Why is reflector design important?
Reflector design is one of the most critical components of a T5-HO fixture. It has a radical impact on lamp heating, light output, lamp and ballast life, as well as overall efficiency. The reflector should be designed to allow for each individual lamp to have its own individual reflector that separates it from the adjacent lamps. This provides up to 20% more reflector surface than flat reflectors, therefore providing better efficiency and lumen output.
Most importantly, the individual lamp well design eliminates heat transfer from adjacent lamps. The lumen output of the T5-HO is sensitive to bulb wall temperature. The performance of many lamp types is dependent on the bulb wall temperature. This is particularly true for fluorescent lamps, for which both light output and electrical power input–and thus, luminous efficiency–vary with the temperature of the coldest spot on the bulb wall.
The lamp temperature is a function of the heat balance between the lamp and its surroundings. The light output of a fluorescent lamp varies according to the mercury vapor pressure inside the lamp. The coldest spot on the bulb wall controls this pressure. The ballast may start the lamp, but the light output can be very low if the bulb wall temperature is low. A rise in bulb wall temperature beyond its rated operating point will generally result in reduced light output and shortened lamp life.