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chapter 10
Copyright Cengage Learning. Powered by Cognero.
Page 1
Indicate whether the statement is true or false.
1. Solar collector efficiency is higher under higher fluid inlet temperatures.
a.
True
b.
False
2. Collector absorber plate temperature can exceed 350 degrees if stagnation occurs on a bright summer afternoon.
a.
True
b.
False
3. Heat dumps and over-temperature protection are not required on drainback-type solar thermal systems.
a.
True
b.
False
4. Fluid flow through a heat exchanger is not required when a swimming pool is used as a heat dump.
a.
True
b.
False
5. Under stagnation conditions, fluid in the collector may vaporize.
a.
True
b.
False
Indicate the answer choice that best completes the statement or answers the question.
6. What two reasons make domestic water heating a practical application for solar thermal systems?
a.
intermittent load; heating starts at low temperatures
b.
year-round load; heating starts at low temperatures
c.
intermittent load; heating starts at high temperatures
d.
year-round load; heating starts at high temperatures
7. What configurations may be used for a solar domestic water heating system?
a.
internal heat exchanger only
b.
external heat exchanger only
c.
either internal or external heat exchanger
d.
no separate heat exchanger is required
8. When does a solar collector array serve as a heat emitter?
a.
when configured solely as a water heating source
b.
when the over-pressure relief valve opens
c.
when the over-temperature relief valve opens
d.
during nocturnal cooling
9. What type of piping is used with most solar water heating systems today?
a.
copper tubing
b.
corrugated stainless steel tubing
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chapter 10
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c.
glass tubing
d.
soldered stainless steel tubing
10. What would result from increasing the pressure rating of the relief valve?
a.
A smaller expansion tank would be required.
b.
A larger expansion tank would be required.
c.
The size of the expansion tank would not be affected.
d.
Boiling in the collector array would be prevented.
11. Which code requirements may vary between locations?
a.
use of double-wall heat exchangers and collector array grounding
b.
percent of total heat load that may be supplied by solar energy
c.
requirement for grounding and pressure-relief valves
d.
none, because of the requirement of uniform code requirements
12. What is the primary purpose of a thermosiphon cooling loop?
a.
to prevent stagnation
b.
to prevent freezing
c.
to be used as a heat dump
d.
to extend the life of piping
13. Which statement is true of a domestic hot water plus system?
a.
Solar energy is used for all the hot water and space heating load.
b.
Solar energy is used for most of the hot water and most of the space heating load.
c.
Solar energy is used for most of the hot water and a small portion of the space heating load.
d.
Solar energy is used for a small portion of the hot water load and most of the space heating load.
14. What should be installed where a solar water heating system connects to the building’s plumbing?
a.
thermostatic mixing valve
b.
pressure relief valve
c.
globe valve
d.
heat exchanger
15. What software measures performance of a solar domestic water heating system?
a.
F-FLOW
b.
F-CHART
c.
F-PERCENT
d.
FLOW PERCENT
16. What is NOT a typical operating mode for an antifreeze-protected solar combisystem?
a.
solar collecting mode
b.
water heating mode
c.
space heating mode
d.
discharge mode
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17. What is the base chemical used in most automobile antifreeze solutions?
a.
ethylene glycol
b.
propylene glycol
c.
polypropylene glycol
d.
ethanol
18. What is the freeze point temperature in an antifreeze-protected solar thermal system?
a.
32°F
b.
the point at which ice crystals begin to form
c.
the point at which all liquid has turned to a solid
d.
the point at which the system piping may burst
Name:
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Date:
chapter 10
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Page 4
Answer Key
