Topics: All categories in the pool
1: Which refrigerant class listed below is the most flammable?
- A-1
- B-2
- A-3
- C-3
2: Where is an EPR valve located on a multi-evaporator system?
- Suction line at the compressor
- Suction line of the coolest evaporator
- Suction line prior to the accumulator of the lowest temperature system
- Suction line of the warmest evaporator
3: What is Absolute Zero?
- -400F
- -640F
- -773F
- -460F
4: Fractionation occurs when
- when a fraction of refrigerant is added as the full charge
- some of the blended refrigerant evaporates or condenses before the rest of the blend
- the pressures decreases as the heat load decreases
- the pressures increase as the heat load increases
5: The difference between saturated liquid and saturated vapor is
- heat
- volume
- temperature
- pressure
6: What is not a requirement of a class T machine room?
- fire hose connection to the building fire protection system
- automatic ventilation
- self-closing doors
- tight fitting doors
7: Usually dry bulb temperature is
- higher than wet bulb temperature
- same as wet bulb temperature
- lower than dry bulb temperature
- not important and shall be ignored
8: What is used to check very low air pressures in air conditioning duct?
- Barometer
- Anemomter
- Manometer
- Vacuum gauge
9: What kind of system uses two different refrigerants in separate systems dependent on each other?
- Low pressure
- Simple
- Cascade
- R-414B
10: What type of fuses must be used on a HVAC system?
- TR Type, Duel Element, Time Delay
- Fast blow
- 10% lower than RLA
- none of the above
11: Which oil is hydoscopic?
- SW30
- mineral
- animal
- polyolester
12: What is considered a cooling agent?
- any liquid used for the transmission of heat when vaporization occurs
- any liquid used for the transmission of heat when condensation occur
- any liquid used for the transmission of heat without vaporization
- any liquid used for the transmission of heat without condensation
13: What type of pressure relief device is used on a CO2 system?
- Glove valve
- Gate valve
- Fusible plug
- Rupture disk
14: How many square inches per square foot?
- 24
- 98
- 64
- 144
15: Liquid refrigerant flashing, or turning to vapor, in the liquid line may be due to
- liquid line that is too small
- shortage of refrigerant
- liquid line that had too high vertical lift
- All of the above
16: NH3 is
- lithium bromide
- R-718
- R-508A
- ammonia
17: A “U” or “UM” marking a on a nameplate of a pressure vessels signifies compliance with Section VIII of
- the ASME Boiler and Pressure Vessel Code
- Section 11.3.1.5 ASHRAE 15 Standard
- the ANSI Standard 10.7.2
- both the ANSI Standard 10.7.2 and ASHRAE 15 Standard 11.3.1.5
18: Heat that changes the physical state of a substance without effecting a change in its temperature is known as
- lost heat
- specific heat
- latent heat
- sensible heat
19: Name a reason that does not cause reduced condenser air quantity
- High ambient temperature
- Prevailing winds
- Dirty fan blades
- Dirty Coil
20: Ammonia (NH3) is a group III refrigerant
- True
- False
21: The normal operating evaporator temperature of R-410A for air conditioning is typically
- 45F
- 158F
- 32F
- 155F
22: Ammonia vaporization takes place at what temperature?
- -32F
- -28F
- -110F
- -460F
23: Which occupancy can ammonia be used in?
- commercial
- depends on the quantity of freon
- industrial
- redifential
24: A motor starter is a device that includes an overload and a _______?
- contactor
- 2-pole contacts
- duel-coil
- all of the above
25: The leaving chilled water set point for comfort cooling is typically?
- 45
- 66
- 38
- 60