Editor's note: In case you missed this local voices post this past week, our sustainable living blogger Chip Small wrote about ways to keep cool this summer. Give it a read, then share your thoughts with him and other readers in the comments below. Thanks.
To say that it's been a hot summer is an understatement; much of the Midwest is experiencing the hottest July on record, and we have plenty of warm weather still to come.
With air conditioners running nonstop across the Metro to keep our homes and businesses tolerable, I've wondered just how much of an impact these heat waves have on our energy consumption--and whether there's anything we can do about it.
Air conditioning accounts for almost 20 percent of energy consumption in U.S. homes1, and can account for half of the summertime electric bill. Running a central AC for an hour uses 3.5 kWh of electricity--as much energy as if you accidentally left the refrigerator door open for ten hours2.
Any other efforts an environmentally conscious homeowner might make to save energy (like unplugging your cell-phone charger, or turning off the lights) are negligible on a hot day when the AC is running.
We recently moved to a new house--without central air conditioning--just before the summer heat wave. We have a single window unit on the first and second floors--the upstairs one in my four-year-old's room, so we've jury-rigged a series of fans to try to move some of the cool air to the two other bedrooms, with limited success. Henry has to pile on blankets at night while the rest of us are a little too warm for comfort.
I perused a list of tips for saving money on cooling your house2 to see what we are doing right, and what else we should be doing. Many of the tips only apply to home with central air (turning up the thermostat one degree can save 3 percent on your energy bill, for example).
Strictly from an energy efficiency standpoint, window units have some advantages--a window unit uses around a quarter of the energy of a central air system, and you just cool the rooms you need.
Additionally, a lot of cool air can be lost--and energy wasted--from a central air system via leaky ducts in a hot attic.
Perhaps the biggest advantage that we have, though, are the pair of large oak trees in our yard. By providing shade and evaporative cooling, well-positioned trees can keep your house up to 20 degrees cooler and provide 40% savings in energy costs. Not only does the shade keep the house cooler, but air conditioners work more efficiently when shaded.
Using drapes or blinds to keep out direct sunlight keeps rooms cooler (keeping the heat out in the first place is cheaper than paying to remove it). We check the nightly forecast to assess whether we can turn off the AC and turn on the window fans--though such nights have been few and far between this summer. Keeping the oven turned off is a priority in this hot weather--ordering take-out becomes even more appealing than normal.
What else could we be doing?
Painting your house a light color, and having a white or metal roof, helps reflect sunlight and can save 20% on cooling costs, but this list of tips was written for a warmer part of the country--I'd rather have the extra sunlight soaked up in the winter by my dark blue house with asphalt shingles.
Extra attic insulation and new Energy-Star windows would surely help, though it would take years realize those savings. Ceiling fans would probably help--we'll consider that for next year.
Since the ultimate goal is to keep you cool (and not necessarily your house), this web site also includes a number of tips such as rinsing off in the shower, wearing a wrung-out shirt, and using cold packs.
In the meantime, I'm inclined to do as my forebears in the South did in the years before everyone had air conditioning--sit on the front porch and drink iced tea.
Do you have other tips? I'd be curious to hear them.