RMS Ventilation & Airflow Management 3

Question 1

What is the recommended minimum exhaust fan airflow rate for a typical residential sub-slab depressurization system?

Accepted Answer

30-70 CFM

Answer

Most residential SSD systems operate effectively in the 30-70 CFM range, though actual requirements depend on sub-slab permeability and building size.

Question 2

During a post-mitigation test, radon levels remain elevated despite an operating SSD system. What should the contractor investigate first?

Accepted Answer

Check for unsealed cracks, openings, or bypass pathways

Answer

Persistent elevated radon after SSD installation often indicates unsealed penetrations or cracks that allow radon to bypass the pressure field.

Question 3

Heat Recovery Ventilators (HRVs) are sometimes used as part of a radon mitigation strategy primarily to:

Accepted Answer

Dilute indoor radon while recovering heating/cooling energy

Answer

HRVs dilute indoor radon concentrations by introducing fresh outdoor air while recovering thermal energy from exhaust air to improve efficiency.

Question 4

When a radon mitigation pipe must pass through a conditioned living space, which installation practice is required?

Accepted Answer

All pipe joints must be permanently sealed gas-tight

Answer

When mitigation pipes run through conditioned space, all joints must be permanently gas-tight sealed to prevent radon from escaping into the living area.

Question 5

What does 'stack effect' refer to in the context of radon entry into buildings?

Accepted Answer

Buoyancy-driven airflow that draws soil gases upward into a building

Answer

Stack effect describes buoyancy-driven air movement where warmer indoor air rises and exits at upper levels, drawing cooler soil gas (including radon) in at lower levels.

(RMS) Radon Mitigation Specialist Practice Test

(RMS) Radon Mitigation Specialist Practice Test

RMS Ventilation & Airflow Management 3