The Energy Star program, created by the Environmental Protection Agency in 1992, has been adopted by the European Union and many other countries. It provides efficiency ratings for HVAC equipment as well as many other products.
Buying HVAC equipment is largely a numbers game: output, requirements, efficiency are all represented mathematically. If you’re math challenged or short on time, look for the Energy Star label and be done with it.
It will assure you that the appliance you’re purchasing, uses significantly less energy than required by Federal standards. Although these products cost more than standard models, they pay you back in lower energy bills within a reasonable amount of time.
If you want to dig a little deeper so you can understand some of what goes into determining appliance size (output capability), your home’s requirements (load), and the efficiency of your HVAC equipment, below are some terms you should understand.
A BTU, or British thermal unit, is a measure of heat. Specifically it is the heat required to raise the temperature of one pound of water one degree F. When you see it in the specifications for a furnace, boiler, heat pump or air conditioner, however, it is the maximum rate at which an appliance can produce (heat) or remove heat (cool) from your home. A 100,000 BTU furnace, for example, can produce 100,000 BTUs per hour when running at full capacity.
Heating load is the rate at which BTUs must be added (winter) or removed (summer) in order to maintain comfortable temperatures. Peak heating load is the amount of heat that must be added per hour time to keep the space warm on the coldest days of winter, Peak cooling load is the amount of heat that must be removed per hour to maintain a comfortable room temperature during the hottest days of summer. Estimating peak loads is something your Precision Home Performance technician can help you with.
AFUE, or Annual Fuel Utilization Efficiency, is the standard measure of efficiency for boilers and furnaces. Given as a percentage, AFUE tells you how much of the input energy the unit can convert to output energy for warming your home.
SEER, or the Seasonal Energy Efficiency Ratio is a rating based upon the efficiency of an air conditioner or heat pump when in the cooling mode. The higher the SEER, the more energy efficient the unit. The government's current minimum SEER rating is 13. An older unit with a SEER of 10 is 30 percent less efficient that one with a SEER rating of 13.
HSPF, or the Heating Seasonal Performance Factor, is a rating based on the efficiency of a heat pump when in the heating mode. The higher the HSPF, the more efficient the unit. The current industry minimum is 7.70 HSPF.