Combined ERV/Ducted Heat Pump supply return – GreenBuildingAdvisor

If you try to only use the existing ductwork, you usually lose the ability to run the ERV in constant circulation mode unless you also run the main furnace blower. Running the main blower in the furnace use a LOT more energy compared with running the ERV alone. You also lose the ability to optimally place the ERV’s supply and return vents.

You can do hybrid systems. I’m working on that in my own home right now, with ERV return vents to be located in bathrooms, and maybe also the laundry and kitchen. Those are the areas that tend to introduce the most “bad stufF” into the indoor air, so if you draw air from those areas, you tend to draw air out of the home from the areas with the highest concentration of contaminants. This is the best bang for the buck way to go. I put the supply registers in the bedrooms, and sometimes also living room — the goal is to put fresh air supply into the spaces where people spend the most time, and remember that you tend to spend a big chunk of the day sleeping in bedrooms. You don’t have to have a pair of ducts to every room in the home to be able to get most of the benefit of an ERV, there are a lot of advantages to at least trying to do a targeted system with dedicated ducts to the most optimal places.

Bill