It is a common misconception that mechanical ventilation without recovery will cost a homeowner hundreds, if not thousands, of dollars a year in energy costs. If we tighten up a home and then put a 6" hole in the wall and bring in outside air, we must be running the electric bill through the roof. The truth is, we're actually talking tens of dollars - a year - in most cases. Take my home for example: I live in New England in a roughly 2,000 square foot home with oil heat. I got an estimate of $38-$144/year to operate an AirCycler® g2-k, depending on the tightness of my home. That’s roughly $3-$12/month. How do we know? We calculated it.

Our new Annual Ventilation Cost Calculator, developed in partnership with Residential Energy Dynamics, is the first calculator made available for getting the estimated annual energy cost of operating an exhaust, supply, hybrid exhaust-supply or even balanced ventilation system, using information that a homeowner or contractor has readily available. At minimum, the user can get an estimated annual energy cost by entering the zip code of the home, square footage, number of stories and bedrooms, and the heating fuel type. For a more targeted estimate, the user has the option to enter details like exhaust fan flow rate and furnace fan power. Using this information the calculator will produce an annual energy cost range. The low-end cost of the range is for older, leakier homes (that require less mechanical ventilation) while the higher-end cost is for newer, tighter homes (that require more mechanical ventilation). The estimate takes into consideration both the electricity cost to operate the system itself and the cost to condition the air coming in. 

We are excited about this tool for two big reasons. First, by calculating these very affordable costs we can see that recovery is not the only method of providing energy efficient ventilation. In fact, when you compare the energy cost, installation and purchase price of these types of systems, they’re some of the best options on the market. Second, building scientists and raters have long been using advanced software to do these calculations - but that doesn't help the homeowner or installer trying to quantify these costs. We are now bridging that gap by providing a simplified option that any homeowner, contractor or architect can use.

If you’d like to try it out yourself, you can access the calculator here. Feedback is welcome!

You can also see the assumptions made to get to these calculations here.

Written by Carly Maltais — May 13, 2015