Fan in Hood

[Shultz]

I know nothing at all about this, but would fans last longer if they were blowing IN rather than sucking warm salt air through them?

Well all what I know & have read would agree with that, but some people say no? you can get fans that are designed for aquariums (not seen them here in UK) so many those are what they are on about?

Cheers Shelton.

 

[Shultz]

OK, pic....

 

[Gatorfreak]

I posted earlier about using (2) 80mm fans. They are silent but aren't getting the job done. Yesterday was the first run with the lights on for several hours. Tank temp went from 82 to 85 in about 4 hours. The fans were pulling out warm air but not fast enough. The air under the hood was quite warm. I have MH lights.

I have the low speed 80mm Panaflo fans. They move 24 CFM each. At least for my setup, more CFM is needed. Just thought I'd share my experience.

 

[Shultz]

Did you try turning them around & having them blow cooler air into the hood & see whether that makes a difference, in personal experience is a better temp blowing than sucking (Oo-er missus!!)

Cheers Shelton.

 

[Gatorfreak]

Computers have the fans pulling the hot air out. I assumed that must be the best way since they are designed like that. In this application, I can see how blowing into the hood would be better since that air would get blown down onto the surface of the water, increasing evaporation and therefore cooling the water. I may give that a shot just to see what happens.

 

[MarkW19]

Shelton: I'm undecided as where to place my 80mm...

I may cut a hole in the left of the lid, then have the fan on the outside blowing into the lid and out of the other hole at the right.

Or, I can still cut a hole but place the fan INSIDE the lid.

Which would you do?

Is there a certain way round to have the fan btw? Which side should the sticker be on?

 

[Shultz]

Computers have the fans pulling the hot air out. I assumed that must be the best way since they are designed like that. In this application, I can see how blowing into the hood would be better since that air would get blown down onto the surface of the water, increasing evaporation and therefore cooling the water. I may give that a shot just to see what happens.

I have fans both pushing air in & taking air out on my PC, but I do agree its more normal to air being sucked out in that case (no pun intended) I think it is the increased evap that actually makes the blowing in work better on an aquarium? Or it did in my case?

Shelton: I'm undecided as where to place my 80mm...

I may cut a hole in the left of the lid, then have the fan on the outside blowing into the lid and out of the other hole at the right.

Or, I can still cut a hole but place the fan INSIDE the lid.

Which would you do?

Is there a certain way round to have the fan btw? Which side should the sticker be on?

Depends on your lid setup tbh? I have my fans mounted on the back outside as I don't have room on the inside due to having 4 x T5 tubes in there. I put them on the back as I thought it looked neater not seeing them since I can see both ends of my tank?

I also cut to holes in the top of my lid that I have put vent covers over so I can have them open or closed depending on the tank temp, because of the reflectors on the tubes I get no light coming out of these though

Mounting it inside if you have the room should make no difference really, I used a hot glue gun to mount mine.

If you look on one side of the fan there will be 2 arrows, one showing which way around it spins & the other showing the direction of the flow.

I can post a couple of pics if it helps?

Cheers Shelton.

 

[MarkW19]

With the T5 reflectors, do these create more heat inside the lid and therefore make tank temp warmer than it would be without the reflectors?

 

[Shultz]

I would have to guess yes, since they are silver coloured to reflected the light then I presume they reflect heat as well, but I don't think they would make very little difference tbh?

Cheers Shelton.

 

[MarkW19]

I guess just a piece of silver foil would do a similar job?

 

[Shultz]

More than likely, might not be as good as actual reflectors, but having said that alot of peeps just paint the inside white.....

Cheers Shelton.

 

[MarkW19]

Cool, will get a large piece of silver foil then. Will also stop me from getting blinded every time I open the lid

Hopefully it won't affect the water temp. Then again, a large piece of foil above the lights may stop the fan from working as well as it could?

 

[Shultz]

Well for what it will cost it certainly won't hurt to try?

Cheers Shelton.