Efficiency

Heat Pump Efficiency

Heat pumps are air conditioners you can run in reverse to also heat.  The primary energy efficiency rating for air conditioner is SEER or (seasonal energy efficiency ratio).  This ratio is based on assumed factors, over the full cooling season.  It’s similar to the MPG rating on a new car.  Compare SEER first and then look at the EER.  The EER is (energy efficiency ratio).  This is the amount of cooling the unit produces in btu divided by the amount of electricity the unit uses in watts.  Cooling btu/electric watts.

The minimum SEER for a new AC unit is 13.  13 SEER is more efficient than 10 SEER.  The EER for a 13 SEER unit would be aproximatly 11.3.

12000 btu (1 ton) /1000 watts (1 kW) = 12 EER

The measure used for the heat pump is COP (coefficient of performance).  This measure is also kwh heat output/kwh energy input.

Both of these calculations should be used to compare one brand or model with another.  Always ask for an operating cost calculation based on EER and the normal compressor run hours for your area.  In other words if the proposed unit is a 12 EER, if you live in an area with 1500 compressor run hours, your energy use would be 1500 kWh per ton.  At 15 cents/kWh your annual cost would be $225. per ton.

The quality of the installation can reduce the efficiency of the unit by a significant amount.

The bottom line on efficiency is to hire a competent contractor.