Questions on canopy construction

[steveoutlaw]

I'm getting ready to start construction on my new canopy and have a few questions. I have one set of these fans:

 

http://blueribbonkoi.com/catalog.cfm?catalog_id=247

 

Now the questions:

 

1. Should the canopy be open top?

2. Should I have the fans blowing in or out of the canopy?

3. Do I need 2 sets of fans (one blowing in and one blowing out)?

4. Is it better to put the fans on the side of the canopy blowing (or pulling air) across the top of the tank or is it better to mount them in the top of the canopy blowing down (or pulling air up and out)?

 

Thoughts?

 

Thanks.

[dhoch]

Are they for evaportive cooling? or bulb cooling?

 

What I did is blowing in from the back, closed top, with a gap in the back for air escape...

 

Dave

[ctreptow]

Good questions..

 

I have always had my fans blowing out. I would have 2 holes on one side to let cool air in and have the fans on the opposite side pulling the air through the canopy. I feel the goal is to get the hot air out. As for open top I am moving to a t5 setup and I will consider an open top canopy. Since heat rises I think this will prevent the heat buildup inside. I'm jus not sure about the light leaking out of the top.

 

Chris

 

 

 

I'm getting ready to start construction on my new canopy and have a few questions. I have one set of these fans:

 

http://blueribbonkoi.com/catalog.cfm?catalog_id=247

 

Now the questions:

 

1. Should the canopy be open top?

2. Should I have the fans blowing in or out of the canopy?

3. Do I need 2 sets of fans (one blowing in and one blowing out)?

4. Is it better to put the fans on the side of the canopy blowing (or pulling air) across the top of the tank or is it better to mount them in the top of the canopy blowing down (or pulling air up and out)?

 

Thoughts?

 

Thanks.

[dandy7200]

Fans should blow on the bulbs and across the water. Exhausting pulls moist air right over your endcaps. Put a vent or a small hole that can be covered with eggcrate on the top or back of the hood to allow for evaporation. Also there is a PAR increase with t-5 when fans are being blown on the bulbs.

[steveoutlaw]

I have 3 250w MH and 4 110w VHOs. My goal is to be able to keep a constant temperature in the tank while not letting the MH heat the water too much. I guess the question would be, is it more efficient to cool the tank by removing the hot air from the canopy by having the fans facing out? Or is it more efficient to cool the tank by blowing air across the water for more evap and forcing it out an opening with the fans facing in?

[Norboo]

Heat rises. I would put the fan on the top to push the heat out and one in the back to blow fresh cool air in.

[JMsAquarium]

I have 3 250w MH and 4 110w VHOs. My goal is to be able to keep a constant temperature in the tank while not letting the MH heat the water too much. I guess the question would be, is it more efficient to cool the tank by removing the hot air from the canopy by having the fans facing out? Or is it more efficient to cool the tank by blowing air across the water for more evap and forcing it out an opening with the fans facing in?

 

 

Ideally, both ways. You can put one fan blowing at the water and two extracting the air out of the canopy.

[Scott_LM]

I will add my two sense.

 

Most of the heat added to our tanks is radiated from the bulbs, not do to the temperature difference between air and water. This problem is not significantly solved by removing air from the canopy. The best way to combat this is by providing alternate cooling methods (ie chiller, evaporation, etc). The point here is removing the hot air from the canopy does little to remove heat added to the tank, unless by removing that air you provide greater evaporation. It is much like your car in the summer. Cracking your window or using that new fancy gadget from TV(solar powered fan) will do little to cool your car.

 

Evaporation is the most economical way to cool a tank (within reason), so I always suggest fans blowing onto the water from outside the canopy. Fans blowing directly on water create the most evaporation, plus the positve air pressure forces some that warm air out the canopy. This also gives greater life out of your fans. Blowing fresh air in limits corrosion on the fan itself.

 

It is also important to note, also mentioned above, that some bulbs operate more effiecently at lower temperatures, so blowing air across them is a good idea as well.

 

FWIW....

 

Also, so not to get sued, the uselessness of the Solar powered fan that mounts on the cars window is only my opinion as is everything posted above.

[dandy7200]

Exactly. Bulb heat is radiant. Bulb heating air is convection. Remove the air and you still have radiant. There is no temperature differance in the two just efficiency. Don't waste your power on exhaust. Aim the fans at the water.