No Matter How Hot It Is, Physics Says These Two Methods Won’t Actually Cool Your House

Rhett Allain
8 min readJul 14, 2024
Photo: Rhett Allain. An infrared image of an opened refrigerator (using FLIR One Pro)

What do you do when your house is super hot (because it’s crazy hot outside)? There are two options that you will often see in both movies and commercials (and maybe you have tried these yourself). Well, I hate to be the bearer of bad news — but these methods don’t really work. OK, they “sort of work” — don’t worry, I’ll explain.

Opening the Refrigerator

Why is that the short version for refrigerator is “fridge” but there isn’t a “d” in the full name? That always confuses me. Spelling eludes me, but I have at least a medium grasp of physics. So, let’s look at this method.

Here’s the situation. Your AC broke and the house is too hot. Oh, let’s just open the fridge. The inside of the fridge is cold so this should cool down the house. Nope. It doesn’t really work.

To really understand the problem, we need to look at the physics of your normal refrigerator (there are some weird ones out there too — but that’s for later). It’s basically an insulated box with a heat pump attached to it. This makes stuff (on the inside) cold by allowing a compressed fluid expand and get cold. In order to repeat the process, this fluid is then compressed — which causes it to get hot. The key is that the compression is performed…

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Rhett Allain

Physics faculty, science blogger of all things geek. Technical Consultant for CBS MacGyver and MythBusters. WIRED blogger.