Radon Mitigation System

[John Raffensberger]

I've never seen this type of system before. Looks like it's pressurizing the space below the slab. No vent pipe found to the outside. The little sign says clean screen periodically.

Thanks for your help,

John

[hausdok]

Uh John?

Picture?

[Les]

I have never seen anything like that either. In fact, I don't see anything.

[Rook]

It's a pressurized system that forces air into the space below the slab and thus forcing the radon to divert away from the foundation. They are not as common as the typical fan with PVC vent to exterior, but do exist. The EPA says:

9.3.7 Under conditions where soil is highly permeable, reversing the air flow in an active sub-slab depressurization system and forcing air beneath the slab may be effective in reducing indoor radon levels. (Note: The long-term effect of active sub-slab depressurization or pressurization on the soil beneath building foundations has not been determined. Until ongoing research produces definitive data, in areas where expansive soils or other unusual soil conditions exist, the local soils engineer shall be consulted during the design and installation of sub-slab depressurization or pressurization systems.)

http://www.epa.gov/radon/pubs/newconst.html

[gbrasseur]

A picture would be helpful John[:-hspin]Do you have one?

[hausdok]

Guess not, since he made that post 8-1/2 months ago.

OT - OF!!!

M.