HVAC Intro and CORE

As refrigerant absorbs heat, it evaporates into a low-temperature vapor. What is this process referred to?

• Compression

• Condensation

• Direct expansion

• Subcooling

What are the dividing points between the low-pressure and the high-pressure sides of the system?

• Evaporator and condenser

• Compressor and the metering device

• Filter-drier and sight glass

• Suction line and discharge line

Where can you gain access for service?

• Service valves, access valves, or process stubs

• Thermostat terminals

• Schrader cores only

• Sight glass only

If a system is in operation, do you want to front-seat or back-seat a service valve?

• Front-seat

• Mid-seat

• Back-seat

• Crack open only

A PT chart shows the pressure–temperature relationship of what?

• Air–water mixtures

• Combustion gases

• Refrigerants

• Lubricating oils

What are the PT charts based on?

• Ambient air properties only

• Saturation properties for which a refrigerant evaporates and condenses

• Compressor displacement only

• Specific heat capacity at constant pressure

What must be present for the PT relationship to match?

• Vapor only

• Liquid

• Oil

• Superheated vapor

If a unit has had a leak or major component failure, what should you take?

• Refrigerant pressure reading

• Oil sample

• Moisture indicator reading

• Superheat measurement

What will finding and repairing leaks in a system help to conserve?

• Refrigerant

• Compressor oil

• Filter-drier media

• Condenser water

What should you NEVER flush field tubing with?

• Dry nitrogen

• Alcohol-based solvent

• Liquid refrigerant

• Clean, dry air