Fermentation Chamber from Beverage Fridge

[djonesax]

So, I picked up this glass door fridge to be used as a fermentation chamber.

The way I see it I have two simple options for quick temp control.

1. Use the current thermostat and make a note of the ambient air temperature at each position on the dial.

2. It looks like it would be pretty simple to swap out the current thermostat for an STC-1000 but I wanted to ask the experts since I have never done it before.

Ideas?

Thanks,

David

 

[grrickar]

I have a wine fridge and the thermostat is stuck - meaning it runs all the time. With it on utility power it will freeze 5 gallons of beer in about 3 days. I bought an STC1000+ and put the fridge into it, and it maintains temps well. The issue I have now is the unheated part of my basement this time of year is colder than I want to use for fermenting (perfect for lagering though!) so I need a heat wrap to provide warmth. I plan to get some from the pet store next time I am in town...

 

[djonesax]

so I need a heat wrap to provide warmth. I plan to get some from the pet store next time I am in town...

I had a question about the heat. I ferment in a room that never gets above 70 and wonder if I really need a heat source. I suppose if I were stepping up the temp for a diactyl rest, it would raise the temp faster than waiting for the fridge to warm up but I wonder if its really worth it in my situation.

David

 

[SmokeyMcBong]

O.P., no need to swap out the thermostat. Just wire the stc to two plugs, one hot and one cold. Plug the fridge into the cold plug and attach the stc's probe to your fermenter. The stc will cut the fridge in and out as necessary. I wouldn't go the ambient temp route. Also, I don't run a heat source in my ferment fridge. The room its in is warmer then I'll ever need to ferment anything...

 

[grrickar]

I had a question about the heat. I ferment in a room that never gets above 70 and wonder if I really need a heat source. I suppose if I were stepping up the temp for a diactyl rest, it would raise the temp faster than waiting for the fridge to warm up but I wonder if its really worth it in my situation.

David

Yeast generate heat as they work through the fermentation process. A 70 degree room with a 5 gallon fermenter going full bore could be 74 degrees or better inside.

I prefer to ferment in the mid 60s with most yeasts, and they finish cleaner that way. Try fermenting some hot and taste the difference. The key to good beer (IMO) is control of the fermentation temp.

Remember brewers make wort, yeast make the beer...

 

[djonesax]

I guess "swap out" wasn't the correct choice of words. Bypass the thermostat is more accurate. The thermostat looks to be inline so there it's really only acting like a basic switch. I guess if I wanted to use he stc-1000 in-place of the thermostat I'd have to run separate power to the stc-1000 and then move the the leads from the thermostat to the cold relay connections on the stc-1000?

I was trying to do this in a way that would leave the existing wiring to the compressor intact and allow me to mount the temperature controller inside the fridge. Otherwise, I'd probably just buy a Johnson control and be done with it.

 

[djonesax]

Final product... I have done done basic testing and it works and cools very fast.

 

[aouellette86]

nice work, im currently doing the same on a true gdm-12

 

[djonesax]

Cool, these fridges are the perfect fit for larger fermenters and very easy to modify.

 

[jackyl]

nice work, im currently doing the same on a true gdm-12

I have a GDM 12 and it is trivial. The compressor at the bottom has a standard plug, so you just insert your temp controller there and then the evap coil fan runs all the time, and will actually heat your fridge too.

 

[djonesax]

the evap coil fan runs all the time, and will actually heat your fridge too.

I wired mine so that the fan stops with the compressor since the only job of the fan at that point is to move the air around to provide an average temperature for the thermostat. I figured since my probe was being directly attached to the fermenter, I didn't need to worry about it. Besides it was going in an entertainment room and I wanted it as quiet as possible. Its a dual phase controller and I prewired it for a heat source if I decide I want one.

David

 

[aouellette86]

I wired mine so that the fan stops with the compressor since the only job of the fan at that point is to move the air around to provide an average temperature for the thermostat. I figured since my probe was being directly attached to the fermenter, I didn't need to worry about it. Besides it was going in an entertainment room and I wanted it as quiet as possible. Its a dual phase controller and I prewired it for a heat source if I decide I want one.

