EPA Section 608 Universal Certification ExamType III (Low-Pressure Appliances)Hard
A technician is performing a recovery from a low-pressure chiller. To prevent the recovery compressor from freezing up, what substance is typically circulated through the chiller during recovery?
- AGlycol solution
- BHot water
- CWarm nitrogen
- DBrine solution
Show answer & explanationAnswer & explanation
Correct answer: B. Hot water
Circulating warm water through the chiller's water box helps maintain the chiller at a temperature above freezing, preventing the refrigerant from dropping too low and potentially freezing any water that might be present, which could damage the recovery compressor or chiller components.
Why the other options are wrong
- A. Glycol solution is also typically used as a primary or secondary coolant in the chiller, not for warming during recovery.
- C. Nitrogen is an inert gas used for pressurizing or breaking vacuum, not for circulating as a heat source during recovery.
- D. Brine solution is typically used as a secondary coolant in the chiller itself, not for warming during recovery.
Low-Pressure Recovery Freeze Protection
During low-pressure chiller recovery, circulating warm water through the chiller's water box helps prevent the refrigerant from getting too cold and freezing, protecting the recovery unit and chiller components.
- Circulate warm water.
- Prevents refrigerant from dropping below freezing.
- Protects recovery compressor from slugging/damage.
- Protects chiller tubes from freezing.
Memory trick: Keep the chiller 'Warm and Cozy' with hot water, don't let it 'Freeze Out'!