Minimum Window Requirements for a Window Air Conditioner

Size Requirements

• Window air conditioners have gotten smaller and more efficient in recent years. You can now purchase compact units to fit in smaller spaces. To determine the dimensions of your new air conditioner, take a careful measurement of the height and width of your window opening. When shopping, check the manufacturer's specifications for minimum window measurements. Don't worry about your window being too big; the installation instructions will tell you how to curtain off extra space and necessary materials will be included.

Structural Requirements

• Window air conditioners fit into double-hung windows. Make sure the window frame is solid and that there is no weak or rotted wood around the window. If the structure shows any sign of damage, you need to repair it before installing your new air conditioner. Heavy units will come with a support bracket to mount to the wall. If your AC does not come with a bracket but you'd like to minimize the weight placed on your windowsill, you can purchase a bracket at your local hardware store.

Energy Requirements

• Before buying, find out the unit's electrical requirements. Most units with a cooling capacity of 15,000 BTUs or less will run on the room's existing circuit. If the unit has a cooling capacity of more than 15,000 BTUs, however, you may need to install a 220-volt circuit to handle the air conditioner's electrical needs. Make sure that your new window AC is near an electrical outlet. If there is not one nearby, consider installing one. Using an extension cord is not a good idea because the electrical current weakens the farther it travels. You will end up with a hot power cord and an underpowered AC.

Considerations

• In order to help your air conditioner run efficiently, purchase a unit that is the correct size for your room. An AC that is too small will run continuously, and one that is too big will not be as energy efficient as one that is the appropriate size. If possible, install the AC on a shady side of the house. The AC will cool the room most effectively if you position it near the center of the room, so try to avoid installing the unit in corner windows.