Kegerator Cold Box Using a Mini Fridge

I've seen some old posts regarding building an insulated cold box with a mini dorm fridge strapped to the side to provide the cooling. The idea interests me becasue I can build a wing to my bar to house two taps. But I haven't seen enough posts or even any recent posts that makes me feel confident that it'll work.

Here's what I plan on doing. Construct a cold box that's big enough to hold a 1/4 barrel, corny keg and CO2 tank. The box will be insulated with 2" foam insulation. A new mini-fridge with the door removed attached to the side with a cutout equal to the door opening, and a muffin fan to circulate the cold air into the cold box. And another muffin fan and tube to pipe cold air up into the tower. The entire unit will be clad in knotty pine boards to match the bar.

Is the mini-fridge powerful enough to cool down the kegs? And do I simply crank the thermostat all the way up and use a Johnson Controls thermostat on the power plug to manage the temp?

Thanks

I really hope you get some answers here. I'm looking to build a kegerator in a closet and run the tap through the wall into the dining room and haven't seen anything that would really work. A build like this could be perfect for me.

Here's my rough plans on what OI want to build. Ideas? Comments?

From what I've read, with such a small fridge, you'll need to get rid of the heat generated by the compessor running all the time. Wonder if there is some way to just use the guts of the fridge and isolate the compressor outside of the enclosure.

The side where the fridge sits will be open to allow ventilation and removal for servicing if needed. Perhaps I should consider adding a little more headroom above the frisdge and add a muffin fan to blow out the warm air, which would also pull in cooler air nearer the floor.

With regards to running all the time I read one posting on a forum that it's dependent upon the amount of insulation. The mnore insulation the less heat gets into the box, and the less the compressor has to run. But no postings I've read stated any facts. There was on posting that said the 1.7 cf fridge compressor was the same size as the 4.4. cf fridge compressor. I haven't validated that claim.

With regards to tearing it appart, I read one posting were someone did that. It took him two attenpts. He busted a leak in the coil on the firt one and had to start over. As my layout has the compressor outside of the box I don;t think heat from the compressor will be an issue. The biggest advantage of tearing the fridge apart would be space savings. You save the 10"-12" of depth that the fridge compartment takes up. It also can help with better air flow through convection. The cold plate in the fridge is the "freezer" compartment in the corner where the cold air would settle. Adding a muffin fan in the compartment bushes the cold air out int the box and pull the warmer air from the top in. I also plan on having a muffin fan box with a tube running up to the tower to help keep the hoses cold. This would also help with the general air circulation. Finally, I plan on putting a smail pail of DampRid in the compartment to remove moisture that would cause condensation in the cold box. So I'm using up the "floor" space in the fridge.

Another advantage of your idea would be to keep the total enclosure the same size and relocate the CO2 tank outside of the insulated cold box. Mmm.... Do I want to risk blowing $75 I paid for the fridge and try pulling it apart?

BTW, the overall dimension is 2'x4', which makes use of standard dimentions for materials. A simple 2"x4" frame supports 1/8" plywood, which is then clad on the outside with tongue-and-groove knotty pine boards to match the bar. A panel would be cut out of the front between the centers of the two 2"x4"s that define the insulated cold box. Adhesive strips of door gaskets would help keep the warm out. Two slip joint hinges pn the left and sliding bar latches on the right secure the panel. Slip joint hinges would allow the full panel to be removed for easy servicing.

@FantasticBastard, there are several posts on building a walkin coorler. Most use an air conditioner as the cold air source. One of the more complete threads is this one.

billvann said:

I've seen some old posts regarding building an insulated cold box with a mini dorm fridge strapped to the side to provide the cooling. The idea interests me becasue I can build a wing to my bar to house two taps. But I haven't seen enough posts or even any recent posts that makes me feel confident that it'll work.

Here's what I plan on doing. Construct a cold box that's big enough to hold a 1/4 barrel, corny keg and CO2 tank. The box will be insulated with 2" foam insulation. A new mini-fridge with the door removed attached to the side with a cutout equal to the door opening, and a muffin fan to circulate the cold air into the cold box. And another muffin fan and tube to pipe cold air up into the tower. The entire unit will be clad in knotty pine boards to match the bar.

Is the mini-fridge powerful enough to cool down the kegs? And do I simply crank the thermostat all the way up and use a Johnson Controls thermostat on the power plug to manage the temp?

Thanks

Click to expand...

Mini fridge thermostat only goes down to probably 30F and up to 50F. Why would you need an external controller? Most of us use those because we converted freezers that don't go that high.

You need a $5 food service thermometer, a Sharpie, and plenty of patience.

@Thadius856, I thought folks would use the Johnson Controls unit because it's more accurate. And if I were to rip the fridge apart and just stick the cold plate in the box, I would have to either make sure the thermostat can reach the box, or just hard wire it in the on position and use the external control.

I was just wondering this. I have a chest freezer, but it won't fit in my basement (through the door or the opening down the stairs) so it sits unused. A dorm fridge/mini fridge would work if only slightly bigger. Mini fridges can be had for real cheap in college towns.
Does anyone know the difference in electricity used by a mini fridge vs a full sized fridge? With the cost of materials to make it bigger a used full size fridge might be a better use of money.

billvann said:

@Thadius856, I thought folks would use the Johnson Controls unit because it's more accurate. And if I were to rip the fridge apart and just stick the cold plate in the box, I would have to either make sure the thermostat can reach the box, or just hard wire it in the on position and use the external control.

Click to expand...

From what I can tell, most people use them because they don't want to rip the thing open and replace the thermostat. There's nothing that says you can't do that if you have the technical expertise. Many freezer models even appear to have thermostats that can be adjusted to just above freezing using just the coarse adjustment screw.

Edit: For those who use Johnson Controls A419s, most of them chose that model over other controllers because they can be bought pre-wired. They're as big of a shortcut as you can get in the controller world. If you want more accuracy or a pretty display, a LOVE controller seems to be the way to go, but will entail wiring it up.