Cheap Fermentation Chamber

[wfowlks]

Can you post some finished pics? I'd like to see it with the coils and all. How did you attach them? I am attempting pretty much the same thing this weekend except I am doing a wooden frame for mine.

I have the day off today since I work a 9/80 schedule. (M-Th 9 hrs, alternating fridays 8 hrs/day off).

I went to Lowes to look at sheet metal. It is WAY to expensive, aluminum being like 3x the cost of sheet steel. So I just decided to spend $13 and get some tin snips, and use the skin from the fridge as a cover for the coils. I'll be posting pix every 5 pix, because that is how many you can attach at once.

 

[wfowlks]

So, started out by cutting the side off of the fridge with the tin snips. Make sure you wear gloves if you use tin snips, not cheap ones either, the heavy duty ones. I got bit by a piece of the metal that came up on the corner. But like a real man, I don't bleed, I just swear a lot. But really, it was not fun to deal with, so just be careful.


I got the siding cut, and I used the back of a hammer to just run along it and scrape off all the excess foam. I suppose a metal spatula would have done the same thing, but I don't have a lot of tools.



After trying to bend the freezer flat by hand, I noticed that it was arching the middle, where I wasn't holding it, which can be bad if it pinches the coolant line. So I laid the compartment down on a table, across a board of wood. Held down the center portion while I bent it flat. If you have a workbench you may want to use another piece of wood to hold it in place, I would just caution though, that if you do that you can't see if you are pinching the coolant lines.


Here is 1 side flattened.


Here is the other


I am going to try to fit it inside the hole that I unmounted the other one from and lay it in the separation between the rack that I used inside and the top layer of insulation. More pix to come shortly stay tuned!

 

[RTL]

Nice build I have been looking at using a window air conditioner but this might be more efficient and cost effective.

The idea of compressing gases causing them to cool sounded strange so I looked it up on HowStuffWorks, so this is the condensed version. Compressed gases heat up not cool, and the cycle is as follows according to HowStuffWorks:
1. Refrigerant (usually ammonia gas) is compressed which heats it up and can cause it to condense into the liquid phase.
2. This gas/liquid flows through the heat exchanger on the outside of the fridge to cool it with ambient air.
3. The gas then flows through the expansion valve which rapidly depressurizes (if thats a word) it causing extreme evaporative cooling (can reach -27*)
4. This expanding and cooling gas flows through the heat exchanger on the inside of the fridge cooling down the internal air, the cycle repeats as the compressor draws air from the internal heat exchanger.

Hopefully someone who does HVAC will throw their two cents in.

Keep the pics coming, great thread.

 

[wfowlks]

Nice build I have been looking at using a window air conditioner but this might be more efficient and cost effective.

The idea of compressing gases causing them to cool sounded strange so I looked it up on HowStuffWorks, so this is the condensed version. Compressed gases heat up not cool, and the cycle is as follows according to HowStuffWorks:
1. Refrigerant (usually ammonia gas) is compressed which heats it up and can cause it to condense into the liquid phase.
2. This gas/liquid flows through the heat exchanger on the outside of the fridge to cool it with ambient air.
3. The gas then flows through the expansion valve which rapidly depressurizes (if thats a word) it causing extreme evaporative cooling (can reach -27*)
4. This expanding and cooling gas flows through the heat exchanger on the inside of the fridge cooling down the internal air, the cycle repeats as the compressor draws air from the internal heat exchanger.

Hopefully someone who does HVAC will throw their two cents in.

Keep the pics coming, great thread.

If you were going to use a window ac, you would be bound to put the fermentor by the window, (which I don't have many of), but if you just had it in the house it generates A LOT of heat, and consumes way more energy than a mini fridge.

That is pretty much correct about the modern fridges and is the basic principle behind how the new one will operate.

