Daikin UWL030B5 - Pipe diameter determination

25
* Determining the diameter of pipes in the air conditioning system
The pipe diameter is determined based on the following:
The water speed should be determined by the recommendations in the rst table and design the water pipe diameters
accordingly, or you can determine the water pipe diameter based on water ow in the second table.
m
w
= water ow m
3
/s
v = water speed m/s
Table 1: Recommended water speed (m/s)
Table 2: Pipe diameter and resistance loss in unit length
Note: Parameters in the preceding table may vary based on the design manual. For details, see the <HVAC Design Manual>.
v
m
d
w
14.3
4
=
Diameter (mm) 12 20 25 32 40 50 65 80
Closed water system 0.4 - 0.5 0.5 - 0.6 0.6 - 0.7 0.7 - 0.9 0.8 - 1.0 0.9 - 1.2 1.1 - 1.4 1.2 - 1.6
Open water system 0.3 - 0.4 0.4 - 0.5 0.5 - 0.6 0.6 - 0.8 0.7 - 0.9 0.9 - 1.0 0.9 - 1.2 1.1 - 1.4
Diameter (mm) 100 125 150 200 250 300 350 400
Closed water system 1.3 - 1.8 1.5 - 2.0 1.6 - 2.2 1.8 - 2.5 1.8 - 2.6 1.9 - 2.9 1.6 - 2.5 1.8 - 2.6
Open water system 1.2 - 1.6 1.4 - 1.8 1.5 - 2.0 1.6 - 2.3 1.7 - 2.4 1.7 - 2.4 1.6 - 2.1 1.8 - 2.3
Diameter of the steel
tube (mm)
Closed water system Open water system
Water ow (m3/h) kPa/100m Water ow (m3/h) kPa/100m
15 0 - 0.5 0 - 60 -- --
20 0.5 - 1.0 10 - 60 -- --
25 1.0 - 2.0 10 - 60 0 - 1.3 0 - 43
32 2.0 - 4.0 10 - 60 1.3 - 2.0 11 - 40
40 4.0 - 6.0 10 - 60 2.0 - 4.0 10 - 40
50 6.0 -11.0 10 - 60 4.0 - 8.0 --
65 11.0 -18.0 10 - 60 8.0 -14.0 --
80 18 - 32 10 - 60 14 - 22 --
100 32 - 65 10 - 60 22 - 45 --
125 65 - 115 10 - 60 45 - 82 10 - 40