NCC 2016 Volume Three
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Section E Heating, Ventilation and Air Conditioning
Condensate drains and bleed down drains installed in heating, cooling and air-conditioning equipment (including evaporative coolers) other than cooling towers must discharge to any of the following—
an evaporative tray if specified by the manufacturer; or
a sanitary drainage system by way of a tundish or self-sealing device, which complies with either clause 4.6.7.8 or clause 13.21 of AS/NZS 3500.2 ; or
a surface water drainage system; or
an absorption pit, but only if a sanitary or surface water drainage system is not available and the discharge water will not cause damage to buildings or facilities by changing soil moisture conditions; or
a stormwater downpipe directly over the connection to the roof gutter; or
directly to the stormwater downpipe below the connection to the roof gutter provided a means of overflow or reverse flow protection is incorporated.
Drains from a cooling tower must discharge to a sanitary drainage system in accordance with any applicable trade waste agreement.
In this clause, bleed down drain means a drain that collects fluid from a valve used for bleeding and purging; evaporative tray means a tray used to gather excess moisture or condensation for the purpose of evaporation.