Thanks. My house was built in 2004 so there's no HRV unit. As you mentioned an indicator is window condensation and that seems to be in check. Everything in the house is original including windows, roof, front doors, furnace, water heater, attic insulation etc. so it's not as tight as it was. I'm just trying to keep everything running as best I can. In years past with the humdifier set to outside temperatures I would notice condensation on certain windows so now I just leave it off (plus issue mentioned earlier) and make sure to open curtains and blinds to monitor moisture levels; It's also nice to let the sunshine whenever possible.