Hi all,

New eQuest user, attempting to model some alternate HVAC system configurations for a new building. I set up the building, zones, internal loads etc., then created the first set of HVAC systems as packaged single zones with DX cooling and electric heat. Did a save-as, changed all the units to hot water heat and created a hot water loop. So far no issues. Now did another save-as and changed the units to VAV, with chilled water cooling, and created a chilled water loop. No change to the heating system configurations. In this model the cooling loads on each AHU increased by about 50%, and the total annual heating energy increased by a factor of 5. I have perused the detailed reports looking for causes and can find nothing. Zone load reports are identical, but the system design parameters show dramatically higher cooling requirements for the chilled water architecture. Zone temperatures are fine in both models.

Any thoughts out there?