Refrigerant Piping A Trane Air Conditioning Clinic Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002

period one Refrigerant Piping Requirements Refrigerant Piping Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc Vapor-Compression Refrigeration expansion device condenser compressor evaporator A B C D

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc Interconnecting Refrigerant Piping compressor condenser evaporator expansion device dischargeline suctionline liquidline A B C D

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc Refrigerant Piping Requirements s Return oil to compressor s Ensure that only liquid refrigerant enters the expansion device s Minimize system capacity loss s Minimize refrigerant charge s Insulate lines that are routed through very warm spaces (Liquid line)

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc Scroll Compressor stationaryscroll drivenscroll intake discharge intake dischargeport motorshaft seal

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc Return Oil to Compressors compressor condenser evaporator expansion device dischargeline suctionline liquidline warmliquid hotvapor coolvapor

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc Thermostatic Expansion Valve (TXV) external equalizer remote bulb evaporator TXV refrigerantvapor distributor liquid refrigerant

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc Subcooling B A pressure enthalpy { subcooling C mixture of liquid and vapor saturated vapor curve saturated liquid curve expansiondevice condenser evaporator compressor

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc Condenser Evaporator Compressor Expansion Device

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc Pressure Drop in a Suction Line impact on system performance, % capacitycapacity 100 efficiencyefficiency pressure drop, psi (kPa) 2(13.8)2(13.8) (27.6)4(27.6)6(41.4)6(41.4)10(69.0)10(69.0)12(82.7)12(82.7)8(55.2)8(55.2) R-22R-22

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc Minimize Refrigerant Charge liquid line suction line condenser evaporator filterdrier compressor dischargeline

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc Involve the Manufacturer s If provided, use refrigerant line sizes recommended by manufacturer

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc General Piping Requirements s Use clean Type L copper tubing u Copper-to-copper joints: BCuP-6 without flux u Copper-to-steel (or brass) joints: BAg-28, non-acid flux s Properly support piping to account for expansion, vibration, and weight s Avoid installing piping underground s Test entire refrigerant circuit for leaks

period two Suction Line Refrigerant Piping Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc suction line Requirements for Sizing and Routing s Ensure adequate velocity to return oil to compressor at all steps of unloading s Avoid excessive noise s Minimize system capacity and efficiency loss

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc suction line Sizing “ Rules ” minimum velocity 1,000 fpm (5 m/s)based on diameter of riser for vertical risers 500 fpm (2.5 m/s) percentage of minimum for horizontal sections riser velocity maximum velocity4,000 fpm (20 m/s) maximum pressure drop 3 psi (20 kPa)based on specific system requirements old rules for R-22new rules for R-22

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc suction line Process for Sizing 1Determine total length of piping 2Calculate refrigerant velocity at maximum and minimum capacities 3Select largest pipe diameter that results in acceptable velocity at both maximum and minimum capacities 4Calculate total equivalent length of straight pipe and fittings 5Determine pressure drop due to pipe and fittings 6Add pressure drop due to accessories

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc Unloading Refrigeration Circuits reciprocating compressor with cylinder unloaders scroll compressors manifolded on a single circuit

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc velocity, fpm (m/s) evaporator capacity, tons (kW) 1(3.5)5(17.6)10(35)50(176)100(352)200(703) 1,000(5.1) 500(2.5) 2,000(10.2) 5,000(25.4) 20(70) 2(7.0) 1/2 (12) 5/8 (15) 7/8 (22) 1 1/8 (28) 1 3/8 (35) 1 5/8 (42) 2 1/8 (54) 2 5/8 (67) 3 1/8 (79) 3 5/8 (105) R-22 suction line Determine Refrigerant Velocity pipe diameter, in. (mm) 3/8 (10) 4 1/8 (130) 3/4 (18)

