about that "Sleep Genie" air conditioner. I'd think that air conditioning a small sleeping space would require way less energy than cooling an entire house or apartment, at least if the conditioner has a vent to the outside to dump the heat.....DB

Cutting down the space to be air conditioned, just to what you're using works. In my vintage (1955) travel trailer, the bed is in a tiny room about 7 x 5 feet... often I can sleep with just a fan on, and a glass of ice water before bed, but when it stays hot all night, i cut on my little 500 watt ac, and it does a fine job with minimal effort. It'd be great to have a home below the surface of the ground or a geodesic dome, hay bale structure, but what I have is fine for now and all i need. I prefer to simplify.

The idea of not using air conditioning is great, but in reality, its needed in a lot of places. I live in Ottawa and even though the temperature may only hit 27 or 28 degrees C, the humidity is just murderous. I would love the option of increasing the efficiency of my household, but I live in a rental apartment, which is all a lot of people can afford right now, and that means that I can't modify the unit at all, and I can do it put up blinds and drapes and pray the heat doesn't cook me and my poor cats alive. I try to minimize AC when I can, but I really just want a more efficient unit period, if people can design a better engine like the Cyclone Regenerative Power Engine, why can't they make...the Blizzard Regenerative Power AC Unit?

Air conditioning is, as said here, one of the most obvious uses for solar power. But this doesn't mean we need a solar air conditioner. It means we need solar panel systems on our homes and efficient air conditioners (and everything else). Nothing new and fancy. Nothing more is needed. The extra power will just be there when we run the air conditioners.
Personally I like the idea of only cooling small spaces at night. I'd have no problem enclosing my bed at night like that- not everyone is claustrophobic. If I'm not going to be using the other space anyway, why bother? What does bother me is that this is intended for a bed, which is used mostly at night, but they say it can be powered by solar, which is a daytime power source unless you store the energy (which is silly unless solar is already providing all your daytime power, too). So, solar powering (among other things) a whole-house or as-much-space-as-needed air conditioner during the day, and efficient, small-space air conditioning at night. Good idea.

If you live in central Texas like I do, more windows, sky lights, and whole house fans means living in a house that's only 95 degrees instead of 100. Might be OK if you're willing to suffer, but most of us are not.

There's a reason all of these 'old style' means of comfort were largely abandoned. They don't work as well. And these solutions are even less effective in the city, where few trees and lots of concrete and asphalt add 10 or more degrees to an already hot summer. Fans and windows work best in the country in houses with lots of trees and air space around them. This is exactly the kind of housing we're trying to get away from, since they make mass transit very impractical and require much more land and resources per person.

AND, my favorite, a real available (NOW) solar unit.

http://www.solcool.net/

How did you guys miss this one?

Why not put a tank of water in the ground , use a closed loop thermo siphon and and north oriented radiator plate to cool it during the winter and then pump the chilled (frozen rock hard?) water through a valence during the summer to keep things cool?

In many hot countries thicker walls -well insulated are a must, but hot air is kept out by smaller windows - windows are covered to prevent heat gain from sun - this renders indoor spaces 20 degrees cooler - yes like a cave but use cooler light bulbs, and use fans in each room, moving air crossing skin causes evaporation people stay cooler. don't use appliances indoors until cooler hours. hope these tips help, R

what happened to the sycamore seed fan?

What does Allison Arrieff have against conditioning a small space? The idea is to cool only what you need to cool. Technically you could keep your food fresh by chilling your house to 40°, but that is the least efficient way to do it. The same is true of air conditioning. The goal is to make me feel cool, not to keep the ceiling of the unused guest bedroom at 65°.

It seems that Ms. Arrieff wants to keep all her luxuries and be energy-efficient at the same time (if you're burning up all your resources at half the speed, it's still too fast, non?); I suppose most of us are guilty of this to varying degrees, aside from those who have what they need to survive and nothing more. We are fooling ourselves to think we can have our cake and eat it too. Poor Ms. Arrieff's unconscious will be claustrophobic as she sleeps... In all our consumerism, we have become so petty, it's really shameful.

I live in Manhattan, which is muggy and hot at night, and I get by with a cold shower before bed and a 10" fan. Also change the sheets every other day (not very green!)

With the cost of energy likely going way up, AC will be used less, cutting the urban heat island effect. The less AC we use, the less we'll need. I find that it's actually hotter late at night in my apartment because everyone has put on their AC and they're venting heat outside.

I find myself acclimating within a few minutes if I walk into a store or restaurant with inadequate AC. (Starbucks has been turning up their thermostats of late.) I just tell myself I am living in Italy.

First option should always be to try and cool yourself without using AC. Use water to wet yourself (shower) or clothing. As the water evaporates it cools the skin. Moving air increases the effect - a fan. Or use a fan to blow air past a block of ice. If you have the option (not in an apartment) move to the coolest spot in the home (basement).

http://greenterrafirma.com/keeping-cool-without-air-conditioning.html

I have only this to say: temp controlled space suits!

As Rosaly says, the best thing to do is to keep heat off, not to spend energy to kick it off when it has been allowed to get inside.
To avoid a "cave" effect (thick walls and small windows) and to solve the problem in existing not-so-sustainable buildings, paint the roof white.
The albedo of a roof painted white is enough to cut down the heat inside by three-four Celsius degrees. Very simple and cheap. And in winter it reduces the radiant heat loss.

I think the best 'solar powered a/c' are trees. I know it's not for every climate, but here in Toronto it's relatively easy to get some trees around your house. A friend of mine has 3 trees around his house and it's amazingly cool all summer long. The most he needs is a couple of ceiling fans to move the air around.

If we had more trees, it wouldn't get so hot to begin with, so I guess it becomes a preventative solution as well.

Go trees!

Keeping the the air moving is key. In a recent renovation, we oriented casement windows to catch prevailing winds, installed ceiling fans in key locations, and installed a great (and quiet!) whole-house fan (AirScape). These are relatively cheap compared to A/C and have been working well. When things get really unbearable, we flip on a ductless wall-mounted A/C unit (LG).
http://boehmarchitecture.com/documents/holworthy_home.html

"First option should always be to try and cool yourself without using AC. Use water to wet yourself (shower) or clothing. As the water evaporates it cools the skin."

Step right up everyone and gaze at the amazing MOSSMAN! He is well hydrates, comfortable in warm weather... and smelly.

Just one comment on ice storage. It really is never more efficient than standard AC units. It takes a lot of energy to change ice to water. Typically this is only a dollar saver and only if you have Time of Use rates and/or high demand charges from you utility. Also these really aren't innovations they have been around in the industry for more than a decade or more (think 70's oil crisis). Except for maybe AC in a Can :)

I learned a very valuable lesson this summer. We are in the middle of a (minor 5day) heat wave and the large a/c that cools my entire downstairs has gone out. Rather than buying a new one yet, we have resorted to running the a/c's in the bedrooms but keeping the thermostat at a higher temp. and using a high velocity fan in the hallway. We also have been using the celling fans in all the rooms. Is it as cool as my big, old a/c? No, but it keeps the house liveable. Only one room has been very warm.