All-air systems fall into two general categories - constant volume and variable air volume (VAV). Constant air volume systems accomplish cooling and heating by varying the supply air temperature and keeping the air volume constant. VAV systems keep the air temperature constant and vary the air supply volume.

A/C: 12-15 years. Your product had 0-2 repairs in the last 3 years.

If possible, keep your indoor HVAC unit as close to the center of your home as you can. This will reduce the amount of ductwork you'll need, saving you money on repairs and your energy bills. Other ideal locations for the indoor unit include pantries, utility closets, basements, or small closets in a middle hallway.

Best Places If space permits, the most convenient place for the furnace, or air handler unit (AHU) if it's equipped with air conditioning, is in the basement of the home. The ductwork can branch up from the AHU in a central trunk, and divide into separate sections that supply each room.