RRNC and Passive Radon Systems
What is RRNC?
RRNC (Radon Resistant New Construction) refers to the process of preparing a new home for the future installation of a radon system during the early construction phase and is identical to the installation of an ADC System rough-in. RRNC is built in from the ground up, following a few easy steps:
- Prepare and seal the ground and install a tee – we recommend the specially designed ADC-T and PVC pipe prior to pouring the slab.
- Also prior to pouring the slab, fill in the area around the T and pipe with aggregate and cover the entire slab area with a vapor barrier.
- After pouring the slab, seal all large openings in the slab (including sump pits) and joints.
- Route vent pipe through the attic to at least 12 inches above the surface of the roof.
- Install a wired electrical junction box.
What is a Passive Radon System?
The terms "RRNC" and "passive system" are increasingly used interchangeably, but traditionally there have been significant technical differences. According to the U.S. EPA, some builders "rough in" what is generally called a passive system, building in just steps 1 and 2 above and capping off the pipe. Although this is becoming common in new home construction, the U.S. EPA and many other experts do not recommend this practice, preferring instead either the RRNC pipe installation process described above or a full, active radon system.
Do RRNC and Passive Systems Reduce Radon?
A passive system or RRNC might provide a small reduction in radon levels, but an active system will reduce radon in nearly every home. The risk to homeowners when they buy a home with RRNC or passive system is that both terms give the impression that a home is safe from radon. A home with RRNC or a passive radon system is not guaranteed to resist radon nor is it guaranteed to be radon free.
These two simple and relatively inexpensive additional steps will make a passive or RRNC system active:
- Add a radon fan.
- Test the radon level.
No more steps are necessary, and the benefits of installing an active radon reduction system are numerous.
Active Radon System Benefits
An active radon reduction system reduces the entry into the home of radon, other soil gases and moisture, making the home healthier and reducing the likelihood of moisture-related new-home problems such as warping wood, odors and mold or mildew. After installing an active radon system, a certified radon mitigation contractor will provide a radon reduction guarantee. An active system
- Improves indoor air quality
- Reduces radon, moisture, odor, allergens
- Provides a more comfortable living environment
- Adds more livable space
- Preserves the building’s structure
- Protects interior fit and finish