Heating and Cooling Equipment Efficiencies

Where users do not have information regarding equipment efficiency they may input the year installed. Estimates of the annual average efficiency are provided for the period 1970-2010, pending new data efficiencies post 2010 are assumed to be the same as the latest available year. These estimates are based on two main sources, GAMA (1996) and shipment data complied by the Appliance Standards Group, LBNL. We constrain these base estimates so that they remain within the ANSI/BPI 2400-S-2012 (BPI, 2012) minimum standards recommended for whole house energy modeling.

There are several equipment types for with we do not have adequate data to make annualized shipment weighted efficiency estimates, and those are given below. In addition Energy Star equipment has year=0, this is intended to indicate "applies to all years", in the case of Energy Star all qualified units are modeled with the current year minimum efficiency.

 Equipment Type
 Efficiency Unit Value Notes
 Ground Coupled Heat Pump
   or "geothermal"
 HSPF/SEER (see note)
Because we don't have shipment data for GCHPs, if users opt to model them based on year installed they are modeled using the efficiency values for Air-Source types of the same year. It will be best for users to get the nameplate efficiency of their unit.
 Electric baseboard heater
 Wood Stove (fuel = cord wood)
Heat content of cord wood: 20,000 kbtu/cord.
 Wood Stove (fuel = pellet wood)AFUE
Heat content of pellet wood: 16,400 kbtu/ton.
Notes on Wood Fuel:
  • Cost of cord wood: $250/cord. 
  • Cost of pellet wood: $294/ton.
  • Source energy factor for all wood: 1.01.
  • CO2 emission coefficient for all wood: 1.6 lbCO2/Mbtu.