The higher the SEER (seasonal energy-efficiency ratio), the better the efficiency. Look for a SEER rating of at least 15. Sizing is key when it comes to AC. A contractor will look at windows, floor space, ceiling height, insulation, local climate, and more to calculate the correct size for your house.
Mounted on the wall or ceiling, ductless air conditioners provide targeted, zoned cooling. Single-zone mini-splits are available for cooling one room, while multi-zone systems connect one outdoor unit to several indoor units. The indoor units include a fan and evaporator coil in the same cabinet.
The less ducts leak air or allow heat transfer, the more efficient your HVAC system will be. More efficient ducts can also reduce the size, and therefore the cost, of the cooling and heating system you need, which means you could save money on both equipment and future energy bills.
A furnace uses natural gas, propane, or heating oil to make and circulate heat through air ducts and vents. The higher the AFUE (annual fuel utilization efficiency), the better efficiency and lower your utility bills.
In heating mode, an air source heat pump moves heat from the outside air inside. In cooling mode, it takes heat from the inside air and moves it outdoors. Geothermal heat pumps circulate water or refrigerant through underground pipes, pulling heat from the ground for heating and pushing it to the ground for cooling.