There are several industry efficiency ratings, explained below by product category, which provide you with a basis for comparing the products you’re considering.
In addition to understanding each efficiency rating, check out our Energy Calculator to see how much you could be saving.
The Seasonal Energy Efficiency Ratio (SEER) is the industry-standard rating for air-conditioning efficiency. SEER rates cooling output (BTUs) divided by the watt-hours of electric energy input during an average summer. Higher-rated equipment saves money in the long-term due to lower operating costs. SEER ratings of 14 or above earn Energy Star’s label.
EER stands for Energy Efficiency Ratio, and measures how well an air conditioning system operates at a specific temperature (typically 95 degrees Fahrenheit). It’s a measure of how much energy a system uses compared to how much cool air it produces.
The higher the SEER and EER rating on your system the less energy your system will use to make you comfortable.
HSPF stands for Heating Seasonal Performance Factor, and measures the heating efficiency of a heat pump. It’s a ratio of heat produced over a season to the amount of electricity used. As with SEER and EER ratings, a higher number indicates greater efficiency. Because heat pump units heat and cool, they’ll have both SEER and HSPF ratings.
The Annual Fuel Utilization Efficiency (AFUE) measures a furnace’s efficiency over the course of a season. It rates the amount of heat radiated for each dollar spent on fuel. An AFUE of 90 percent or higher for gas furnaces (85 percent for oil-fueled units) is required to qualify for the US government’s Energy Star label. This means 10 to 15 percent of fuel is lost through the flue. Higher-rated equipment saves you money on utilities.
The Minimum Efficiency Reporting Value, or MERV, rates an air filter’s ability to trap impurities. This tells you how well they filter the air by measuring the amount of particles removed (which should be large) and the size of the particles (which should be small). Filters that trap a larger amount of smaller-sized particles, such as dust or germs, are most efficient. The higher the MERV rating, the better the filtering, according to Energy Star.