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I'm building a LED ceiling lamp. The idea is to mix different tones of white to get desired tone.
It will initially have 120W LEDs and maybe more later
It will probably never run at full power but I want to be able to.

It consists of two parts. Upper part where psu and electronics are, and lower part where LEDs are.
The parts are separated by sheet metal.
The dimensions are 1020x620x150
The upper parts height is 50mm
The upper part is sealed from top (by ceiling) and from bottom (by metal sheet)
The upper part will have holes in it.

I want to make the lamp as shallow as possible and for that reason I've come up with this idea for airflow generation:

  • Use large fans to lower noise generation.
  • Turn them on their side.
  • To force air to move in one direction block top on one side of fans, and bottom on other side of fans (images 2, 4)

Would this kind of configuration work or will I have to use small fans at high rpm?

3D overview of ceiling lamp 3D close up of fans 2D schema of ceiling lamp 2D schema of fans

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  • $\begingroup$ what part of your construction do you actually want to cool? the placement of the fans in the middle seems a bit arbitrary $\endgroup$ Commented Feb 26, 2018 at 18:41
  • $\begingroup$ The led-s will heat up the metal sheet so i will be cooling that and the PSU. Fans are in middle as I thought it would give more space for air to come in from the sides. $\endgroup$ Commented Feb 26, 2018 at 18:54
  • $\begingroup$ maybe lining up 40mm or 50mm case fans on two opposite sides would cause a more homogenous airflow and actually move cool air in and warm air out $\endgroup$ Commented Feb 26, 2018 at 18:57
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    $\begingroup$ That's a good idea. Seems so obvious now, don't know why I didn't think of it before. Thanks. $\endgroup$ Commented Feb 26, 2018 at 19:23
  • $\begingroup$ You are starting out the wrong way. Either pick LEDs with the color temperature you want or pick tricolor adjustable LEDs to mix to the tone you want. $\endgroup$ Commented Feb 26, 2018 at 19:50

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No, this will not work well (as I read your plans). You should configure your fans (of any size) to draw air from inside the chassis and expel it outside the chassis. This will require vents on the perimeter of the chassis to allow air in.

No 'blocking' is necessary except that the outflow face of the fan should be sealed around the outflow vent perforations to ensure all air entering the fan is drawn from the chassis.

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  • $\begingroup$ The top and bottom are sealed, and sides will have small holes in them. So if I move the fans from middle to one side it will work better? $\endgroup$ Commented Feb 26, 2018 at 18:33
  • $\begingroup$ I'm not sure if you're describing the fans or the chassis. However, moving the fans to the middle should help ensure even airflow to both sides of the chassis. $\endgroup$ Commented Feb 28, 2018 at 1:36
  • $\begingroup$ Also, I assumed from your drawing that your constraints required the fans to vent through the top of the chassis (opposite the LED array). But, similar to other comments, if you can find fans that will vent through the narrow edge of the plenum and put intake vents on the opposite side (also a narrow edge of the plenum), that would be best. $\endgroup$ Commented Feb 28, 2018 at 12:43
  • $\begingroup$ I'm sorry about the horrible drawing. The application I used was difficult to work with. I should have described it in more detail with words. There are 50mm fans for sure, which is perfect fit. $\endgroup$ Commented Feb 28, 2018 at 12:45

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