I am modeling a low-rise apartment building. The measure that I'm having trouble with is installing split-system heat pumps. The baseline has simple electric strip heating and window mounted AC units. The measure uses the 'HVACTemplate:System:UnitaryHeatPump:AirToAir' & 'HVACTemplate:Zone:Unitary' objects, while the baseline uses; 'ZoneHVAC:Baseboard:Convective:Electric', and 'ZoneHVAC:WindowAirConditioner' objects in the residential zones.
The heat pump shows increased heating & cooling energy. I've determined, based on the *Zsz & *Ssz files, that the Zone & System Sizing loads are higher in the measure than the baseline (the baseline doesn't have an *Ssz). I have done my best to make the sizing options in the HVACTemplate objects in the measure match the Sizing:Zone objects, and that all the schedules controlling htg, clg, and fan operation match those in the baseline. There is also no outside air, for the system.
Any insight on how the zone sizing might be affected by the HVACTemplate objects, and how I can bring the loads inline with the baseline model would be appreciated.
(The baseline model was developed using OpenStudio v1.2, subsequent changes were made with a text editor)
Please see attached files, and thanks in advance for your help!
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Eric Youngson
503 468 7021
322 NW 6th Ave. Suite 200 | Portland,
Oregon | 97214