Wednesday, August 19, 2015

Savings Challenge, Week 23: Use Air Conditioning Efficiently

We're just coming off a short but severe heat wave, with the heat index peaking at over 100 for several days in a row. Most of our neighbors, I suspect, spent most of that time inside with the air conditioning cranked up...and paid a tidy sum for the privilege. Bankrate reporter Sheyna Steiner, who leads off the Bankrate savings challenge for week 23 with the confession that "air conditioning reigns" in her house all summer, routinely pays about $30 more for electricity during the summer months than she does in the wintertime. (She posts a graph of her electric bills for the past 14 months that shows her bill in dollars, her usage in kilowatt-hours, and the average temperature, and you can clearly see how her usage ticks steadily upward as summer temperatures rise.)

To see if she could keep this cost down, Steiner decided to "crank up" the temperature in her house all the way to—wait for it—78 degrees. She claimed she couldn't go any higher than this during the day because of her three dogs, even though the American Kennel Club says dogs only "begin to show signs of overheating when the air temperature is between 81 and 85 degrees Fahrenheit." Steiner was irked to find, after suffering through a whole month of sleeping in a 78-degree house, that turning up the thermostat by a whopping 2 degrees in June had only saved her $4 over what she'd spent in May...and she'd actually spent $17 more than she had the previous June. (The average monthly high temperature, according to her graph, was exactly the same both years.)

Well, I hate to break it to this lady, but at our house, we have actually gone through entire summers without using the air conditioner at all. This summer, we have used it exactly once, on a sultry July day when our window fans running at full blast were unable to drop the indoor air temperature below 90 degrees by bedtime. So we spent that night camped out on the futon in the office with the window AC running on low and the cats amusing themselves by running back and forth over us all night. And just that one night (plus a couple of hours during the day) reminded us how costly air conditioning really is; our electric usage in July jumped to a whopping 421 kilowatt-hours, compared to 294 the previous year. 

So how do we manage to get through most of the summer without AC? Well, our main tool is electric fans, of which we have a wide assortment:
  • A tiny desk fan mounted on a stand made of scrap wood (to replace its original clip-on mount) that sits by my side as I work, pointed straight at my head, and keeps me tolerably cool throughout the day.
  • A huge, powerful, and noisy floor fan, which Brian puts in the kitchen window atop a small, portable bookshelf to drive hot air out of the house and pull cool air in through the other windows. By doing this in the evening, we can manage to get the indoor temperature down to a tolerable level for sleep, and then we set it up again in the morning to pull in as much cool air as possible before the outdoor temperature gets too high. The only problem with this strategy is that we sometimes have to switch everything off in a hurry when the cool air we're pulling in becomes laced with marijuana smoke from next door. 
  • A dual window fan that we keep in the bedroom to pull cool air in during the night. Brian shuts it off and pulls down the shade when he gets up around 5am to pee, so the light won't come into the room and wake me up too early. Since this fan can switch from intake to exhaust, we've also tried using it in the office to blow air out on the upwind end of the house when our neighbor is smoking, while pulling cool air in from the windows on the mostly smoke-free other end. This is better than nothing, but it just can't generate as much airflow as the big floor fan.
  • Another desk fan that sits on a small end table at the foot of our bed, pointed straight at us as we sleep, to help cool us directly during the night. For a while, we were moving this one between the bedroom and the living room so we could also use it to cool ourselves while we sit on the couch to watch TV in the evening, but eventually we decided to splurge and spend 15 bucks on a duplicate fan for the living room, so now we don't have to keep moving it back and forth.
  • A ceiling fan in the kitchen, which runs whenever we're in that room to keep us cool as we eat...and sometimes when we're not, just to help keep air circulating through the house.
These fans, combined with a few other tricks I outlined in an earlier post, are usually enough to keep us tolerably comfortable even on the hottest summer days. However, tolerably comfortable isn't exactly the same thing as comfortable, so I was intrigued to see an article titled "Stay Cool Naturally" in this month's issue of Mother Earth News. Unfortunately, most of the tips of offered on staying cool without AC were things I'd already tried, such as:
  • Acclimatize yourself to the heat. The article says that the more time you spend in an air-conditioned environment, the harder you'll find it to adjust to normal summer temperatures. This is fine for me, since I don't have AC at home to get used to anyway, though not so great for Brian, who has to work every day in an air-conditioned office. However, I draw the line at going out in the blazing hot midday sun just so it will feel cooler inside when I come home. I've been taking my walk during the relatively cool morning hours, and during the heat wave, even that was enough to exhaust me. The house felt cooler compared to the outside, but I sure didn't, and it took me about an hour of sitting in front of a fan chugging cold water to feel close to normal again.
  • Cool yourself with water. Even on the hottest days, I can't stand an ice-cold shower, but I have been adjusting the taps to a mix with more cold than hot. I've also tried the technique of soaking a cloth in cold water and draping it around my neck, but it doesn't seem to help much, and it's really not practical to do while sleeping.
  • Use swamp coolers. Evaporative coolers, or swamp coolers, send a stream of air over water, which is supposed to pull heat out of the air as the water evaporates. Unfortunately, that only works in a climate where the water can evaporate, and with the humidity around here at over 75 percent, this technique doesn't work too well. 
The only new tips I saw that looked potentially useful were in the "Readers' Tips" section. One reader recommends soaking your feet in a tub of cool water, which he says "can cool you off for hours." Another suggests freezing a bottle of water—he recommends salt water, since it freezes at a lower temperature—and putting it in front of your fan to add an extra chill to the air it sends your way. So when the next heat wave hits, maybe I'll try pulling out one of those tricks before I consider another expensive bout of AC use.
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