Kaysun Mini Amazon III, Engineering Data Book

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Mini Amazon III Series
120
Figure 3-5.5: Drain piping air vents

Air conditioner drain piping should be installed separately from waste, rainwater and other drain piping and should
not come into direct contact with the ground.

Drain piping diameter should be not less than the indoor units’ drain piping connection.

To allow inspection and maintenance, the piping clamps shipped with units should be used to attach drain piping to
indoor units – adhesive should not be used.

Thermal insulation should be added to drain piping to prevent condensation forming. Thermal insulation should
extend all the way to the connection with the indoor unit.

Units with drain pumps should have separate drain piping systems from systems that use natural drainage.
5.2 Water Traps
For indoor units with a high negative pressure differential at the outlet of the
drainage pan, a trap should be fitted to the drain piping to prevent poor drain
-
age and/or water being blown back into the drainage pan. Traps should be ar -
ranged as in Figure 3-5.6. The vertical separation H should be in excess of
50mm. A plug may be fitted to allow cleaning or inspection.
Figure 3-5.6: Drain piping water traps
5.3 Selecting Piping Diameters
Select branch drainage piping (the drain piping connection to each unit)
diameters according to indoor unit flow volume and select main drainage piping diameters according to the combined
flow volume of the upstream indoor units. Use a design assumption of 2 liters of condensate per horsepower per hour. For
example, the combined flow volume of three 2HP units and two 1.5HP units would be calculated as follows:
Combined flow volume = 3 x 2 L/HP/h × 2HP = 18 L/h
+ 2 x 2 L/HP/h × 1.5HP
Tables 3-5.1 and 3-5.2 specify the required piping diameters for horizontal and vertical branch piping and for main piping.
Note that main piping should use PVC40 or larger.
Table 3-5.1: Horizontal drain piping diameters
PVC piping
Nominal diameter
(mm)
Capacity (L/h)
Remarks
Slope 1:50 Slope 1:100
PVC25 25 39 27
Branch piping only
PVC32 32 70 50
PVC40 40 125 88
Branch or main piping PVC50 50 247 175
PVC63 63 473 334