Why are coolers covered with curtains?

Question

Iron

Here, for example, like this:


I remember somewhere I saw a mention that it improves something, but I don’t remember what and how. Tell me, please.

Answer 1

Everything is quite simple - the volume of incoming air \u003d the volume of outgoing air. Thus, by narrowing the outlet, we got a stronger flow of directional air.
And so in the answer from above there was a mention that would direct air to a more necessary part for cooling. what would blow not into the board or wires, but onto the radiator

Answer 2

Dust protection?

Answer 3

usually this is done in power supplies to control the air flow in the right direction

Answer 4

If these "curtains" are conical (funnel-shaped), then this is probably in order to direct air flows to the center of the cooled surface (to the center of the crystal).

Answer 5

rather from foreign objects, he already passes dust through himself.

Answer 6

I had a shutter in the power supply, I put a thermal sensor there - at low loads the temperature is lower with a shutter, at high loads the cooler spins up to full and, apparently, the shutter interferes with the air flow, so when the shutter is removed and under heavy load, the temperature is noticeably lower.