Cooling fan install on a hood (96 powerquad or other)

I should have mentioned I have an open top and open back. (lots of ways for air to flow in/out)

Tangster: "...pulling in fresh cool air along the entire rear length of my hoods then all the new cool air falls right onto the water's surface and all the hot air ir removed faster."

You said something about your hood being totally enclosed however and using a 'plenum' to draw the cool air in? This is great I can't wait to get my aquarium hood finished and not so ghetto-looking. I think you need a totally enclosed hood to cut down on evaporation, But w/ an open back, that's not completely enclosed, this plenum thing seems to be something I might need. This way [ <--X ~~~ X--> ] is how the lighting companies design their lights so there must be a big advantage (i.e. gallons of RO water saved). The other way of pointing the fans in one direction instead of outwards is efficient for cooling but accelerates unwanted evaporation of our precious RO/DI water.

Thanks for all your help! DIY is definately the way to go . 8)

 

The evaporation is what you are looking for as it off sets the heat and increase the gas exchange at the waters surface.. Water is not as precious as the corals and fish To me anyways I always leave a coid of about 3 inches above the top rim of the tank and then the entire lengyh of the tank you have to have away for the air to get in there . And to replace the gases ..that are excaping at the waters surface..

 

If you blow inward you blow dust and debris in your lights and half to clean more often I made that mistake and bulbs dont last as long for some reason.

 

i have 4 fans on my diy hood. the 2 on top of the hood pull hot air out since heat rises and stays on 24/7. one in and one out for the sides of the hood set to go on/off with the metal halides. the hood is not sealed, the light fixture is not enclosed and the side holes are bigger than the fans for better circulation. all fans are 4" 65cfm wired to 120v.

 

This is a non-factor because you are either goign to blow dust in or suck it in... Either way it is going to get into the housing....