IMC 501.3

IMC 307.2 / ASHRAE

CRAH condensate drains must have a P-trap to prevent pressurized under-floor air from blowing back through the drain line. Without a trap, the raised floor plenum pressure will force air through the drain, preventing condensate from draining and potentially causing water damage.

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 / NFPA 110 7.8

Generator exhaust must be routed away from building air intakes to prevent carbon monoxide and diesel particulate from entering the building. Most codes require a minimum separation of 15-25 feet between exhaust discharge and any air intake opening.

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.