How much ventilation for solar controller?

[Wanderlust]

I am installing extra solar panels and replacing the controller with a Morningstar TS60 (PWM). The existing controller is mounted in a narrow cupboard and I'm thinking this is not a good idea due to poor ventilation. The upgraded system may get up to 45 amps of input.

The Morningstar manual just says it's OK to install it in a ventilated cabinet (which this one isn't). The trouble is there is no good place to mount it that is not ugly or in the way.

Does anyone have experience with how hot the controllers get?

[Andina Marie]

A small circulating fan may be sufficient to distribute the heat over the entire cabinet. There may be an output on the controller or you can get an automatic vent control switch that will only run the fan when the batteries are on charge.

[rebel heart]

I think you're fine with ambient air flow. Use a hole saw to cut a small hole below, and another above, the controller allowing it to vent (if you have a space like that). It will get warm but warm is fine.

If you really want to get fancy you could run a little 12v fan right off the panel side of the controller so it would only spin when there's charging current. But any simple-easy-low-power fan probably isn't ignition protected and probably shouldn't be left for years barely noticed tucked around a corner.

I have ambient airflow for 270w of solar and it's more than adequate, including being in 80f water with 100f+ deck and air temperatures.

[S/V Alchemy]

+1 on the small computer fan idea. It could be as small as the one-inch type found in older laptops. Cut a hole in the bottom of the cabinet and a hole in the top, ideally offset from the bottom hole. The fan goes in the top hole. This will draw ambient air across the unit and will exhaust warmed air out. If you wanted to get clever, you could make an adjacent locker a wet locker or the place you keep towels!

[noelex 77]

It is frustrating that manufacturers don't provide better guidelines for this sort of thing.

The Morningstar TS60 has a generous heat sink for a its rating so I think there is likely to be a reasonably margin.
However keeping electronics cool helps the life considerably.

Passive cooling relies on air convection rising vertically so try and keep the top and bottom reasonable clear. A few inches at least. Simple measures like holes in shelves can help, if the a clearance is marginal.

If you can do this I doubt you will need a fan. Measure the heatsink temp with an IR thermometer during operation to get some idea how the installation is performing. Below 60 deg C is acceptable, but lower is better.

Another option, is to improve the passive cooling by mounting the electronics on some aluminium plate. This needs some thermal coupling to the heatsink to have any effect but with aluminium cased electronics it can occasional provide some addition cooling at low cost, with no power consumption and complete reliability.