EnergyPlus HSPF Calculation - Rated Supply Air Fan Power Per Volume Flow Rate

asked 2024-01-26 10:57:43 -0500

Sebastien Brideau's avatar

updated 2024-01-27 07:00:19 -0500


in EnergyPlus, you can get a calculated output of HSPF for heat pumps. The Coil:Heating:DX:Multispeed object (although SingleSpeed is similar) requires a Rated Supply Air Fan Power Per Volume Flow Rate.

The manual states:

The Rated Supply Fan Power Per Volume Flow Rate is a user-entered value, with a default of 773.3 W/(m3/s)) if the user leaves this input field blank. The default value is taken from ANSI/ASHRAE Standard 210/240-2008 where it is defined for systems which do not have an Indoor Coil (Evaporator) fan furnished as part of the system.

If the heat pump data I have includes a fan, should this value be zero? What I mean is, if the heating capacity, electrical power input, and COP data already account for the fan, wouldn't including this just mess up the HSPF calculation as it would double-count the fan? Wouldn't most heat pumps which include fans include the fan in the performance data?

Also, I tried to make this number zero and it seems to revert to the default value, but I'm not sure. I set to very near zero, and I get close to the rated HSPF.


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