Deck 43: Air Source Heat Pumps

Question 1

When brazing a four-way reversing valve, a wet rag could be wrapped around the body of the valve to minimize the chance of internal damage to the valve.

Answer 1

True

Question 2

An air-to-air heat pump ____ heat from the outside air and deposits it in the conditioned space.

A) adds
B) removes
C) creates
D) restricts

Answer 2

B

Question 3

The ____________________ is a four-port valve that has a slide mechanism in it.

Answer 3

four-way reversing valve,four way reversing valve

Question 4

The term ____________________ indicates the source of heat while the system is operating in the heating mode and the medium that is ultimately being treated.

Question 5

The component used to switch the heat pump unit between the heating and cooling modes of operation is the ____.

A) four-way valve
B) bi-valve
C) two-way valve
D) switching valve

Question 6

A common method of starting defrost uses an air pressure switch that measures the difference in pressure ____.

A) between the fan compartment and the evaporator coil
B) between the outdoor pressure and the fan discharge pressure
C) of the air across the outdoor coil
D) of the refrigerant in the condenser and the pressure in the coil

Question 7

TXVs used in cooling-only air-conditioning units and heat pumps are interchangeable as long as they are the same size and for the same refrigerant.

Question 8

The larger line in an air-to-air split-system heat pump is known as the ____ line.

A) vapor
B) liquid
C) transient
D) gas

Question 9

The coil of the air-to-air heat pump system that is the indoor unit is known as the ____________________ in the heating mode.

Question 10

The coil of the air-to-air heat pump system that is the indoor unit is known as the ____________________ in the cooling mode.

Question 11

When a compressor is changed, the four-way valve also must be changed.

Question 12

Termination of the defrost cycle by temperature occurs when the temperature sensor reaches ____.

A) 35°F
B) 45°F
C) 50°F
D) 65°F

Question 13

It is common for the outdoor unit to ice-up when the heat pump is operated in the cooling mode.

Question 14

The coil that serves the inside of the house in a heat pump is known as the ____________________.

Question 15

What prevents cold air from being circulated to the heated space during the defrost cycle?

A) The auxiliary heater turns on to "temper" the air.
B) All of the dampers close automatically.
C) The indoor fan motor turns off.
D) Both a and b are correct.

Question 16

The water-to-air heat pump might not need auxiliary heat because the water can be at relatively constant temperature all winter.

Question 17

In the emergency heat mode, the auxiliary heat source becomes the primary heat source because of heat pump failure.

Question 18

During operation, the compressor motor will rotate in the opposite direction to change the direction of refrigerant flow.

Question 19

The main valve in a pilot-operated four-way reversing valve is moved by pressure created by the ____.

A) refrigerant boiling in the coil
B) pressure reduction in the condenser
C) change in the action of the metering device
D) low and high side pressure difference

Question 20

The smaller line in an air-to-air split-system heat pump is known as the ____ line.

A) gas
B) vapor
C) solid
D) liquid

Question 21

A(n) ____________________ thermostatic expansion valve has a check valve built into the body of the TXV.

Question 22

When oil or gas auxiliary heat is used with a heat pump, the heat pump indoor coil must be located  ____________________ of the oil or gas heat exchanger.

Question 23

The lowest outside air temperature at which the heat pump system can satisfy the heating needs of the structure without requiring auxiliary heat is called the ____________________.

Question 24

Why must the air from a heat pump operating in the heating mode be distributed carefully?

Question 25

Some heat pump systems when not capable of meeting the heating needs of the structure are equipped with second-stage heat, called ____________________.

Question 26

In time-temperature defrost controls, the temperature that actuates the control is the temperature of the ____________________ coil.

Question 27

Most heat pump systems are designed to operate in the heating mode when the solenoid is not energized. This is referred to as "____________________ in the heating mode".

Question 28

The coefficient of performance of a heat pump operating in the heat mode tends to ____________________ as the outside air temperature drops.

Question 29

A common metering device is a combination flow device and check valve. This device is referred to as a(n) ____________________.

Question 30

When a heat pump is added to an electric furnace, the indoor coil must be located after the ____________________ strips.

Question 31

What action must the four-way reversing valve take to operate the heat pump system in the defrost mode?

Question 32

What is the formula for the COP of a heat pump operating in the heating mode?

Question 33

____________________ involves the removal of heat from a place where it is not wanted and depositing it in a place where it makes little or no difference.

Question 34

What is it meant by the terminology "time or temperature terminated" defrost cycle?

Question 35

In heat pump systems the sensing bulb is typically exposed to high temperatures and could rupture the valve diaphragm. For this reason, a(n) ____________________ TVX is usually used.