Design, Processing And Installation Of Condensated Drain Pipe - McQuay MDS030AR Applications Manual

4.4 Design, Processing and Installation of Condensated Drain Pipe

4.4.1 Design of Condensated Piping
Size selection of main pipe and vertical pipe of condensated water
Choose the pipe size according to the condensated water flow from the main pipe of indoor unit
and the following table; Suppose the condensated water flow of 1 HP is 2L/h, then the condensated
water flow of 3# 2HP and 2# 3HP is calculated as follows:
2 L/h x 2(HP) x 3(sets) +2L/h x 3(HP) x 2(sets) = 24L/h.
Main horizontal pipe Vs condensated water flow rate
Polyethylene pipe
JIS
VP20
VP25
VP32
VP40
VP50
Note:
Suppose the moisture is 10% in the pipe.
After the header pipe, the pipe should be larger or equal to VP30.
Vertical pipe Vs condensated water flow rate
JIS Polyethylene pipe diameter mm
VP20
VP25
VP30
VP40
VP50
VP65
VP75
Note:
The vertical pipe should be larger than VP30
For example, The condensate pipe of one 2HP
and two 4HP indoor units are connected to a
pipe as shown on the right, and its water drain-
age capacity is:
4L/h + 8L/h
So the horizontal vertical pipe diameter shall be
30 or more, and the diameter of the vertical
diameter shall not be less than that of the hori-
zontal vertical pipe.
allowable flow rate L/h
diameter mm slope
20 39
25 70
31 125
40 247
51 473
allowable flow rate L/h
20
25
31
40
51
67
77
2=20L/h
Design & installation Guide For McQuay MDS Multi System
1/50 slope 1/100
27
50
88
175 Suitable for the header pipe
334
220
410
730
1 440
2 760
Suitable for the header pipe
5 710
8 280
Condensate pipe
group of multiple units
2HP
25
30 or more
4HP
25
Remark
unsuitable for the
header pipe
Remark
unsuitable for
the header pipe
2HP
25
Pipe mouth facing downward
to prevent foreign matters
Air vent pipe
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