DOUBLE-ENDED LIGHTING
an SE globe, DE lamps feature two wires
at either side of the tubular outer glass
that simply and safely fasten into sockets
on a fixture. The internal arc tube on a
DE is generally about 2-in. shorter and
notably thinner than the standard SE
tube. This generates much more light
density from a smaller focal point.
In the hydroponics retail market, there
are a range of DE HPS bulbs available
in 750- and 1,000-W options and
they are priced around 25-50% higher
than a 1,000-W SE. This difference in
pricing is amplified as a customer needs
to ensure they have the appropriate
high-voltage ballast to fire the globe
and a specific DE-capable reflector.
There are a range of high-quality
luminaires that are sold as a complete
fixture with globe, ballast and reflector.
Benefits
With all of these costs, the customer
always asks: “Is it really worth it?”
The answer is a resounding yes.
To justify the upgrade, we have to
understand what makes this technological enhancement so much better for our
lamp exposure, as well as plant growth
and yield. Double-ended bulbs improve
on both the quality and quantity of
the plant-useable light emitted by SE
lamps, and are also more efficient for
10-30% increase in light intensity and
PAR output over traditional SE bulbs.
DE lamps emit more ultraviolet and
infrared light than traditional SE
bulbs, which increases potency
and essential oil production
in select plants.
The DE globe also
has a number of other
design improvements to
increase light output and
quality. With the two sockets
attached to the arc tube, the
DE eliminates the obsolete and
light-degrading wire frame that holds
the arc tube in place in standard SE
globes. The DE also uses quartz for
the outer glass—a superior product to
the borosilicate used in regular HPS
globes—and they are filled with nitrogen instead of xenon or argon, which
improves thermal conductivity.
These upgrades are a significant
improvement for your crop, but the
durability of DE globes is equally
impressive. With the excellent light
maintenance they provide, your lamps
will maintain high-quality outputs for
longer than any other horticultural SE
“DOUBLE-ENDED HPS LAMPS, USED BY COMMERCIAL GROWERS
FOR ABOUT 10 YEARS, HAVE RAPIDLY GROWN IN POPULARITY
WITH HOBBY GROWERS OVER THE PAST FIVE YEARS.”
your light coverage, electricity and
maintenance bills. This is achieved
primarily because the lamps are run
at extremely high frequencies. This
avoids acoustic resonance,
improves optimal output
and maintains output over
time. The resulting reaction provides a more
stable temperature
and operating current.
Ensuring the arc tube
is functioning more
efficiently provides an
improved spectral coverage
and DE lamps generally have a
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Maximum Yield USA | November 2015