Getting more work done with less effort sounds great in any context. But in the context of air conditioners, furnaces, heat pumps, and programmable thermostats it means lowering your energy bills and helping the environment. A high efficiency unit does the work of cooling or heating your home or office while using less energy to do it.
After the Clean Air Act, the U.S. Environmental Protection Agency started an R&D program to make the things we use every day more efficient and therefore make less pollution. The Energy Star certification was born from this program. It was a big deal back in 1992 when those first behemoth computer monitors with Energy Star stickers on them would “go to sleep” if you left them alone for a few minutes. Soon after, more office products started getting certified and in 1995 air conditioners did too.
For air conditioning systems, the measures of SEER(1) and EER(2) are used to determine efficiency. Both ratings are expressed in numbers typically between 13 and 18. And in both cases, the higher the better. Furnaces are rated by AFUE(3) which is a measure of gas usage. The old standard unit is an 80% efficient furnace. The new stuff can get you into +98% territory.
So now you might say that I really haven’t explained anything. That SEER and AFUE are still just meaningless acronyms. Well fear not, the real definitions are below. Arm yourself with this knowledge and become the envy of all your friends. Or watch their eyes glaze over. It all depends on the company you keep and their love for working smarter not harder.
1. Seasonal Energy Efficiency Ratio: SEER is the total heat removed from the conditioned space during the annual cooling season, expressed in Btu, divided by the total electrical energy consumed by the air conditioner or heat pump during the same season, expressed in watt-hours.
2. Energy Efficiency Ratio: EER is the ratio of the average rate of space cooling delivered to the average rate of electrical energy consumed by the air conditioner or heat pump. This ratio is expressed in Btu per watt-hours (Btu/W.h).
3.Annual Fuel Utilization Efficiency: AFUE is a measure of a gas furnace’s efficiency in converting fuel to energy, by projecting the average thermal efficiency for a complete heating season.