HW Unit 17
How can a technician tell which direction a solenoid valve should be installed?
Normally there will be an arrow stamped on the body of the valve to indicate the direction of refrigerant flow.
What is the difference between a water source heat pump and an air source heat pump?
Instead of two air coils, water-to-air heat pumps use one water coil and one air coil, In heating, water source systems use water as their heat source and the indoor air as the heat sink. In cooling, water source systems use the indoor air as their heat source and the water as the heat sink.
Along with the refrigerant that is being discharged, compressors will discharge which of the following as it leaves the compressor?
Oil
Where in the system is an oil separator installed?
An oil separator can be installed anywhere in the system.
What is the purpose of a solenoid valve?
A solenoid valve is a flow control device that stops or allows the flow of a refrigerant in a refrigeration system.
What is most often used as a secondary refrigerant in geothermal systems?
Water or a mixture of water and anti-freeze such as propylene glycol, methanol, or ethanol.
Which of the following are used to separate and collect some of the oil in the discharge line as it leaves the compressor and then return it to the compressor's crankcase?
Oil separators
Where are packaged water-source heat pumps normally located?
Inside the building
What is the function of an oil separator in a refrigeration system?
An oil separator is used to separate and collect some of the oil in the discharge line as it leaves the compressor and return it to the compressor's crankcase.
What type of system requires a secondary refrigerant?
Closed loop systems require a secondary refrigerant in the closed loop.
Which refrigeration device would most likely be installed in the discharge line leaving the compressor to prevent liquid refrigerant from draining from a raised condenser into the compressor head?
A check valve
Moisture indicators are normally part of:
A sightglass.
Where are vibration eliminators installed in a system?
On the suction and discharge lines leaving the compressor.
Where is the compressor located in most water source heat pumps?
With all water source heat pumps, the compressor and refrigerant components can all be located inside the building
Using heat-reclaim coils will help improve a building's overall:
Heat efficiency.
When is the water coil in a water-source heat pump the acting evaporator?
In the heating cycle
Why do some systems have discharge check valves?
To prevent liquid refrigerant from flowing back to the compressor from the condenser during the off cycle of the system.
Why do the refrigerant and water travel in opposite directions through the water coil?
The water and refrigerant always travel in opposite directions. This counter- flow design improves efficiency by placing the coldest water against the coldest refrigerant and the warmest water against the warmest refrigerant.
In most commercial refrigeration systems, most of the excess refrigerant that is not being used is stored in:
The liquid receiver.
When is the water coil in a water-source heat pump the acting condenser?
In the cooling cycle