Where should HVAC UV light be installed near the evaporator coil?

HVAC UV light should be mounted just downstream of the evaporator coil on the supply side, aimed directly at the coil and drain pan so the surfaces stay in constant line of sight. This placement targets the moisture-prone coil area where biofilm tends to grow and keeps the coil cleaner between maintenance visits. The lamp is typically installed inside the supply plenum near the coil face with enough clearance for service access and without shining on wiring or plastic components. On A‑coils, a two-lamp setup can cover both coil faces when one lamp can’t see all fin surfaces. Technicians serving the Denver metro, including Westminster, often see the best results when the bulb is positioned to evenly bathe the coil and pan.

For a clean, effective install, look for:

• A gasketed access panel and viewing port
• A safety interlock that cuts power when the panel opens
• Bulb replacement on the manufacturer’s schedule
• Shielding to protect plastics and wiring

Always shut off HVAC power before opening panels or handling a UV light.

Updated: 2026-10-02

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