HVAC Excellence
✅✅
Heat which causes a change in temperature of a substance is called. -
-sensible heat.
✅✅
Heat added to a substance without a rise in temperature; (example: liquid refrigerant
to gas) this process is called? - -Latent heat
✅✅
Heat added to the refrigerant in a vapor state after the evaporator process is called. -
-Superheat
A scroll compressor moves refrigerant by means of. - ✅✅-Involute spirals
The movement of heat by way of fluid or is called air or gas. - ✅✅-Convection
The movement of heat through a solid object is called. - ✅✅-Conduction
✅✅
The standard unit for measuring the QUANTITY of heat in a substance is (intensity
would be temp) - -British thermal unit
A refrigerant gives up heat when it. - ✅✅-It condenses
✅✅
Why must refrigerant in the suction line be slightly warmer than the saturation
temperature? - -Prevent liquid slugging of the compressor
✅✅
It is desirable for refrigerant in the suction line to be slightly superheated in order to. -
-Insure liquid refrigerant does not enter the compressor
The state of the refrigerants in the suction line should be. - ✅✅-Low pressure / Low
temperature vapor
The state of the refrigerant entering the condenser is. - ✅✅-High pressure / Highly
superheated vapor
The evaporator. - ✅✅-Transfers heat from the refrigerated space to the refrigerant
✅✅
Which of the following is not a thermodynamic property of refrigerant. -
-Flammability
✅✅
The sequential order of stepson the vapor-compression process are. -
-Compression, condensation, expansion, vaporization
, ✅✅
If a 30 pound container of R-410A refrigerant has been stored over night at 70'F, the
pressure in the cylinder should be approximately. - -201 psig
Fan airflow pressures are usually measured in. - ✅✅-Inches of water column (WC)
Zero psia (pounds per square inch absolute) is. - ✅✅-A pressure which cannot be
further reduced
Zero psig ( pounds per square inch gauge) is. - ✅✅-The same as atmospheric
pressure
✅✅
The temperature at which moisture will start to condense from the air is called. -
-Dew point temperature
A compound pressure gauge measures - ✅✅-Pressure and vacuum
A mechanical shaft seal is necessary on a - ✅✅-Open drive compressor / external
force
✅✅-Liquid refrigerant in the compressor clearance space
Liquid slugging is. -
The clearance space in a reciprocating compressor. - ✅✅-Has no effect on
compressor capacity
✅✅
Which of the following types of air conditioning compressors is most energy efficient
- -Centrifugal ( BTU/Kilo watts )
✅✅
Which of the following represents the right order for the functions of a condenser. -
-De-superheats , condenses , sub-cools
Refrigerant R-134a vapor enters the condenser at 124 psig, 100'F. It leaves as a
✅✅
liquid from the condenser sub-cooled 20'F, and the pressure will be approximately. -
-124 psig
✅✅
There are three basic types of condensers, the air cooled, the water cooled and the
BLANK cooled. - -Evaporative
10lbs. Of refrigerant passing through a water cooled condenser will lose 20 BTU of
heat per lb. if 10lbs. Of water passes through the condenser with an entering
✅✅
temperature of 80'F. The temperature of the water leaving the condenser is. -
-100'F
✅✅
Heat which causes a change in temperature of a substance is called. -
-sensible heat.
✅✅
Heat added to a substance without a rise in temperature; (example: liquid refrigerant
to gas) this process is called? - -Latent heat
✅✅
Heat added to the refrigerant in a vapor state after the evaporator process is called. -
-Superheat
A scroll compressor moves refrigerant by means of. - ✅✅-Involute spirals
The movement of heat by way of fluid or is called air or gas. - ✅✅-Convection
The movement of heat through a solid object is called. - ✅✅-Conduction
✅✅
The standard unit for measuring the QUANTITY of heat in a substance is (intensity
would be temp) - -British thermal unit
A refrigerant gives up heat when it. - ✅✅-It condenses
✅✅
Why must refrigerant in the suction line be slightly warmer than the saturation
temperature? - -Prevent liquid slugging of the compressor
✅✅
It is desirable for refrigerant in the suction line to be slightly superheated in order to. -
-Insure liquid refrigerant does not enter the compressor
The state of the refrigerants in the suction line should be. - ✅✅-Low pressure / Low
temperature vapor
The state of the refrigerant entering the condenser is. - ✅✅-High pressure / Highly
superheated vapor
The evaporator. - ✅✅-Transfers heat from the refrigerated space to the refrigerant
✅✅
Which of the following is not a thermodynamic property of refrigerant. -
-Flammability
✅✅
The sequential order of stepson the vapor-compression process are. -
-Compression, condensation, expansion, vaporization
, ✅✅
If a 30 pound container of R-410A refrigerant has been stored over night at 70'F, the
pressure in the cylinder should be approximately. - -201 psig
Fan airflow pressures are usually measured in. - ✅✅-Inches of water column (WC)
Zero psia (pounds per square inch absolute) is. - ✅✅-A pressure which cannot be
further reduced
Zero psig ( pounds per square inch gauge) is. - ✅✅-The same as atmospheric
pressure
✅✅
The temperature at which moisture will start to condense from the air is called. -
-Dew point temperature
A compound pressure gauge measures - ✅✅-Pressure and vacuum
A mechanical shaft seal is necessary on a - ✅✅-Open drive compressor / external
force
✅✅-Liquid refrigerant in the compressor clearance space
Liquid slugging is. -
The clearance space in a reciprocating compressor. - ✅✅-Has no effect on
compressor capacity
✅✅
Which of the following types of air conditioning compressors is most energy efficient
- -Centrifugal ( BTU/Kilo watts )
✅✅
Which of the following represents the right order for the functions of a condenser. -
-De-superheats , condenses , sub-cools
Refrigerant R-134a vapor enters the condenser at 124 psig, 100'F. It leaves as a
✅✅
liquid from the condenser sub-cooled 20'F, and the pressure will be approximately. -
-124 psig
✅✅
There are three basic types of condensers, the air cooled, the water cooled and the
BLANK cooled. - -Evaporative
10lbs. Of refrigerant passing through a water cooled condenser will lose 20 BTU of
heat per lb. if 10lbs. Of water passes through the condenser with an entering
✅✅
temperature of 80'F. The temperature of the water leaving the condenser is. -
-100'F
