Is a fan *really* needed in a hood?

[Nathan1]

I'm building my own hood out of 1 inch oak. It is 6 foot long with two 400W MH, one 175W MH and two VHO. I will be using a PFO parallel reflector and am planning to have a glass shield (lens) mounted to the hood.

Is a fan really necessary, or can these bulbs survive just fine with heat?? Would a vent be sufficient?

-Nathan

 

[Fatal Morgana]

No fan is needed for the bulb. They don't care much about temperature, in fact, I heard, MH bulb runs better at higher temperature.

If you have heat issue with the hood, you may want to either vent it (open back is one option), or consider putting in fan.

 

[SnowManSnow]

I would think that you would at least leave your hood open back. Reason being not nessissarily for the bulbs, but as how 2 MHs would raise your tank temp.

Just my 2 cents.
B

 

[reefdood]

Helps evaporation which cools the water and also allows for topoff with kalk. My bulbs are noticibly bluer with the fan on than without, as well. Run it to come on with the lights and go off with them too.

 

[Anonymous]

I make the canopy top slats instead of solid, which helps the warm air rise out.

 

[comatose]

if your building your own hood i would still add the fan just in case down the road you find you need it especially in the summer, wire it so you can turn on the fans when you want.

 

[Nathan1]

Thanks for the tips!

-Nathan

 

[Anonymous]

If you haven't used MH before, you may be surprised at the amount of heat they generate. With a well-vented hoot and sufficient height above water, you may get lucky, but I wouldn't bank on it. I would suggest a fan. Or pendants.

My .02 as well.

HD

 

[Unarce]

That's another reason why I like using DE bulbs. 99% of the time, they're encased in a hood (or pendant) and glass. So, you can pretty much place fans anywhere without having them effect the performance of the bulb (and maybe avoid needing a chiller).