Passive Cooling Added To Tempeh Incubator

Having used the tempeh incubator that I made just recently, I’ve noticed that the heat collects within the case to the point I need to open it to let out some of the heat off and on during the incubation time after 8 hours.  At that time, the tempeh mixture starts to create heat from the fermentation.  I’m going to guess it’s because of my home being 80 degrees most of the time, however it’s not good to make excuses.

What I ended up doing was setting up a passive cooling setup involving a water pump, vinyl tubing, & miniature radiator, & fan.

Here are links to amazon where I ordered everything

Tubing from water pump (to be connected to reducer, below):
http://www.amazon.com/gp/product/B0046ECL80?psc=1&redirect=true&ref_=oh_aui_detailpage_o00_s00

Reducer to connect the 1/2 inch tubing from the pump to the 5/16 inch tube of the radiator:
http://www.amazon.com/gp/product/B003VAUMX6?psc=1&redirect=true&ref_=oh_aui_detailpage_o01_s00

The fan I use to vent through the radiator:
http://www.amazon.com/gp/product/B00G05A2MU?psc=1&redirect=true&ref_=oh_aui_detailpage_o03_s00

Water pump I’m using (of course anything can be used):
http://www.amazon.com/gp/product/B0012UZYMG?psc=1&redirect=true&ref_=oh_aui_detailpage_o05_s00

Miniature Radiator:
http://www.amazon.com/gp/product/B00CFDS3JA?psc=1&redirect=true&ref_=oh_aui_detailpage_o05_s01

Of course I was haphazard with my choices since I couldn’t find anything else locally.  I gave up and just went amazon, but the ideas are here!

I tested it tonight after installing everything:
Here you see a test setup I used to make sure everything was in good shape.  The pump I attached to the wall in the back, and the hose coming out to the reducer (out of sight near the floor) which connects to 5/16 inch hose to the radiator.  From the radiator, notice the hose leading out, and runs parallel to the hose back into the water to exhaust back into the case.  This setup works the way I like it to work – not overly excessive amounts of heat being removed, but enough that I can keep it on all the time.  The heater I use has enough power to heat the water more than the radiator can remove it.  I have a digital temperature controller thermostat coming in the mail that is 2-stage, and will control the heater & the cooling on separate circuits.  Once the temperature is set, it will turn on the heater once the water is below a certain temp and will turn off once it reaches a max temp.  When the water reaches a certain high temp, it will push power to the water pump & fan which will cool the water.
what I have coming in the mail the beginning of next month is:
http://www.amazon.com/gp/product/B011296704?psc=1&redirect=true&ref_=oh_aui_detailpage_o04_s00

After placing holes in the proper places for the tubing, this is the (almost) final outcome:
Of course I am going to optimize the tube placement, and find a better placement for the radiator/fan setup along with the air pump.

I’m debating on trying a different idea for the cooling using a cooling block instead of a radiator, then attach a peltier cooling unit to that with a CPU heat sink to that.  That would change from a passive cooling to active cooling, and would definitely drop the temperature significantly.  Once the temperature controller comes in, I’ll see if that’s even necessary.