Halide Bulb Orientation

[RCS]

Anyone know if bulb orientation (vertical/horizontal) makes a big difference in either output or bulb life on most bulbs? I have fixtures that utilize a pendant reflector and would orient the bulbs vertically. They're mogul-based bulbs. I've seen some bulbs with specific mounting directions, but most don't seem to have anything at all.

 

[cee]

http://www.advancedaquarist.com/2002/1/review

 

[hawkeye31657]

ok so does anyone in the club have a light tester could you let me know i am thinking of getting one just so i know when i need to replace a bulb and run some test on different bulbs

 

[RCS]

Hey Dave,

I've read that article a few times. My concern isn't the placement of the nipple on the bulb, but the actual orientation of the bulb itself. Most "reef" fixture have the bulb mounted horizontally, but the pendant I'm getting have the bulb vertically mounted, with the base on top and the bulb hanging down. I don't know if there would be any problems with that. Ushio makes "vertical" and "horizontal" mount bulbs, but most other manufacturers don't specify.

 

[cee]

The 2nd and 3rd graphs are direct comparisons for an identical bulb in the two different mounting orientations. Also, there's data there for other bulbs run in a vertical position. All his PAR values are taken at 24", and Sanjay Joshi measures at 18", so you can make a direct comparison. Remember, intensity scales as the inverse of distance from the bulb squared.

Dave

 

[RCS]

So you don't think there would be any adverse effects (shortened life, potential fire hazard, misfiring, etc.) in a vertically-mounted halide?

I hope not, I've got 19 low-bay fixtures coming sometime in the next week! :lol:

 

[cee]

Lifetime may be shortened, since the hottest part of the plasma will be near the ignitor electrodes. Everything else you are concerned about should be no different than in a horizontally-mounted fixture.

 

[RCS]

I can deal with that. Since it's a propagation setup these will be used on, replacing the bulbs in a timely matter should be beneficial. Thanks!