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

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

3. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 Vapor-Compression Refrigeration expansion device condenser compressor evaporator A B C D

4. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 Interconnecting Refrigerant Piping compressor condenser evaporator expansion device dischargeline suctionline liquidline A B C D

5. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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)

6. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 Scroll Compressor stationaryscroll drivenscroll intake discharge intake dischargeport motorshaft seal

7. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 Return Oil to Compressors compressor condenser evaporator expansion device dischargeline suctionline liquidline warmliquid hotvapor coolvapor

8. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 Thermostatic Expansion Valve (TXV) external equalizer remote bulb evaporator TXV refrigerantvapor distributor liquid refrigerant

9. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 Subcooling B A pressure enthalpy { subcooling C mixture of liquid and vapor saturated vapor curve saturated liquid curve expansiondevice condenser evaporator compressor

10. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 Condenser Evaporator Compressor Expansion Device

11. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 Pressure Drop in a Suction Line impact on system performance, % capacitycapacity 100 efficiencyefficiency pressure drop, psi (kPa) 2(13.8)2(13.8) 96 92 98 94 90 4(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

12. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 Minimize Refrigerant Charge liquid line suction line condenser evaporator filterdrier compressor dischargeline

13. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 Involve the Manufacturer s If provided, use refrigerant line sizes recommended by manufacturer

14. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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

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

16. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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

17. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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

18. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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

19. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 Unloading Refrigeration Circuits reciprocating compressor with cylinder unloaders scroll compressors manifolded on a single circuit

20. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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)

21. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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)

22. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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)

23. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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)

24. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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

25. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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)

26. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 Double Suction Riser largerriser smallerriser trap

27. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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)

28. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 Calculate Total Equivalent Length L eq is based on r/d radius of curvature (r) diameter (d)

29. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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)

30. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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)

31. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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

32. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 TXV Installation external equalizer line remote bulb evaporator TXV refrigerantvapor distributor liquid refrigerant

33. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 single distributor on circuit Evaporator Coil Connection TXVbulb must rise above height of evaporator must drop below header outlet suction header

34. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 single distributor on circuit Evaporator Coil Connection TXVbulb must rise above height of evaporator must drop below header outlet suction header

35. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 multiple distributors on circuit Evaporator Coil Connections TXVbulb must drop below lowest header outlet double-elbowconfiguration must rise above height of evaporator

36. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 suction line Riser Traps Are Not Required

37. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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

38. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 Suction-Line Accumulator s Check with equipment manufacturer to determine if required, recommended, or discouraged photo provided by Henry Technologies

39. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 suction line Reciprocating Compressors pipeanchor pitch

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

41. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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

42. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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

43. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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

44. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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) 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)

45. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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)

46. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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)

47. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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)

48. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 Selected Discharge Line Size 1 5/8 in. (42 mm) compressor condenser 1 5/8 in. (42 mm) riser

49. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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)

50. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 discharge line Add Pressure Drop of Accessories s Angle valve = 1 psi (6.9 kPa) s Ball valve = 1 equivalent ft (0.3 m)

51. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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

52. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 discharge line Reciprocating Compressors pipeanchor pitch

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

54. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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

55. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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) {

56. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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

57. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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

58. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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

59. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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

60. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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

61. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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.

62. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 Involve the Manufacturer s If provided, use refrigerant line sizes recommended by manufacturer

63. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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)

64. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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)

65. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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

66. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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)

67. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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

68. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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

69. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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)

70. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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)

71. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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

72. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 liquid line Evaporator Coil Connections TXV distributor evaporator solenoidvalve

73. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 liquid line Refrigerant Accessories sightglass TXV liquid line solenoid valve filter-drier evaporator condenser

74. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 Liquid Line Routing route the horizontal leg below the riser evaporator condenser condenser evaporator

75. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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

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

77. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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

78. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 Hot-Gas Bypass to Evaporator Inlet evaporator condenser compressor hot-gas bypass valve TXV distributor suction line liquid line

79. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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

80. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 Hot-Gas Bypass Risers hot-gas bypass riser suctionline compressor drain leg oil-returnline condenser hot-gas bypass valve

81. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 hot-gas bypass line Connection to Evaporator evaporator distributor liquidline hot-gas bypass line solenoidvalve TXV

82. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 hot-gas bypass line Connection to Evaporator evaporator distributor hot-gas bypass line solenoidvalve checkvalves TXV

83. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 Hot-Gas Bypass to Suction Line evaporator condenser compressor hot-gas bypass valve suction line liquid line liquid-injection valve TXV

84. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 hot-gas bypass line Connection to Suction Line condenser compressor suction line liquidline hot-gas bypass valve liquid-injection valve solenoidvalve

85. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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)

86. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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

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

88. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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

89. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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

90. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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

91. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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

92. Air Conditioning Clinic TRG-TRC006-EN © American Standard Inc. 2002 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

94. 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.