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc suction line Determine Refrigerant Velocity velocity, fpm (m/s) pipediameter, in. (mm) 20 tons (70.3 kW) 10 tons (35.2 kW) 1 1/8 (28)7,000 (35.6)3,500 (17.8) 1 3/8 (35)4,600 (23.4)2,300 (11.7) 1 5/8 (42)3,250 (16.5)1,625 (8.3) 2 1/8 (54)1,850 (9.4) 925 (4.7) 2 5/8 (67)1,200 (6.1) 600 (3.1) 3 1/8 (79)850 (4.3) 425 (2.2)

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc riserhoriz/drop 3/8 (10)370 (1.9)275 (1.4) 1/2 (12)460 (2.3)350 (1.8) 5/8 (15)520 (2.6)390 (2.0) 3/4 (18)560 (2.8)420 (2.1) 7/8 (22)600 (3.1)450 (2.3) 1 1/8 (28)700 (3.6)525 (2.7) 1 3/8 (35)780 (4.0)585 (3.0) 1 5/8 (42)840 (4.3)630 (3.2) 2 1/8 (54)980 (5.0)735 (3.7) 2 5/8 (67)1,080 (5.5)810 (4.1) 3 1/8 (79)1,180 (6.0)885 (4.5) 3 5/8 (105)1,270 (6.5)950 (4.8) 4 1/8 (130)1,360 (6.9)1,020 (5.2) suction line Minimum Allowable Velocities minimum velocity, fpm (m/s) pipe diameter, in. (mm)

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc Select Suction Line Size riserhoriz/drop 20 (70.3)1,850 (9.4) 10 (35.2)925 (4.7) circuitcapacity, tons (kW) minimum velocity for 2 1/8 in. (54 mm) pipe, fpm (m/s) velocity inside 2 1/8 in. (54 mm) pipe, fpm (m/s) 980 (5.0)735 (3.7) riserhoriz/drop 20 (70.3)3,250 (16.5) 10 (35.2)1,625 (8.3) circuitcapacity, tons (kW) minimum velocity for 1 5/8 in. (42 mm) pipe, fpm (m/s) velocity inside 1 5/8 in. (42 mm) pipe, fpm (m/s) 840 (4.3)630 (3.2)

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc Selected Suction Line Sizes compressor evaporator 2 1/8 in. (54 mm) 1 5/8 in. (42 mm) riser 2 1/8 in. (54 mm) drop

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc Double Suction Riser 20 (70.3)3,250 (16.5) 5 (17.6)810 (4.1) circuitcapacity, tons (kW) minimum velocity for 1 5/8 in. (42 mm) riser, fpm (m/s) velocity inside 1 5/8 in. (42 mm) pipe, fpm (m/s) 840 (4.3) 20 (70.3)4,600 (23.4) 5 (17.6)1,150 (5.9) circuitcapacity, tons (kW) minimum velocity for 1 3/8 in. (35 mm) riser, fpm (m/s) velocity inside 1 3/8 in. (35 mm) pipe, fpm (m/s) 780 (4.0)

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc Double Suction Riser largerriser smallerriser trap

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc Sizing a Double Suction Riser s Sizing the smaller riser s Sizing the larger riser 5 (17.6)1,150 (5.8) circuitcapacity, tons (kW) minimum velocity for 1 3/8 in. (35 mm) riser, fpm (m/s) velocity inside 1 3/8 in. (35 mm) pipe, fpm (m/s) 780 (4.0) 15 (52.8)2,450 (12.4) circuitcapacity, tons (kW) minimum velocity for 1 5/8 in. (42 mm) riser, fpm (m/s) velocity inside 1 5/8 in. (42 mm) pipe, fpm (m/s) 840 (4.3)

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc Calculate Total Equivalent Length L eq is based on r/d radius of curvature (r) diameter (d)

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc L eq for Long-Radius Elbows equivalent length, ft (m) “ old ” data “ new ” data 1 1/8 (28)1.9 (0.6)0.8 (0.24) 1 3/8 (35)2.2 (0.7)0.9 (0.27) 1 5/8 (42)2.6 (0.8)1.0 (0.30) 2 1/8 (54)3.4 (1.0)1.4 (0.43) 2 5/8 (67)4.2 (1.3)1.5 (0.46) 3 1/8 (79)5.1 (1.6)1.7 (0.52) elbowdiameter, in. (mm)

