Quick Reference -HVAC (Part-2)
November 17, 2020 7 Comments
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A.C Capacity |
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| Ton | KW | H.P |
| 0.64 | 2.1 | 0.8 |
| 0.80 | 2.8 | 1 |
| 1.00 | 3.7 | 1.25 |
| 1.28 | 4.6 | 1.6 |
| 1.60 | 5.6 | 2 |
| 2.00 | 7.31 | 2.5 |
| 2.56 | 9.35 | 3.2 |
| 3.20 | 11.6 | 4 |
| 4.00 | 14.4 | 5 |
| 4.48 | 16.7 | 5.6 |
| 6.40 | 22.1 | 8 |
| 8.00 | 29.1 | 10 |
| 1TON= | 1TON=3000 K.Cal/Hr | |
| 1TON=1200 BTU/Hr | ||
| 1TON=3.516 KW | ||
| 1TON=1.25 HP (VRV / VRF Only) | ||
| 1TON=4.7 HP | ||
| 1TON=12660 KJ/Hr | ||
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Split AC Copper Pipe Size (Blue Star) |
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| A.C Capacity | Suction Pipe | Discharge Pipe (Liquid) |
| Up to 1 Ton | 12.7mm (1/2″) | 6.4mm (1/4″) |
| 1 To 4 Ton | 15.9mm (5/8″) | 9.5mm (3/8″) |
| 5 To 6 Ton | 19.1mm (3/4″) | 9.5mm (3/8″) |
| 7 To 8 Ton | 22.2mm (7/8″) | 12.7mm (1/2″) |
| 9 To 11 Ton | 28.6mm (1 1/8″) | 12.7mm (1/2″) |
| 12 To 19 Ton | 28.6mm (1 1/8″) | 15.9mm (5/8″) |
| 20 To 27Ton | 34.9mm (1 3/8″) | 19.1mm (3/4″) |
| 28 To 42Ton | 41.5mm (1 5/8″) | 19.1mm (3/4″) |
| Normal Split A.C Copper Pipe Maximum Length = 15Meter | ||
| VRV System Copper Pipe Maximum Length = 150Meter | ||
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Split AC Copper Pipe Length |
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| A.C Capacity | Maximum Pipe Length | Maximum Indoor & Outdoor Height Difference |
| 0.5 Ton | 15 Meter | 5 Meter |
| 0.6 Ton | 15 Meter | 5 Meter |
| 0.75 Ton | 15 Meter | 5 Meter |
| 1 Ton | 20 Meter | 10 Meter |
| 1.5 Ton | 25 Meter | 10 Meter |
| 2 Ton | 25 Meter | 10 Meter |
| 2.5 Ton | 30 Meter | 10 Meter |
| 3 Ton | 30 Meter | 20 Meter |
| 3.5 Ton | 30 Meter | 20 Meter |
| 4 Ton | 30 Meter | 20 Meter |
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Split AC Copper Pipe Additional Refrigerant Charge |
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| Total Pipe Length | 50 Meter | 60 Meter | 70 Meter |
| Additional Refrigerant | None | 250 gm (25gm/Meter) | 500 gm (25gm/Meter) |
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Copper Pipe Thickness |
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| Pipe Size | Thickness | Tube Gauge | Type |
| 6.4mm (1/4″) | 0.8 mm | 21 | Soft |
| 9.5mm (3/8″) | 0.8 mm | 21 | Soft |
| 12.7mm (1/2″) | 0.8 mm | 21 | Soft |
| 15.9mm (5/8″) | 1 mm | 19 | Soft |
| 19.1mm (3/4″) | 1 mm | 19 | Soft |
| 22.2mm (7/8″) | 1 mm | 19 | Hard |
| 28.6mm (1 1/8″) | 1.2 mm | 18 | Hard |
| 34.9mm (1 3/8″) | 1.2 mm | 18 | Hard |
| 41.5mm (1 5/8″) | 1.3 mm | 18 | Hard |
| De-Oxidized Copper Tubes (DHP) , Copper 99.9% | |||
| Soft Copper as per ASTM B68 | |||
| Hard Copper as per ASTM B75 / ASTM280 / BS 2871 | |||
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Gas Pressure For any Ton Capacity |
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| Refergerent | Suction Pressure (PSI) | Discharge Pressure (PSI) | Standing Pressure (PSI) |
| M/C ON | M/C ON | M/C OFF | |
| R 22 | 60 To 70 | 250To 300 | 156 |
| R 32 | 120 | 490 | 260 |
| R 134A | 35 | 158 To 199 | 95 |
| R 290 | 65 | 275 To 300 | 125 |
| R 404A | 87 | 270 To 356 | 190 |
| R 407C | 63 | 247 To 307 | 153 |
| R 410A | 110 To 120 | 400 To 500 | 250 |
| R 417A | 65 | 261 | 140 |
| Nitrogen Pressure Test |
Vacuum |
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| 3 Minutes | 150 PSI | <= 500 Micron | for 24 Hours |
| 5 Minutes | 325 PSI | ||
| 24 Hours | 500 PSI | ||
| vacuum | < 500 Micron | ||
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System Problems |
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| System Problem | Discharge Line Pressure | Suction Line Pressure | Suction Line Temperature | Compressor Amp |
| Over Gas Charge | High ↑ | High ↑ | Low ↓ (Ice on Suction Pipe) | High ↑ |
