Hvac 208 final exam Correct Questions & Answers!

What is the function and operation of a reversing valve - ANSWER Reverses refrigerant flow and provides both heating and cooling. Diverts the discharge gas. What are common failures of reversing valves and causes - ANSWER Stuck valve Overheating Bad coil Leaking by from discharge gas flowing back into the suction line How is metering of refrigerant accomplished with a heat pump? - ANSWER We need to add check valves bypass lines and bi-directional txv's What components should be energized during defrost operations? - ANSWER Compressor Aux heat Reversing valve Indoor fan What components should be de-energized during defrost operations? - ANSWER Outdoor fan ANSWER So the pump doesn't freeze What is economic balance point? - ANSWER When the system changes from heat pump to normal furnace heating What is thermal balance point? - ANSWER Compares the capacity of the heat pump to the heat loss of the space What is supplemental heat? - ANSWER Runs at the same time as the heat pump and is only sized big enough for what the heat pump can handle What is emergency heat? - ANSWER When the reversing cycle heat pump isn't operating in the defrost mode, all available strip heaters will energize What are the types of water source heat pump loops? - ANSWER Open loop> fresh water added and old water is dumped Closed loop> the same water is circulating all around What are the types of geothermal heat pump systems? - ANSWER Ground coupled heat pump Ground water Surface water What are the types of closed loop gwhp? - ANSWER Vertical Slinky Horizontal