Manufacturers of products certified by the ARI Standard 330 for ground-source closed loop heat pump equipment publish a capacity rating for each model, cataloged at the standard entering water rating conditions of both 77 degrees for cooling and 32 degrees for heating.
The cooling EER, heating COP and fluid flow for both is also published.
In calculating the cooling Standard Energy Efficiency Rating (EER) and the heating Coefficient of Performance (COP), a penalty for the water pump effect of 0.8 watts per gallon per minute per foot of head is added to the measured power input. This approximates a 25 percent total pump efficiency.
In addition, a 17-foot pressure drop is added for the loop to determine the total pressure drop of the system for the pumping penalty.
The ARI Standard EER should not be confused with the SEER, or Seasonal Energy Efficiency Ratio. SEER is a measure of seasonal cooling efficiency under a range of weather conditions, assumed to be typical for a location, and of performance losses due to cycling under part load conditions.
Closed loop systems for use in Canada also should be rated in accordance with the Canadian Standards Association (CSA) and the Canadian Earth Energy Association (CEEA).