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc pressure drop, psi/100 ft (kPa/10 m) evaporator capacity, tons (kW) 1(3.5)5(17.6)10(35)50(176)100(352)200(703) 1.0(2.3) 0.5(1.2) 2.0(4.6) 5.0(11.5) 20(70) 2(7.0) 2 1/8 (54) 2 5/8 (67) 3 1/8 (79) R-22 pipe diameter, in. (mm) 1 5/8 (42) 10.0(23.0) suction line Determine Pressure Drop 1 3/8 (35) 1 1/8 (28) 7/8 (22) 3/4 (18) 5/8 (15) 3 5/8 (105) 4 1/8 (130)

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc suction line Add Pressure Drop of Accessories s Suction filter = 2 psi (13.8 kPa) s Angle valve = 1 psi (6.9 kPa) s Ball valve = 1 equivalent ft (0.3 m) suction line filter

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc TXV Installation external equalizer line remote bulb evaporator TXV refrigerantvapor distributor liquid refrigerant

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc single distributor on circuit Evaporator Coil Connection TXVbulb must rise above height of evaporator must drop below header outlet suction header

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc single distributor on circuit Evaporator Coil Connection TXVbulb must rise above height of evaporator must drop below header outlet suction header

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc multiple distributors on circuit Evaporator Coil Connections TXVbulb must drop below lowest header outlet double-elbowconfiguration must rise above height of evaporator

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc suction line Riser Traps Are Not Required

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc suction line Other Considerations s Do not use suction riser traps: they are not required s Pitch horizontal sections to drain toward evaporator s Insulate entire suction line u Prevents condensation u Minimizes loss of capacity due to heat gain s Install suction-line filter close to compressor u Manual shutoff valves allow isolation for replacement s Install access ports to measure suction pressure and superheat

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc Suction-Line Accumulator s Check with equipment manufacturer to determine if required, recommended, or discouraged photo provided by Henry Technologies

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc suction line Reciprocating Compressors pipeanchor pitch

period three Discharge Line Refrigerant Piping Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc discharge line Requirements for Sizing and Routing s Ensure adequate velocity to return oil to compressor at all steps of unloading s Avoid excessive noise s Minimize efficiency loss

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc discharge line Sizing “ Rules ” minimum velocity 1,000 fpm (5 m/s)based on diameter of riser for risers 500 fpm (2.5 m/s) percentage of minimum for horizontal sections riser velocity maximum velocity3,500 fpm (17.5 m/s) maximum pressure drop 6 psi (41 kPa)based on specific system requirements old rules for R-22new rules for R-22

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc discharge line Process for Sizing 1Determine total length of piping 2Calculate refrigerant velocity at maximum and minimum capacities 3Select largest pipe diameter that results in acceptable velocity at both maximum and minimum capacity 4Calculate total equivalent length of straight pipe and fittings 5Determine pressure drop due to pipe and fittings 6Add pressure drop due to accessories

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc (3.5)5(17.6)10(35)50(176)100(352)200(703) 1,000(5.1) 500(2.5) 2,000(10.2) 5,000(25.4) 20(70) 2(7.0) 1/2 (12) 5/8 (15) 7/8 (22) 1 1/8 (28) 1 3/8 (35) 1 5/8 (42) 2 1/8 (54) 2 5/8 (67) 3 1/8 (79) R-22 discharge line Determine Refrigerant Velocity velocity, fpm (m/s) evaporator capacity, tons (kW) pipe diameter, in. (mm) 3/8 (10) 3/4 (18) 5/16 (8)

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc discharge line Determine Refrigerant Velocity 7/8 (22)4,050 (20.6)2,025 (10.3) 1 1/8 (28)2,400 (12.2)1,200 ( 6.1) 1 3/8 (35)1,550 ( 7.9) 775 ( 3.9) 1 5/8 (42)1,100 ( 5.6) 550 ( 2.8) 2 1/8 (54)650 ( 3.3) 325 ( 1.7) velocity, fpm (m/s) pipediameter, in. (mm) 20 tons (70.3 kW) 10 tons (35.2 kW)

