Passive vs. active radon systems

Both move radon out of your home, but they're not equally reliable. Here's how to tell which one you have — and which one you need.

Passive systems

A passive system uses natural convection (warm air rising) to draw soil gas up a vent pipe with no fan. Many newer homes are built with a passive rough-in. It's low-cost but inconsistent — performance varies with weather and season.

Active systems

An active system adds a continuously running fan, creating reliable suction regardless of conditions. If a passive system doesn't hold the home below the action level, upgrading to active (adding a fan) is the standard fix.

Which you need

If you have a confirmed radon problem in an existing home, you almost certainly want an active system. Passive is mainly relevant for new construction or as a starting point that may need a fan added.