said by nunya:Would an ERV make any difference in an old drafty house. E.G., would the "least path of resistance" rule apply to air as well?
In my house I have the furnace, water heater, bath vents, and dryer. I'm sure they are pumping copious amounts of air out of the house, which means air is coming in from somewhere anyway.
We have an old leaky house. I had an energy audit with a blower door test, and was given an ordinal list of improvements to reduce outside air infiltration. We did the top items on the list: Insulating all outside walls, weatherstripping doors better, sealing unused windows. Other items on the list were rebuilding windows to eliminate window weights, and then insulate those cavities, insulating basement walls. The ERV didn't even make the list. So in a loose house, your money is better spent on other stuff.
I also draw air with the bath and range vents, but I am not worried about backdrafting because I have a direct vent water heater and 90+ furnace drawing outside combustion air. Only the gas dryer draws combustion air from inside.
So anyway, after the insulation and weatherstripping, the auditor re-did the blower door test, showed me the reduced infiltration, and gave me my rebate certificate. With that, the state program paid for most of the audit and paid me for part of the improvement cost.