Refrigerant Piping Design And Installation - McQuay MDS030AR Applications Manual

Design & installation Guide For McQuay MDS Multi System
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4.3 Refrigerant Piping Design and Installation

4.3.1 Refrigerant Piping Design ( Including Selection of Refnet Joint )
Capacity combination
The indoor units & outdoor units should have a relationship as follows:
50%
Note:We strongly recommend that the capacity modulation equals to 100%.
Refrigerant piping limit
Piping
Max. length(m)
The length from the first branch to the remotest unit L(m)
Height between indoor
unit and outdoor unit
Height
Height between indoor unit and outdoor unit
Note: the equivalent length is calculated as follows:
One refnet joint equals to 0.5m, one distributor kit equals to 1.0m.
The above table is based on the 8/10HP unit.
Outdoor unit
Refnet of gas side
Refnet of liquid side
Liquid valve Gas valve
L1
D1
D3
D3
Throttle unit
D1
L3
indoor units' cap
outdoor units' cap
Actual length
Actual length
Equivalent length
Outdoor unit is above
Indoor unit is above
Refnet of gas side
Refnet of liquid side
L2
D1
D1
D4
D2 D4
D2
a b
Indoor unit
The max. equivalent length L from the first refnet joint to the indoor unit L
D1 D1
L4
D3
D4 D2 D4 D2
f
e
130%
Allowable value
250m
125m
150m
40m
50m
40m
15m
D4 D2 D4 D2
c d
The max. equivalent length L
D1
L6
L5
D3
D3
D4 D2 D4 D2
g
h
piping section
L +L + L
1 2 i
L +L + L
1 2 i
L +L + L
2 3 i
-
-
-
D4 D2
i