light heat

[MikeDeL]

Im pretty sure it is the energy the bulb is using that creates the heat, and not the light. Flouresents run cooler the incandesants, so that would lead me to believe its the energy usage creating the heat. Either way you do it you should get cooling. I would think you would get more cooling if there was no glass between the fans and the lights because you would get cooling from evaporation as well as from air circulation.


Mike

[Nano_Steve]

and the evaporation was what i was worried about when designing. since these fans are so high powered i wanted the evaporation to occur in the sump/fuge area and not from the display tank simply because i didnt want saltcreep in the canopy to mess with all the glass covering the mh. i wanted as much light as possible to go through for better efficiency.

thanks for the replies all, youve put my worries to rest, and ill be sure to take lots of pics tomorrow during construction!

-steve

[adaminaustin]

tank canopy
metal halide
fan
glass
water

[Tim Marvin]

Well, if you have them blowing on the water they will evaporative cool, but then you'll get a lot of creep on the glass to clean daily. Above the glass may be a better deal.

[brewercm]

Is your canopy tall enough that you can ditch the glass altogether?

[GaryP]

The purpose of the fans is to move air over the water to help evaporation. A tank works like a big evaporative cooler. Increasing air flow increases evaporation, and thus increase the amount of cooling for the tank. You're not really cooling the bulb or the air, you are simply increasing evaporation.

The hardest time I have with cooling is when the windows are open in the fall and spring and its a little humid. That's because the air is already saturated with water and have less capability to absorb evaporation. Extremely dry air like we have in the winter increases evaporation. Of course air conditioned air is dryer than what's outside.

Gary