Energy Recovery Ventilator (ERV)
A ventilation system that exchanges stale indoor air for fresh outdoor air while recovering 70-80% of the energy (heat and moisture) from the outgoing air stream. Essential for tight, efficient homes.
Why It Matters
Modern well-sealed homes need mechanical ventilation to maintain air quality. An ERV does this without throwing away the energy you already paid to heat or cool the air.
Related Tools
Related Terms
Air Sealing
The process of identifying and sealing unintentional air leaks in a building envelope — including gaps around pipes, wires, ducts, windows, and the attic hatch.
ACH50 (Air Changes per Hour at 50 Pascals)
The number of times the total air volume of a house is exchanged per hour when the house is depressurized to 50 Pascals (about 0.2 inches of water column) during a blower door test.
Blower Door Test
A diagnostic test that uses a calibrated fan mounted in an exterior doorway to depressurize the house and measure the total air leakage rate, expressed in CFM50 or ACH50.