A quality UV light is designed to reduce the growth of select mold (penicilium citrinum and aspergillus niger)1 on or around your indoor cooling coil UV lights are most effective when positioned close to the source inside the coil. This action helps keep them from becoming airborne and recirculating throughout your home, supporting improved indoor air quality. Our Performance UV light systems are available in single-bulb or double-bulb configurations for different coil sizes.