My large fermentation chamber on the cheap.

[Katfeesh]

Hmmmm.. I was always told those compressors wouldn't work without the fridge being upright because of the oil inside of them. Old wive's tale maybe?

The fridge is upright it's a mini fridge on the end providing the cooling to a homemade box.

 

[BadDeacon]

Subbed. I recently made an ad hoc ferm chamber from a hurricane Katrina window unit and a cardboard box. I am making plans to build something more permanent, but it's working nicely right now.

Great work btw!!!!!

 

[c3hutson]

Thanks. It's working very well. I've been able to hold a carboy at lager primary temps in the first chamber and ale primary temps in the second. The third is not thermostatically controlled (yet), but I keep things in secondary in there.

Added a heat lamp to the second chamber cause I was actually running into about a degree lower than set point when there was a big difference between the chambers due to the passive air flow through the fans.

 

[retheisen]

Most of the old top freezer bottom fridge units operate on a "hot air rises" principle. The evaporator (cooling element) is in the upper freezer section with a blower passing freezer air over the cooling coil. There is a simple plastic diverter valve that controls how much of the output of the fan travels to the lower warmer refrigerator section and how much stays in the freezer section. There is minimal insulation between the warm and the cool section. And there is also a set of "hot air returns" at the top of the refrigerator section that feed up into the bottom of the freezer section (probably toward the front of the unit). The built in thermostat maintains the temperature of the refrigerator section by cycling the compressor and the freezer temperature is allowed to "float" based on the compressor cycle time and the setting of the plastic diverter near the cooling coil fan.

I suspect that with some clever manipulation of the airflows and some additional insulation a cheap craigslist top and bottom refrigerator could be converted into a two zone fermentation chamber or a combination cold bottle storage at the top and cool fermentation chamber at the bottom.

Get two temperature control units. The "freezer" unit cycles the compressor to maintain your cold serving temp. The "refrigerator" until controls a pair of small dc fans with weighted vanes (like the dryer vents you see on the side of houses sometimes) that pull cold air from the freezer section into the refrigerator section and push warm air from refrigerator into freezer to maintain the fermentation chamber temp. Seal up any unused vents between the two chambers and add some insulation to help maintain the temp differential and I think it could work.

 

[Oddball]

You just gave me a great idea....

I am going to build another compartment on top of my chest freezer to hold a 15 g conical. I was trying to work out how I could turn it upright, remount the compressor etc. so that it would work, but this way I will have a lot more space for a 15 gallon conical (and eventually 2 of them) and still have room for some carboys underneath.

Much appreciated!

 

[c3hutson]

You may have even better luck using insulated PVC off the freezer for a cooling loop to another chamber.