EPA Section 608 Universal Certification ExamType III (Low-Pressure Appliances)Easy
A technician is preparing to recover refrigerant from a low-pressure chiller. Which of the following is an acceptable method for increasing the pressure in the chiller to aid in refrigerant recovery?
- AIntroducing ambient air into the system.
- BUtilizing hot water or an external heat source.
- CApplying nitrogen from a high-pressure cylinder directly to the system.
- DRunning the chiller's compressor with the condenser fan off.
Show answer & explanationAnswer & explanation
Correct answer: B. Utilizing hot water or an external heat source.
To speed up refrigerant recovery from a low-pressure system, the pressure inside the chiller can be increased. This is safely and effectively achieved by applying heat, such as hot water or an external heat source, to the chiller.
Why the other options are wrong
- A. Introducing ambient air contaminates the system with non-condensables and moisture.
- C. Applying nitrogen directly is dangerous due to high pressure and potential for contamination.
- D. Running the compressor could damage the unit and is not a standard recovery pressure-increasing method.
Low-Pressure Chiller Recovery Aids
Methods used to increase the pressure within a low-pressure chiller to facilitate faster refrigerant recovery.
- Heating the chiller is a common method.
- Increases vapor pressure of the refrigerant.
- Helps overcome pressure differential during recovery.
Memory trick: Heat helps low-pressure go fast!