Unit 31-49 Short Answers |120 Questions| With Correct Answers.

explain the difference, with respect to superheat, between a dry type evaporator and a flooded evaporator {Ans: the dry type evaporator operates with a certain amount of superheat, while a flooded evaporator operates with no superheat}why must the expansion tank always be located higher than the boiler? {Ans: to permit the air in the connecting line to rise to the tank without being trapped in the line}In a lithium bromide system, the refrigerant boils at 40 degrees F. What is the corresponding pressure? {Ans: 29.7 inches vacuum}what would happen if a hydronic system was installed without an expansion tank? {Ans: when water is heated, it expands a great deal, if the expansion tank wasn't there, the relief valves would open and cause constant flooding.}define angular alignment {Ans: both the motor shaft and shaft pump are at the same angle as each other}which type of fan create more pressure from inlet to outlet and is more desirable for a commercial duct system? {Ans: forward curved centrifugal fan}