Alternative to Air-con
 

Long time lurker, first time poster.

Air-conditioning is one of the biggest consumers of energy, so it's no surprise that EcoRenovators focus on it. I thought I'd share my alternative to turning your house into a refrigerator.

I fitted an inexpensive box fan into my window on the far end of the house, facing outward. On the near end a couple windows remain open. The fan is plugged into a $7 lamp timer programmed to come on between 11pm and 7am. The effect is a "corridor of cool" that gradually sweeps through the entire house.

Just for giggles, I decided to calculate the energy efficiency rating (EER) of my setup as if it were an A/C unit. At 120 watts (measured with Kill A Watt) and 2000 CFM (complete guesswork, based on this similar product, a 20 *F difference in air temperature translates to an EER of 363 Btu/Whr. Yowzers! That's a CoP of over 100! To get as inefficient as the best air-cons out there, the temperature difference would have to drop to a miniscule 0.6 *F.

This has worked well for me in several different shape dwellings. If someone wanted to do it at home, my advice would be: go with the prevailing winds, exhaust on the top floor, and intake from the coolest surrounding area (preferably shaded, grassy, and away from pavement).

As far as comfort, the indoor temperature is routinely 10 *F cooler than outside in the hottest part of the day. Sleeping is a dream, because I get the refreshing night air drifting through the bedside window without the obnoxious thrumming of a fan in my ear.

Now someone just needs to one-up me with a differential thermostat!

I do the same thing at night. A thermostat wouldn't be a bad thing though. Some mornings I wake up and its pretty chilly!

What about an evaporative cooler? Wouldn't the equivalent efficiency rating be even higher?

Depends on the humidity and the power consumption. If someone had one of these and could measure the energy / water consumption, I could figure out exactly what the EER would be.

What part of the country do you live in? Here, in the South, our nights are still in the 80's. A box fan just isn't going to help much. I have a whole house attic fan and that still doesn't help. The humidity is just horrendous.