Monday, July 22, 2013

Essay: Putting Air Conditioning in Perspective

This is my relatively new, high-efficiency AC unit.
 We are advised by a number of reliable sources that our air conditioning should be set at 78 degrees during these hot, dog days of summer. (Note: That is hot, dog days, not hotdog days.) Our bodies, we’re told by HVAC engineers, max out at 79 degrees inside and after that, discomfort sets in.

If misery is not enough of an incentive, then cost might be. Every degree under 78 inside increases our cooling bills by six percent and if your house is big, as so many are, the bill can be substantial. A 78 degree $100 bill would be $148 at 70 degrees.
This cools me while I write.
I was raised in South Carolina at a time before AC was in 90 percent of homes and almost all businesses, even though it was invented in 1902 and generally taken to the market in 1939. Not even the upper middle income engineers and other professionals I knew had window units, and central air was unheard of.

Fans were the coin of the heat realm and if I recall correctly, my mom used to say, “Moving hot air is not much better than still hot air. It’s still hot.” That hot mass would occasionally inspire Mom to creativity. She’d place a fan behind a block of ice or on a chair in front of an open refrigerator—even as she superheated the kitchen by frying chicken for supper.

Those 50-pound blocks of ice were easy to come by and pretty cheap in the 1950s. A lot of people—mostly poor, like us—still had ice boxes in their kitchens, left over from the 1930s and ‘40s when appliances were built to last forever. Trees were planted on the east and west sides of houses to dent the effect of morning and afternoon direct sun and porches were used as social gathering places, catching breezes, sipping tea and telling tall Southern tales. South Carolina was a humid oven at the time. With climate change, I estimate, the Roanoke Valley has just about the summer climate I grew up in, especially in mid-to-late summer.

Ceiling fans are in every main floor room.
Today’s problems with getting cool are considerably more complex because our culture has moved from the front porch to the living room where it parks in front of a 52-inch TV or a laptop while central air moans in the background.

In old houses like my son’s 1915-era brick four poster in Old Southwest Roanoke, central air is not an option because the engineering it would require runs in the many thousands of dollars. His family has to be content with room AC and in a 3,500-square-foot, three-story house, that’s a lot of focused cooling, one requiring planning in its use.

It means about half or more of the rooms go without AC and exercising careful choice in the ones that do. Bedrooms, kitchen, TV or activities rooms get the AC and only when they’re in use. It’s still expensive when the temperature runs in the 90s outside even with a more limited use.

My house is small: 1,450 square feet, of which I use about 850 on the main floor. That’s what I cool when I cool it and I only turn on the AC when it’s miserable outside and more than 83 inside. I can live with 82 and if it’s cloudy outside, we can go to 85. Heat toleration is about the only benefit I can point to in growing up in South Carolina.

Love this metal fan from the '50s on my collectible shelf.
I have a new, efficient AC system, a complete re-insulation of the 66-year-old Cape Cod and an electric bill that would have looked about average 30 years ago.

When I had the house’s insulation renovated and updated a year or so ago, the people doing the work said that I had the equivalent of a 36-inch-by-36-inch window open all the time because of ill-fitting doors, no insulation between floors, ducts that didn’t fit tight at the vent and the like.

My new windows were great, but they gave a false sense of leak-proof security. There are a thousand ways for hot air to get into the house and cold air to escape and the challenge is to minimize them.

I’ve read that the average American home uses AC in equivalent amounts to driving the family car 10,000 miles a year. In China and India, which have the bulk of the world’s people and a lot of high temperatures, AC use is growing 20 percent a year.

Fans still blow in every room I live in—sometimes one overhead, one at chest level in a room. They keep the cool air moving. In the middle of the night, I often get up, turn off the AC, open windows and place a fan in them. That’s easy to do when you’re an old man and the bathroom is calling four or five times a night.

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