fan question
- Thread starter cjr579
- Start date
broomer5
Active Member
I'll toss in my opinion.
Please realize this is just an opinion. I haven't done any tests to support it.
Our goal is to provide intense lighting for our reef tanks.
The lamps get hot - there's no way to prevent this.
Our concern then is to keep the heated air inside the canopy from heating the water surface.
We know that water evaporating at the surface will cool the water. We know that the water will be heated by the lighting - no matter how the air is moving within the canopy.
The question always comes up "how should the fans be mounted - blowing in or blowing air out" ?
I chose to mount the fans in the top of the canopy - each blowing out and up ~ allowing cooler ambient room temperature air to be drawn into the enclosure ~ past the lamps ~ and drawn up.
It "exhausts" out the top.
Heat rises.
You want to get the hot air inside the hood OUT ~ not just blowing around inside. Forcing air INTO the hood does not help to keep it from reaching the water surface.
It moves the air - but it doesn't move the air up and away from the water surface near as well as having the fan(s) mounted to blow out.
Water's going to evaporate no matter how you have them mounted ~ so there will always be some degree of a water cooling effect. It just seems to make sense to me to keep as much of this warm air from actually reaching the water surface.
If we don't heat the water excessively - we should not have to have excessive evaporation required.
I do think that each canopy design, lamp selection, wattage, ambient room temperature, water circulation and fan placement .... along with other factors will affect each set up.
Especially when dealing with water temperature.
Each of us choose how we do it - and in most cases - we accept our choice and the results. Sometimes we think it's the best way, but as I said earlier ~ I've never tried it with fans blowing in.
I'm sure that works well too - but I think blowing out is a better approach for me.
Please realize this is just an opinion. I haven't done any tests to support it.
Our goal is to provide intense lighting for our reef tanks.
The lamps get hot - there's no way to prevent this.
Our concern then is to keep the heated air inside the canopy from heating the water surface.
We know that water evaporating at the surface will cool the water. We know that the water will be heated by the lighting - no matter how the air is moving within the canopy.
The question always comes up "how should the fans be mounted - blowing in or blowing air out" ?
I chose to mount the fans in the top of the canopy - each blowing out and up ~ allowing cooler ambient room temperature air to be drawn into the enclosure ~ past the lamps ~ and drawn up.
It "exhausts" out the top.
Heat rises.
You want to get the hot air inside the hood OUT ~ not just blowing around inside. Forcing air INTO the hood does not help to keep it from reaching the water surface.
It moves the air - but it doesn't move the air up and away from the water surface near as well as having the fan(s) mounted to blow out.
Water's going to evaporate no matter how you have them mounted ~ so there will always be some degree of a water cooling effect. It just seems to make sense to me to keep as much of this warm air from actually reaching the water surface.
If we don't heat the water excessively - we should not have to have excessive evaporation required.
I do think that each canopy design, lamp selection, wattage, ambient room temperature, water circulation and fan placement .... along with other factors will affect each set up.
Especially when dealing with water temperature.
Each of us choose how we do it - and in most cases - we accept our choice and the results. Sometimes we think it's the best way, but as I said earlier ~ I've never tried it with fans blowing in.
I'm sure that works well too - but I think blowing out is a better approach for me.
flamingkingofhe
Active Member
my tank is set up so 2 blow in and 2 blow out
cosmo
Member
I made a custom canopy and I have 3 250w MH and 2 160w VHO's. I have 2 4" radio Shack (65cfm each) fans and mounted both at one end blowing out. At the other end I cut out a 4"x6" hole that is an intake vent. I covered it with a heating register. The air is pulled all the way across the lighting from end to end. My tank temp goes up 1 degree when the mh's are on. When the mh's are off and the VHO's are on the heaters are sometimes on, I need to change the fans to go on with th MH's. Seems efficient to me. Hope this helps
cosmo
cosmo