Topics: All categories in the pool
1: What is the boiling point of refrigerant governed by?
- Evaporator temperature
- P&T relationship
- Compressor RPM's
- Condenser sub-cooling
2: In designing duct work, pressure and ______ need to be considered
- length
- CFM
- duct sealant used
- all of the above
3: With a 5/8" X 5/8" x 3/4" tee, what size is the center connection?
- 3/8"
- 1/2"
- 3/4"
- 5/8"
4: A VRF system is a direct system
- true
- false
5: A halide torch is most useful with a freon compression system
- to detect refrigeration leaks in piping joints
- to release a sticking valve
- to sweat flanges on the refrigeration piping
- to remove from from TXV's and evaporator coils
6: A chilled water pump suction gauge reads 10 psig. Discharge gauge reads 48 psig. The head in feet of the pump is working against
- 108
- 38
- 116
- 88
7: The Board of Boilers adopts by reference
- the MACS Pressure Vessel Code of Massachusetts
- Montreal Protocol Safety Code
- MSCA Code
- the 1997 ANSI/ASHRAE Safety Code
8: Increasing superheat will do what to your system?
- Increase liquid flow
- Nothing
- Decrease liquid flow
- Increase gas flow
9: Refrigerant restricted in 2004 but used for transition for decades:
- R-22
- R-11
- R-134A
- R-123
10: A check valve is a device
- designed to allow the flow of refrigerant gas in both directions
- that is always spring loaded
- with a pressure drop
- found on high pressure steam systems
11: It takes how many BTU/hr to melt one pound of ice at 32F
- 212
- 144
- 970
- 180
12: Ammonia vaporization takes place at what temperature?
- -110F
- -32F
- -28F
- -460F
13: Heat transferred by conduction from one body to another is done
- via radiation
- via liquids
- via solids
- via heat rays
14: Viscosity is
- the ability of oil to flow
- measure of weight
- the coefficient of external friction
- a measure of heat content
15: Before determining if a machinery room equipment is excluded from following Ashrae 15, you must determine how many pounds of refrigerant per _____ cubic feet?
- 10,000
- 100,000
- 100
- 1,000
16: One ton of refrigeration is defined as ______ btu/minute.
- 200
- 12,000
- 60
- 720,000
17: How far from the ground does a relief valve need to be?
- At least 20' above grade
- Not more than 3' above grade
- At least 25' above grade
- At least 15' above grade
18: If the power element of an expansion valve should lose its charge the valve would
- overfeed the evaporator
- go closed
- underfeed the evaporator
- go open
19: A cross charged power element on an expansion valve would normally be used in what temperature range?
- -100F to -40F
- 0F-38F
- 30F to 50F
- -40F to 0F
20: Liquid shall not occupy more than ____ of the volume when the temperature of the refrigerant is 90F.
- 75%
- 80%
- 90%
- 100%
21: What is the typical air conditioning operating pressures for 410A?
- 60 psi suction, 210 psi discharge
- 25 psi suction, 125 psi discharge
- 105 psi suction, 350 psi discharge
- None of the above
22: The location of a thermal bulb of a TXV affects
- subcooling
- the amount of liquid in the condenser.
- the amount of liquid refrigerant in the evaporator
- the amount of liquid returning to the compressor
23: Two systems using separate refrigerants that are superimposed upon one another is called
- booster
- indirect
- single stage
- cascade
24: A relief valve discharge capacity is rated in
- PSIA
- PSIG
- temperature minus pounds of air per second divided by release rate squared
- Pounds of air per minute.
25: Pressure relief devices are marked with a ____________ signifying compliance with the ASME Boiler & Pressure Vessel Code.
- UM or UL
- UL and UR
- UV or UR
- UL and UM