Mist cooler adaptation for terrarium humidifier

This assembly fits on a reptile terrarium fogger/humidifier I bought, to adapt it for office cooling duties. Since (news flash) energy has been a tad higher lately, I've tried to find more economical alternatives to air con. Air con is an absolute essential in the under insulated roof space that is my home office, but, I've actually not run it all summer because of this device.

This was inspired by the appearance of evaporative style coolers which use ultrasonics to generate mist, which is blown at you, it's a fine mist it doesn't make you wet because it evaporates from you immediately… but it hits you, and evaporates, and you're in the draft of the fan, so therefore it has a significant cooling effect.

The thing about the coolers you can buy for this purpose, is they simply aren't serious enough to make more than a small difference, but the concept is good, so I decided to see what I could do if I went really crazy… actually I could have gone a lot crazier, and I'd love it if someone would take this to yet another new level… but this was easy, requiring only a minimum of design effort and a few off the shelf purchases, and it was enough.

Minimally, the adapter is one print, which you can bolt an 80mm fan to and pop on the top of the terrarium fogger/humidifier unit, with an elastic band to make it snug (in the photos you can see I used a wide white band I had which seemed perfect for the job). My USB fan is speed controllable, but I don't think that's too important.

I made 20cm and 10cm extension pipes to go friction fit on the end, useful if you want to stand it the other side of a desk, blowing across the desk at you, but without losing it's way and cooling everything on the back of the desk, but not you so much. Depending on the weight of your fan and the rubber band you use you may or may not be able to achieve 40cm unsupported as I have in my photos.

I printed this in black ABS using variable height layers, the extension pipes need no support, the fan unit does, it's best printed with the square base down, and I used tree support which worked out great.

The terrarium fogger/humidifier was one https://www.amazon.co.uk/Coospider-Terrariums-Humidifier-Reptiles-Amphibians/dp/B081X5VBVD the fan was https://www.amazon.co.uk/gp/product/B06XRCDZDH (or one very like it) and I used 30mm M4 bolts. 35mm would be better, but 30mm is JUST enough for the fan I bought with the grill removed from the side facing inwards, and it is what I had. The holes were made 3.9mm to allow an M4 bolt to tap into the plastic, tighten them sympathetically.

I added a version with a slightly narrower fitting for the terrarium, which allows the existing seal (that comes with one of the terrarium bits) to be removed and reused, it's quite a chunky seal compared to a rubber band so the fitting has to be shrunk a bit for it to still fit with that on instead.