AIREDALE R410A - Liquid Subcooling Calculation Method; Pressure Loss and Subcooling Calculation

Installation
Liquid Sub Cooling
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method.
Given the following as an example:
Refrigerant R410A
Condensing temperature (54.4°C) equivalent
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Liquid lift 20m
Piping friction loss 0.21 bar
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Pressure Loss due to Liquid Lift
Note:- At normal liquid temperatures
the static pressure loss due to
elevation at the top of a liquid lift
0.115 bar/m.
Lift = H x spl
Where
H = Height (m)
spl = Static pressure loss
Lift = 20 x 0.115 = 2.3 bar
Total Pressure Loss in Liquid Line
TPL Liquid = Lift + PFL + Valves
Where
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= 0.21 +0.5 + 2.3
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Nett Pressure at Expansion Valve
= Condensing pressure - Total pressure loss in liquid line
Saturation temperature at the nett pressure
at expansion valve (30.99 bar) = 52°C
(from refrigerant tables)
Sub Cooling Required
= Condensing temperature - Saturation temperature
= 34 - 3.01 = 30.99 bar
Subcooling = Condensing temperature — Saturation temperature (Nett pressure at expansion valve)
= 54.4 - 52 = 2.4 °C
Therefore liquid sub cooling required to prevent liquid
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Precision Air Conditioning SmartCool™ 16 - 60
37
SmartCool Technical Manual 7525371 V1.2.0_03_2013
Installation