HVAC Excellence 4

An evaporator pressure regulating valve (EPR) is used to keep evaporator pressure from dropping too low.

• True

• False

R-410A systems require TXVs with lower flow rates than R-22 systems.

• True

• False

A drain trap is only necessary on systems with horizontal airflow.

• True

• False

Air in the system will lower suction pressure and discharge pressure.

• True

• False

Compressor noise and overheating after startup may indicate low oil in the system.

• True

• False

Brazing copper to steel should be done with a 15% silver alloy.

• True

• False

Soap bubbles are an acceptable universal leak detection method.

• True

• False

The best time to check subcooling is while the system is off.

• True

• False

Overcharging a cap tube system results in high head and high suction pressure.

• True

• False

The presence of flash gas indicates ideal refrigerant conditions.

• True

• False