The size of your AC unit does not correspond to how much it will cool your home. What matters is that it is the right size unit. If your unit is too small for your home’s square footage, it will not be able to effectively cool the whole house. If the air conditioner is too large for your house, it will start up and shut down frequently throughout the day because it does not have to run as long to keep your home cool. This puts additional strain on the machine, which means it will require more maintenance and repairs.