What are efficiency ratings?
Furnaces feature an Annual Fuel Utilization Efficiency (AFUE) rating, measuring a gas furnace's efficiency to convert the fuel to energy. Air Conditioners and Heat Pumps feature Seasonal Energy Efficiency Ratio (SEER) rating to measure the cooling efficiency. Heat pumps also are rated for Heating Seasonal Performance Factor (HSPF) to measure the heating efficiency. In all cases, the higher the rated number, the more efficient the product.
Look for ENERGY STAR products
The ENERGY STAR program is a voluntary labeling program lead by the Environmental Protection Agency (EPA) and the Department of Energy. Product literature with this label meet the ENERGY STAR requirements because the product features efficiency ratings beyond the standard rate. For the consumer, this could mean savings on monthly gas and electric utilities.
When shopping for a new heating or cooling system, the current minimal efficiency ratings are 13 SEER for air conditioning systems installed in Northern climates and 14 SEER for heat pumps and air conditioners installed in any other region; 14 SEER for packaged systems; and 80% AFUE for gas furnaces ENERGY STAR products are 14.5 SEER and higher for air conditioners and heat pumps; 14 SEER for packaged systems; and 90% AFUE and higher for gas furnaces.
Employ the "Goldilocks and the Three Bears" philosophy
The size (capacity) of the heating/cooling system should be just right. A system too large will cool the home too quick just to satisfy the thermostat setting, and will not remove enough moisture from the air. This will also cause the product to start and stop more, shortening the life of the equipment. If the size is too small, then the furnace will continually run in the winter; and in the summer, the air conditioner will do the same.
A ton is not equivalent to 2000 lbs. in cooling
Don't worry, a three-ton air conditioner doesn't actually weigh three tons. One ton is the same as 12,000 British Thermal Units per Hour (BTUH). Gas furnaces are measured by BTUH input. A respectable, licensed HVAC contractor can help with the correct size. (See our tips on what to look for in a contractor).