Our company builds rather large video walls that are driven by computers next to them. In one of our current project the size of the installation is 21 55" displays side by side in portrait mode and 4 computers. The total heat dissipation would be maximum 8000 W, distributed evenly along the housing. This whole setup is in a standalone, about 15 meters long installation. Both the displays and the computers implement forced heating internally.

The interior decoration company that builds the housing asked the question: How big and what kind of ventilation holes should they plan for?

I was searching the net and found certain solutions and online calculators (https://www.engineersedge.com/heat_transfer/convection.htm), also a related question here on Engineering (How to design a cooling chimney for a computer server?) but these are concerned with surfaces being cooled.

In my case the surfaces are irrelevant -I would think- as all devices have forced cooling, therefore I should care about the warm air they produce and push out of their individual chassis.

Please give me a handle, what is the best approach to calculate the venting hole requirements.

  • $\begingroup$ You need sufficient airflow to keep the equipment within its specified operating range. It sounds like this is not the first wall for the company - what has been done before? Check out heat transfer ie the amount of air to move an amount of heat and consider forced ventilation cf natural... $\endgroup$
    – Solar Mike
    Jul 6 '18 at 5:42
  • $\begingroup$ Yes. Some installations were small to have kW range of dissipation to care about, some had forced air flow with fans, some had built-in air-conditioner. All are special somehow. In heat transfer calculations the speed of the air is a parameter. I have only an estimate of the speed of the self-propelled rising air and this speed also depends on the resistance of the venting holes. Unfortunately forced cooling is not an option with this installation. $\endgroup$
    – PepitoSh
    Jul 6 '18 at 5:58
  • $\begingroup$ make sure you have sufficient depth ie total volume and holes as large as possible if you can't use forced ventilation - but why not have a row of quiet fans halfway up the array and promote airflow that way? $\endgroup$
    – Solar Mike
    Jul 6 '18 at 6:04
  • $\begingroup$ Yes, this was my naive approach as well: have a grill atop of the housing, but there should be inlets at the bottom as well. Maybe. Maybe the depth of the housing is enough to allow the air circulate. I just don't know what would be the solution. The installation is in a museum where noise is a concern, this is why fans should be avoided. But maybe we need them. $\endgroup$
    – PepitoSh
    Jul 6 '18 at 6:13
  • $\begingroup$ for natural ventilation you need holes top and bottom : big hint hot air rises, cold air enters at the lowest point... $\endgroup$
    – Solar Mike
    Jul 6 '18 at 6:16

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