Air-conditioners keep our homes cool and comfortable, especially during the hot summer months. They work by taking the warm air from inside the room, cooling it, dumping the heat outside, and then re-circulating the cooler air back into the room.

However, even with recent advances in technology, air-conditioners are still some of the most inefficient machines we have.

This is why it is important to check the efficiency of all air-conditioning units. For this purpose, all air-conditioners come with an Energy Efficiency Ratio or EER. The EER is the unit’s cooling output in British Thermal units per hour (BTU/hr.) divide by its energy input in Watts at specific indoor and outdoor temperatures.

A higher EER value means a more efficient air-conditioner. The most efficient ones have an EER value of about 13.

Finding the right air-conditioner for your home isn’t just about cooling output and EER though. A/C units, on the average, consume about 2000 kilowatt-hours of electricity in a single year, and this amounts to about 3,500 pounds of carbon dioxide emitted at the power plant. Efficient air-conditioners can lower these values by about 20 to 50 percent, with the most efficient ones able to reduce consumption by up to 70 percent. This not only helps save money, it also helps save the environment.

When looking for your next A/C unit, always remember to check the EER value.