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chapter 13
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Page 1
Indicate whether the statement is true or false.
1. Air-to-water heat pumps always have an external circulator to support flow through the heat pump.
a.
True
b.
False
2. When referring to heating and cooling capacity, one ton represents the average heat transfer rate associated with
melting one ton of ice over a 24-hour period.
a.
True
b.
False
3. In mild climates where sub-freezing temperatures occur only a few days per year, it is acceptable to operate a self-
contained air-to-water heat pump with water flowing through the outdoors.
a.
True
b.
False
4. In general, the larger the temperature difference between the source media and the load media, the higher the heat
pump’s COP.
a.
True
b.
False
5. For an air-to-water heat pump, COP generally increases with increasing outdoor temperature.
a.
True
b.
False
Indicate the answer choice that best completes the statement or answers the question.
6. What is the primary purpose of thermal storage used as a buffer?
a.
to provide additional space for thermal expansion of the fluid
b.
to match the rate of heat production of the heat pump to the heat delivery rate from the distribution system
c.
to allow diurnal operation of the heat pump
d.
to prevent short-cycling of the heat pump
7. Which type of system generally has a higher seasonal average COP when properly designed and installed?
a.
air-to-water heat pump
b.
geothermal heat pump
c.
air-to-water and geothermal heat pumps typically have the same COPs
d.
COP does not apply to geothermal heat pumps
8. What component controls the direction of movement of a reversible heat pump’s reversing valve?
a.
pilot solenoid valve
b.
check valve
c.
auxiliary boiler valve
d.
capillary tubing
9. In the example at the end of the chapter comparing a geothermal heat pump installation to an air-to-water heat pump
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chapter 13
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installation, which factor had the biggest influence on payback period?
a.
COP
b.
average outside temperature in winter
c.
percent of heating load satisfied by an auxiliary heating source
d.
installation cost
10. Which component of the vapor compression refrigeration cycle significantly increases both temperature and pressure
of the fluid?
a.
evaporator
b.
compressor
c.
condenser
d.
thermal expansion valve
11. For a heat pump system with diurnal heat storage, when is the most favorable time for the heat pump to operate during
winter?
a.
daytime
b.
overnight
c.
early morning
d.
late evening
12. What is the low temperature material from which a heat pump absorbs heat?
a.
sink
b.
source
c.
supply
d.
storage
13. Which parameter is typically NOT user-configurable in air-to-water heat pump performance simulation software?
a.
owner setback schedules
b.
off-peak electrical rates
c.
installation cost
d.
system location
14. What is used in some air-to-water heat pump combisystems to determine whether the system is enabled for heating or
cooling, or remains off?
a.
thermal storage buffer switch
b.
mode selection switch
c.
auxiliary boiler switch
d.
diurnal switch
15. What is the heating capacity of a heat pump?
a.
the ratio of heating load to total heating and cooling load
b.
the percentage of total load it can meet
c.
the rate at which it delivers heat to the load
d.
ratio of beneficial heat output to input electrical energy
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16. In cooling mode, how is the energy efficiency ratio defined?
a.
total cooling effect divided by amount of latent cooling
b.
cooling capacity divided by electrical power input
c.
cooling capacity divided by heating capacity
d.
electrical power input divided by amount of sensible cooling delivered
17. What is the recommended minimum spacing when two outdoor air-to-water heat pumps are installed with their air
intake sides facing each other?
a.
18 inches
b.
2 feet
c.
4 feet
d.
6 feet
18. What circulates through the closed loop piping during the vapor compression refrigeration cycle?
a.
water
b.
antifreeze and water
c.
refrigerant
d.
air
Name:
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chapter 13
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Page 4
Answer Key
