IMC 501.3 / NFPA 110 7.8

IMC 307.2.2

This is a proper installation. When gravity drainage is not possible, condensate pumps are an accepted solution. The key requirement is the overflow safety switch — if the pump fails, the unit must shut down to prevent water damage. Discharge to a laundry sink is an approved indirect waste receptor.

IMC 401.5

Outdoor air intakes and return air openings must have corrosion-resistant screens (min 1/4" mesh) to prevent entry of birds, rodents, and large debris.

IMC 501.3

Mechanical exhaust must discharge to the outdoors, not into an attic or other concealed space, to avoid dumping moisture and contaminants into the structure.

IMC 501.3.1 / NFPA 110 Section 7.8

IMC Section 501.3.1 requires engine exhaust outlets to be located at least 10 feet from any building opening (door, window, or air intake). In high-rise buildings with rooftop generators, exhaust must be positioned to prevent re-entrainment of diesel exhaust into the building HVAC system. Carbon monoxide and diesel particulate entering the building during a fire emergency creates a secondary life-safety hazard.

IMC 506.3

Kitchen exhaust ducts must be steel (min 16 gauge) or stainless steel. PVC will melt from grease-laden exhaust heat and is a severe fire hazard.

IMC 508

Kitchen exhaust systems require makeup air to replace exhausted air. Without it, the kitchen goes negative pressure causing back-drafting of gas appliances (CO hazard) and door operation issues.