HVAC pretest

Select all correct answers. What is the main purpose of evacuating a system?

• To remove air from the system.

• To remove oil from the system.

• To boil off and remove water from the system.

• To increase billable hours.

When do the mountains turn blue?

• When the optimal drinking temperature has been reached, which is roughly 6C (43F) to 10C (50F).

• At exactly 32F/0C.

FREON is the trade name for all automotive refrigerants.

• True

• False

Select all correct answers. If water boils at 100C (212F) under atmospheric pressure:

• the water vapor is much hotter than it was before transforming from liquid.

• the water vapor is exactly 100.1C (212.18F).

• the water vapor is the same temperature as the liquid that is boiling.

• the vaporized water contains more heat energy.

Volkswagen uses both an accumulator and a receiver-dryer together in most of their air condition systems.

• True

• False

The accumulator, if equipped, is located between:

• the compressor and the fixed orifice tube

• the compressor and the expansion valve

• the evaporator and the compressor

• the condenser and the expansion valve

Variable displacement compressors that do not use clutches are now used exclusively by Volkswagen in the North American Region (NAR).

• True

• False

The expansion valve performs the same task as a fixed orifice tube.

• True

• False

Select all correct answers. Why does the HVAC Control Module turn off the compressor at low ambient temperatures?

• To prevent hydro-lock in the compressor.

• The refrigerant may condense inside the compressor.

• It's already cold enough. Roll the windows down.

• The compressor will get too hot trying to convert so little latent heat.

"Compressor off codes" are used as a step-by-step diagnostic tree to diagnose an HVAC system.

• True

• False