Bulb Orientation? metal halides

[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.

I also know I've read this all somewhere (could have sworn it was some of Sanjay's work) but can't for the life of me find it anymore.

[SteveN]

The orientation does make a difference. You need either the VBU or U type lamp. The vbu stab=nds for vertical gase up. The U stands for universal which means any type mounting will work.

[RCS]

Great...any idea how to tell what type a bulb is? Are there a lot of vertical-mount or universal bulbs out there?

[SteveN]

Universal is probably the most common type. With all the pendants around, there are a lot of VBU also. Probably the best thing to do is call the place you plan to order from to clarify which lamp is which before placing the order.