Tuesday, September 01, 2015

Low-Energy Comfort in Summer

Though there have been a few periods of heat and humidity, this has been a remarkably comfortable summer over all. While the western U.S. burns, fries and dries to a crisp, its inspiring beauty, grandeur and livability imperiled by the deepening expressions of climate change, New Jersey seems a sheltered place. The suffering elsewhere and the mild weather offer motivation and means to maintain comfort with minimal dipping into energy and resources.

On a fairly typical day this August, our house was comfortable all day while consuming less than 3 kilowatts of electricity, a crazy low amount. Credit for the comfort goes to nature rather than the air conditioner--a machine that would consume 3 kilowatts in an hour if it were running.  The whole-house energy meter in the photo shows just 210 watts of consumption right now. The number would be lower if the refrigerator didn't happen to be on. If the A/C was laboring away, the consumption would leap to 3500 watts. In that vast difference in energy consumption lies the reasoning behind seeking some other way of keeping the house cool.

Nature has been a particularly great collaborator in comfort this summer because overnight temperatures have often dropped into the 70s and even 60s. Run the house fan for a half hour in late evening or early morning, when the outdoor temperature is lowest, and the house is quickly filled with cool air that, thanks to shade and insulation, can last us through much of the day. The A/C can then be run sporadically to cut the humidity, and need not labor all day long to get the temperature down. It also helps to acclimate one's inner nature by expanding one's comfort zone, so machines need not work hard to keep the indoor temperature within a narrow range.

Though our house at least has a whole-house energy meter, it like most houses is remarkably unintelligent compared to much less pricey possessions, like a car or a cell phone. That lack of intelligence plays out as wasted energy that becomes clear during an evening walk through the neighborhood. The outdoor air may be cool, humidity relatively low, yet many homes will have their air conditioners grinding away, trying to cool indoor air when abundant fresh, cooled air lies just outside.

A modest dream, born of cool evening air, would be for every home and apartment to have temperature and humidity sensors, inside and out, that compare indoor and outdoor air and can tell you when to turn off the A/C and bring the outdoor air in. Cell phones bring us the world. The least a house could do is take note of the air just outside the front door.

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