I went a different direction with mine, I got a piece of 2' long 4" foam core pvc from Lowes and simply screwed a computer fan to the top. I then drilled a few 1" holes near the bottom of the pipe. The fan pulls UP, with a modified thermostat mercury switch to turn the fan off (and in the future a light on) when the lid is opened. Works great in circulating the air.
I bought a 120V fan with plug to use for a blower (link to fan). 3" PVC sits perfectly on top of it. I'm using a 2' section of PVC. I attached the fan to the PVC using ty-wraps. I had some pieces of plastic laying around that I used to make a stand for the fan. Here's the pics of my setup:
I wanted to put a fan in my keezer as well. Wouldn't the moisture be a problem for the electrical fan? Does the fan always stay on, or is there a better way?
My keezer has one of those wire separators that separate the main chamber from the area on top of the hump. I just hung my fan on there with 2 zip ties, blowing sideways. It's better than nothing.
I used a piece of PVC pipe with several holes drill at the bottom and a 45° fitting at the top, then glued a PC cooling fan to that fitting so that it pulls air up through the pipe and directs it at the shanks.
Mine runs with the compressor also, but I like Terd's idea of using a limit switch on the lid. My unit is down for repairs right now, so it's a perfect time to add it!
I have something like this. Will this work good enough if I just set it on top of the compressor hump? Is there a reason everyone seems to use computer fans? Maybe for energy reasons?
Most use pc fans because they're generally inexpensive, run on low voltages, and are sized for the task.
That desk fan would be at least an order of magnitude overkill. Maybe two. And it requires 110vac inside what can become a rather damp (if not outright puddling wet) environment...