best refrigerator

What is the best arrangement for a refrigerator if you want to use it as a fermentation cooler...side by side or freezer on top or freezer on bottom? The one I'm looking at is freezer on top, but I don't know if my wife could use the freezer part (may be the only way I can talk her into the additional expense) while I use the fridge part for temps controllable from 35F to 70F for lagers or cold fermenting ales. I'm worried that if the freezer is going to stay cold enough to keep things frozen, the fridge part would get too cold.

side by side is best for fermentation. I have modified such a fridge and I'm able to lager two cornies in the freezer (measure first) and can store up to 3 carboys in the fridge part.

I have pics here: https://www.homebrewtalk.com/showpost.php?p=59730&postcount=14

Kai

edit:
looks like the image links are broken. TxBrew??

here is a picture of my fermentation/lagering fridge

Kaiser said:

side by side is best for fermentation. I have modified such a fridge and I'm able to lager two cornies in the freezer (measure first) and can store up to 3 carboys in the fridge part.

I have pics here: https://www.homebrewtalk.com/showpost.php?p=59730&postcount=14

Kai

edit:
looks like the image links are broken. TxBrew??

here is a picture of my fermentation/lagering fridge

Click to expand...

That looks nice! I'm jealous... ... but where is Beerdoc's wife going to put her T-bones!?


Beerdoc:

Maybe with whatever fridge you get, you could block off some of the cold air from getting into the fridge. That way your beer wouldn't get too cold and the T-bones wouldn't thaw out? After a little experimenting, it might work.

Anyone else have any ideas?

Lounge Lizard said:

That looks nice! I'm jealous... ... but where is Beerdoc's wife going to put her T-bones!?

Click to expand...

Thanks,

Yeah I forgot about the constraint with the use of the freezer section. But I'd still say that a side-by side might be better (maybe some day you will have a separate freezer) and second you on the fact that some additional modification might be necessary to maintain a very large temp difference between the freezer and the fridge part. This might even be difficult if there is no air moving between fridge and freezer, simply the heat exchange through the wall separating both might be enough.

Kai

Thanks for the cool pics and ideas. What is the usual temp for the refrigerator? My thought would be that it usually runs at around 40F or less?

Beerdoc said:

Thanks for the cool pics and ideas. What is the usual temp for the refrigerator? My thought would be that it usually runs at around 40F or less?

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that is true. If you want to get it higher, you need to mess with the temp control or override it externally. When you override it externally (plugging the fridge into a thermostat) you will loose the ability to control the freezer and fridge temp separately.

Kai

So how do you get separate control of both the fridge and freezer side of your side by side?

PS, I just racked my experiment of simultaneous ale and lager versions of the same recipe brewed. Tasted both and the lager is winning in taste so far, both are at 1.012 from 1.060 OG

Beerdoc said:

PS, I just racked my experiment of simultaneous ale and lager versions of the same recipe brewed. Tasted both and the lager is winning in taste so far, both are at 1.012 from 1.060 OG

Click to expand...

excellent experiment, Doc!

Beerdoc said:

So how do you get separate control of both the fridge and freezer side of your side by side?

Click to expand...

Cheaper models, like that one I used, have the thermostat for the freezer in the fridge compartment and regulate the freezer temp by restricting the flow of air between the freezer and the fridge. Many upscape commercial fridges, however, have a fan that blows cold air from the freezer to the fridge part. That's also what I have done. I added a few fans, which are controlled by a room AC thermostat:



There is also a larger fan on the other side.

Kai

Kaiser said:

Cheaper models, like that one I used, have the thermostat for the freezer in the fridge compartment and regulate the freezer temp by restricting the flow of air between the freezer and the fridge. Many upscape commercial fridges, however, have a fan that blows cold air from the freezer to the fridge part. That's also what I have done. I added a few fans, which are controlled by a room AC thermostat:

There is also a larger fan on the other side.

Kai

Click to expand...

So you use one of those external thermostats? Using this method, do you keep your freezer and fridge part the same temp or is the freezer cooler?

I've got to say, that is a sweet set up. I'm very jealous almost to the point of wanting to find a way to insult you!

God Emporer BillyBrew said:

So you use one of those external thermostats? Using this method, do you keep your freezer and fridge part the same temp or is the freezer cooler?

I've got to say, that is a sweet set up. I'm very jealous almost to the point of wanting to find a way to insult you!

Click to expand...

I feel honored . The only thing you need to be jealous about is having a fridge that is solely dedicated to beer. I can do any modification that I want and don't have to worry about keeping its value.

The freezer part always needs to be colder than the fridge part. Here is what I did:

I moved the compressor controlling thermostat into the freezer:

This will keep the freezer part at a constant temperature. I used a line thermostat for heating/cooling that I was able to adjust to work between -3C .. 6C. There is a little screw in that I could turn to shift the temp range. If you are using an external thermostat, just put the probe into the freezer part.

BTW, I also took out the icemaker part. The motor might be a good motor for building a stirrer for the mash tun in case I ever build a nice brew house.

Now you need a way to control the movement of cold air to the fridge part. Your fridge should already have a hole in the wall separating the freezer from the fridge. At both ends of this hole I added 12V fans:

These fans are controlled by the thermostat in the fridge part. For this you can use a regular low voltage AC thermostat. Watch out for the temp range though. If you want to do lagers, you want to get as low as 7C (~46F) in the fridge part.

One important design parameter to think about is the air-flow difference between "On" and "Off". The greater this difference is, the greater of a temp range you can run in the fridge part. The On air-flow is determined by the strength of the fans (I had to add a large 3rd fan, since the 2 small ones where not good enough) and the size of the hole. The Off air flow is determined by the size of the hole. As you can see, these parameters work somewhat against each other. One thing you could do, is adding some sort of flap on the fan output in the fridge. This flap will be blown open when the fan is on and fall shut when it is off.

Right now my set-up works pretty well, but I haven't tried it in a 80F environment yet. At this point I will see if my fans are strong enough to maintain the 50F that I want in the fridge part.

In order to work correctly, you will also need a significant temp difference between the freezer and the fridge. I always keep the freezer at 0..2C (32..38F) for lagering. I hope that this is enough to keep the fridge at 10C (50F) during the summer.

Kai

Kaiser, Very Impressive.

Beerdoc said:

Kaiser, Very Impressive.

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Thanks,

BTW, controlled movement of cold air is a very powerful means of designing a cooling system for fermentation. All it takes is a cheap PC power supply fan, 12C DC source and a thermostat. On-line I have seen pictures of a design where someone built an insulated fermentation cabinet and is drawing air from his freezer into this cabinet to cool it. The big advantage is, that you are working with low voltage and you can use off-the-shelf AC thermostats.

You can even spend the big bucks and get a digital one. Then you can program a temp schedule into this.

Kai

Has anyone posted instructions or diagrams on how to do the wiring? I'm a left brainer, but my electrical knowledge is lacking.

Beerdoc said:

Has anyone posted instructions or diagrams on how to do the wiring? I'm a left brainer, but my electrical knowledge is lacking.

Click to expand...

look at this:
http://home.elp.rr.com/brewbeer/chiller/chiller.PDF#search='son%2520of%2520fermentation%2520chiller'

Kai