Active vs. Passive Radon Mitigation: What’s the Difference?
If the risks of radon gas in your home are on your radar, you may be wondering which radon mitigation system to install in your home: passive or active. In this guide, we break down each system, along with its pros and cons, to help you make the most informed choice for your home.
What Is a Passive Radon System
A passive radon mitigation system is typically installed during new construction. This setup reduces radon gas levels in a building without using a fan or active mechanical component, which is why it’s called “passive.”
In a passive system, PVC piping runs from under the foundation and vents through the roof. The system relies on natural airflow and the stack effect — warm air rising through the house — to draw radon gas from beneath the foundation and release it through the vent above the roofline.
Pros of a Passive System
Energy-efficient: No fan or electricity needed
Low maintenance: Minimal upkeep once installed
Cost-effective (new homes): Easy and inexpensive to add during construction
Upgradeable: Can easily add a fan later if needed
Cons of a Passive System
Less effective: May not reduce radon levels enough
Weather dependent: Airflow varies with temperature and pressure
Limited retrofit use: Best as a preventive measure in new construction, not for adding to existing homes
May need upgrade: Many systems still require a fan later
What Is Active Radon Mitigation?
The “active” part of an active radon system is the fan. Just like a passive system, an active system has a pipe running from under the foundation to above the roofline to vent radon gas outside. Unlike a passive system, though, it has a radon fan (usually installed in the attic, garage, or outside) that creates suction to draw radon from beneath the house.
Pros of an Active System
Very effective: Consistently lowers radon to safe levels
Reliable: Works year-round, regardless of weather or pressure changes (though your radon levels will still fluctuate)
Good for any home: Can be added to both new and existing houses
Quick results: Reduces radon immediately after installation
Cons of an Active System
Maintenance: Fan may need replacement every 5–10 years (Most contractors offer the manufacturer warranty, but the Radon Guys offer a 10-year warranty to keep you covered,)
Higher upfront cost: More expensive than a passive system
Passive Radon System vs. Active at a Glance
|
Feature
|
Passive System | Active System |
|---|---|---|
|
How it works
|
Uses natural airflow and pressure differences to vent radon
|
Uses a fan to actively pull radon gas from beneath the home
|
| Effectiveness | Moderate; depends on conditions | Highly effective and consistent |
| Maintenance | Lower; no moving parts | Fan replacement every 5–10 years |
| Installation cost | Lower, especially for new homes | Higher due to fan and electrical setup |
| Retrofit friendly | Not ideal for existing homes | Works well for both new and existing homes |
| Upgrade option | Can add a fan later to make it active | Already includes fan |
| Performance in high-radon areas | May not be sufficient | Reliable even in high-radon areas |
Is a Passive or Active System Better for Your Home?
In most cases, an active radon mitigation system is the foolproof way to protect your home from the harmful effects of radon. However, some home builders may be able to get by with just a passive system.
A passive system may make sense if:
You’re building a new home and want built-in radon prevention at a low cost.
The local soil has moderate or low radon potential.
You’re okay with testing after construction and upgrading if needed.
You should choose an active system if:
Radon tests show levels above 4 pCi/L.
You live in a high-radon area or have poor soil ventilation.
You want a guaranteed, long-term solution.
You’re retrofitting an existing home without a passive system.
Upgrade Your Passive System to Active with The Radon Guys
If you're relying on a passive radon system, it might not be enough. The Radon Guys in Nashville, TN can assess your current setup and recommend an active mitigation solution that ensures better, more consistent protection. Let’s upgrade your peace of mind. Schedule your radon evaluation with us today.
