RMS RMS Quality & Compliance 3 — Questions and Answers
Question 1: Which type of fan failure would most directly cause a radon mitigation system to stop functioning while still appearing operational?
- A fan running in reverse
- A fan with a seized motor producing no airflow (Correct answer)
- A fan with a slightly worn bearing
- A fan with an audible hum
Correct answer: A fan with a seized motor producing no airflow
A seized motor produces no airflow despite any residual noise or indicator light, making the system appear operational while it fails.
Question 2: When performing quality control on a sub-slab depressurization system, which measurement confirms adequate negative pressure beneath the slab?
- Static pressure at the fan outlet
- Differential pressure between sub-slab and interior air (Correct answer)
- Voltage draw of the fan motor
- Humidity level in the crawlspace
Correct answer: Differential pressure between sub-slab and interior air
A negative differential pressure reading (sub-slab lower than interior) confirms the system is creating the intended suction.
Question 3: According to EPA standards, where must a sub-slab depressurization system exhaust its air?
- Into the attic for natural dilution
- Outside the building above the eave line (Correct answer)
- Into a mechanical room with ventilation
- Through any exterior wall vent
Correct answer: Outside the building above the eave line
EPA requires exhaust discharge above the eave line and away from windows, doors, and air intakes to prevent re-entry.
Question 4: A homeowner reports that the U-tube manometer installed on their radon system shows equal fluid levels on both sides. What does this indicate?
- The system is operating at peak efficiency
- No pressure differential exists, suggesting the fan may not be operating (Correct answer)
- The system pressure is too high
- The test was conducted correctly
Correct answer: No pressure differential exists, suggesting the fan may not be operating
Equal fluid levels in a U-tube manometer indicate no pressure difference, which means the fan is likely not creating sub-slab suction.
Question 5: What is the minimum number of post-mitigation radon tests required before issuing a compliance certificate under most state programs?
- No testing required
- One short-term or long-term test (Correct answer)
- Two simultaneous tests averaged
- Three consecutive short-term tests
Correct answer: One short-term or long-term test
Most programs require at least one post-mitigation test to verify the system has reduced radon below the action level.
Question 6: Which record must an RMS retain for a minimum period specified by their certifying body after completing a mitigation project?
- Only the client invoice
- Installation records, test results, and system diagrams (Correct answer)
- Fan model numbers only
- Permits issued by local authorities only
Correct answer: Installation records, test results, and system diagrams
Certification bodies require retention of full installation records including test data and system diagrams for quality assurance and dispute resolution.
Question 7: A crawlspace depressurization system shows radon levels dropping from 18 pCi/L to 5 pCi/L post-installation. What is the correct classification of this outcome?
- Successful — goal achieved
- Partially successful — level still above EPA action level (Correct answer)
- Failed — reduction insufficient
- Not evaluable without a second test
Correct answer: Partially successful — level still above EPA action level
At 5 pCi/L, the level remains above the 4 pCi/L EPA action level, so the system requires optimization despite significant reduction.
RMS RMS Quality & Compliance 3
Which type of fan failure would most directly cause a radon mitigation system to stop functioning while still appearing operational?