Leak Detection and Mitigation Flashcards
6 cards from real A2L practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 Leak Detection and Mitigation flashcards as text
What type of leak detector is required for detecting A2L refrigerants?
Answer: A detector specifically calibrated for the A2L refrigerant being used
A2L refrigerant detectors must be calibrated for the specific refrigerant (R-32, R-454B, etc.) since different refrigerants have different detection sensitivities and alarm thresholds.
Where should a fixed refrigerant leak detector sensor be mounted in a room with an A2L system?
Answer: Near floor level, as A2L refrigerants are denser than air
Most A2L refrigerants are heavier than air and settle at floor level when leaked. Sensors must be positioned where the gas accumulates first — typically within 12 inches of the floor.
A leak detector alarms in a residential bedroom with an A2L mini-split. The homeowner is present. What is the correct first response?
Answer: Evacuate the room, open windows from outside if possible, and call the HVAC service company
Even though A2L refrigerants are only mildly flammable, the priority is removing people from potential exposure and ventilating the space before any investigation.
How often should fixed A2L refrigerant leak detection systems be tested and calibrated?
Answer: At least annually, or per manufacturer's recommendations
Fixed detection systems require regular calibration to ensure accurate readings. Most manufacturers recommend annual calibration, with functional (bump) tests more frequently.
What is the difference between a 'threshold alarm' and a 'time-weighted average' (TWA) alarm on an A2L detector?
Answer: Threshold alarms trigger at a specific concentration instantly; TWA alarms trigger based on average exposure over time
Threshold alarms activate immediately when concentration reaches a set point (e.g., 25% LFL). TWA alarms calculate average exposure over a period, useful for occupational health monitoring.
After repairing a leak on an A2L system, what verification is required before returning the system to service?
Answer: Perform a standing pressure test, verify no leaks with an electronic detector, confirm charge amount, and verify leak detection system functionality
Post-repair verification must confirm the repair is sound (pressure test), no other leaks exist (electronic sweep), the charge is correct, and all safety systems are functional.