When you hear HVAC technicians refer to “sizing” an air conditioner or heater, they’re not talking about how the unit will fit inside of your home. While that’s certainly part of their expertise and something they should take great care in doing, what this terminology actually refers to is the unit’s output.
It’s going to take a very particular amount of power to sufficiently warm or cool your home. Too much power is bad, and so is too little. We’ll explain the specifics down below, as well as what your options are if your system turns out to be the wrong size.