We are trying to model a building with enthalpy wheel OA energy recovery.
After completing the entire model and getting all set up in detailed edit mode, when we add in an enthalpy wheel for even just one zone, the cooling energy increases. Heating energy does decrease.
We tried to:
1. Control sequence of operation for OA exhaust delta enthalpy (also same result if control when fans on and control by differential T)
2. As a test, it made no difference if it was enthalpy wheel, sensible wheel, enthalpy HX, sensible HX or heat pipe... same story with cooling increased.
3. Even with fan pressure rise set to '0' (no fan energy), cooling increased.

We have tried a multitude of combinations and keep getting similar results.

Tom Lawrence, Ph.D., P.E., LEED-AP