12V fan or 120???? That is the Question

madman

I have my flowering cabinet built. Aft erh llight is hung, there is roughly 36" from the floor to the light when it is fully raised. It is 30" wide and 30" deep inside demensions. Today I hooked up the 2-2ft PLL55w CFL for a total of 4 bulbs. These puppies are really bright, a nice little light for a samll space. They put out some heat and was wondering if my 120mm 12V pc fans (one intake and one exhaust) will keep this cabinet cool enough. I havent received the fans yet, they will be here by the end of the week. Do you think I should just put 2 120V ac 4 inch fans in there instead? How much more electricity will the 120V use over the 12V? I need to double up on some landscaping material to black out the vents and I dont think the 12V fans will push air through the material. Any advice would be appreicated.

Thanks a bunch,


Madman

ISO2BWELL

Hopefully, none of the fans are pushing against the construction cloth...they should be free in the intake and exhaust.

The 12V fans will need a small transformer to be plugged into the 110 outlets. I just went to a thrift store and they usually have a box of them around. Just be sure to pick one that is 12V, and has sufficient amperage for your fan. Cut the connector off the end, and wire it to the two wires on the fan, using wire nuts.

The 12V I have in my drying cabinet can move quite a bit of air...and with just the CFL's in that space it might be sufficient. One blowing in, another drawing out.

ISO

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madman

Thanks ISO, now I am back to the problem about keeping light out of my fan grills. It was suggested that I cover them with landscaping cloth. So back to the drawing board.

Madman

ISO2BWELL

Madman, maybe we're thinking of two different materials. Can you give me a link to what you are talking about for this material?

ISO

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madman

I bought it at Home Depot, it is black material that blocks weeds in your garden. Kinda like a nylon mesh. Come in a 3'x50' roll. I placed it in front of a smaller fan and the air flow was restricted. Dont think them pc fans will push air threw it . What can I use to block the light?

Madman

ISO2BWELL

What I did in my dry closet was make a 12" cardboard "tube", and mount the fan on one end of it with duct tape, then, it went to a screen on the side wall of the closet. Inside the tube are "bulkheads", pieces of cardboard that block 60% of the tube, but mounted on opposing sides. This way, any light will have to wind it's way around the bulkheads...there will be very little (if any) light left when it reaches the fan, and the air can wind around the bulkheads very well.

Be sure to place the bulkheads about 3" - 4" apart in the tube.

I've attached a drawing of a design that should be sufficient. A bit labor intensive to create, but I believe it works fine.

ISO

Attached Images

light blocking tube.jpg (27.8 KB, 12 views)

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jangel

Smart!

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Pappy

Great idea, but if you can place the bulkheads at an angle, it will increase the efficiency of the airflow. With the bulkheads at right angles to the tube's walls, there will be lots of turbulence making the fan work harder and decreasing the volume of air moving through. Just a thought.

Pappy

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ISO2BWELL

Sound wisdom Pappy! Thanks...I never really considered that, as the fan's do OK with the 90 degree baffles...but could be doing much better if they were at odd angles. I'll have to give that design a try.

ISO

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