Earlier this year, we wrote a post about the cooling limits of an air conditioning system in a home. This is called the temperature differential of an AC, which is how much the air conditioner can lower the indoor temperature compared to the outside. The temperature differential for residential ACs is 20°F.
Of course, this doesn’t mean every air conditioner can work the same for every house. A small air conditioner may be able to lower the temperature by 20°F, but for only a limited area. This is the air conditioner’s capacity, which is separate from the temperature differential. The capacity of an air conditioner is how many BTUs of heat it can remove from a house in an hour. For example, a small window AC can remove about 5,000 BTUs/hour from a space, but this is only enough to cool down a single room. Larger central ACs can remove 12,000 to 60,000 BTUs/hour.