Canopy Fans..Ever considered this??

[Horace]

Have any of you ever considered used a dual window fan to blow some major air into your canopy???? These things are pretty darn quiet too. I imagine you could get 1 or 2 of these in a 48" to blow into the rear of your canopy if it has an open back like mine does. My canopy is about 9 1/2" tall on the inside so I would have a hard time fitting it "inside" but I could mount it to the rear with no problems. For around $60 you could have 4 huge fans and a TON of air movement in your canopy! Here is an example of the fans Im talking about.

http://altura.speedera.net/ccimg.catalogcity.com/200000/209100/209194/products/6097276.jpg

[Horace]

Bueller? Beuller?

[tang_man_montreal]

I saw one of these units at my local Home depot.
The one I saw also had a temp controller bulit in as well.

I'm considering these as well... Curious if anyone has looked into these seriously.

[dannieboiz]

that's a great idea, but what's the footprint of em'? I'm about to finish up my new 18" canopy about to do some holes for some fans but this might be good. Just have it sit in the back of the opening.

[Horace]

Most of them are from about 10" - 12" in height. They also extend quite a ways too so that they accomidate a full windows width. I am thinking you could mount 2 of these to the rear of a 48" tank. 4 8"- 9" fans running is some SERIOUS air flow. I think that might greatly lower the heating problems of some higher wattage systems.

[tang_man_montreal]

Hehe.. Imagine a 72" canopy!

[dannieboiz]

I'm going to HD during lunch. :-) I think with that kind of flow you might have to buy a stronger heater. lolz

[Horace]

I wasnt even planning on getting a heater... I think my lights will keep it plenty warm enough :P.

[tang_man_montreal]

My heater is on at night...
As for the fans, they have a thermostat (at least the one I saw did)... so they only turn on as needed. :)

[gearhead]

interesting idea. i will have to definately look into these for the 125g i'm getting next month.

[dannieboiz]

I think a heater is a definitely needed. The tempt sensor is only for external air not water temp. Right now in my 50g with just 4xpc 55w my tank hoover between 79-82 degrees but when I leave my window open I've watch my tempt drop below 78 degrees with just a 6" fan blowing air into the tank. I went to HD but didn't see this. What section would it be in? Where did you find that picture perhaps you can link it to use so we all can spec it out.

One more issue we might run into is if the CFM is too strong we'll have water flying all over the place. Even with my little 6" fan I notice water splattering when I angle it downward slightly. With such a big fan and the short distance from rear to front (16" inches in my case) the air back firing from the front of the canopy may cause a down draft. If it's really only 10 or 12" sq then maybe 1 set per side might be a better idea. But do you think a push and pull effect or all push would be better?

[ckhorne]

Keep in mind that more CFM doesn't necessarily equate to more cooling. In our case, once the lights are cooled, pushing more air across them isn't going to lower the temp anymore.

For example, say that a light without a fan runs at 200 degrees. Then say with a fan at 50cfm, that light runs at 150 degrees. At 300cfm, it might be 140 degrees. At 10,000 cfm, it might be 135 degrees.

I'm not an thermodynamics engineer, so I have no idea how accurate those numbers actually are. But my point stays the same- with the same temperature air to cool, you're going to reach a limit.

Now evaporative cooling is a different story...

[zatlinrf]

Also, how much space is required behind these between the tank and wall to suck air in?

[Entropy]

If you do end up using one of these units, pay attention to the power usage. Some of these fans can suck major juice. I use a 9 inch 3 speed fan on my setup, but it is way too noisey for a normal setup. My tank is in wall, so you cannot hear it on the viewing side.