Category Archives: Fermentation Chamber

Refrigerator Conversion Part 6 – Finishing up and other observations

Here are some final thoughts on my refrigerator conversion and other related observations.
If you missed the first post, start here: Part 1: Introduction
That post has a run down of most of the materials, tools and supplies needed for this project.

Difficulty: level_4

This project requires a few inexpensive special tools, but will most likely take an entire weekend, lots of improvisation, some thorough cleaning and the cost of the fridge takes it to level 4.

Posts for this Project:

Part 1: Introduction
Part 2: Clean up
Part 3: Disassembly
Part 4: Door modification
Part 5: Shelf building
Part 6: Finishing up and other observations (this post)

Pros and Cons of other setups I’ve seen:

A/C units to cool down a fermentation chamber

I had serious reservations about the ability of a window air conditioner to maintain 34 degF in a cabinet of sufficient size in the middle of summer, let alone have enough capacity to lower the temperature of your fermenting beer at any reasonable speed

Dorm fridge powered fermentation chamber

I know this seems to be all the rage with fermentation chambers, but again, I didn’t see how it would be able to handle the cooling needs of a chamber of the size that I needed.

Gutting a full size fridge and re-installing those components in a customer insulated chamber

This was my “ultimate” plan from the beginning, but when I planned out the costs of the wood, the insulation and the FRP panels to line the inside, I was close to double or tripel (see what I did there) the cost of the fridge itself.  I then had the realization that if I found a fridge large enough, the capacity of the freezer alone would be enough to serve my needs.

Temperature Controller:

A temperature controller is a MUST for any fermentation cabinet.  My first controller for my keezer was the Ranco ETC-111000 single stage temperature controller.  I’ll have a post about my wiring at some point.

There are plenty of options out there.  For this lagering fridge as well as my other two converted dorm fridges, I actually made a simple Arduino based temperature controller.  There isn’t really anything novel about them, except that I wanted the challenge of designing my own system.  Below is a picture of the controller setup I’ve got on this lagering cabinet that I just built.  Basically the Arduino controller has a temperature probe inside the fridge to detect temperature and it cycles the fridge on and off through a relay box to maintain temperature.  The display on the box shows 3434.  It’s my simplified way of showing a setpoint of 34 degF and a cabinet temperature of 34 degF.

012 - Temperature Controller

Google search for Arduino Temperature Controller

 

I do however have a Raspberry Pi and am looking at going to the BrewPi setup or some derivative.  I really geek out on that stuff and it gets me really excited when I think about that possibility.  Here are some good links:

Official BrewPi

Home Brew Talk thread on using all the BrewPi code, but a standard Arduino

Small Tip for the Newbie

If you are new to temperature control, note that for best results, you need to set your fridge or freezer to maximum cold and let the temperature controller do the rest.  All of these temperature controllers basically power cycle the fridge/freezer on or off to control the temperature.

How to move a fridge from point A to point B:

You’ll hear many times that you can’t lay a fridge on it’s back or it will ruin the compressor.  This is half-true.  You can lay a fridge on it’s back to transport it, BUT when you get it to your house, you just need to get it upright so that the compressor fluid drains back into the compressor before it is powered on again.  I generally just get it to my garage, get it upright again and let it sit overnight.  I’ve done this 4 times with no dead fridges.

As an FYI, we’ve got a 2005 Honda Odyssey and with the middle seats taken out and the back seats folded into the floor, it has fit all 4 of those fridges inside with the tailgate all the way closed.  If you have a trailer, more power to you.

Oh, another important tip.  Remove all of the shelves from the fridge before laying it on it’s side.  All of those things are meant for gravity to hold them in place and when you put the fridge on it’s back, they all usually fall out of their slots.

What I tried to do with another fridge (drilling FAIL):

I was always under the impression that every important mechanical component was either at the back or underneath.  I was proven wrong one time when attempting to install a draw catch latch to a fridge.  I started drilling the pilot hole in the side of the fridge for the screws and the psssssssshhhhhh of the magic refrigerant come blowing out.  RIP fridge.

Simplified explanation of how a refrigerator works:

A refrigerator is simply a mechanical system that removes heat from an insulated cabinet.  That’s as far as I’m going with that.

You may also hear someone tell you that a refrigerator won’t work in a garage.  The reason behind this is that when the ambient temperature gets below the internal temperature of the freezer or close to it, the temperature difference gets closer to zero (T_ambient – T_freezer).  An A/C compressor or refrigerator compressor system relies on a temperature difference to function, so if you take away this difference, it won’t function properly.

Having said that, we live in central Indiana and have 3 refrigerators and one deep freezer in our garage.  We only have a problem with our primary overflow fridge with the ice maker in deep winter, where it doesn’t produce enough ice.  Except during long cold spells (where it can get close to freezing), our garage is usually about 55 degrees in the areas directly adjacent to a living space and in our bump out (furthest away) it is maybe low 40’s.

The more unknown part is that almost all top and bottom refrigerators are essentially a freezer on top that does all the work and bleeds cold air to the refrigerator compartment.  If you get to tearing one apart, you’ll see this.  Also if you’ve ever had a fridge with weak magnetic seals, you may notice that when you slam one of the doors, the other one pops open.  That’s because they are linked.

