A system loses part of its charge over the course of several months, but a careful search during a service call turns up nothing at all. Which detection approach fits that situation best?
Correct Answer
A) Fluorescent dye added to the system, then checked with an ultraviolet lamp on a later visit
A leak that takes months to show up releases so little at any moment that a detector sweep may find nothing. Fluorescent dye works on the clock instead of the instant: it circulates with the oil, seeps out wherever refrigerant is escaping, and leaves a glowing stain that keeps building between visits. On a return trip an ultraviolet lamp shows the accumulated evidence even though the leak is still too small to sense directly. Dye should be a type approved for the system and added in the quantity the manufacturer specifies.
Why This Is the Correct Answer
Dye accumulates. Instead of trying to catch a tiny escape during the few minutes a probe passes a joint, the dye marks the spot continuously and the stain grows between visits. That makes it the right tool for slow, seasonal or intermittent losses that defeat instant-reading methods.
Why the Other Options Are Wrong
Option B: Bubble solution brushed over every joint in the system during the first visit, working from the compressor outward
Bubble solution is excellent once a leak is narrowed to a small area, but soaping every joint in one visit is impractical, and a leak this slow may never raise a bubble however methodical the sweep.
Option C: A halide torch passed slowly along the length of the suction line and around each fitting
A halide torch reacts only to chlorine, so it is blind to modern refrigerants, and it brings an open flame to the work. Extending the sweep to every fitting does not change either problem.
Option D: A standing pressure test with the unit shut down for an hour or two
A standing pressure test can show that a leak exists somewhere but never locates it, and a loss spread over several months may not move the gauge at all in an hour or two.
Memory Technique
Dye has patience. It keeps working while you are on other calls.
Reference Hint
Leak repair and verification requirements appear in 40 CFR Part 82, Subpart F. Dye selection follows equipment manufacturer approval.
More epa-608-type-2 Questions
A walk-in cooler condensing unit holds a full charge of twenty-five pounds of R-404A, which is below the fifty pound threshold that brings an appliance under the leak repair provisions. What still applies to this unit?
An office building has thirty water source heat pumps on a common water loop, and each one left the factory assembled, hermetically sealed and charged with four pounds of R-410A. How is one of those units classified?
A data sheet for an unfamiliar refrigerant lists a boiling point of about fifty-five degrees Fahrenheit at atmospheric pressure. What does that tell a technician holding Core and Type II certification?
A technician holds Core, Type I and Type III certification and is sent to recover the charge from a twenty ton rooftop unit charged with R-410A. What does that combination of sections allow on this job?
A fleet garage technician holds only the vehicle air conditioning certification issued under Section 609 and is asked to recover the charge from the shop's own rooftop air conditioner. What does that credential allow?
A split system's outdoor unit, indoor coil and the line set the installer ran and brazed between them are being considered. For the purposes of the refrigerant rules, what makes up the appliance here?
On a new installation the line set is brazed to a factory charged outdoor unit and an indoor coil shipped under a nitrogen holding charge, with the outdoor unit's service valves still closed. What does the recovery requirement call for before that brazing?
A rooftop unit's data plate has weathered until the charge figure cannot be read, and the technician needs the full charge to place the appliance under the evacuation and leak provisions. Where should that figure come from?
A computer room air conditioning unit holds forty pounds of R-407C and connects to a remote air cooled condenser through refrigerant piping run and brazed by the installer. How is that unit classified?
A shop's office manager, who holds no technician certification, is sent to a supply house to pick up a new recovery machine for the commercial crew. What does the sales restriction require at that counter?
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