Question 1
Question
Conventional gas- and oil-fired boilers are currently used in the vast majority of residential and light commercial hydronic systems in North America.
Question 2
Question
The cast-iron sectional boiler is currently one of the most common boilers used in residential and light commercial buildings in North America.
Question 3
Question
If a cast-iron boiler is significantly oversized and experiences long off-times between firing cycles, much of the heat stored in the boiler's thermal mass can be carried up the flue by air currents passing through the combustion chamber.
Question 4
Question
Many boilers currently used in North America were designed with the intent that flue gases would condense within the boiler.
Question 5
Question
Condensing boilers are designed with large heat exchanger surfaces capable of extracting more heat from the exhaust gases compared to the heat exchangers in conventional boilers.
Question 6
Question
In full storage ETS systems, all energy used during the subsequent on-peak period is purchased and stored during the peak cycle.
Question 7
Question
The term "hydronic heat pump" always refers to a heat pump that delivers heat to a flowing stream of water.
Question 8
Question
The heating capacity of the heat pump drops rapidly with increasing source water temperature.
Question 9
Question
It is not advisable to maintain water flow through the condenser whenever the heat pump is operating.
Question 10
Question
The decision to use a wood-fueled boiler involves a time commitment much more demanding than for conventional heat sources operating on natural gas, propane, fuel oil, or electricity.
Question 11
Question
Most cast-iron sectional boilers are limited to use in __________ hydronic systems.
Answer
-
"bare-bones"
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packaged
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closed-loop
-
distributed
Question 12
Question
The combination of metal and water weight gives cast-iron boilers the ability to absorb a significant amount of heat. Such boilers are said to have a high __________.
Answer
-
life cycle
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thermal mass
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efficiency factor
-
size
Question 13
Question
One type of boiler design surrounds the combustion chamber with a water-filled heat exchanger. This arrangement is called a __________ boiler.
Answer
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hydraulic
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condensation
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steam
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wet-base
Question 14
Question
Analysis of combustion processes reveals that significant amounts of heat can be recaptured from the exhaust stream if the water vapor it contains can be _________.
Question 15
Question
Boilers with low thermal mass tend to have __________ cycle efficiencies due to lesser amounts of heat remaining in the boiler following burner shutdown.
Answer
-
lower
-
unpredictable
-
higher
-
dependable
Question 16
Question
A boiler operates at __________ efficiency only when it is being fired continuously under nonvarying conditions.
Answer
-
steady-state
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measurable
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DOE-certified
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manufacturer
Question 17
Question
A __________ is a device for converting low-temperature heat into higher temperature heat.
Answer
-
thermal converter
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radiating unit
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flue gasket
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heat pump
Question 18
Question
A flow restriction or stoppage in the __________ can lead to rapid formation of ice crystals on the cold heat exchanger surfaces separating the water and refrigerant.
Answer
-
storage tank
-
water source
-
evaporator
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closed-loop
Question 19
Question
In solar anti-freeze based combisystems, the outside heat dump provides a way for the system to shed excess heat. It is activated if the temperature of the thermal storage tank reaches a _________ upper limit.
Answer
-
manufacturer recommended
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DOE enforced
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user-set
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local fire code
Question 20
Question
It is vital that the solar collectors and all exposed piping in a drain-back system be pitched a minimum of __________ toward the storage tank to allow complete drainage.
Answer
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1/4 in./ft.
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1/2 in./ft.
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1/8 in./ft.
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1/16 in./ft.