I should stop over thinking and complicating it, if I was to put my extractor fan pushing air in my 100mm intake pipe then a few computer fans running of a small transformer in the exhaust duct?
I would pull air out of the box and vent away but have the fan wired so that when you use the compressor the fan runs constantly, that way when the compressor gets up to pressure and shuts off the residual heat is still being removed. I would have the vent outside in summer and inside in winter to make use of it too.
small update to this project. I have since added a bathroom extractor fan to the inlet side of my box. It pushes air into the box. On the exhaust I have 4x 80mm computer fans, I have them running off a 1.5a led driver and move a lot of air for the size. Have not tested with the compressor inside and hot yet but I expect to see good results.
I have also added some different air filters. They are much larger than the standard plastic units with a paper filter inside. I needed to make an adaptor to fit them but over looked the width they added which caused them not to fit in the box hence adding the elbows. These alone have made the compressor noticeably quiter. I have a electronic auto drain as the manauly drain is a bit of a faff to get at when in the box then all problems should be fixed
Have been using the plasma cutter tonight so compressor been worked. It was hot in the garage tonight, with the fans running the box never went over 26 degrees which I think is a great success, fans make barley no noise at all and air filters have made it slightly quiter. Hope my project helps anyone else hoping to do the same
Hi Pondy, I've been reading your post with great interest, as I just got a compressor almost identical to yours and now want to build a soundproof box for it, I've seen a few different designs on the net and I'm going to borrow ideas from all of them. It's to be used for a classic Mini I'm restoring.
I'd be very interested to know what fittings you used for the AirFilters and if possible where you got them from, the fittings and the new filters, as I've been trying to work out what the size is.