That’s all folks…Thanks for reading!

 

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Refrigerator Conversion Part 5 – Shelf Building

The last major step in the build of the refrigerator conversion is to build the shelving inside the fridge to support your fermenters.
If you missed the first post, start here: Part 1: Introduction
That post has a run down of most of the materials, tools and supplies needed for this project.

Difficulty: level_4

This project requires a few inexpensive special tools, but will most likely take an entire weekend, lots of improvisation, some thorough cleaning and the cost of the fridge takes it to level 4.

Posts for this Project:

Part 1: Introduction
Part 2: Clean up
Part 3: Disassembly
Part 4: Door modification
Part 5: Shelf building (this post)
Part 6: Finishing up and other observations

Goals:

You could choose to keep the standard shelf in the bottom, but why?

My goals for the fridge from the beginning were:

  1. Sturdy enough shelf on the bottom to support a full 1/2 barrel keg
  2. Bottom section should also be able to accommodate
    1. Corny kegs with all fittings and hoses attached
    2. Glass carboy with standard airlock
    3. 1/2 barrel keg with all fittings and hoses attached
    4. DIN (German) keg with all fittings and hoses attached
    5. Fit at least 4 standard size fermentation buckets
  3. Top Section to accommodate 3-4 standard fermentation buckets with 3 piece airlocks
  4. Future capability to partition upper and lower section to have two temperature zones.  The freezer section was to short as standard to accommodate them.

Building the Shelf:

As I stated, I wanted to maximize the space available.  The shelf that came with the fridge wouldn’t have been strong enough for goal 1.  It also was about 2 inches taller than the hump in the back of the fridge.  All refrigerators should have one.  On the other side are the compressor and some of the other guts.

To build the bottom shelf, I utilized the back of the hump as a support for the back of the shelf and build out the other support with 2×4’s.  You’ll of course need to customize for your fridge, but what I’ve done should give you some thought for your project.

really ready for disassembly

This is sort of in reverse, but here is the bottom shelf installed.  I had a fleeting thought of somehow keeping the bottom drawers for yeast and hop storage, but since I will always be fluctuating temperature, I didn’t really feel it was necessary.

bottom shelf installed

bottom shelf front

You’ll notice the legs have a small angle cut into them.  The bottom of the fridge had a 5 degree slope to it (presumably for drainage of spilled liquids).  The middle leg was for additional support in the middle of the shelf, and also to stop the shelf from sliding out.  It catches on a small hump in the bottom.

bottom shelf side view

I put 4 buckets inside to see how they fit.  WOW!  Just barely.  I knew it would be close.

shelf with 4 buckets

 

barely fits

So next, I cut another piece of FRP board to cover the bottom shelf.  I also created a wood frame for the top shelf.  I had a section of wire shelf that was just wide enough to span the width of the wood frame.  I didn’t feel however, that it was strong enough to support the weight of 3 full fermentation buckets.  I added another support to span the shelf.  I used wire shelf to allow sufficient airflow between the top and bottom of the cabinet.

fridge with various items inside

I also made the top of the shelf height just tall enough to clear the control panel inside the fridge.

top shelf wire mesh

Per goal 4, I went ahead and cut a piece of FRP panel to completely cover the top shelf.  I’ll modify this if and when I decide to work out temperature control for two different zones.

top shelf option

I don’t like the bare exposed wood, so I do plan to seal it with some paint or varnish.  I got this done just in time for me to brew the beer that will occupy the fridge for the next two months, so the painting will have to wait.

Up next…

Finishing up and other observations

Posts for this Project:

Part 1: Introduction
Part 2: Clean up
Part 3: Disassembly
Part 4: Door modification
Part 5: Shelf building (This post)
Part 6: Finishing up and other observations

Like this post?

Consider sharing on your favorite social hangout or making a small donation to help me purchase something to make another post.

Refrigerator Conversion Part 4 – Door Modification

Now that we’ve broken it down, let’s build it back up!  Since the fermentation chamber is all one big cabinet, it is only appropriate that it has one big door.
If you missed the first post, start here: Part 1: Introduction
That post has a run down of most of the materials, tools and supplies needed for this project.

Difficulty: level_4

This project requires a few inexpensive special tools, but will most likely take an entire weekend, lots of improvisation, some thorough cleaning and the cost of the fridge takes it to level 4.

Posts for this Project:

Part 1: Introduction
Part 2: Clean up
Part 3: Disassembly
Part 4: Door modification (this post)
Part 5: Shelf building
Part 6: Finishing up and other observations

Door Modification

I wasn’t confident when taking the doors off that I would be able to align them well enough, so I made the brackets and drilled a few pilot holes before removing the doors completely.  In hindsight, measuring the gap would have been good enough.  Some of those pictures will be repeated here for clarity.

Bracket fabrication

You’ll need to make these first whether you do it with the doors still on the fridge or not.