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc discharge line Minimum Allowable Velocities riserhoriz/drop 5/16 (8)220 (1.1)165 (0.8) 3/8 (10)250 (1.3)185 (0.9) 1/2 (12)285 (1.4)215 (1.1) 5/8 (15)315 (1.6)235 (1.2) 3/4 (18)345 (1.8)260 (1.3) 7/8 (22)375 (1.9)285 (1.4) 1 1/8 (28)430 (2.2)325 (1.7) 1 3/8 (35)480 (2.4)360 (1.8) 1 5/8 (42)520 (2.6)390 (2.0) 2 1/8 (54)600 (3.0)450 (2.3) 2 5/8 (67)665 (3.4)500 (2.5) 3 1/8 (79)730 (3.7)550 (2.8) minimum velocity, fpm (m/s) pipe diameter, in. (mm)

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc Select Discharge Line Size riserhoriz/drop 20 (70.3)1,100 (5.6) 10 (35.2)550 (2.8) circuitcapacity, tons (kW) minimum velocity for 1 5/8 in. (42 mm) pipe, fpm (m/s) velocity inside 1 5/8 in. (42 mm) pipe, fpm (m/s) 520 (2.6)390 (2.0)

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc Selected Discharge Line Size 1 5/8 in. (42 mm) compressor condenser 1 5/8 in. (42 mm) riser

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc pressure drop, psi/100 ft (kPa/10 m) evaporator capacity, tons (kW) 1(3.5)5(17.6)10(35)50(176)100(352)200(703) 1.0(2.3) 0.5(1.2) 2.0(4.6) 5.0(11.5) 20(70) 2(7.0) 7/8 (22) 1 1/8 (28) 1 3/8 (35) 2 1/8 (54) 2 5/8 (67) 3 1/8 (79) R-22 pipe diameter, in. (mm) 1 5/8 (42) 10.0(23.0) discharge line Determine Pressure Drop 3/4 (18) 5/8 (15) 1/2 (12)

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc discharge line Add Pressure Drop of Accessories s Angle valve = 1 psi (6.9 kPa) s Ball valve = 1 equivalent ft (0.3 m)

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc discharge line Other Considerations s Do not use discharge riser traps: they are not required s Pitch horizontal sections to drain toward condenser s Insulate only to prevent accidental burns or when system must operate in cold ambient conditions

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc discharge line Reciprocating Compressors pipeanchor pitch

period four Liquid Line Refrigerant Piping Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc liquid line Requirements for Sizing and Routing s Ensure that only liquid refrigerant enters expansion device s Minimize refrigerant charge s Avoid excessive noise and pipe erosion

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc Subcooling enthalpy, Btu/lb (kJ/kg) 241(1,662) pressure, psia (kPa) 293(2,020) 125°F(51.7°C) subcooling saturated liquid curve mixture of liquid and vapor 110°F(43.3°C) {

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc Impact of Refrigerant Density Change A 7/8 (22)high18.0 (10) -5.7 (3.2) =12.3 (6.8) B 1 1/8 (28)high18.0 (10) -3.8 (2.1) =14.2 (7.9) A 7/8 (22)low12.9 (7.2) -7.4 (4.1) =5.5 (3.1) B 1 1/8 (28)low7.2 (4.0) -5.2 (2.9) =2.0 (1.1) available subcooling, °F (°C) liquid line diameter, in. (mm) leaving subcooler loss due to piping outdoor temperature remaining at TXV

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc liquid line Sizing “ Rules ” maximum pressure drop 6 psi (41 kPa)5°F (2.8°C) subcooling remaining at inlet to expansion device at all operating conditions maximum velocity 360 fpm (1.8 m/s)600 fpm (3 m/s) old rules for R-22new rules for R-22

