Homeowner in Granby (Estrie): radon measured with an ionization chamber and electret detector before installing the mitigation system.
Before625 Bq/m³
After27 Bq/m³
Reduction96%
The building
Year built: 1976 Basement: partially finished Monolithic slab Suction: 1 suction point
Installation: 3 h Investment: 2 799,99 $ + tax (standard)
Solution installed
Active sub-slab depressurization (SSD) by a C-NRPP certified crew. 1 suction point under the slab, connected to a sealed exhaust pipe; a fan creates negative pressure that intercepts radon before it enters the home.
Result
Confirmation test 48 hours after startup: 27 Bq/m³, well below Health Canada's 200 Bq/m³ action level (ideal target < 100 Bq/m³).