You could probably substitute something else, but when I turned around at the hardware store, this angled aluminum was right there and the light bulb went off.  You’ll use this to make some brackets that will rigidly fix both the refrigerator and freezer doors to each other.

support on hinge side

bracket for door handle

Measure the gap between the doors

If upon disassembly, you just wanted to take the doors off, you’ll need to measure the gap first.  I used a pair of digital calipers to illustrate, but a tape measure will be accurate enough.

Measuring door gap

*Side note: If you are looking to buy a pair of calipers, the Mitutoyo 500-196 are by far the nicest I’ve used.  Fairly pricey, but high quality.

Cut aluminum angle to size

You’ll need one for each side of the door.  I chose to make mine about 20″ long.  A standard hack saw will do the job.

Cutting aluminum angle with hack saw

 Then drill the holes

pre-drill aluminum angle

I used a 1/8″ drill bit to create through holes for the #8 sheet metal screws I was using.  DO NOT PRE-DRILL THE FRIDGE DOORS WITH THE DRILL BIT!

pre-drill for sheet metal screws

Supplies - Sheet metal screws

Cutout for handle side

Pre-drill some holes for the corners and then cut with the tin-snips.

Tools - Tin snips

notch for door handle

Use your file to clean up the cuts and remove any burrs.

Tools - File set

You can see in one of the first pictures, that I pre-mounted them to the doors with just a few screws so that I would have the holes properly located.

Door Construction

Now it’s time to get the door put back together.  Take both doors and set them up on a table.  I just laid some 2x4s (my favorite) across some saw horses.

2x4 supports for door

doors aligned

I went ahead and removed the door hinge support plate, since it was unnecessary at this point.

removal of freezer door support

Unless you want to keep them, you’ll need to remove the door panels.  This will maximize the space inside the fridge.  Each fridge is different.  You’ll want to poke around the magnetic seal to find out how yours is connected.  Previous fridges I’ve worked on have all had screws run right through the seal that held the panels on.  The seals on this fridge however were held into place by some channels that ran the perimeter of the door.  I discovered more awesome dirtiness when I removed them.

removal of disgusting seals

 

There are screws holding the channels to the door.  Go ahead and remove all of them.

channels for seals

 

Once the channels are all removed the door panels should come right off with no resistance.

removing panels

panels removed

 

The foam in the door of the last fridge I took apart was contoured for more insulation and I had to cut it down (requires patience), but with this fridge, it was nice and flat.

This is also a good time to go ahead and attach the door brackets.  Remember to align the doors by the distance you measured before removing them from the refrigerator cabinet.

pre-drill aluminum angle

Here is what the other side of the panels look like if you are interested.

back side of fridge door

backside of freezer door

Cutting the new interior panel

You’ll need the FRP panel for this step.  Alternately you could use a large sheet of plastic.  Just pick something that won’t harbor mold easily.  The FRP label specifically states that we’ll be good with using it.

Supplies - FRP Board

There are various methods of cutting this stuff posted on the internet.  Perhaps someone reading this will have a better tip, but the best one I read was using “tin snips” or aviation shears.

Tools - Tin snips

You want the panel to be smaller than the overall dimensions of the door, but big enough so that when you re-attach the seals and/or channels, you won’t crack the panel.  I just went around about 1/8″ less than the outside dimensions of the doors.  Lay out your dimensions as square as you can get them.  I simply used my large carpenters square.

lines laid out on FRP

When cutting, it is helpful to curl the panel as you go.  In my experience, this really helps to prevent cracking the panel along the cut.  You may want to choose a small section and practice cutting.

curl while cutting FRP

Now that the panel is cut to size, you’ll want to drill some through holes for the screws.  If you don’t pre-drill holes, you’ll have a heck of a time and you run the risk of cracking the panel.  Use your most clever method of transferring the hole locations from the fridge to the newly created panel.  I moved the panel to align at each set of holes and transferred the hole location with a small carpenters square.  You can probably go a little oversize on this to allow for inaccuracy, but not too much.

transferring holes to FRP

When drilling, DO NOT drill with the fridge doors underneath.  Just overhang the panel slightly and drill through.

drilling holes in FRP

You can clean the marks on the FRP panel with acetone.  Be careful however.  Acetone likes to melt plastic.

Supplies - Acetone

Once all of the holes are drilled, you should be ready to re-install the channels.  You may find that as careful as you were, some of the holes won’t line up.

re-attaching channel for seals

You’ll then need to cut the unnecessary portion of the seal.

If your door is like this one, you will have a gap between where the freezer door and refrigerator doors were.  You can go all out and trim a piece of the unused channel to span this gap, or you could just cut a shorter piece to bridge the gap.

door seal installation

intermediate seal

It doesn’t look pretty now, but I’ve got to get on with planning my big brew.  I’ll get back to doing it up properly later.

full seals on door

You can re-install the door now, or wait until after the next step of making the shelves.

Up next…

Shelf Building

Posts for this Project:

Part 1: Introduction
Part 2: Clean up
Part 3: Disassembly
Part 4: Door modification (This Post)
Part 5: Shelf building
Part 6: Finishing up and other observations

Like this post?

Consider sharing on your favorite social hangout or making a small donation to help me purchase something to make another post.