the finger test is only useful to a certain degree.
also, it doesn't matter too much wether it has a grille or not. if the mesh is tight, then i will actually force the air to go FASTER, making it COOLER.
the finger test is only useful to a certain degree.
also, it doesn't matter too much wether it has a grille or not. if the mesh is tight, then i will actually force the air to go FASTER, making it COOLER.
The air travelling through the holes may well be faster, but the overall volume/time would be less. I'm sure my open fan on the back pulls out mote air than it would if it had a grille. I don't mean a wire grille, I mean a lot of 2mm holes in a plate.
The guys who design Formula one cars have the right idea about cooling. Draw air in through a small hole into a widening chamber. The loss of pressure as it expands cools it down, then pass it over the radiator more slowly to give it more time to pick up the heat.
If I were really that serious, I ought to measure the temps with no fan, fit the fan but leave the grille and measure again, then cut the grlle and measure again. But I'm not... as it is, they're much cooler, the mess is invisible, and i'm happy with it.