Q: What is a Heat Recovery Ventilator (HRV)?

A: New Construction is based on a point system. A Small dwelling unit (<1500 square feet of conditioned air space and <300 square feet of fenestration area) needs .5 points, a Medium dwelling unit (>1500 and <5000) requires 1.5 points and a Large dwelling (>5000) unit 2.5 points.

Last week I wrote about how you can earn points for controlling air leakage and providing better ventilation. You can earn more points if your (Air Changes per Hour) ACH is below 2 and an HRV is provided for ventilation.

The inside of a home is its own ecosystem. Moisture comes from cooking, washing, showers and breathing. Excess moisture is breeding grounds for mold, mildew, fungi, dust mites and bacteria. In addition to moisture the inside of a home produces gases like carbon monoxide or other pollutants that escape into the air. Products like paint, gas ranges, water heaters, unvented space heaters will produce gas in your home.

A great solution to better whole house ventilation is to use a Heat Recovery Ventilator (HRV). One fan blows the stale polluted air out of the home while the other replaces it with fresh air. What makes an HRV unique is the heat-exchange core. The core transfers heat from the outgoing stream to the incoming stream in the same way the radiator in your car transfers heat from the engine’s coolant to the outside air. Depending on the model, HRV’s can recover up to 85% of the heat in the outgoing airstream..

We are big believers in using HRV’s for whole home ventilation. We have one in our model home for your viewing. What I have found as a side benefit is how well they control dust. Our model home is almost dust free.

I also enjoy reading the paper daily. Thank you for doing so.

Build for life.

See you next week when I will discuss high efficiency Heating and Cooling equipment.

Please submit questions to jon@quailhomes.com Jon can be reached direct at 360.907.5800. Tune into Green Building with Jon Girod on 1550 a.m. on Saturdays at 9 am. See you next week!