Best way to use fans to reduce Metal halide heat?

[jamirlima]

To reduce heat from metal halide besides chiller people use small fans in the canopy or clip on fans.

Which is more effective to cool the tank temperature? blowing the air on the surface of the water or air blowing towards the metal halide bulbs?

Would an exhaust fan on the back of the tank facing outside the tank work too?

Thanks

[rytrearc]

What works for me is a fan on either side of the fixture so air is constantly renewed. Plus a fan blowing over the sump.

[jamirlima]

<a href=showthread.php?s=&postid=14538835#post14538835 target=_blank>Originally posted</a> by rytrearc
What works for me is a fan on either side of the fixture so air is constantly renewed. Plus a fan blowing over the sump.

Either side of the fixture? so the fan would be hanging on both side of the reflector under the canopy?

[matt210G]

I too am looking for this answer ? I have two 12v fans to install into my canopy. Should the fans suck cool air into the canopy from the room or blow warm air out of the canopy into the room ? Perhaps a combination of both ? Any thoughts ? I am using 3 x 400w HQI ??

[Padrino]

i am installing 4 12 V dc fans right above my reurn section in my sump. This will aid with evaporation process and help cool my tank

[Padrino]

oh good water circulation really helps with this!

[matt210G]

is cooling the MH bulbs uneccessary ? The heat build up in my canopy is very high !! 3 x 400w HQI's. Withe cost of the bulbs I would like to maximize there life span and also diminish a little bit of DT evaporation ?

[Jsin]

I have two fans on both ends of my canopy. All four fans are blowing into the canopy. I tryed one side blowing in and the other out to create a draft across the lights but the back of my conopy is open. I found that the fans worked better for cooling the way I have it now both end blowing into the canopy, this forces the hot air up and out the cracks in the top and the back. Just my 2 cents

[moondoggy4]

I 2nd Jsin

[Padrino]

yes that would be good. i have a hanging fixture no canopy so thats why i mentioned the sump good work!

[Toddrtrex]

All of my MH light fixtures have built in fans into them (( they are all full fixtures )). Without clip-on fans over the sumps I wouldn't be able to keep the temps in check. Still shocked how much heat can be removed just from their use.

[NanoReefWanabe]

your fans should always blow in....into your lights, into your canopy, into your sump, into your stand, etc...the forced air will escape somewhere...

you also wont have saltcreep issues killing your sensitive 12V fans by sucking moist warm air out...