Window Unit AC Tips

Size

Buy a window unit designed to cool the space in which it will be used. An oversized unit will use more energy and leave the room too cold. An undersized unit will run more and may not cool the room sufficiently. The U.S. Department of Energy recommends you figure 20 Btu per square foot of space in the room. A room measuring 10 feet by 12 feet needs a unit with 2,400 Btu. Rooms with ceilings higher than 8 feet or lots of windows may need additional Btu to remain comfortable. Also consider the plug where you'll be plugging in the unit. A standard household plug is rated for 115 volts. If your window until AC is rated for more volts than this, you'll need to have an electrician install a higher rated plug.

Some window unit ACs have louvers that allow you to direct the airflow, an advantage if you have to install your air conditioner in a window in a corner or away from the center of a wall. If you live in an area that's very dusty or has a lot of pollen, look for a unit with a filter. You can also buy units with timers, handy for setting the unit to come on before you go to bed at night or before you return from work each day.

To install a window unit AC, open the window, set the unit on the window ledge, extend the baffles on either side of the unit and close the window. Use a level to make sure the air conditioner is level. This will help the drains work properly. Your air conditioner will work more efficiently if you install it in a shady spot on the north or east side of the house. If this isn't possible, shade the unit with an awning or by planting trees or shrubs. Direct sun on the unit reduces efficiency by as much as 10 percent. Don't block the vents; avoid putting hot lamps, computers or televisions next to the unit's thermostat.

Set the fan on your unit on high to move the air as much as possible. But if the weather is very humid, you'll be more comfortable with the fan on low. Dial the thermostat up as high as is comfortable. The less difference between the outside temperature and the setting on your air conditioner, the more money you will save. Add a ceiling or floor fan to move more air. This may allow you to be more comfortable at a higher temperature.