The T5 fluorescent lamp is currently available in three
designs, all with different application areas.
The T5 fluorescent lamp with maximum luminous efficacy
Available in outputs 14,21,28 and 35W. They have the highest luminous efficacy up
to 104 lm/W. Using these fluorescent
lamps you can normally plan for the most energy efficient luminaire
solutions.
Application
areas are in principle unlimited, but as examples can mention: offices,
department stores, schools hospitals and industry. The Fluorescent lamp can be dimmed and the
service life rate is a full 17.000 hours due to a lower light depreciation
over time.
The T5 fluorescent lamp with maximum luminous output
These are available in outputs 24, 39, 49, 54 and
80W. They have higher luminous output
and are available in the same lengths as above. However, the luminous
efficacy is a little lower. These lamps should be used if you want a lot of light within the same Luminaire lengths. These fluorescent lamps can ideally be used, for example, as indirect lighting, background lighting, within industry and in installations with high ceiling s.
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It is also suitable
to use this type of fluorescent lamp in single lamp luminaires instead of
using fluorescent lamps with maximum luminous efficacy in some twin lamp
luminaires.
Note that these
fluorescent lamps have a higher luminance than T5 fluorescent lamps with
maximum luminous efficacy, which should be considered especially with
luminaires that only provide direct light. They can be dimmed and the service
life rate is 17.000 hours.
T5 circular lamp
The circular T5 fluorescent lamp only really has the lamp
diameter in common with both the straight T5 fluorescent lamps. The circular lamp’s luminous efficacy is
lower,, approx. 83 lm/W and the average rated life is approx. 12.000
hours. Furthermore, the fluorescent
lamp emits its maximum luminous output at approx. 25°C and not as the linear
T5 fluorescent lamps at 35°C
Application areas
for the T5 circular fluorescent lamp are nevertheless immense, as its form is
well suited for aesthetically attractive luminaire designs for surface
mounted and pendant luminaires to name but a few.
The new “design lumen” for use in light calculations for
lighting installations.
The T5 fluorescent lamp was introduced on
to the market at the start of 1995 and is now growing rapidly on the market
thanks to its unique characteristics,
which have been effectively utilized in the development of our T5 luminaires.
An important
advantage is the fact that T5 fluorescent lamp has its maximum luminous
output at approx. 35°C, an ambient temperature that better corresponds with
the conditions that normally prevail inside and interior luminaire. As the manufacturers of light sources have
now chosen to document the T5-fluorescent lamp in the new design lumen this
will also affect the documentation of our luminaire efficiency.
The design lumen,
which is only intended to be used in light calculations will document a lower
luminous from the T5 fluorescent lamp than what we were used to. The reason why the luminous output is lower
is because they wish to document the light source’s luminous output at a
lower ambient temperature (25°C) than where the T5 fluorescent lamp has its
maximum luminous output (35°C) . The calculation luminous outputs, design
lumen, is approx. 10-14% lower from the T5 fluorescent lamp at an ambient
temperature of 25°C than at 35°C
It should be noted
that it is still the same efficient T5 fluorescent lamp, which will document
a lower luminous output at a lower temperature and that the new luminous
output will only be used in lighting calculations.
The introduction
of the design lumen has had the result that we much increase our current
luminaire efficiency values for lighting calculations and these will then be known
as Light Output Ratio working (ηW) values.
The explanation for this is as follows: When performing light measurements from a luminaire, the luminous output is first measured from the fluorescent lamp burning freely in an ambient temperature of 25°C, this is then compared with the luminous output that leaves the luminaire when the fluorescent lamp is installed in the luminaire. As the luminous output from the T5 fluorescent lamp increases when the temperature rises from 25°C to approx. 35°C till now, reduced the measured degree of Light Output Ratio (LOR) by using a correction factor that compensates for the increase that can be maximally obtained from the fluorescent lamp. For this reason our T5 luminaire have up until now been documented with about 5% lower luminaire efficiency. Now that it has been decided to introduce the design lumen (the luminous output that applies 25°C which also applies for light measurements and calibration of the free burning fluorescent lamps) we must replace the correction factors that were previously used – this is so the correct ηW can be documented. |
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