QUOTE(Racer Chris @ Aug 26 2015, 04:51 PM)
I have an even better cooling system planned, one that is good enough to sell with the rack.
I'm currently testing the thermoelectric closed loop cooling system.
The chilling unit I bought is listed as 50W capacity, but I'm actually drawing closer to 150 watts including the controller, transformer, fan, and circulating pump.
First tests were a little disappointing - the lowest temp reached was still above my desired setpoint and the unit was running constantly - but the rack is uninsulated, just protected from air currents. I did install a triple track sliding door with 1/4" birch plywood panels.
I found that by reducing the water flow rate my thermal transfer rate improved and the temp dropped some more.
I added minimal insulation where it was convenient, but still far from what a fully enclosed unit could be.
Now it reaches a lower setpoint (59.5 deg. F) and it holds the bottle temps to about half a degree variation.
The next step will be designing the cooling system to be compact and as an integrated part of the product.
I'm ready to build a fully enclosed rack next, with double glazed panels and a better prototype chiller attached.