Here's a snipit of what I remember from my days in thermodynamics. When the gas is compressed, it causes it to lose energy (heat). The gas being brought the the expansion chamber into the interior cooling coils becomes endothermic (heat absorbing), as it has more volume to expand to, drawing the heat from the surrounding environment. After it absorbs the heat, since it is a closed system, it tries to expand, and is pulled by the compressor through the cooling coils (the copper tubes along the skin, to dissipate some heat with the surrounding environment. And is then brought back into the compressor to start the cycle again.

The older one worked a bit different, and the best resource I found was wikipedia.

http://en.wikipedia.org/wiki/Absorption_refrigerator#Single_pressure_absorption_refrigeration

IMO the new mini fridge being energy star compliant, is the best option for my situation. I like it because it gives off less heat and is a bit quieter.

 

[wfowlks]

So I built a little guard out of wood to hold the compressor up at the right hight, and I anchored it to the bottom rack. Its turned upside down so that its easier to screw in



I tried to screw it in with the aluminum guard that was on it, but the right side was too distorted from when I initially dismantled the fridge.



So I decided just to remove the encasing. To do so I just used the tin snips and cut a wide wedge VERY CAREFULLY to each element, and carefully moved it out of the way. I did manage to get stabbed a few more times from the metal slivers. I think it went all the way to the bone of my thumb this time but it was narrow so luckily I don't need stitches. So learn from my experience



Cut out the metal, and got it flipped over to the right side. Did it carefully because I didn't want to bend/break anything, and they weren't protected by the aluminum guard that I just removed.



I ended up having to remove the top portion to slide it in, as I tried to get the cooling component in via the slit that was from the previous fridge, but it was to small, and I didn't want to risk bending the coil and breaking it. I'd rather pay the $2 for another bottle of liquid nails.


Got the thermostat and probe attached to the freezer compartment. Next is to secure the coils to the side, and then re-glue the top.

Lesson: If your layout is similar to mine, wait till the end to attach the top. It will save you some hassle.

But anyway back to building. More pix to come

 

[wfowlks]

Ok, So here is what everyone wants, the finished product (hopefully, just started the overnight test) pictures and run down. I think I am going to call this the Blood, Sweat and Beer Fermentation Chamber, because I got a lot of cuts from the metal, it was 104 degrees today with about 70% humidity, and I had a beer. As I am writing this we are in the middle of a severe thunderstorm.

But anywho, Back to what everyone wants: Pictorials!


So after cutting away the aluminum guard. I was left with the copper coils. I decided to affix this to the side, I used one of the screw in metal plates that came out of the top of the fridge. Just be careful if you do that, not to pinch the line.



On the back, there was not enough room to bend the lines around the left side, so I ended up trying to squish them all on the back, and I ended up bending down the lines as you can see in the lower left hand corner. Just make sure to bend them smoothly. Take your time. You already spent all that time taking the fridge apart, the last thing that needs to happen is you brick your fridge, because you were in a hurry.




Here are all the coils taped in, You can see the configuration on the back, I was just trying to figure out how to fit them all, so that I didn't have to cut more metal. It ended up being only a 16 inch sheet i needed on the back and the length of the side of the fridge worked perfectly.


You can see I took the back of the fridge and used it to cover up the coils on the left side of the Fermentation Chamber.


Here is the back once i attached the sheet over the coils. Also the white tube needs to be insulated from the copper coils.


Side note:

Anyone know how to petition a Moderator/admin to change the name of my thread. I want to append to the end: (The blood, sweat and beer build)

 

[wfowlks]

I cut out a bit of insulation for the cooling tube that goes up to the plate inside the fermentation chamber. You can see it here, I also insulated the tube from the coils a bit, using a small piece left over from my tall collar keezer build.


Setting up the test, the 1 gallon of water in there with my NEW temp controller, however I'm not using it as a temp controller just a temp gauge.


