HVAC Design & Operation: Heating & Engine Cooling Quiz

A cooling system with a 50/50 mix of water and ethylene glycol in a cooling system with a 15 pound pressure cap will have what boiling point?

• 217° F

• 212° F

• 257° F

• 227° F

At what temperature does an engine run cleanest with least wear?

• 150°F

• 100°F

• 180°F

• 200°F

The waste heat from an engine is expelled into all of the following, EXCEPT:

• Engine oil

• Exhaust system

• Refrigerant

• Metal engine parts

What causes coolant to return to the radiator?

• Water pump pressure

• Vacuum in the cooling system

• Thermostat closing

• Coolant diverter valve

Engine coolant is typically made up of what?

• 50% Antifreeze/50% water

• 75% Antifreeze/25% water

• 33% Antifreeze/67% water

• 25% Antifreeze/75% water

Technician A says to cover all possible vehicle conditions, coolant must have a high freezing point. Technician B says coolant must have a low boiling point. Who is correct?

• Technician A only

• Both Technician A and B

• Technician B only

• Neither Technician A nor B

How is the air delivery temperature controlled during A/C operation?

• By controlling the amount of recirculation air

• By controlling the amount of opening in the heater control valve

• By controlling how much air passes over the heater core

• By controlling the amount of air that passes through the radiator

Which of the following is NOT a control method for HVAC systems?

• Vacuum

• Cables

• Electronics

• Hydraulics

Technician A says the job of the cooling system is to warm up the engine quickly. Technician B says the job of the cooling system is to remove heat that is absorbed by the engine. Who is correct?

• Both Technician A and B

• Technician A only

• Neither Technician A nor B

• Technician B only

Which of these devices controls the flow of coolant through a cooling system based on temperature?

• Thermostat

• Heater control valve

• Water pump

• Temperature diverter valve