When we talk about the grid behind which the fans are installed, this applies both to the anchoring points of the fans of the box and, for example, to the grid which can have an electrical supply, since in the end its destination is the same: to avoid that one can put the fingers inside and accidentally touch the blades of the fan but by being the least restrictive possible to the passage of the air to favor the cooling. Why is this design so important?
The fan installation grid and its importance
The ventilation grill may seem like a small thing, but in reality you can make a lot of mistakes with it. Sharp edges inevitably cause noise as air passes through them, and distances between holes or rails are very important to performance (in fact, engineers measure the distance and size of these in micrometers). To balance it all out, the engineers themselves have come to conclusions about what is best based on trial and error (like almost everything in science), and we’re talking literally.
Before coming up with the ideal combination of layout, distance, shape and materials to achieve the best airflow performance, engineers spent many hours trying out every possible combination you can imagine, even using wood! drawings!
Air intakes are even more important than vents, and in that regard, they may come as some surprise: why are they so important? But if it’s just a hole through which the air enters! Once again, the air intakes are not simple holes but the result of hundreds of hours of engineer work, testing which method is the one that allows the air to pass better while making less noise.
In the old days, when the air intake was actually just a hole in a box, the air would flow in uncontrollably, and therefore the cooling efficiency was notable for its absence. Nowadays engineers spend months properly channeling the airflow so that it gets exactly where it needs to go (the material that generates heat) and can deploy its magical cooling effect with the best efficiency. Therefore, there are flaps that greatly influence the airflow of the fan installed behind them.
Honeycomb grilles have long been used as the best solution for any type of fan, and it is really a very good solution and above all cheap and easy to manufacture. However, there is another type of ventilation grill that is even more effective at letting air through and making it less noisy, even though they are more expensive to manufacture: rod grilles. These rods are aluminum and cylindrical in shape, so there are no corners where air can “catch” and make noise, and their diameter is such that the air will not hit them either, so the noise generated is minimum and air flow is maximum.
As of now, there aren’t many manufacturers that implement this type of grill for their fans, and in fact, just be quiet! and few others do it but only in specific products such as their power supplies and not in boxes.
Why don’t we see these designs on PC cases?
Almost all PC cases have their honeycomb-shaped grilles, and as we mentioned before, this design is good enough for anyone who doesn’t care about peak performance, being also simple and cheap to manufacture. because they just have to punch the honeycomb shape in the steel of the box itself instead of having to weld or somehow embed those cylindrical aluminum rods.
So the answer to the question is simply due to the manufacturing costs, and that includes not only the cost of the materials but the cost of the time it takes to embed or weld these rods into the steel instead of just stamping it. . No more no less.