How Many BTUs Of A/C Do I Need For My Home?

We don’t need to go outside, look at a thermometer, or even to peek outside the skylights of the Consumerist Bunker: we can tell when temperatures are beginning to climb in much of the United States, because search engine traffic begins to pour in to old posts about how to figure out how many BTUs you need when shopping for a room air conditioner. Fear not, overheated Consumerists: we’re always here to help.

Here’s a handy chart based on information from the cool people over at EnergyStar. It’s not a precise measurement: according to our breezy and cool colleagues over at Consumer Reports, the type of appliance you might need will also depend on what you use the room for, and how many people are usually in it. For example, if you’re buying a unit for a kitchen or a an open-plan room that includes a kitchen, you’ll need about 4,000 additional BTUs to compensate for that whole “cooking” thing that happens in kitchens.

Consumer Reports also offers suggested models for different types of sizes of rooms, and broad ranges of capacities that might work for different room types ranging from tiny bedrooms to huge living rooms.

You’ll need 10% more capacity for rooms that are very sunny, and 10% less if there’s no sunlight coming in the windows at all.