How many fans are needed??

[maddmaxx]

I am doin some research into fans for my system. couple questions...

my canopy will have 4x72" VHO actinics with 3x 250w MHs in it. should I go with one or two fans for the canopy. if one. should I have it pulling in air and maybe have a vent on the other end for the air to escape? of if I go with two fans, should one go on each end and act like and intake/exhaust type fan system? also if two would it be smart to place them directly in the middle of the canopy so it blows right across the halides and directly towards the exhaust fan? or stagger them on each end of canopy?

also if my tank is placed flush against the wall, meaning the stand, tank, and canopy flush against the wall, should fans or vents be added to the stand area for air ventilation????

any help would be great, thank u in advance....

 

[maddmaxx]

bump...

 

[Duvallj]

Its hard to slap a number on it.

I like going with computer fans as they are easy to obtain, standardized, and many are ment to run very quiet.
Going with 4fans would probably be a good start. 140mm to 200mm is what I would use. Running them on the lower side would make them silent running. If you need more you can either add more or crank up the voltage.

As for position it sounds like the canopy will be running enclosed? Placing two inputs on either side and two exhaust on the top would be the most efficient. However one side as intake and the other as exhaust would work as well.

If its open back I've ran fans all kinds of ways. In the end I didn't notice much difference, it just seem any airflow helped.

As for stand exhaust, it depends on whats in there. I had a chiller in mine, but the chiller's exhaust went right to two 120mm fans for exhaust. It would very well.

 

[maddmaxx]

The canopy will be an open back. I was thinking of 2x 4" fans. One on each side as an intake exhaust type system... and as far as the stand goes. It will only be the sump. Its a big sump tho. Its a 220g tank wit a 125g sump. So the sump will literally take up the whole stand.. and as far as the type of fans. Not sure about computer fans. I wouldn't kno how to wire them or what to wire them to. I usually just used a fan that I could plug into an outlet...

 

[OCCOFNY]

most computer fans (also called box fans) are 110 volts. They usually have pigtails on them so you will have to do some wiring but that's not difficult. They are quiet and move quite a bit of air. For your stand i think one would be sufficient. As long as there is a place for supply air to enter the stand. For you canopy I would just go with leds, but that's my preference . Good luck with your build, Neil

 

[maddmaxx]

most computer fans (also called box fans) are 110 volts. They usually have pigtails on them so you will have to do some wiring but that's not difficult. They are quiet and move quite a bit of air. For your stand i think one would be sufficient. As long as there is a place for supply air to enter the stand. For you canopy I would just go with leds, but that's my preference . Good luck with your build, Neil

I already have the tank up and running honestly. ill be moving back to my house in new jersey when its finished being renovated after the hurricane last yr. currently I have it inwall in my basement here. but when I return to the house in jersey ill have a stand and canopy for it. so lighting I already have. also I might consider pulling the tank off the wall a lil bit honestly, so there will be access for constant fresh air for the back of the stand and canopy. been doin some thinking.

 

[OCCOFNY]

Actually that's the best approach. Think it through to make the best decision for you. Good luck

 

[grigsy]

Yes, for sure, with that set up you are going to want two fans.

It would be best to position one fan at each opposite end of the fixture.

Face the fans in the same direction. That way, one fan is pulling air into the canopy and one fan is drawing air out of the canopy.

BTW - 3 x 250 watt and 4-72" VHOs = one awesome lighting system. Better than just about anything out there.

 

[moondoggy4]

I ran all my fans in, I had 4 fans in a canopy with dual 175 MH with T-5's.

 

[maddmaxx]

Yes, for sure, with that set up you are going to want two fans.

It would be best to position one fan at each opposite end of the fixture.

Face the fans in the same direction. That way, one fan is pulling air into the canopy and one fan is drawing air out of the canopy.

BTW - 3 x 250 watt and 4-72" VHOs = one awesome lighting system. Better than just about anything out there.

thank you sir. I want to be able to not worry about light for any coral or worry about placement anywhere. I can do as I want inside of the tank

 

[grigsy]

Well then, you have the right light. Metal Halides + VHOs is a great combination for color and growth.

 

[maddmaxx]

I think im gunna pull the tank off of the wall like I mentioned. I am thinking of putting 2 clip on fans on the back of the canopy and let them just oscillate around, with the open back and off the wall, should be fine for air movement. or possibly do the two oscillating fans and just put a vent on each end of the canopy, or possibly just do something like a fan on the ends of the canopy and have it like a run way still, one pulling air into the canopy and one fan pulling air out of the canopy..

the intake/exhaust on each end of the canopy is what I used many times before, but the fans were kinda loud and light spilt out thru the fans, so figured if I put a clip on fan, it will be more silent, hidden, and move much more air then two smaller fans....

grrrrrrrrrr idk....

 

[maddmaxx]

Well then, you have the right light. Metal Halides + VHOs is a great combination for color and growth.

yes I already have the lights, they are on over the tank now..

 

[Duvallj]

Open back canopy should help a lot.
I still vote dc computer fan to an dc. If your not too keen on diy, rapidled has a dc adapter that can hook up two fans to it, $21 plus cost of fans.

You can pick out your own fans, many out there can run pretty much silent.

To mount them I just hit a ziptie with two staples to the hood. Then hooked it around the pc fan through the screw mount hole. They just kind of hanged from top, but arn't heavy and seemed pretty secure.

4 fans across the back, in/out, ect would be hidden and quiet.

 

[vpaul79]

I just put three 4" fans in my canopy blowing air in running two 250W halides. I can tell that after 8 hours the reflectors are barely luck warm to the touch, so I would say one per light

 

[maddmaxx]

Do I need high speed fans or medium speed fans or low speed fans? im guessing if I put one on each end of the canopy that is 72" long im goin to need medium to high speed fans?