1. General information on the Philips T5 VHO
and HO Extreme Temperature system
1.1. Introduction
Philips T5 VHO and HO Extreme Temperature are fluorescent
lamps with a diameter of about 0.63 in with the latest
technologies incorporated. These T5 VHO (Very High Output)
and HO (High Output) Extreme Temperature lamps have
temperature optimized performance and have a high lumen
output in a very broad temperature range (65–170°F). This
performance is achieved by adding an amalgam to the lamp.
Furthermore, two auxiliary amalgams are used for a faster
system run-up.
Philips T5 VHO Extreme Temperature lamps are especially
designed for mid-bay and high-bay applications with typical
mounting heights of 16 feet and above, such as factories, sports
arenas, train stations, warehouses, airports, and many more.
The advantages of fluorescent lighting in these applications are
good light distribution, beam control, instant hot restrike, long
life, dimmability and low maintenance costs. They are also well
suited for compact and indirect lighting fixtures where ambient
temperature is a critical element.
Philips T5 HO Extreme Temperature lamps are especially
designed for cold and warm applications, such as coolers,
outdoor luminaires, unconditioned warehouses, compact
luminaires (e.g. wall washers) or hot factory environments.
The lamps can be used in luminaires where currently the
same types with cold spot technology are used.
Philips T5 VHO and HO Extreme Temperature lamps are
designed for operation with high frequency electronic ballasts
for maximum efficacy.
The Philips T5 Extreme Temperature range consists of
the following types:
T5 VHO 95W Extreme Temperature (46 in)
T5 HO 54W Extreme Temperature (46 in)
They are available in the color temperatures 835 and 841.
Features of Philips T5 VHO and HO Extreme Temperature ranges
The lamps have the following characteristics:
• A high initial lumen output of approximately 7,200 lumens
for the VHO lamps
• A lumen output of more than 90% of the maximum lumen
output between 65°F and 170°F (lamp ambient temperature)
due to amalgam technology
• A fairly constant lumen level during lamp life due to a
tri-phosphor layer in combination with new coating technologies
• Narrow lamp diameter of about 0.63 inches
• Good color rendering (85 CRI)
• Rated average life of 25,000 burning hours at a 3 hr switching cycle
• Rated average life of 35,000 burning hours at a 12 hr switching cycle
• Low mercury
• To secure an optimal and hassle free operation, T5 VHO lamps
have a lamp cap with flattened pins which only fit into Gx5
lamp holders
1.2. Optimum operation of T5 lamps with
amalgam technology
The luminous flux of a low-pressure mercury lamp is determined
by the mercury vapor pressure in the lamp. In an amalgam lamp,
the mercury vapor pressure is determined by the amalgam itself
and not by the coldest spot in the lamp as with regular Philips T5
HE and HO lamps. An amalgam is an alloy of mercury and other
metal(s) and ensures a near-constant mercury pressure over a
wide temperature range. As a result of that, the lumen output is
more than 90% of the maximum lumen output between 65°F
and 170°F.
OEM Design Guide
Philips T5 VHO and HO Extreme Temperature Lamps and Ballasts
3