| Under Gas Charge | Low ↓ | Low ↓ | High ↑ | Low ↓ |
| Capillary Block | Low ↓ | Low ↓ | High ↑ | Low ↓ |
| Less Air Flow on Evaporator (Indoor Unit) | Low ↓ | Low ↓ | Low ↓ | Low ↓ |
| Less Air Flow on Condenser (Outdoor Unit) | High ↑ | High ↑ | High ↑ | High ↑ |
| Dirty Condenser (Outdoor Unit) | High ↑ | High ↑ | High ↑ | High ↑ |
| Low Ambient Temperature | Low ↓ | Low ↓ | Low ↓ | Low ↓ |
| High Ambient Temperature | High ↑ | High ↑ | High ↑ | High ↑ |
| Insuffient Compressor | Low ↓ | High ↑ | High ↑ | Low ↓ |
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Insulation Thickness |
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| Refrigerant Pipe | Insulation | Drain Pipe | Insulation |
| 22.22mm To 28.58mm | 19mm | 25mm / 32mm /40mm | 6mm |
| 12.7mm To 19.05mm | 13mm / 19mm | ||
| 6.35mm To 9.2mm | 9mm / 13mm | ||
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Referent Pipe Insulation |
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| Pipe | Pipe size | Insulation Type (EPDM or NBR) | |
| Standard conditions 86°F (30°C), < 85% | High humidity conditions(a) 86°F (30°C), >85% | ||
| Liquid Pipe | 1/4″ (6.35 mm) To 3/8″ (9.52 mm) | 3/8″ (9 mm) | 3/8″ (9 mm) |
| 1/2″ (12.70 mm) To 2″ (50.80 mm) | 1/2″ (13 mm) | 1/2″ (13 mm) | |
| Vapor Pipe | 1/4″ (6.35 mm) To 7/8″ (22.23) | 1/2″ (13 mm) | 3/4″ (19 mm) |
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The distance between the supports of the copper pipes. |
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| Diameter | Distance (m) |
| ≤ 20 mm | 1 Meter |
| 20 To 40 mm | 1.5 Meter |
| ≥ 40 mm | 2 Meter |
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The permitted length and drop difference |
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| Pipe length | Max. pipe length | <= 240 Meter |
| Equivalent length from the first branch to the farthest indoor unit | <= 40 Meter | |
| Drop height | Drop height between indoor unit and outdoor unit | <= 110 Meter |
| Drop height between indoor units | <= 30 Meter | |
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Factory Fabricated |
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| Duct Size | Gauge of GI sheet |
| 1 – 900 mm | 26 |
| 901 -1200 mm | 24 |
| 1201 -1800 mm | 22 |
| 1801 – 2100 mm | 20 |
| 2101 – above | 18 |
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Site Fabricated |
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| Duct Size | Gauge of GI sheet |
| Upto 750mm | 24 |
| 750mm- 1500 mm | 22 |
| 1510 mm- 2250 mm | 20 |
| above 2250 mm | 18 |
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Horizontal Ductwork |
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| Ducts Size | Maximum Spacing | |
| Area (m2) | Diameter | |
| less than 0.4 | less than 125 mm | 2.5 Meter |
| 0.4 to 1 | 125 to 1000 mm | 2 Meter |
| more than 1 | more than 1000 mm | 1.2 Meter |
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Vertical Ductwork |
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| Ducts Type | Maximum Spacing (Meter) |
| round | 3.6 Meter |
| rectangular | 3 Meter |
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Rectangular Duct Sheet Thickness as per CPWD |
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| Longest side (mm) | Minimum sheet thickness | |
| Galvanized Sheet Steel (GSS) IS: 277 | For Aluminum IS:737 | |
| 750 mm and below | 0.63mm (22 Gauge) | 0.8mm (20 Gauge) |
| 751 mm to 1500 mm | 0.8mm (20 Gauge) | 1mm (18 Gauge) |
| 1501 mm to 2250 mm | 1mm (18 Gauge) | 1.5 mm (15 Gauge) |
| 2251 mm & above | 1.25mm (16 Gauge) | 1.8 (13 Gauge) |
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Round Duct Sheet Thickness as per CPWD |
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| Longest side (mm) | Minimum sheet thickness | |
| Galvanized Sheet Steel (GSS) IS: 277 | For Aluminum IS:737 | |
| 150 mm to 500 mm | 0.63mm (22 Gauge) | 0.8mm (20 Gauge) |
