R3250Hz Universal Outdoor Series Technical Manual
141
GD Chigo Heating & Ventilation Equipment Co., Ltd.
4.3 Upwards drainage (drain pump)
For Four-way cassette (compact)
For Round-way cassette
4.4 Convergent drainage
4.4.1. The number of indoor units should be as small as possible to prevent the traverse main
pipe overlong.
4.4.2. Indoor unit with drain pump and indoor unit without drain pump should be in different
drainage system.
4.4.3. Selecting the diameter
Number of connecting indoor units → Calculate drainage volume → Select the diameter
Calculate allowed volume =Total cooling capacity of indoor units(HP)×2 (l/ hr)
Allowed volume(lean 1/50) (l/ hr)
I.D. (mm)
Thick
Hard PVC
∽
≤14
￠
25
3.0
Hard PVC
14
＜∽
≤88
￠
30
3.5
Hard PVC
88
＜∽
≤334
￠
40
4.0
Hard PVC
175
＜∽
≤334
￠
50
4.5
Hard PVC
334
＜∽
￠
80
6.0
