HVAC FC 01

Choose the correct description for scroll compressors:

• There is less vibration than from a reciprocating compressor.

• Both scrolls remain stationary during operation.

• There are more moving parts than in reciprocating compressors.

• They are noisy.

When adjusting superheat setting with a thermal expansion valve, what effect does increasing the superheat have on the system?

• starves the evaporator

• floods the evaporator

• cools the evaporator

• none of the above

Heat exists down to absolute zero which is measured at a temperature of

• -400 degrees F
• -420 degrees F
• -440 degrees
• -460 degrees F

Return air openings for heating, ventilation and air-conditioning systems shall not be taken from a closet, bathroom, toilet room, kitchen, garage, boiler room, furnace room or unconditioned attic, however, a ___ is not prohibited.

• boiler room

• furnace room

• unconditioned attic

• bedroom

As outlet ____ the crankcase pressure regulator opens?

• As oulet pressure decreases

• As outlet pressure increases

• As oulet temperature decreases

• As outlet temperature increases

From the list below, select the BEST definition of a vibration absorber:

• It is recommended to compress the vibration absorber while installing

• The flexible absorber should be fastened to the unit or to a wall at the end pointing away from the vibration source

• Only one should be placed on line

• They should not be placed on compressor suction lines near the condenser

An adjustable V-pulley for a belt drive motor is moved FURTHER from the other flange. This change will widen the pulley giving the effect of a smaller diameter pulley. The fan speed will

• decrease

• increase

• double

• triple

Clear space above ground of the lowest portion of mechanical equipment suspended from a floor shall be AT LEAST ___ inches.

• 6
• 4
• 10
• 8

What instrument measures moisture in the air?

• manometer

• hygrometer

• pitot tube

• anemometer

What is any portion of a refrigerating system under condenser pressure?

• cooling system

• circulating system

• high side

• low side