Fresh air in, stale air out — and a little pressure on the house

An energy recovery ventilator — an ERV — pulls fresh outdoor air into the house and pushes stale indoor air out at the same time. Both streams run through the unit together.

As they pass, the ERV transfers heat, and some moisture, from one stream to the other. You get a swap of air without dumping all the heating or cooling you already paid for.

For radon, the unit can be set so a little more air comes in than goes out. The house is then slightly pressurized. Indoor air wants to leave through cracks in the foundation, instead of letting soil gas sneak in.

That is useful. It is not a replacement for a mitigation system under the house. Pulling radon from below the slab or crawl space is still our main job. We add an ERV when it belongs in the plan for your house — not as a stand-in for that system.

Whether an ERV makes sense is something we decide on a free on-site survey. The detailed quote comes after we have seen the house. After we install, we can test to confirm the work is doing what it should.