Water-Damage-in-Luminaires-Root-Causes-and-Prevention

When a luminaire is illuminated, the air temperature within its sealed cavity rapidly rises, increasing internal pressure. This forces air to escape through sealed surfaces, wire outlets, or gaps in the lamp housing. During rainfall or power outages, the temperature inside the cavity drops sharply, creating negative pressure. Moisture is then drawn into the inner cavity through these gaps. Over repeated cycles, humidity within the cavity accumulates to critical levels, leading to condensation. Additionally, sealing gaskets undergo repeated deformation under pressure differentials, causing fatigue or failure, which may result in direct water penetration into the luminaire.