HVAC drain system

DRAINAGE SYSTEM FOR HEATING UNIT, ventilation and AIR CONDITIONING (HVAC). The invention relates to a HIVAC drainage system. There is a need for a IiIVAC drainage system that operates well in a vehicle moving on an uneven terrain. A HVAC unit is mounted on a central portion of an inner roof panel on an open air inlet. A collection recess is formed by the panel and surrounding the opening air inlet. concentric walls formed by the internal ceiling panel in recess collection involving IEIVAC unit. Each wall has one or more gaps formed therein. The gaps in adjacent walls are misaligned relative to each other so that fluid can not flow in a straight line through gaps in adjacent walls. Drainage holes are formed in the inner roof panel. drainage grooves formed in the inner ceiling panel communicate the recess collection with corresponding drainage holes.