Drive temperatures went from a steady 38°C to touching 54°C over four days in late June, which is the sort of number that gets your attention.

The cupboard is a good location for every reason except the physical one. It is central, it is near the incoming line, it is out of the way, and it means the fan noise happens somewhere nobody sits. It is also a sealed box with a door, and the inside of a sealed box ends up at whatever temperature the equipment decides.

First instinct was a bigger fan. This was wrong, and it took an afternoon of moving air around to work out why: there was nowhere for the air to go. A more powerful fan in a closed cupboard is a device for stirring hot air vigorously. The intake and the exhaust were both drawing from and dumping into the same eight cubic feet.

The fix was two vents, not one. A low one on the door and a high one through the side panel into the hall, so cold air is pulled in at the bottom and hot air leaves at the top on its own. Convection does most of it; the existing case fans do the rest.

Steady state is now 36–39°C through the warmest week of the summer, which is better than the original figure, and the fans are quieter because they are no longer fighting.

Two things I would tell anyone putting a machine in a cupboard. Measure before and after, because 'it feels cooler' is not data and you will convince yourself of anything. And think about the path the air takes through the whole space, not about the fan — the fan was never the constraint.

Total cost: two vent grilles and a hole saw.