| 501 mm to 750 mm | 0.8mm (20 Gauge) | 1mm (18 Gauge) |
| 751 mm to 1000 mm | 0.8mm (20 Gauge) | 1mm (18 Gauge) |
| 1001 mm to 1250 mm | 1mm (18 Gauge) | 1.5 mm (15 Gauge) |
| 1251 mm and above | 1.25mm (16 Gauge) | 1.8 (13 Gauge) |
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DUCT Support OR Gripple Wire Support |
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| Duct Size (mm) | Spacing (M) | Size of MS Angle (mm x mm) | Size of Rod Dia (mm) |
| Up to 750 | 2.4 | 32x32x3 | 8 |
| 751 to 1000 | 2 | 40x40x5 | 10 |
| 1000 to 1500 | 2 | 40x40x5 | 10 |
| 1501 to 2250 | 2 | 50x50x6 | 12 |
| 2251 to above | 2 | 50x50x6 | 12 |
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Round Duct Support |
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| Round Duct Size (mm) | Spacing of Supports (m) | Size of M.S. Angle (mm) | Dia. of Hanger Rod (mm) |
| Up to 500 | 1.5 | 40 x 40 x 6 | 12 |
| 501 to 1200 | 1.5 | 40 x 40 x 6 | 12 |
| 1201 to 2250 | 1.5 | 50 x 50 x 6 | 15 |
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Normal Ducting: |
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| Larger duct-dimension | Spacing of Supports (m) | Sheet thickness, SWG (mm) |
| Up to 750 mm | 1.5 To 2 | 2 24 G (0.63 mm) (25×25 GI flanges acceptable) |
| 751 to 1500 mm | 1.5 To 2 | 22 G (0.80 mm) (25x25x3 MS flanges up to 1000mm; 40x40x5 MS flanges beyond 1000mm) |
| 1501 mm to 2250 mm | 1.5 To 2 | 20 G (1.00 mm) (40x40x5 MS flanges) |
| Above 2250 mm | 1.5 To 2 | 18 G (1.20 mm) (50x50x6 MS flanges) |
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Supporting details for Low-Pressure system |
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| LARGER SIDE OF DUCT mm | SUPPORTING ANGLE mm |
VERTICAL ROD DIAMETER mm |
MAXIMUM SPACING BETWEEN SUPPORTS mm |
| Upto 900 | 40x40x6 | 10 | 3000 |
| 901 to 1500 | 50x50x6 | 10 | 3000 |
| 1501 to 2400 | 50x50x6 | 10 | 2400 |
| 2401 and above | 65x65x6 | 12 | 2400 |
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Supporting details for Round Duct |
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| DUCT DIAMETER mm | STRAP | ROD | |||
| No | WIDTH mm | THICKNESS G | No | DIAMETER mm | |
| Upto 600 | 1 | 25 | 22 | 1 | 7 |
| 601 to 900 | 1 | 25 | 20 | 1 | 10 |
| 901 to 1250 | 2 | 25 | 20 | 2 | 10 |
| 1251 t o1500 | 2 | 25 | 18 | 2 | 10 |
| 1501 to 2100 | 2 | 25 | 18 | 2 | 10 |
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Diffuser size |
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| Area | Ceiling Height | Diffuser size(dia.) |
| Up to 12 sqmm | 2.4 – 2.7m | 200mm |
| Up to 12 sqmm | 3m | 250mm |
| Up to 20 sqmm | 2.4m – 2.7m | 250mm |
| Up to 20 sqmm | 3m | 300mm |
| Over 20 sqmm | multiple diffusers | |
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Additional refrigerant charged volume |
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| Liquid pipe Size | R410A (kg/m) |
| 6.4 mm | 0.022 |
| 9.5 mm | 0.057 |
| 12.7 mm | 0.11 |
| 15.9 mm | 0.18 |
| 19.1 mm | 0.26 |
| 22.2 mm | 0.37 |
| 25.4 mm | 0.45 |
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Drain Pipe Capacity |
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| Condensate water volume : V (L/h)=Indoor Unit (HP)x2 | I.D (mm) | Thickness (mm) |
| V ≤ 14 | Φ 25 | 3 |
| 14 ＜ V ≤ 88 | Φ 30 | 3.5 |
| 88 ＜ V ≤ 175 | Φ 40 | 4 |
| 175 ＜ V ≤ 334 | Φ 50 | 4.5 |
| 334 ＜ V | Φ 80 | 6 |
| *If Slop is <1% than select next higher Size of Drain Pipe | ||
JIGNESH PARMAR
Thanks……@Jignesh
It is only like you to help others
Very good
Thanks…….Jignesh
@Jignesh Parmar, found the document really informative. Could you please let me know about the codes or standards that you had followed for the design and data accumulation for AC calculations…
Assalamu alaikum , In AC capacity table it was like 1TON =1200 BTU/Hr. Please correct it brother @Jignesh.Parmar .Thank you
Very useful information for refrigration and air conditioning system