A window air conditioner cools you off and can help you manage energy costs. This guide helps you learn about different types and how to choose one for your home.
A window air conditioner, also known as a window A/C or a room air conditioner, is designed to cool a single room and can be a good, easy-to-install option if a central air conditioning system is not practical or if you want to cool a single room rather than the whole house.
Depending on the model, a window air conditioner can operate in different modes. The cooling mode takes in room air, cools it and directs it back into the room. Some models allow you to select from several preset cooling levels; the air conditioner cools at the selected level until you change the setting or turn the unit off. Other models let you set a desired temperature for the unit to maintain. The air conditioner operates until it senses that the air is at the desired temperature and then cycles off, cycling back on when the temperature rises above the specified setting. A fan-only mode uses less energy because it doesn't provide cooling. The appliance simply circulates and filters the room air. Some window air conditioners have a heating mode. As with the cooling function, you set the desired temperature and the heating system cycles on and off to maintain it.
Follow the air conditioner manufacturer's instructions for safety, installation and operation.
The right air conditioner helps you cool a room efficiently. An undersize unit won't cool adequately while one that's too large will not remove enough humidity, leaving the air feeling damp. To find the proper air conditioner, determine the square footage of the room you want to cool by multiplying the room length by its width. You also need to know the air conditioner's BTU (British Thermal Unit) rating, which indicates the amount of heat it can remove from a room. A higher number means more cooling power for a larger room. Compare your room size to the BTU rating:
Consider conditions that may reduce the cooling need — the room is always shaded, for example — and those that may increase it — the room receives a lot of direct sunlight or regularly has more than a couple of occupants. Keep in mind that as the BTU rating increases, the size and weight of the air conditioner does as well.
EER stands for Energy Efficiency Ratio. A higher EER indicates a more efficient air conditioner.
Most window air conditioners are designed to fit double-hung windows, which have a sash you can raise or lower. Measure the inside dimensions of the installation window carefully to make sure you find a model that fits. Don't rely on estimates. Here are some other things to think about:
Never alter an electrical plug. Contact a licensed electrician if you have any doubts or questions about the circuit or outlet or if work such as installation of a new circuit or plug is necessary.
There are several things you can do to help a window air conditioner cool your home:
Simple maintenance helps keep an air conditioner operating efficiently and can maximize its lifespan. Unplug the air conditioner before performing maintenance. Here are some common procedures:
To learn about ENERGY STAR and room air conditioners, visit the ENERGY STAR room air conditioners page.