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc liquid line Process for Sizing 1Determine total length of piping 2Obtain subcooling provided by condenser 3Determine refrigerant velocity 4Select smallest pipe diameter that results in acceptable velocity at maximum capacity 5Calculate total equivalent length of pipe and fittings 6Determine pressure drop due to pipe and fittings 7Add pressure drop due to accessories 8Calculate loss of subcooling due to pressure drop and elevation change

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc System Operating Envelope saturated suction temperature condensing unit, high OA temperature condensing unit, low OA temperature evaporator, high cooling load evaporator, low cooling load system cooling capacity

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc System Operating Envelope high cooling load, high OA temperature A B D C high cooling load, low OA temperature low cooling load, high OA temperature low cooling load, low OA temperature saturated suction temperature system cooling capacity

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc effect of cooling load and outdoor temperature Subcooling Leaving Condenser highhigh18 (10.0) lowhigh21 (11.7) A highhigh18 (10.0) B lowhigh21 (11.7) lowlow 13 (7.2) highlow 5 (2.8) C lowlow 13 (7.2) D highlow 5 (2.8) subcooling leaving condenser*, °F (°C) cooling load outdoor temperature * This example system uses a TXV for the expansion device.

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc Involve the Manufacturer s If provided, use refrigerant line sizes recommended by manufacturer

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc evaporator capacity, tons (kW) 1(3.5)5(17.6)10(35)50(176)100(352)200(703) 100(0.5) 50(0.25) 200(1.0) 500(2.5) 20(70) 2(7.0) 5/16 (8) 3/8 (10) 1/2 (12) 5/8 (15) 2 1/8 (54) 1 5/8 (42) R-22 pipe diameter, in. (mm) 1 1/8 (28) 1,000(5.1) liquid line Determine Refrigerant Velocity velocity, fpm (m/s) 7/8 (22) 1 3/8 (35) 1/4 (6) 3/4 (18)

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc liquid line Determine Refrigerant Velocity 1/2 (12)850 (4.3) 5/8 (15)525 (2.7) 3/4 (18)350 (1.8) 7/8 (22)250 (1.3) 1 1/8 (28)150 (0.8) 1 3/8 (35)100 (0.5) velocity, fpm (m/s) pipediameter, in. (mm) 20 tons (70.3 kW)

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc liquid line Calculate Total Equivalent Length evaporator condenser 5/8 in. (15 mm) riser 5/8 in. (15 mm) 5/8 in. (15 mm) drop

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc evaporator capacity, tons (kW) 1(3.5)5(17.6)10(35)50(176)100(352)200(703)20(70) 2(7.0) R-22 pipe diameter, in. (mm) liquid line Determine Pressure Drop pressure drop, psi/100 ft (kPa/10 m) 1.0(2.3) 2.0(4.6) 5.0(11.5) 10.0(23) 20.0(46) 50.0(115) 5/8 (15) 7/8 (22) 1 1/8 (28) 1 3/8 (35) 1 5/8 (42) 1/2 (12) 3/4 (18) 2 1/8 (54) 3/8 (10) 5/16 (8) 1/4 (6)

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc liquid line Add Pressure Drop of Accessories s Filter-drier = 6 psi (41.4 kPa) s Solenoid valve = 4 psi (27.6 kPa) s Sight glass = 1 equivalent ft (0.3 m) s Angle valve = 1 psi (6.9 kPa) s Ball valve = 1 equivalent ft (0.3 m) solenoidvalve

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc liquid line Pressure Drop Due to Elevation evaporator condenser 15 ft (4.6 m) vertical rise creates pressure drop 11 ft (3.4 m) vertical drop creates pressure gain

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc liquid line Pressure Drop Due to Elevation liquid temperature, °F (°C) pressure drop/net liquid rise, psi/ft (kPa/m) 40(4.4)60(15.6)80(26.7)100(37.8)120(48.9)140(60.0)160(71.1) 0.425(9.6) 0.450(10.2) 0.475(10.7) 0.500(11.3) 0.525(11.9) 0.550(12.4)

