ERV with dedicated duct system
I would like to follow Martin’s advice about using an independently ducted ERV in my cold edge of Zone 4 new construction. There will be two Carrier Performance line gas furnace/AC systems, one on the main level and one on the finished walk-out basement lower level. About 2300 sq ft of finished space on main level; 2000 finished plus 1000 additional conditioned on lower level, with tall ceilings on both.
The contractor thinks I only need one conventionally installed ERV (ERVXXSHB1100) tied to the furnace on the main level. He says the ERV has an intake & exhaust fan that is independent of the heating & cooling system. It will work even without running systems. He has the same in his house and says it works great. I will have 2-stage furnace & AC with ECM fan.
One side note on using the ERV tied to main level. In the middle of the house is a very open staircase (16×9) which will probably mix air from both levels more than most houses.
The additional duct system would be $500, adding about 2-3% to the HVAC cost. I don’t mind the additional cost if it makes sense. Based on some of Martin’s numbers, seems I would make that money back in a couple of years with lower operating costs (although I may be overproducing PV electricity anyway–won’t know till it’s too late to change anything). Thanks.