Water entry into a building can damage the floor, interior walls, and other interior finishes leading to costly repairs and loss of use of the room or building. Anecdotal observations point to packaged terminal air conditioners (PTAC)—wall-based, in-room heating and cooling units often found in hotels, apartment buildings, healthcare facilities and in some single-family homes—as a path for water to enter a building during wind-driven rain events. IBHS completed a series of tests to understand why this happens and to measure water penetration under simulated high wind and rain conditions.

Different PTAC units were tested at different heights and exposed to different wind speeds. The volume of water penetrating the interior was recorded.