David

thats my plan as well, ill just wire in the evap fan with the cooling output on the thermostat, no need to have the fan running at all times

 

[jackyl]

I'm pretty sure you need it to run more often than that to prevent the evap coils from building up ice. At least, I read that in my research but never tested it with the cover off to see.

 

[djonesax]

I'm pretty sure you need it to run more often than that to prevent the evap coils from building up ice. At least, I read that in my research but never tested it with the cover off to see.

I thought about that but most of the time the fridge wont run long enough to ice over. If it becomes a problem, it will be an easy fix.

David

 

[jackyl]

I don't know a ton about this yet, so of course do what you want. But here's the profile of a cold crash with one 11g fermenter and two better bottles cold crashing in my GDM-12.

The blue dark blue horizontal bars are the compressor running, the light blue is mandatory wait time to prevent short-cycling. Do you trust the fan running only when the compressor is to keep those evaporator coils free of ice? Also what about temperature stratification?

I get the noise issue and the BrewPi/True are going through their first lager cycle in this graph, but there's no way I risk the compressor given that run profile in the crash.


Edit: original image didn't have time scale on it

 

[djonesax]

I don't know a ton about this yet, so of course do what you want. But here's the profile of a cold crash with one 11g fermenter and two better bottles cold crashing in my GDM-12.

The blue dark blue horizontal bars are the compressor running, the light blue is mandatory wait time to prevent short-cycling. Do you trust the fan running only when the compressor is to keep those evaporator coils free of ice? Also what about temperature stratification?

I get the noise issue and the BrewPi/True are going through their first lager cycle in this graph, but there's no way I risk the compressor given that run profile in the crash.

I have been thinking a lot about this reply, sorry for the slow response. I have not used my fridge yet but was planning to brew this weekend. How has yours been working? Once it gets down to cold crash temps, how often is your compressor kicking on and how long does it take to get the beer down to temp? I'm not so worried about stratification since the probe will be attached to the fermenter and the fan will move the air wile the compressor is on. I am worried about ice as you mentioned though.

Thanks,

David

 

[actech]

I could be wrong, its happened before. lol But if you are keeping this in temps above freezing I cannot see how it will ice up. Most domestic fridges defrost either every 24 hrs or more common every 8hr of compressor run time. This is keeping a freezer compartment at 0. The evaporator is in the freezer and the diverter controls cold air down to fridge to cycle the thermostat. If the evap is never maintained at below freezing temperatures, I cant see it building enough ice to stay in an off cycle. Does this fridge only device even reach freezing temps in evap? does it have factory defrost ability? If not frost is not a worry

 

[jackyl]

I have been thinking a lot about this reply, sorry for the slow response. I have not used my fridge yet but was planning to brew this weekend. How has yours been working? Once it gets down to cold crash temps, how often is your compressor kicking on and how long does it take to get the beer down to temp? I'm not so worried about stratification since the probe will be attached to the fermenter and the fan will move the air wile the compressor is on. I am worried about ice as you mentioned though.

Thanks,

David

It's been working well. It kicks on roughly every 30 minutes for 3 minutes (mandatory BrewPi min run time - of that 3 minutes, only about 1 is necessary) at a time, although I think that's in part due to the fact that I didn't insulate teh temp probe on the fermenter. My next batch, I'll do that and probably see a longer idle time.

I could be wrong, its happened before. lol But if you are keeping this in temps above freezing I cannot see how it will ice up. Most domestic fridges defrost either every 24 hrs or more common every 8hr of compressor run time. This is keeping a freezer compartment at 0. The evaporator is in the freezer and the diverter controls cold air down to fridge to cycle the thermostat. If the evap is never maintained at below freezing temperatures, I cant see it building enough ice to stay in an off cycle. Does this fridge only device even reach freezing temps in evap? does it have factory defrost ability? If not frost is not a worry

See that's the thing. These are not domestic fridges and do not have a freezer, diverter, or home fridge defrost heat wire - the combo evaporator coil / air circulation fan moving above-freezing air over the coils is the defrost, and the evaporator coil does get below freezing when it runs. So now you have no defrost cycle when it is not running if you set it up so the fan only runs during cooling cycles.

