Airedale SmartCool 11-233kW - Manual (Page 21)

Precision Air Conditioning SmartCool
TM
– D
Precision Air Conditioning
21
Installation, Maintenance and Commissioning Manual :6877419 02/2013
Liquid Sub Cooling The degree of liquid sub cooling required to prevent flashing of liquid refrigerant can be calculated by
the following method.
Given the following as an example:
· Refrigerant R410A
· Condensing temperature (54.4°C)
· Liquid lift 20m
· Piping friction loss 0.21 bar
· Losses through valves and fittings 0.5 Bar
1. Determine the pressure drop due to pipe friction = 0.21 Bar
2. Pressure drop due to valves and fittings = 0.5 Bar
3. Pressure loss due to liquid lift = height x 0.115 = 20 x 0.115 = 2.3 bar
Note:- At normal liquid temperatures the static pressure loss due to elevation at the top of a liquid lift
0.115 bar/m
Therefore:- Total pressure loss in liquid line = 3.01bar
Condensing pressure @ Condensing temperature (54.4°C) = 34 Bar
Total pressure loss in liquid line = 3.01 Bar
Nett pressure at Expansion valve = 34 - 3.01 = 30.99 bar
Saturation temperature at the Nett pressure at expansion valve (30.99 bar) = 52°C
(from Refrigerant tables)
Sub cooling required
= Condensing temperature — Saturation temperature at the Nett pressure at expansion valve
= 54.4 - 52 = 2.4 °C
Therefore liquid sub cooling required to prevent liquid flashing = 2.4 °C
Packaged Unit Pre-Charged Refrigerant Volumes
Indoor unit kg / circuit HGRH kg / circuit Indoor unit kg / circuit HGRH kg / circuit
SC19D055-W2W2 5.75 5.90 SC19D033-W2F0 5.68 5.83
SC19D070-W2W2 7.32 7.47 SC19D038-W2F0 7.25 7.40
SC19D080-W2W2 7.32 7.47 SC19D045-W2F0 7.25 7.40
SC25D080-W2W2 8.51 8.70 SC19D064-W2F0 9.60 9.81
SC25D090-W2W2 10.85 11.07 SC19D070-W2F0 9.61 9.81
SC25D100-W2W2 10.85 11.07 SC19D076-W2F0 9.61 9.82
SC31D100-W2W2 12.04 12.30 SC25D045-W2F0 8.44 8.63
SC31D120-W2W2 12.04 12.30 SC25D050-W2F0 10.78 11.00
SC31D130-W2W2 12.04 12.31 SC25D055-W2F0 10.78 11.00
SC19D033-W2C0 5.68 5.83 SC25D067-W2F0 10.79 11.04
SC19D038-W2C0 7.25 7.40 SC25D073-W2F0 10.79 11.04
SC19D045-W2C0 7.25 7.40 SC25D080-W2F0 10.80 11.04
SC19D064-W2C0 9.60 9.81 SC31D055-W2F0 11.96 12.23
SC19D070-W2C0 9.61 9.81 SC31D065-W2F0 11.97 12.23
SC19D076-W2C0 9.61 9.82 SC31D075-W2F0 11.97 12.23
SC25D045-W2C0 8.44 8.63 SC31D077-W2F0 11.97 12.26
SC25D050-W2C0 10.78 11.00 SC31D080-W2F0 11.98 12.27
SC25D055-W2C0 10.78 11.00 SC31D083-W2F0 11.98 12.27
SC25D067-W2C0 10.79 11.04
SC25D073-W2C0 10.79 11.04
SC25D080-W2C0 10.80 11.04
SC31D055-W2C0 11.96 12.23
SC31D065-W2C0 11.97 12.23
SC31D075-W2C0 11.97 12.23
SC31D077-W2C0 11.97 12.26
SC31D080-W2C0 11.98 12.27
SC31D083-W2C0 11.98 12.27
(1)Fitted with optional hot gas re-heat
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