Deck 9: Climate Controlsupplemental Truck Heatingcooling

Question 1

Temperature sensors are used to send signals back to the electronic control unit for the HVAC system. These sensors contain a temperature dependent resistor known as:

A) A variable resistor
B) A thermostatic switch
C) A thermistor
D) A ranging resistor

Answer 1

C

Question 2

Pulse width modulated water valves are electronically controlled by electrical impulses from:

A) The control unit
B) The heater core
C) The evaporator
D) Control panel cable

Answer 2

D

Question 3

What would happen to the performance of the HVAC unit if the manual coolant shut off valve on the engine were closed?

A) The unit could cool but not control temperature in the main cab.
B) The unit could cool but not control temperature in the sleeper compartment.
C) The unit would not heat or control temperature of either the cab or sleeper compartment.
D) All of the above statements are possible scenarios.

Answer 3

D

Question 4

The blend air system controls air temperature by:

A) Controlling the flow of coolant circulated through the heater core.
B) Controlling the volume of cold air produced by the evaporator.
C) Controlling the function of an electrical element.
D) Controlling a vent door to mix the air through the heater core with fresh air or air circulated through the evaporator coil.

Question 5

What is the component that controls the position of the vent doors on a blend air system?

A) Solenoids
B) Thermistors
C) Stepper motors
D) Rotory motors

Question 6

If a coolant heater shuts down due to a flame out while running the unit will:

A) Attempt to restart once
B) Attempt to restart twice
C) Attempt to restart three times
D) Do not attempt to start and immediately trip a fault light

Question 7

Which of the following is not an advantage of a fuel fired cab interior heater?

A) Heat the cab or sleeper
B) Keep the fuel warm in the winter
C) Keep the trucks batteries fully charged
D) Use less fuel than idling the trucks engine

Question 8

If an HVAC control panel is equipped with a recirculation feature it means that:

A) When activated the recirculation door is closed preventing dust and contaminants from entering the cab.
B) Cooling time when air conditioning is selected will be lower.
C) The recirculation feature will not operate in the defrost mode.
D) All of the above statements are true in regards to the recirculation feature.

Question 9

Auxiliary power units have an additional advantage over both the coolant and interior heaters in that:

A) They can heat the air in the cab or sleeper
B) Keep the engine warm for easy starting
C) Produce electrical power for appliances and accessories
D) Use less fuel than idling the trucks engine

Question 10

Which of the following is not and advantage of an engine coolant heater?

A) Heat cab or sleeper
B) Keep engine warm for easy winter starting
C) Faster windshield defrost time in winter
D) Cools cab and sleeper

Question 11

Supplemental temperature control systems are used:

A) To prevent long periods of engine idling reducing greenhouse gases.
B) Prevent much wear and tear to the vehicles engine caused by idling.
C) Save large quantities of diesel fuel by eliminating idling.
D) All of the above are reasons to use a form of supplemental temperature control system.

Question 12

What component is responsible for controlling the temperature at the outlets of a manual water-valve controlled system?

A) A water valve
B) A thermistor
C) A blend door
D) A pulse modulated solenoid valve

Question 13

On the water-valve controlled system the flow of coolant through:

A) The radiator is restricted
B) Though the heater core is restricted to increase temperature
C) Through the heater core is restricted to decrease temperature
D) The engine thermostat

Question 14

Which of the following is an advantage of truck stop electrification?

A) Eliminate idling of the trucks engine reducing harmful greenhouse gasses
B) Ability to operate any electrical appliance with an onboard generator
C) HVAC hose supplies air at the desired temperature to the cab of the vehicle
D) All of the above statements is an advantage of truck stop electrification

Question 15

Which of the following are methods of controlling the temperature inside the vehicle cab?

A) Water-valve control system
B) Blend air system
C) Supplemental heating and cooling systems
D) All of the above