Section 310.1/Condensate Disposal
UMC 310 covers condensate drain requirements for cooling coils and condensing equipment including traps and secondary drain protection.
Condensate from cooling coils, condensing furnaces, evaporative coolers, and similar equipment must be collected and drained to an approved disposal point. The condensate drain must be trapped with a minimum trap depth equal to the fan static pressure to prevent air from blowing through the drain. Condensate drains must be piped to a floor drain, indirect waste receptor, or the building exterior (not over public walkways). Equipment in attics, on ceilings, or above finished spaces must have a secondary drain pan or a secondary drain connection to prevent water damage from a clogged primary drain.
Why this section exists
Cooling coils generate significant volumes of condensate, especially in humid climates. A clogged condensate drain causes water to overflow the drain pan and damage ceilings, walls, and floors below the equipment. An untrapped drain allows conditioned air to blow out through the drain line, reducing system performance and potentially pulling sewer gases into the air stream. Secondary drain pans and overflow switches provide backup protection that prevents costly water damage.
What plan reviewers look for
Plan reviewers check the mechanical drawings for condensate drain routing from each cooling unit to the disposal point. They verify that traps are shown on the drain line with the trap depth noted. They check for secondary drain pans or secondary drain connections on equipment above finished spaces. They verify the drain terminates at an approved location.