Primary reading of the temp controller in Celsius. Equivalent temp: 73.4 degrees



I decided to use Velcro to stick the front onto the chamber, easy peel off, etc. I might go and get enough velcro to use for the whole side instead of just top and bottom, if I find that to much air is leaking out.



It has dropped a few degrees already since I started writing this update. SOOO excited. I'm hoping to see what the lower limit I can get with the chamber in the overnight run, since its not hooked into the temp controller.


Just a few notes. The fan you put inside should be going as long as your using the chamber, it keeps the air circulated and equal temp throughout the chamber.

Another note is, if you are willing to be more vigilant you don't need a temp controller, the settings on fridges these days are pretty good at keeping things a constant temp. I normally set mine on 3-4 for the mini fridges, and its about 45 degrees.

Final Breakdown of cost for finished product. I broke it up into categories, so that if you have it you can remove it.


Fermentation Chamber:
$25 - 2" x 4' x 8' - EPS foam board
$6 - Plywood board
$6 - Walmart Fan(can substitute a comp fan)
$30 - Mini fridge (Craig's list it)
$5 - Metal wire frame organizer (yard sale)
Ferm total: $72

Temp Control:
$21 - Ebay Temp controller
$8 - Project enclosure from Radio Shack
$3 - outlet plug
Controller Total: $32

 

[RTL]

If you were going to use a window ac, you would be bound to put the fermentor by the window, (which I don't have many of), but if you just had it in the house it generates A LOT of heat, and consumes way more energy than a mini fridge.

That is pretty much correct about the modern fridges and is the basic principle behind how the new one will operate.

Here's a snipit of what I remember from my days in thermodynamics. When the gas is compressed, it causes it to lose energy (heat). The gas being brought the the expansion chamber into the interior cooling coils becomes endothermic (heat absorbing), as it has more volume to expand to, drawing the heat from the surrounding environment. After it absorbs the heat, since it is a closed system, it tries to expand, and is pulled by the compressor through the cooling coils (the copper tubes along the skin, to dissipate some heat with the surrounding environment. And is then brought back into the compressor to start the cycle again.

The older one worked a bit different, and the best resource I found was wikipedia.

http://en.wikipedia.org/wiki/Absorption_refrigerator#Single_pressure_absorption_refrigeration

IMO the new mini fridge being energy star compliant, is the best option for my situation. I like it because it gives off less heat and is a bit quieter.

Makes sense. The whole unit would have been in my garage but it's hot enough out there already and I would like it to be efficient. Thanks for the info, keep it coming.

 

[wfowlks]

SUCCESS!!!!

So the temp dropped to 5 degrees overnight. And since I took the picture it has dropped another 0.1. Brewing starts on Wednesday.

 

[wfowlks]

One thing to also note, since I raised up the compressor a bit, the fridge kept leaning back. So what I did was I screwed a wooden plate onto the back kind of like a kick stand.



The new enclosure on the back, adds 8 inches to the depth. This could be reduced if you put the compressor closer to the back panel. I just wanted to give it as much air as possible.
If I had a taller rack, I would probably put the compressor unit below.

Also, I felt the side of the fridge, using the metal to cover the coils allows it to dissipate heat better. The panel was warm to the touch but not hot.

So the total dimensions are:
28" Deep, (20" foam enclosure + 8" compressor mount)
32" Wide
30" Tall

 

[thewurzel]

Nice job
I was going to try that myself at one time as i had difficulty finding something the right size to fit into basement that would hold my conical.
But in end I found freezer that fit into my basement.

I use the same controller and hooked it straight into the freezer omitting the freezers own thermostat. that gave me the ability to have a always Live socket and a heat socket inside the freezer.

 

[Dr1nkBeer]

I was thinking about something very similar... I was going to build it out of soem solid birch (i have some extra laying around) then insulating the inside.. but.. for refridgeration... i was going to buy a used 12v dc camping cooler.. and pull the refridgerant device off (its got a fan and all) and attach to the top... and use a laptop power supply with a temp controller on/off device...

