There’s no plan for a regular home handyman column here, but I notice many people going about heat wave management the wrong way, so here’s what you need to know. First, what you can do quickly, and without air conditioning, which is a lot if you’re smart.
(1) Keep the sun out! Windows facing south to west need shading. Exterior awnings, a wonderful old technology that comes in cheerful striped colors, are the best thing for this; second choice is Venetian blinds, which can stop the sun and allow ventilation; third is a plain white window shade. The awning is best because it interrupts all the radiation outside the house instead of letting it in through the window and then reflecting only some of it back out. (Actually, a tree is best, but the twenty-year installation period puts it in a category by itself.)
These devices need management; if you don’t adjust the shades, you’re living in a greenhouse.
(2) Dump the hot air out of your house in the evening! This is done with a window fan installed in the top (preferably) of a window, in a room where you will mind the noise least, usually a guest room or the kitchen, running to blow out. If you can put it on the second floor, you will exhaust the hottest air in the house and convection helps you. (Don’t use a window facing your prevailing wind, though!) It is much more efficient at moving air through the house set to exhaust, and the incoming air in other rooms won’t stir up all the papers on your desk. We successfully used two of the $20 box fans you can find at the hardware store for my daughter’s LA apartment, mounted in a plywood panel, but you will probably be happier with something more expensive, like 3C614 or 4TM66 from Grainger. I use one 3500 cfm fan in a four bedroom house in Berkeley successfully.
Mounting this fan can require some tools and improvisation; you want it inside the window so the window can be opened and closed without removing it. You can’t just put it on a table pointing vaguely at an open window, but it doesn’t need to seal perfectly around the sides; the outgoing jet will actually induce some additional air flow around the edges by the Venturi effect. Remove the insect screen from this window, it greatly impedes the fan’s performance (the coarse grid that keeps fingers and the cat out is not a problem).
The fan needs to be managed as well. Turn it on in the late afternoon or evening, as soon as the outside temperature is below the inside. Partly open a window in each of the rooms you want to occupy, for example, the living room and bedroom (the total open area of these inlet windows should be about two to three times the area of the fan, . Each of these will generate a jet of nice cool air perpendicular to its opening (you cannot steer this jet by the direction you are sucking from) that’s nice to sit or sleep in front of. In the morning, turn it off, close the windows to keep out as much hot daytime air as possible, check the shades, turn off all the electrical devices you can, especially lighting, and go to work or the beach.
I cannot overemphasize how much cheaper and more environmentally responsible a fan is than air conditioning, nor how much more effective it is than most people realize if used properly. A small air conditioner for one room draws five times as much electricity as a 3500 cfm exhaust fan.
Circulating fans are pretty much useless, though sitting in a warm breeze is nicer than sitting in warm still air, and sometimes you can put a box fan in a doorway to help the air move through the house.
Finally, put in compact fluorescent light bulbs wherever you can use them. These are a license to print money, especially if you are air conditioning, and many are now dimmable (Google “dimmable cfl” for sources like this one). You get two thirds off the top of your electric consumption for each one right away, with a comparable reduction in heating up your house, and the color balance is now entirely comparable to traditional incandescents. A few applications need incandescent bulbs for aesthetic reasons (by the way, a halogen lamp is only a little more green than an ordinary incandescent), but consider this a luxury that entails a hit to the welfare of the planet, and your pocketbook. A few lights that are almost never used, like the bare bulb in your attic, are not worth replacing with cfls, and in contrast, lighting like exterior floodlights that run all night every night are prime candidates, and right away. If your landlord pays for your electricity, he should not only pay for the cfls but buy you a nice bottle of Scotch if you install them. (Tech vocabulary note: in the lighting industry, what most people call a bulb is called a lamp, and the fixture that holds it is a luminaire.)
Maintaining a house full of incandescent bulbs should be regarded as a socially gauche kind of behavior. You wouldn’t light a cigarette in someone else’s house; why would you trash the planet by mismanaging your own?
Longer-term/expensive options include:
an attic-installed whole house fan, sized to replace the air in the house every two-to-five minutes (just calculate the cubic feet of occupied space), drawing hot air from the top of the space so the chimney effect helps;
good double-glazed windows, preferably with differential reflectivity coatings (see your local lumber yard about this very effective option);
a white roof;
and plant that tree now!
If you use an air conditioner, think of it as a very expensive device to carry all the heat that gets in your house out; the less heat you let in, the fewer hours you have to pay it to work. The expensive part is the compressor that cycles on and off; the fan part that just circulates air through it is pretty cheap, so just because it’s making noise doesn’t mean it’s costing a lot. How does heat get in your house? Sun (that window shading is really important), open doors and windows, conduction through windows and uninsulated walls, any electric device, proportional to its wattage and how long it runs (read labels; you may be surprised at what matters and what doesn’t), gas appliances like the oven or range, and people. Before you start it up, use the fan arrangement described above for a half hour; you’ll be pleasantly surprised, and you can probably get through many nights with no AC at all quite comfortably.