Revision history [back]

The Supply Air Temperature setpoint in the model is modeled as if it were the thermostat temperature, thus forcing the system to have a very high amount of airflow to meet the setpoint. Intuitively, the equipment will produce air much colder or hotter than zone air to cool/heat the zone.

To fix this model, I changed the supply air temperature setpoint controller to SingleZoneHeating and include a SingleZoneCooling after the cooling coil. This will adjust the supply air temperature to meet the load in the space, and gives a more reasonable (but still high) 0.97 m3/s (2000 cfm) fan sizing.

But the larger question is what sort of HVAC system do you want to model? Right now, you are modeling a VAV system with heat recovery, heating coils served by a heat pump hot water loop, and an air-cooled chiller serving a cooling coil. This is not a typical system for a residential project, and the resulting pump energy is half of your total annual electricity use. I think what you want is a zonal heatpump with an ERV, both of which are ZONE HVAC objects available in the thermal zones tab.

Also your model is using 2.9 m^3 (~770 gal) of water per day which seems high.