 

[wfowlks]

I was thinking about something very similar... I was going to build it out of soem solid birch (i have some extra laying around) then insulating the inside.. but.. for refridgeration... i was going to buy a used 12v dc camping cooler.. and pull the refridgerant device off (its got a fan and all) and attach to the top... and use a laptop power supply with a temp controller on/off device...

The only problem I could see arising is that a camping cooler may not be able to cool more than 1 carboy efficiently, and it might burn out its compressor.

I just put my lager in 10 gallons of Oktoberfest, and It was able to bring it down from 70 degrees down to about 54 degrees in about 4 hours.

 

[Dr1nkBeer]

Good point. They claim to be able to hold temp 10 -20 degrees below ambient temps.. My basement is just around 60 all year long but creeps to 70 in summer. Its goo enough for all other brews pretty much... Its a cheap enough project and could always upgrade the refrigerant device if it fails to perform. But def. a good point..

 

[divi2323]

Remember that with fermentation, you're not just dealing with ambient temperatures. Yeast create heat during their process and although it's only a few degrees depending on what you're brewing, it's that much more energy you need to pull out of the chamber.

I'd like to know how many BTU's yeast put out based on how many of them they are. It would be interesting.

 

[carlisle_bob]

....

I'd like to know how many BTU's yeast put out based on how many of them they are. It would be interesting.

Hi

X pounds of water (15 gal x 8 = 120 lb) times Y degree ( say 2) = 240 btu's. How many BTU's per hr depends a lot on how fast the fermenter sheds heat.

They invented BTU's to make that particular calculation easy.

Bob

 

[wfowlks]

Hi

X pounds of water (15 gal x 8 = 120 lb) times Y degree ( say 2) = 240 btu's. How many BTU's per hr depends a lot on how fast the fermenter sheds heat.

They invented BTU's to make that particular calculation easy.

Bob

Pulling out my engineering nerd-ness, I looked up in my old Thermodynamics book, and water is 8.34 lbs/gallon at 60 degrees.

at 200 degrees it is 8.0 lbs/gallon.

 

[wfowlks]

Just a quick update. The fridge has been holding at 54 degrees, for the past week, while the ambient temperature inside has been ~ 80 (its been 104 outside and the House AC can't keep up). But anywho, after it hit, it has only been running about 50% of the time. I touched the insulation, and the part where the front comes off where I have the tape, I can feel that as cold. I may have to try to figure out how I can better the insulation, Maybe one of those emergency blankets, or stuff the inside with the cheap 1/4 inch foam.

 

[wfowlks]

So it has been holding at about 5.3 degrees for about 2 weeks now. I figured out it was because the temp probe that is placed on the freezer panel is causing the fridge compressor to shut off, and shutting off at a higher temp than my temp controller. I ended up just letting the mini-fridge temp controller dangle inside, away from the freezer panel. Hopefully this allows me to bring it down closer to 1-2 degrees, and doesn't burn my compressor out.

 

[wfowlks]

So... I think I found the real reason that my temp was slowly rising by about 0.5 degrees per week...

The freezer panel has Iced up, I think it was because I turned off the fan to see if I could drop the temp to 1 degree. This is not going to be fun to defrost....



The ice portion has even taken over about 1/4 of the fan. There is ice inside the fan!



I am not sure if this is from an evaporation from the fermenters, or if there is an air leak, or if the air when I closed it up was just that humid. But something will need to be addressed before the next lager

 

[wfowlks]

Long time update:
So after a move, it has survived! I wasn't able to completely seal all the holes to prevent the condensation build up. However, I did find that a way to counter this was to put the carboys in my keezer overnight after brewing, to bring the temp down to about 38, then let it warm up for a few hours then stick it in. This way the compressor only had to turn on to maintain the temp, and not to cool it down. It also helped to improve my lager taste because of the lower fermentation temps up front.