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General Category => Equipment and Software => Topic started by: kgs on December 21, 2012, 09:42:53 PM

Title: Small fridge for temp control?
Post by: kgs on December 21, 2012, 09:42:53 PM
I'm reopening my temp-control project, focusing on small-to-medium fridges. (Chest freezers are out -- I don't want to lift items in or out, and I don't have room in my apartment office for a pulley.)  I ferment my beer in 5-gallon buckets or Better Bottles.

Has anyone done this recently?  Costco has a freezerless model that looks promising -- http://www.costco.com/Urban-Islands-Refrigerator.product.11614942.html . I'm thinking there will be sales right before and Christmas that I could pounce on, especially since I'm off next week.
Title: Re: Small fridge for temp control?
Post by: anje on December 23, 2012, 02:54:32 PM
Hmm, that one does look promising.

I keep eying the mini-fridges that keep appearing on Craigslist (university town, so we have considerably more of those than full-size units listed), but they tend to have a compressor taking out a nice chunk at the bottom and are usually too short for a fermenter with an airlock above that point.

Probably obvious, but if you can go to the store, bring along an empty fermenter WITH an airlock (assuming you use one) to see if it fits.
Title: Re: Small fridge for temp control?
Post by: kgs on December 23, 2012, 04:51:16 PM
Yes, traveling with an empty fermenter plus airlock has become my fridge-shopping MO. You are right about the compressor. The freezerless model has one, but because it doesn't have a freezer, it has more height. In theory it will do fine with my fermenters, but I try on clothes before I buy them, too.

The other thing I am doing is watching the sales ads like a hawk for a wine fridge.
Title: Re: Small fridge for temp control?
Post by: 1 atm Brewing on January 07, 2013, 06:44:58 AM
I had trouble finding a fridge that didn't have the compressor in the back bottom corner, they are very common now. I finally decided to buy one of them and find a way to make it work. I bought a 4.4 cu. ft. Magic Chef off of Craigslist. My 7-gallon plastic fermentor fits well vertically in the fridge. There's room for the fermentor & bubble cap plus a few inches. I also brought my fermentor for a fit-check before buying.

I tossed out all of the shelving including the small freezer door. Even though I'll likely never control the fridge to lower than 60F I didn't want the freezer frosting up. The drink racks on the door came off very easily. It's just a plastic shell held on with small Phillips-head screws. The sealing gasket on the perimeter of the door didn't seat well without the door shelving so I glued it back onto the door.

Now the door almost closes, it stops about an inch from fully closed. However since my bucket fermentor has a slight outward taper, there really is enough depth at the base of the fermentor. The interference is at the top where the lid is wider. Right now I just push the door closed and hold it shut with a luggage strap. The fermentor is canted at a small angle when the door is closed but I don't think that has much effect on the fermentation. Next I'm going to try removing a strip of insulation on the door near the lid to free up a little more space for the door to close. I'm also considering cutting a hole in the side of the fridge to run a blow-off tube through when needed.
Title: Re: Small fridge for temp control?
Post by: yugamrap on January 22, 2013, 09:34:04 PM
I was given a small-ish fridge that has a freezer unit in it.  It had enough vertical clearance to ferment in a 7.9-gallon bucket or a 6-gallon carboy - but it wasn't deep enough so the door wouldn't close all the way.  I I removed the door liner that had the shelves on it, but that was still not enough.  So, I removed the entire door assembly and built a wooden "collar" out of 2x10 that extended the depth of the fridge and re-mounted the door.  Then I put the whole works on an inexpensive furniture dolly to help support the collar and make it easy to move around.  It doesn't get cold enough for lagering (I have another fridge for that) but it will ferment a 6-gallon batch of lager or ale just fine.

Title: Re: Small fridge for temp control?
Post by: beerrat on January 23, 2013, 12:47:30 PM
Take a tape measure and check bottom and top clearance before you buy.  It took me a while to find one that I could use without major modifications.

Back in 2011, I bought a Vissani 52-Bottle Wine Cooler at HomeDepot.  It was one of the few small refrigerators/chillers that would fit a 6 gal carboy or a 5 gallon bucket.  It was $200.

Still working out fine.  Easily fits 6 gal glass carboy, or buckets with no modifications.  I use a ranco temp controller with it.  I do primary lager fermentation at 50F with no issues.  I did have to raise the unit off the carpet with some wood blocks for air circulation as it did get hot running in the summer.

You can see the old thread here: http://www.homebrewersassociation.org/forum/index.php?topic=7465.msg119716#msg119716
Title: Re: Small fridge for temp control?
Post by: Phibiche on June 19, 2018, 09:32:54 AM
I apologize for bump an old topic from the dead, just have a few interesting observations from personal experience, maybe someone will need this information in the future
There are some folks out there who have used digital thermostats to control chest freezers, making them operate as a fridge.

You could do the same with your fridge, operating it as a chiller.

Essentially: you need a digi thermostat and a relay. You can set the thermostat to the desired temp and it'll kick off the relay, thus turning the fridge off. When it warms up, it'll close the relay and the fridge will start chilling again.

Should be pretty inexpensive to do. Depending on the thermostat, you could program it to operate differently at night vs. during the day, though I'm not sure why you would want to do that.
I have two old R12 fridges in an unheated garage and there is a noticeable difference in their operation, summer and winter. But it’s nothing I’m concerned about because they are full of beer; but the temperature fluctuations I can tolerate for a bottle of beer may not be suitable for food.
So, you pays your money and you takes your choice.
There’s nothing to stop you putting your fridge in an igloo, if you want to, but it may not work as well as it would in a nice heated kitchen where it was intended to go..
But here are two plausible reasons why a minimum temperature limit is suggested by manufacturers and may affect the operation.
The first will be familiar to split air conditioning engineers as over condensing.
If the condenser is too cold there is a possibility of the refrigerant gaining too much sub-cooling, reduced condenser pressure and reduced flow through the capillary tubes feeding the evaporator. In other words, there will be a reduction in the machine’s capability to do its work. This may result in damage, long term.
Hydrocarbons (R-600 and the like) obey the same laws of thermodynamics as everything else. Their transport properties are selected to be close to the conventional CFC and HFC refrigerants
The second reason will be familiar to people from the old school of refrigeration who worked on butcher’s cold rooms that were often outside the backs of shops in all weathers. It can affect some types of thermostats (not all, just some) where the temperature inside the fridge is warmer than the temperature outside in the winter. If parts of the stat, say its bellows, are mounted on the outside facia, the gas charge inside the stat can condense in the bellows section at low temperatures and cause it to give very erratic control. This is quite rare, but it can happen, even with a domestic fridge. Good luck!