A: Unfortunately, there’s no simple rule of thumb for determining the ideal size of system for each home. For example, depending upon the construction of your home, one (1) ton of air conditioning can cool anywhere from 300 to 800 square feet of home. The only way to insure the size of the system you purchase will be large enough to heat or cool your home, but not any larger than you need, is to have your home’s individual heating and cooling needs evaluated by a licensed professional. A JC Heating & Cooling Estimator will perform a FREE detailed In-Home Energy Analysis to determine a selection of systems that will work best for your home’s needs and your budget.