We programmed the thermostats and the ERV (energy recovery ventilator) and we discovered something really nice: The air is really really fresh inside the house. It is almost crisp. I think it is a combination of 3 things:
1) The new system is more appropriately sized for our house. Our old system would blow cold air forcefully and then shut off. The new system seems to be more gentle with its temperature adjustments.
2) The new thermostats have a programmable fan. We have it set to run for 10 minutes every hour if there has been no heat or air conditioning in the last hour. That helps keep the air from getting stale.
3) The ERV is set to run 30% of the time (18 minutes of every hour). When it runs, the ERV takes air from the 2nd floor bath rooms and replaces it with fresh air from outside the house, dumping the fresh air back in to the 2nd floor air supply ducts. If the HVAC system is running, that fresh air will ultimately get circulated throughout the whole house.
