July has arrived, and it brought the heat with it. As I type this, it's 91 degrees outside, with a heat index of 104. Our house doesn't have central AC, just a couple of room-sized units (one mounted through the wall and one in a window) that are fairly noisy and power-hungry, so I tend to save those for emergencies and cool off in other ways if I can. In case anyone else is in the same boat, I thought I'd share some of the tricks I've tried for keeping cool without AC and how well they worked.
Trick #1: Bring in cool air. When I got up this morning, the temperature in the house was a balmy 84 degrees. However, a quick peek at the local weather report showed that it was only 77 degrees outside, so every bit of our inside air that we could swap for outdoor air would make the place cooler. We set up our big fan in the kitchen window, blowing outward, and then opened up lots of windows to draw outside air in. The best part of this strategy is that, while it takes a bit of time for the air exchange to actually lower the indoor temperature, the added air movement makes us feel cooler immediately.
Trick #2: Shut out hot air. The only problem with the first trick I listed is that you have to keep an eye on the outdoor temperature. Once it gets hotter outside than it is inside, you need to shut off the fan and close all the windows to hold in the cooler air, just as you do with the AC on. Doing this seems counterintuitive, because even as the outside temperature climbs, the breeze through the windows still feels cool, and so it seems like shutting up the windows will just makes the house feel warmer. But this blogger at the Vancouver Sun tried it, and he found that the indoor temperature really does stay a couple of degrees lower when the windows are shut. So now I shut the windows as soon as we reach the break-even point. The house may feel stuffy inside, but the temperature stays lower, and I can switch on a fan to provide a bit of a breeze. Which brings me to my next cooling strategy:
Trick #3: Use fans. As Michael Bluejay succinctly explains on his cooling page, a fan doesn't cool a room (except when it's pulling in air a la Trick #1); instead, it cools you directly by blowing away the bubble of warm air that forms around your body. So a fan will do most good when it's focused right on you. I have my tiny desk fan (with its whimsical trimming of expired gift cards) sitting right at my left elbow, and I switch it on whenever I'm seated at the computer. Thus, although the thermostat says it's 88 degrees in the room, my personal temperature is—well, I assume it's around 98.6 degrees, but the point is that I feel quite comfortable. When I move to the kitchen, I switch on the ceiling fan in there, and at night, we keep a table fan pointed at our bed (in addition to the window fan that draws in cooler air from outside).
Trick #4: Lower the shades. Once the windows are closed and no longer needed to bring in cold air, there's not much point in leaving the shades fully open. Lowering them most of the way lets in just enough daylight to see by, but keeps out the full blast of radiant sunshine that can heat the room even if the windows are shut. Personally, I'd prefer to have awnings, so that we could keep the windows shaded even when they were open, but they're probably not worth the money when just pulling down the blinds can do the same job for most of the day.
Trick #5: Get my exercise early. Most days, I like to take a long walk after lunch to give myself a break from work in the middle of the day. However, if I'd done that today, the heat index would have been over 100 by the time I set foot outside. So instead I got my walk in early, around 9am, when the temperature was just over 80 and the heat index around 90. By keeping to the shady areas as much as possible, I managed to get in some activity without arriving home looking and feeling like a boiled lobster.
Trick #6: Drink cold drinks. This one is a little contentious, as some people claim that hot drinks are actually more effective than cold ones for cooling you off. I know from The Number One Ladies' Detective Agency, for instance, that hot tea is often drunk in Botswana for this reason, and Mma Ramotswe and her coworkers actually shudder to hear that Americans put ice in their tea during the summertime. News items, too, will often blithely claim that studies prove hot drinks really are cooling. However, if you dig a little deeper, as this article in Smithsonian magazine does, you'll find that what the study actually shows is that hot drinks can be cooling in the right circumstances. The heat of the tea triggers your body's cooling mechanisms, causing you to sweat more. So if your sweat can evaporate—as it can in the dry climate of Botswana—you will cool off. However, here in central New Jersey, where the relative humidity is currently at 52 percent, a cool drink will be more refreshing. (And besides, what good is having the secret of making your own Frappuccinos if you don't use it?)
Trick #7: Apply a cold cloth. I haven't had to resort to this yet this year, but during last year's heat wave I found it quite helpful to soak a cloth in cold water and drape it around my neck. It would probably be still more effective in a dry climate, where the added moisture could evaporate, but even in humid New Jersey, applying ice-cold water right on those big blood vessels in the neck is bound to draw some heat out of the body.
With this combination of strategies, I haven't had to switch on the AC yet this summer. I'm not saying I expect to make it all the way through the dog days without using it at all, but if this summer is typical (and it could hardly be worse than last year's), we shouldn't have to use it more than once or twice. Summer cooling still accounts for a good chunk of our total power usage; last summer, from June through August, we used 873 kWh and spent about $162 (not counting the surcharge we pay for renewable energy). That's a lot more than the 506 kWh we used during the winter months—but it's still a lot less than the $395 the average American household spent. So if nothing else, our cooling tips are doing a reasonably good job of keeping our bills from overheating.