When I was a kid in Texas, my grandmother lived for a while in a house equipped with a house fan. The thing was quite a novelty—central air is required for life to continue in that molten state of the Union. That anyone lived there before air conditioning is a puzzling fact I cannot get my brain to accept. The house fan, however, is one of the things that must have allowed it.
The thing kicked on with the rumbling sort of industrial efficiency that brings to mind mid-century over-design, and indeed, its effect had much in common with high-velocity wind tunnels—loose teeth let go; hair stood on end; small children flew by. The thing moved some major cubic feet of air, and the draft from outside very rapidly replaced the inside air. The system had a fatal flaw, though. The outside air, even in the chilliest pre-dawn of a Texas summer, clocked in at 80 or 85 degrees. Hardly worked out to be a viable replacement for central air, although it could, in just the right conditions, cool things down very well.
As summer 2009 approaches with its mix of wobbly climate-change news and still-high energy prices, finding viable ways to stay cool without breaking the bank seems especially important.
There are a lot of tricks to increase efficiency that work in New England that wouldn't work in Texas. If you use regular fans, it's an obvious but commonly overlooked notion that bringing in hot air in midday isn't going to help. If it's hot outside, shut the windows, and close the blinds the "wrong" way (so that the louvres point up on the inside) so the smallest amount of sun hits anything inside. That prevents objects and furniture from absorbing heat they'll emit now and later, making it harder to cool your house. Run fans inside to circulate the inside air in the daytime, and place them in the windows only at night, to pull in the cooler air. Shut the windows in the morning to keep that cool air in—collecting and maintaining that cooler air mass is the trick.
Other options exist beyond air conditioning and regular fans. There's a device called a "swamp cooler" that basically combines a fan and cold water. It's limited in its cooling abilities and can increase indoor humidity to uncomfortable levels, so it's better than nothing, but not a great option.
Another choice exists that's especially good in New England, where heat waves can be intense but are almost never long-lived. The old house fan in my grandmother's house mostly circulated hot air, but New England's much chillier summer nights mean that's not true here except in the worst heat waves. House fans have also gotten much quieter and much more appropriately sized—my grandma's probably had the horsepower to cool a factory.
I spoke to Geoff Fleury, a Southampton-based electrician who installs what's now called a "whole house fan." He told me the old-fashioned house fans have a lot of drawbacks, from their over-engineered ability to draw air to problems (potentially hazardous, even) of back-draught through fireplaces or flues.
Fleury installs more modern versions of the whole house fan that minimize such issues and use even less energy than their predecessors. "They mount directly in your ceiling, and they have automatic, insulating doors," Fleury explains. "The newer, smaller fans open with a motorized damper that opens when you run it, then shuts down. That's an advantage in summer and winter. They vent directly into the attic, and typically, if you have one or two gable vents or even soffet vents, there's enough [ventilation].
"They use a fractional amount of electric compared to even a window a/c unit. Your traditional window unit uses anywhere from five to seven amps of electricity—it could end up using the same amount of energy as a whole house fan, but only cool one room."
The cost of a fan depends on a lot of factors—some very small, not particularly effective versions can run as little as a couple hundred dollars, and a small house professional installation might run $1,000 to $1,200. Bigger houses require more or bigger fans and end up costing a fair bit more.
Fleury uses a whole house fan himself. The only problem: it doesn't work as well on nights when it's both hot and humid. "There were a handful of nights when the house felt damp, but we weren't sweating." he says."It was kind of like camping."
Many people use the fans as an a/c assist. "You run it probably 80 percent of the time instead of a/c. And when you do run the a/c, you can use the fan to pull the heat out to cool everything down faster," says Fleury. "You can run the fan for one or two hours, then hit the a/c."
In a climate where the nights are almost never hot, that old technology makes an awful lot of sense in terms of efficiency and cost. It also offers a nice antidote to the stuffy, stale atmosphere houses acquire when they're never opened up.
"What's the first thing people do for spring cleaning?" Fleury asks. "Open all the windows."
Opening the windows in Texas, even in spring, meant exposure to blinding heat. But that's not true here, so my own hacienda will soon sport one of these whole house contraptions. It makes sense from an energy-usage perspective, taking away almost entirely the need to run ungainly, electricity-gobbling window units. It makes a lot of sense to my real estate agent wife, too—the thousand or so bucks we spend now should come back when we sell the much-improved house. It may be old-fashioned and low-tech, but it works.
