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NC-2009 EAp2:Minimum Energy Performance

Modeling DOAS System efficiencies

I am modeling a geothermal heat pump system with a geothermal heat pump DOAS unit. The DOAS unit will be connected to the geothermal loop and will only provide 75 degree outside air to each heat pump within its zone. The heat pumps will all be connected to the OA duct work. The OA will mix with the room return and be supplied to each zone. I am having issues finding a way to model the efficiencies of each piece of equipment. I understand that I will have to probably average all the zone heat pump efficiencies for the plant energy rate. What I am not sure of is how to include the DOAS unit efficiency. It is rated at a much higher COP than the zone heat pumps but they are all included in the geothermal loop plant. Thanks,

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Tue, 11/01/2011 - 21:31

What software are you using? In eQuest you can model DOAS with a dummy zone and the "outside air from system" command. I suggest you post this question to one of the energy modeling list-servs like Bldg-sim. http://lists.onebuilding.org/listinfo.cgi/bldg-sim-onebuilding.org Or search the archives there - a search for DOAS gets 110 hits. I bet your question has been asked and answered a few times.

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