• The best HVAC system never runs. This, of course, depends on the location your home is in. If you live in a moderate climate like Northern California, you can take advantage of free cooling for most of the year. However, if you’re in the midwest, you need equipment with economizer or enthalpy wheels to take advantage of free cooling.
• If you don’t mind the aesthetics. Mini-split systems are cost and energy efficient but aren’t appealing to everyone because the indoor (evaporator) units are hung on walls.
• If your budget allows for it, central air systems coupled with radiant heating and/or cooling provide 40% reduction in operating costs. This is because forced air systems have to heat the entire space before a thermostat reaches its set point. Radiant systems heat or cool the objects within the space and achieve this at lower temperatures.