MH Mogul Air Cooled Reflector.

[Stpatrick]

I am in the process of putting together my upcoming build and I wanted to figure out a way to cool my canopy and came across this. I plan on running a 250 radium on a m80 ballast over a 60 gallon Solana XL. I am concerned with heat in the enclosed hood. If I can find a quite 6" fan and somehow connect these it should work, right? They use these in grow room to keep the room from over heating.

Ideas?

 

[Stpatrick]

Or this

 

[Stpatrick]

Nobody wants to chime in?

 

[davescrews]

They do work-

 

[fragmatic]

My take is they will work IF you duct that heat out using the round ports. If you use them and do not duct the exhaust out of the canopy you have not removed the BTUs. If you do, you are removing BTU from one of the biggest sources of extra heat in the canopy. It is just simple thermodynamics 101.

If they do not have a fan, then you will want to put a small fan in the ducting. If you are going to use more than one, channel the ducting into a small plenum and draw with one fan. You can get such fans at large electronic super stores or Comp USA. Look for one that says it is quiet.

For a plenum you can use aluminum ducting tape from the hard ware store and the right sized dryer type slinky hose.

This will remove the a large portion of the convection, and conduction heat transfer into the canopy. It will remove a portion of the radiation heat transfer simply because the radiant source will less hot. These are the three heat transfer methods that apply in this case.

If the canopy has some openings around the tank seam, I'd let that be the air input for the fan to draw from. This should help with evaporation, as well as evaporation evacuation, assisting in cooling. But, do keep the air in the canopy moving over the water surface for evaporation with another fan perhaps turned on by a thermostat.

 

[Stpatrick]

Glad to see some input. Thank you. I was thinking I would run the second pendent (second picture) And mount it front to back. On the front of the canopy I was going to cut a 6" radius hole and cover with a grill. The back I was going to do the same but install a 4" or 6" muffin fan pulling air out. Do you think a 110 cfm fan will be enough and do I need a fan to the right or left in the back to push air in?

From what I have read these are used in small grow room and do a great job in removing the heat.

 

[Stpatrick]

And! Some of these pendent use the same type German reflector we use in our hobby. You can buy the pendent in the second picture for as little as 59 dollars. They come with the mogul socket and cord. That seems like a great deal.

 

[fragmatic]

The only reasons I see to for pusher fans is to allow for them to be directed at the water surface. Plus, while pulling the heat with a small fan a pusher fan well help move air by providing a positive pressure inside the canopy. The thing with drawing heat with a fan is, the slower the air movement the warmer the air. Warm air pulls less BTUs because it works on a differential basses. Faster moving air will pull more BTU because it hasn't as much time to get warmed up. I'd go with a larger fan, but a quiet one.

I'd point the exhaust up to gain a little more off the warm air rises concept.

 

[Stpatrick]

The only reasons I see to for pusher fans is to allow for them to be directed at the water surface. Plus, while pulling the heat with a small fan a pusher fan well help move air by providing a positive pressure inside the canopy. The thing with drawing heat with a fan is, the slower the air movement the warmer the air. Warm air pulls less BTUs because it works on a differential basses. Faster moving air will pull more BTU because it hasn't as much time to get warmed up. I'd go with a larger fan, but a quiet one.

I'd point the exhaust up to gain a little more off the warm air rises concept.

Perfect. Do you think pushing are through the pendent vs pulling air out would be more efficient? I am also trying to find some low db fans. Anyone know of any/

 

[fragmatic]

Perfect. Do you think pushing are through the pendent vs pulling air out would be more efficient? I am also trying to find some low db fans. Anyone know of any/

Blowing air directly on the water is better for evaporation cooling. As for the fans check on-line parts vendors for computer desk tops used for high end video editing and gaming. These high end custom built computers with two powerful video cards and state of the art CPUs generate a lot of heat. In those web sites you should find a selection of good fans rated in air volume moved and dB noise for use to cool those desk top cabinets.