Change Your UV Bulb



Why change my UV lamps when they still light up?

Ultraviolet lamps are comprised of two electrode filaments (the spring looking wire at each end), a glass and quartz combination vacuum tube, several inert gases and approximately 3 mg of mercury (Hg).

These specialty lamps are designed to provide light energy in the germicidal spectrum of 254 nm (nanometer = one billionth of a meter). As they operate, they slowly loose their germicidal effectiveness, about 15% per year. If the UV system is installed for the sole purpose of protecting HVAC equipment such as coils and blowers—surfaces that stay consistently in the range of the UV lamps, then the UV lamps will be effective for about 18,000 hours or two years.

If the primary operation of the UV system is to aid in the reduction of indoor air contamination, then the recommended lamp replacement interval should be one year. This will ensure needed higher energy levels are maintained to aid in the reduction of moving (airborne) microorganisms circulating through the HVAC system.

UV lamps should then be exchanged after a maximum two year installation period for several reasons, including:

The disinfection effectiveness will be significantly compromised and the system will not be able to generate UV-C light as specified. Note that even though a visible blue glow can seen though the system viewport, the glow is not UV light (which is invisible) but actually a by-product of the operation.

If you decide to change your UV Bulb yourself, remember to:

Always protect eyes from ultraviolet light.
NEVER look at UV lamps in operation.
Unplug or disconnect power before re-lamping or servicing.
Severe eye damage or temporary blinding may occur.