Sometimes an air conditioning system can seem like a magical device. For centuries, people knew how to create heat when they needed it, but they didn’t have methods that could cool the air aside from using water or opening up windows and doors. Then came the electro-mechanical air conditioner at the start of the twentieth century, and we had devices that could send cool air into a room—air cooler than that outside!—with just a few adjustments.
Of course there’s no “magic” to ACs aside from technology. And air conditioners do have limits. You can’t make your air conditioning system turn your house into a freezer, for example (not that you’d want to). A standard residential thermostat has the lowest setting of 60°F. So what are the limits of your home’s AC, and how can you best use this information?