It would be a cool feature to have the control fan power independent of compressor power, so you could do something like run it for 10 minutes (or whatever) longer than the compressor, but I don't think any temp controller out there does that right now.

Anyway I dont know what the right answer is, but I'd recommend watching your coils for a while if you decide to cycle the whole thing.

 

[actech]

"It would be a cool feature to have the control fan power independent of compressor power, so you could do something like run it for 10 minutes (or whatever) longer than the compressor, but I don't think any temp controller out there does that right now."

"Delay on break " time delay relay would make that work. Could be interesting to wire in though.

 

[djonesax]

"Delay on break " time delay relay would make that work. Could be interesting to wire in though.

This sounds very cool. I found this article with more information on these types relays.

http://www.macromatic.com/blog/understanding-time-delay-relay-functions/

It looks like this relay might work but I am not sure about the amperage, since this unit has a max load of 1.5 amps. I would imagine the fan would not draw that much accept maybe at start up.

http://www.amazon.com/ICM-Controls-ICM206-Delay-
Timers/dp/B009PAWXEM/ref=sr_1_1?ie=UTF8&qid=1433008614&sr=8-1&keywords=delay+on+break

The main power would run directly to this relay, and the the power from the STC-1000 would be used as the trigger to activate the relay and open the switch. Once the STC-1000 switches off the power, the delay on break function would hold power to the fan until the time delay has completed.

Do that sound right?

David

 

[djonesax]

I spoke to a lady at DigiKey and she didnt have a comparable component for the price but she thinks the part I pasted from amazon would work fine. I am going to order one and try it.

David

 

[djonesax]

Further down the rabbit hole I go... I am now not so sure the ICM will work after reading the spec sheet.

Macromatic's website defines Delay on Break as this
"Upon application of input voltage, the time delay relay is ready to accept a trigger. When the trigger is applied, the output is energized. Upon removal of the trigger, the time delay (t) begins. At the end of the time delay (t), the output is de-energized. Any application of the trigger during the time delay will reset the time delay (t) and the output remains energized."

The ICM Controls website say something opposite.
"MODE OF OPERATION
With application of power, the load is energized. When the thermostat opens or there is a loss of power, the load is de-energized and the delay period begins. The compressor will not start again during the delay period. ICM Models 204/205/206 provide true thermostat interruption protection"

 

[actech]

Yes thats right and fan amps should be very minimal.

 

[rodduley]

Subbed, anxious to see how this turns out. I have a GDM 26 and am in the process of building a fermentation chamber also.

 

[actech]

http://www.mjbcontrols.com.au/node/22
This is the type relay I was talking about but for some reason not finding one thru a us supplier. Most others want to use low voltage to control another circuit. This one uses the high voltage to keep fan running up to 10 minutes after switch goes off.

 

[djonesax]

http://www.mjbcontrols.com.au/node/22
This is the type relay I was talking about but for some reason not finding one thru a us supplier. Most others want to use low voltage to control another circuit. This one uses the high voltage to keep fan running up to 10 minutes after switch goes off.

I think I found one but it only delays 390 seconds versus 600. The keyword to look for seems to be "OFF delay on break".

http://www.icmcontrols.com/Postpurg...justable-12390second-time-delay-Prodview.html


http://www.supplyhouse.com/ICM-Cont...Delay-on-Break-12-390-Second-Adjustable-Delay

I went ahead and ordered one, if it doesn't work I'm out 20 bucks.

David

 

[actech]

Only problem with that one is it needs 24v to operate the timing where the other runs on line voltage

 

[djonesax]

Crap, I didn't even notice that.

I found this but its kind of expensive.

http://www.grainger.com/product/DAYTON-Encapsulated-Timer-Relay-6A859?functionCode=P2IDP2PCP

David

 

[actech]

http://www.airotronics.com/site/product-delaybreak_TGMB.php
not sure how much or where to get.
everything else I find is low voltage. Can't find where to order the one from Australia either just info on it.

