Furnaces
Heating and air conditioning systems are the biggest users of energy in the home, up to 75% of the utility bill. A new high efficiency furnace can save up to 50% in operating
costs over a ten year old furnace. Many 1990 and earlier model furnaces have efficiencies of 65% or less. The minimum efficiency furnace that can be sold in the United States today is 78%. Furnaces are available that are up to 96.6% efficient.
Air Conditioners may look similar, but check the SEER ratings. Higher SEER numbers save more money. A 13 SEER rated air conditioner uses 23% less energy then a 10 SEER unit. 13 SEER will be the minimum efficiency standard by 2006.

Heat Pumps
Heat pumps are rated in SEER (Seasonal Energy Efficiency Ratio) and HSPF )Heating
Seasonal Performance Factor). SEER and HSPF ratings are like Miler per Gallon rating
of automobiles. Higher SEER and HSPF ratings mean greater energy savings.

Fan Coils
The fan coil is the indoor component of a heat pump system. It includes the fan and the heating/cooling coil. The fan coil is designed for a particular refrigerant, so it must match with the heat pump. A variable speed fan coil can improve comfort with improved humidity control and warmer heating termperatures, and save energy in cooling.