Commercial Air Conditioning
0.1 to 0.5 is a common static pressure for a - ANSWER-commercial duct system go to the inter net
type in the question
350 to 400 cfm is required for - ANSWER-a ton of cooling see unit 37 or the inter net
A ( EPR) valve is used to keep - ANSWER-the evaporator pressure from dropping below the set
pressure see page 622
A accumulator in the suction line will prevent - ANSWER-liquid refrigerant from passing to the
compressor see page 654
A compressor that has a unloader on it - ANSWER-is used to control the capacity of the compressor
when there is less need for the full load, like from 3ton to 2ton capacity
A decrease in system capacity can be - ANSWER-cause by a pressure drop from a long suction line
run
A economizer works buy reading the - ANSWER-outdoor dry bulb and the wet bulb temperatures see
page 1572
A evaporator the has a partial liquid and vapor in it - ANSWER-is a direct expansion or a dry type see
page 511
A fan cycling control ( ACTION ) is the same a low pressure control - ANSWER-it opens on a drop in
pressure and closes on a rise in pressure
A increases in the fouling factor will - ANSWER-decreases the water flow in a water cool condenser
see the enter net
A liquid line in or attach to the suction line is know as a - ANSWER-liquid to suction line heat
exchangers it improves the subcooling of the unit see page 653 and 654
A liquid line receiver is also used when you have - ANSWER-a pump down system to store the
refrigerant in the receiver see page 635
, Commercial Air Conditioning
A liquid line receiver must be able to store - ANSWER-100% liquid refrigerant see page 649 or the
internet
A p-trapped in suction will - ANSWER-assure the oil will get back to the compressor
A pitch of 1" every 10 feet for the suction line - ANSWER-towards the compressor for a split system
see the inter net
A plugged equalization line or oil level regulator on a large ton compressor can cause the - ANSWER-
compressor to lock up because no oil coming back to the compressor see page 465 modern ref.
A refrigerant that displays the same characteristics as - ANSWER-R12 R22 R134 is know as a true
azeotropic blend see page 279
A regulating flow valve also know as water regulating valve - ANSWER-controls the head pressure for
a water cooled condenser page 531
A slide valve is used to control the capacity on a - ANSWER-screw compressor see page 882 modern
refrigeration book
A suction accumulator will prevent - ANSWER-liquid refrigerant from migrating to the compressor
A suction line filter drier is used after a - ANSWER-compressor burnout see page 200
A system may run a higher head pressure if has been - ANSWER-retrofitted with a different
refrigerant see page 265 modern refrigeration book
A system that has one compressor and two or more evaporators is call a - ANSWER-multi split system
page 1334 modern refrigeration book
A system working in a low suction pressure or maybe in a vacuum may not be low on charge but -
ANSWER-the TXV bulb may have lost its charge closing the valve
0.1 to 0.5 is a common static pressure for a - ANSWER-commercial duct system go to the inter net
type in the question
350 to 400 cfm is required for - ANSWER-a ton of cooling see unit 37 or the inter net
A ( EPR) valve is used to keep - ANSWER-the evaporator pressure from dropping below the set
pressure see page 622
A accumulator in the suction line will prevent - ANSWER-liquid refrigerant from passing to the
compressor see page 654
A compressor that has a unloader on it - ANSWER-is used to control the capacity of the compressor
when there is less need for the full load, like from 3ton to 2ton capacity
A decrease in system capacity can be - ANSWER-cause by a pressure drop from a long suction line
run
A economizer works buy reading the - ANSWER-outdoor dry bulb and the wet bulb temperatures see
page 1572
A evaporator the has a partial liquid and vapor in it - ANSWER-is a direct expansion or a dry type see
page 511
A fan cycling control ( ACTION ) is the same a low pressure control - ANSWER-it opens on a drop in
pressure and closes on a rise in pressure
A increases in the fouling factor will - ANSWER-decreases the water flow in a water cool condenser
see the enter net
A liquid line in or attach to the suction line is know as a - ANSWER-liquid to suction line heat
exchangers it improves the subcooling of the unit see page 653 and 654
A liquid line receiver is also used when you have - ANSWER-a pump down system to store the
refrigerant in the receiver see page 635
, Commercial Air Conditioning
A liquid line receiver must be able to store - ANSWER-100% liquid refrigerant see page 649 or the
internet
A p-trapped in suction will - ANSWER-assure the oil will get back to the compressor
A pitch of 1" every 10 feet for the suction line - ANSWER-towards the compressor for a split system
see the inter net
A plugged equalization line or oil level regulator on a large ton compressor can cause the - ANSWER-
compressor to lock up because no oil coming back to the compressor see page 465 modern ref.
A refrigerant that displays the same characteristics as - ANSWER-R12 R22 R134 is know as a true
azeotropic blend see page 279
A regulating flow valve also know as water regulating valve - ANSWER-controls the head pressure for
a water cooled condenser page 531
A slide valve is used to control the capacity on a - ANSWER-screw compressor see page 882 modern
refrigeration book
A suction accumulator will prevent - ANSWER-liquid refrigerant from migrating to the compressor
A suction line filter drier is used after a - ANSWER-compressor burnout see page 200
A system may run a higher head pressure if has been - ANSWER-retrofitted with a different
refrigerant see page 265 modern refrigeration book
A system that has one compressor and two or more evaporators is call a - ANSWER-multi split system
page 1334 modern refrigeration book
A system working in a low suction pressure or maybe in a vacuum may not be low on charge but -
ANSWER-the TXV bulb may have lost its charge closing the valve