 

[djonesax]

This has become a mission for me...

This is rated for 110v and 1A but a fixed 20 Min Off-Delay which may be defeat the purpose when not cold crashing. $21

http://www.digikey.com/product-search/en?mpart=QCS20M110AL&vendor=966

Here is the spec sheet. Page 2 Function C is the delay on break function.

David

 

[jackyl]

20 minutes is probably fine, remember I didn't insulate my fermenter probe so it was at least half exposed to fridge air. I'm doing another one in the next week or so and will actually insulate that probe so I bet it runs a lot less.

 

[djonesax]

This part has a 6 week lead time... I have looked everywhere and this is the only thing I have found for under $100. I found the Airtronics timer but I cant buy just one.

At this point I am thinking maybe I'll just wire in a second thermostat to kick the fan on when the temps get below 45-50 degrees. That way I will only have to listen to the fan contantly while cold crashing. Just waiting to hear back from a couple people that know electrical better than me to confirm that this will work and be safe.

David

 

[actech]

I haven't been able to find one of these relays at local wholesale house. So I just took the old fridge I had and wired it with evap fan on constant and rest running with stc1000. Removed the separation between fridge and freezer,eliminated all excess wiring.IE stat,timer,light,ice maker wiring, mullion heater. (Mullion heater) I need to see if it will work as a heater if needed

 

[djonesax]

I haven't done a real test on mine yet, so I think I will cold crash 10 gallons of water and see what happens. If the coils don't freeze over I'll leave it as is. If they do freeze I'll supply the fan with power from an addition hidden stc-1000 so that fan runs constantly when below say 45 degrees. I have put off brewing until I have better temp control since I had inconsistent results. I think I'm making a bigger deal out of this than I should at this point and just need to get it done and get back to brewing.

David

 

[djonesax]

So last night I did my first test and cooled 10 gallons from 87 degrees to 65 degrees in a few hours. The compressor ran non-stop and evaporator fins did get a little ice/frost on them, since the temp in the chamber got into the 20's before the fermenter eventually reached 65 degrees. The fins defrosted fine after the fermenter temp was reached and the ambient temps balanced out. This isn't really typical for fermentation since it would go into the chamber at close to 65'ish anyway. I'm not worried about this at all.

During the cold crash, when the ambient temp gets into the 20's and the final fermenter temp is just above freezing, it might take much longer for the coil to defrost. I'm thinking maybe it would be better to put the probe in a bowl of water during the cold crash so that the ambient temps wont have to get so low since the water will cool faster than the 10 gallons of beer. The water temperature would rise and fall until an equilibrium was reached between it and the fermenter but it would hopefuly keep the fins from icing over.

I got the thinking this is similar to the way it worked when I cold crashed in my keezer. The Johnson Control kept the ambient temp at 32 degrees and eventually the beer reached that temp too. I wouldn't want to go by just ambient temp in the fridge though, because it would kick the compressor on and off too much I think, sine there is much less space and no other cold masses in the fridge.

I'm going to test a cold crash tonight and see how it goes.

David

 

[actech]

Cold crashing will definitely make it work hard enough to start making ice but I doubt it would stay too long. Been watching mine at a 64 ferment temp and have only caught the compressor running a couple times in days. So that will be great on electric bill. Got the probe taped to the carboy with sticky insulation tape over it. Now to get ingredients to do a brew tomorrow, so I can really check it out.

 

[djonesax]

I'm testing a cold crash now and it seems to be doing alright but the ambient temp is under 20 degrees. I am dropping is 10 degrees at a time and I'm at 47 degrees in the fermenter right now. Also, the only time I haven even heard the fridge running was when I was adjusting the temperature. Other than that it runs so little that I have not been in the room at anytime it kicked on.

This is how I insulated it!

 

[djonesax]

The cold crash test went good. It kicks on more often but I suppose that makes sense being a much larger temperature difference between inside and outside. Overall I'm pleased and not worried about the compressor but when I cold crash with actual beer, I will put the probe in water versus taping to the fermenter, so the ambient temps dont get into the teens for extended periods of time.

David