Contributed by: Uncle Ben
Horizontally oriented lamps are more efficient
for several reasons and should be seriously considered
as the grower shops for a good light solution.
In a horizontal lamp arrangement, the arc tube
that produces the output is oriented with its full
length exposed to the reflective hood insert and plants.
This provides excellent efficiency due to a proper
direct and indirect lighting arrangement.
contrast, a vertically placed lamp/arc tube has the
poles (which don't provide any light) oriented such that
they are facing the plants and the hood, bad deal....
calls for a parabolic type hood to deliver the light to
the plants below. This is very inefficient due to losses
incurred by the light first having to travel the
distance to the inner surface of the parabolic
reflector, and second, by relying on the reflective
properties of the reflector's coating to distribute the
light downward effectively which wont happen. There WILL
be losses. Efficiency takes a big hit with vertically
oriented lamps in parabolic reflectors.
Regarding horizontally oriented reflector
efficiencies - the reflector should be small (for
reasons already stated) and should be well designed with
a gull wing insert which uses a quality baked-on white
enamel designed to resist discoloration from the adverse
affects of heat over time. A much better solution is to
choose a corrosion resistant specular aluminium insert.
The use of quality specular material is the way to go
regarding getting the most from your investment.
Contributed by: Medman
bulbs above 600watts and growing plants taller than
1meter commercial professionals make use of broad side
lighting. The lamps are positioned hanging straight down
between the plants without a reflector.
NOTE: When using any lamp in any orientation it is
always important to prevent heat damage by ensuring
there is ample spacing between the lamp and adjacent
Photo contributed by: Gypsy Nirvana