AHR-110 Exam 3 Study Guide with
Complete Solutions
(T/F): A common term for tropospheric ozone pollution is smog. - ANSWER-True
(T/F): A system with Schrader valve gauge ports will take longer to evacuate than a
system with service valves. - ANSWER-True
(T/F): All 500-series refrigerant blends have temperature glide and have the potential to
fractionate. - ANSWER-False
(T/F): The process of a solid changing to a vapor without passing through the liquid
state is called dehydration. - ANSWER-False
(T/F): The tare weight of a recovery tank is the weight of the tank if it were filled with
water. - ANSWER-False
(T/F): When hot water is used to raise the pressure of a refrigerant tank, the water
temperature should not exceed 120° F. - ANSWER-False
(T/F): When liquid charging into the vapor line, a restricting valve must be used to
vaporize the refrigerant before it reaches the compressor. - ANSWER-True
A ___________ can remove any type of foreign matter that enters a refrigeration
system. - ANSWER-Filter Drier
A _____________ can be used to check the oil composition of a system after a retrofit
has been done. - ANSWER-Refractometer
A ¼ inch service hose will only allow a vacuum pump to pull at _____ CFM, regardless
of the pump's CFM rating. - ANSWER-0.8
A deep vacuum can most accurately be measured in - ANSWER-Microns
A DOT-approved refrigerant recovery cylinder is color-coded - ANSWER-Gray with a
Yellow Top
A large refrigeration system that contains a significant amount of moisture should be
evacuated with - ANSWER-A high CFM vacuum pump
A service technician is charging an R-410A air-conditioning system that has a TXV
metering device. The high-side saturation pressure is 365 psig and the unit's technical
manual specifies 10°F of liquid subcooling. What would the desired liquid-line
temperature be at the outlet of the condensing unit? - ANSWER-100°F
, A system equipped with a fixed orifice metering device should be charge using the
____________ method. - ANSWER-Superheat
A system that contains less than ______ of refrigerant does not require a leak to be
repaired, but it is recommended to do so. - ANSWER-50 lb
A system that is equipped with a _____________ may require additional steps to
ensure that the entire system is evacuated. - ANSWER-Solenoid Valve
A system's total refrigerant charge can be found on - ANSWER-The nameplate of a
package-type air-conditioning system.
A technician is working on an R-404A refrigeration system and determines that the head
pressure is 205 psig and the condenser outlet temperature is 80°F. The technician
correctly concludes that the amount of condenser subcooling is - ANSWER-10°F.
A technician is working on an R-404A refrigeration system and determines that the
suction pressure is 30 psig and the evaporator outlet temperature is 10°F. The
technician correctly concludes that the amount of evaporator superheat is - ANSWER-
13°F
A(n) ____________ leak detector requires a lubricant-specific dye be injected into a
charged system to find the leak. - ANSWER-Ultraviolet
All of the following tasks are part of a refrigerant retrofitting process except - ANSWER-
Ensure that the evaporator fan motor is off during system charging.
An evacuation process that is performed a number of times with nitrogen being used to
break the vacuum, and ends with a deep vacuum is known as - ANSWER-Triple
Evacuation
An increase in the natural greenhouse effect that leads to the heating of the earth is
called - ANSWER-Global Warming
An oily dust spot on a condenser or evaporator coil could indicate - ANSWER-A
refrigerant leak
As a system is charged with vapor refrigerant, the refrigerant tank will likely - ANSWER-
Experience a pressure drop and a temperature drop.
Atmospheric pressure, 0 psig, is the equivalent of about __________ microns. -
ANSWER-760,000
Automatic charging capability, auto-stop features, alarms, and wireless remotes are
features that are found on some - ANSWER-Refrigerant charging scales.
Complete Solutions
(T/F): A common term for tropospheric ozone pollution is smog. - ANSWER-True
(T/F): A system with Schrader valve gauge ports will take longer to evacuate than a
system with service valves. - ANSWER-True
(T/F): All 500-series refrigerant blends have temperature glide and have the potential to
fractionate. - ANSWER-False
(T/F): The process of a solid changing to a vapor without passing through the liquid
state is called dehydration. - ANSWER-False
(T/F): The tare weight of a recovery tank is the weight of the tank if it were filled with
water. - ANSWER-False
(T/F): When hot water is used to raise the pressure of a refrigerant tank, the water
temperature should not exceed 120° F. - ANSWER-False
(T/F): When liquid charging into the vapor line, a restricting valve must be used to
vaporize the refrigerant before it reaches the compressor. - ANSWER-True
A ___________ can remove any type of foreign matter that enters a refrigeration
system. - ANSWER-Filter Drier
A _____________ can be used to check the oil composition of a system after a retrofit
has been done. - ANSWER-Refractometer
A ¼ inch service hose will only allow a vacuum pump to pull at _____ CFM, regardless
of the pump's CFM rating. - ANSWER-0.8
A deep vacuum can most accurately be measured in - ANSWER-Microns
A DOT-approved refrigerant recovery cylinder is color-coded - ANSWER-Gray with a
Yellow Top
A large refrigeration system that contains a significant amount of moisture should be
evacuated with - ANSWER-A high CFM vacuum pump
A service technician is charging an R-410A air-conditioning system that has a TXV
metering device. The high-side saturation pressure is 365 psig and the unit's technical
manual specifies 10°F of liquid subcooling. What would the desired liquid-line
temperature be at the outlet of the condensing unit? - ANSWER-100°F
, A system equipped with a fixed orifice metering device should be charge using the
____________ method. - ANSWER-Superheat
A system that contains less than ______ of refrigerant does not require a leak to be
repaired, but it is recommended to do so. - ANSWER-50 lb
A system that is equipped with a _____________ may require additional steps to
ensure that the entire system is evacuated. - ANSWER-Solenoid Valve
A system's total refrigerant charge can be found on - ANSWER-The nameplate of a
package-type air-conditioning system.
A technician is working on an R-404A refrigeration system and determines that the head
pressure is 205 psig and the condenser outlet temperature is 80°F. The technician
correctly concludes that the amount of condenser subcooling is - ANSWER-10°F.
A technician is working on an R-404A refrigeration system and determines that the
suction pressure is 30 psig and the evaporator outlet temperature is 10°F. The
technician correctly concludes that the amount of evaporator superheat is - ANSWER-
13°F
A(n) ____________ leak detector requires a lubricant-specific dye be injected into a
charged system to find the leak. - ANSWER-Ultraviolet
All of the following tasks are part of a refrigerant retrofitting process except - ANSWER-
Ensure that the evaporator fan motor is off during system charging.
An evacuation process that is performed a number of times with nitrogen being used to
break the vacuum, and ends with a deep vacuum is known as - ANSWER-Triple
Evacuation
An increase in the natural greenhouse effect that leads to the heating of the earth is
called - ANSWER-Global Warming
An oily dust spot on a condenser or evaporator coil could indicate - ANSWER-A
refrigerant leak
As a system is charged with vapor refrigerant, the refrigerant tank will likely - ANSWER-
Experience a pressure drop and a temperature drop.
Atmospheric pressure, 0 psig, is the equivalent of about __________ microns. -
ANSWER-760,000
Automatic charging capability, auto-stop features, alarms, and wireless remotes are
features that are found on some - ANSWER-Refrigerant charging scales.
