What is the disadvantage of air bypass?
A) Excessive air noise in the zones that are not calling
B) It creates a negative pressure in the zone that is calling.
C) Evaporators can freeze and furnaces can trip on high limit.
D) Excessive air noise in the zones that are calling
[Ques. 2] Zone control is accomplished in hydronic systems using thermostats that activate:
A) A zone compressor for each zone. B) A zone boiler for each zone.
C) A zone damper for each zone. D) A zone control valve for each zone.
[Ques. 3] What efficiency advantage do water-source heat pump systems have over air-source heat pump systems?
A) Water is a more efficient heat-transfer medium, and water temperatures are moderated by the earth.
B) It takes less horsepower to pump water than air.
C) Heat has more affinity for water than air.
D) Water is a more efficient refrigerant than either R-22 or R-410A.
[Ques. 4] Underwriters Laboratories standard 181 A covers:
A) Methods of connecting and sealing metal duct.
B) Methods of connecting and sealing ductboard.
C) Methods of connecting and sealing all types of duct.
D) Methods of connecting and sealing flexible duct.
[Ques. 5] What is a dump zone in a zoned air system?
A) The location where exhaust air exits the building
B) The area where refrigerant is vented while reducing system capacity during low-load operation
C) The area immediately under a supply register
D) An area used for dumping excess air and capacity when only one zone is calling
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