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc liquid line Calculate Loss of Subcooling liquid temperature, °F (°C) loss of subcooling, psi/°F (kPa/°C) 40(4.4)60(15.6)80(26.7)100(37.8)120(48.9)140(60.0)160(71.1) 0(0) 1.0(12.4) 2.0(24.9) 3.0(37.3) 4.0(49.7) 5.0(62.2)

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc Subcooling Remaining at Expansion Device 15 (8.3)-9.9 (5.5)=5.1 (2.8) leavingcondenser subcooling, °F (°C) loss due to liquid line remaining at expansion device

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc liquid line Evaporator Coil Connections TXV distributor evaporator solenoidvalve

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc liquid line Refrigerant Accessories sightglass TXV liquid line solenoid valve filter-drier evaporator condenser

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc Liquid Line Routing route the horizontal leg below the riser evaporator condenser condenser evaporator

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc liquid line Other Considerations s Pitch horizontal sections to run alongside suction or discharge line s Insulate lines that are routed through very warm spaces

period five Hot-Gas Bypass Line Refrigerant Piping Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc hot-gas bypass line Requirements for Sizing and Routing s Ensure that oil and refrigerant are not trapped in piping s Avoid excessive noise s Proper routing is more critical than pipe diameter

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc Hot-Gas Bypass to Evaporator Inlet evaporator condenser compressor hot-gas bypass valve TXV distributor suction line liquid line

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc Hot-Gas Bypass Valve Installation condenser compressor hot-gas bypass valve pitch back toward discharge line pilotline suctionline dischargeline pitch away from hot-gas bypass valve hot-gas bypass line

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc Hot-Gas Bypass Risers hot-gas bypass riser suctionline compressor drain leg oil-returnline condenser hot-gas bypass valve

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc hot-gas bypass line Connection to Evaporator evaporator distributor liquidline hot-gas bypass line solenoidvalve TXV

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc hot-gas bypass line Connection to Evaporator evaporator distributor hot-gas bypass line solenoidvalve checkvalves TXV

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc Hot-Gas Bypass to Suction Line evaporator condenser compressor hot-gas bypass valve suction line liquid line liquid-injection valve TXV

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc hot-gas bypass line Connection to Suction Line condenser compressor suction line liquidline hot-gas bypass valve liquid-injection valve solenoidvalve

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc Hot-Gas Bypass Line Sizing 1/2 (12)6,700 (34.0) 5/8 (15)4,200 (21.3) 3/4 (18)2,825 (14.4) 7/8 (22)2,025 (10.3) 1 1/8 (28)1,200 ( 6.1) 1 3/8 (35)775 ( 3.9) velocity, fpm (m/s) pipediameter, in. (mm) 10 tons (35.2 kW)

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc hot-gas bypass line Other Considerations s Insulate entire line to prevent refrigerant vapor from condensing s Minimize overall length of the line s Install solenoid valve if system includes a pump-down cycle

period six Review Refrigerant Piping Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc Review — Period One s Refrigerant Piping Requirements u Return oil to compressor u Ensure that only liquid refrigerant (no vapor) enters the expansion device u Minimize system capacity loss u Minimize refrigerant charge s If provided, use line sizes recommended by the manufacturer

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc Review — Period Two s Suction line u Ensure adequate velocity to return oil to the compressor at all steps of unloading u Avoid excessive noise u Minimize system capacity and efficiency loss

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc Review — Period Three s Discharge line u Ensure adequate velocity to return oil to the compressor at all steps of unloading u Avoid excessive noise u Minimize efficiency loss

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc Review — Period Four s Liquid line u Ensure that only liquid refrigerant enters the expansion device u Minimize refrigerant charge u Avoid excessive noise and pipe erosion

Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc Review — Period Five s Hot-gas bypass line u Ensure that oil and refrigerant are not trapped in the piping u Avoid excessive noise u Proper routing is more critical than pipe diameter

This slide was intentionally left blank. It will be hidden when in “ Slide Show ” view. See “ Notes Page ” view of this slide for the table referenced on Slides 27, 48, and 64.