Building a walk in cooler

Isaac Carlson

Feeling the Heat
Nov 19, 2012
433
NW Wisconsin
I have been needing a walk in cooler for years. We raise Russian boar and harvest wild game. Waiting on the weather got old after the first year.
We have 3 or 4 pigs to this from the herd and hopefully at least a few deer this year (I'm hoping for at least 6 deer). I'm not even going to try waiting on the weather for all of that. I'm building a cooler!

I am putting it inside the house. We have a small porch that houses our freezers and one corner of it would make a great spot for a 5x5 cooler.
it will have an outside door and an inside door, so we can load it from the sidewalk and then bring the meat right into the kitchen for processing.
I think I am going to put 3 rails in it. That way I can hang several animals and keep space around them.

I have the air conditioner. I picked up the insulation today. The temp controls get here on Saturday, which is the opening day of deer season and it is supposed to be pouring rain. That should give me time to wire it up and get it running before a deer knocks on the door asking for a cool place to chill for a couple of weeks.
 
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Corey

Minister of Fire
Nov 19, 2005
2,509
Midwest
Interesting project. When I first started reading, I was thinking 'freezer' but then you mention an air conditioner, so thinking you must really mean 'cooler' / refrigerator. So expecting you may be aiming for a ~40F interior temperature?

Even that is a bit outside 'normal' for an AC unit. They would typically be bringing in ~75F room air and putting out ~50F conditioned air (and on a summer day which might be 80F+). But to maintain ~40F, you'd be asking the unit to bring in ~40F air and spit out something even colder (possibly working into the fall/winter with much cooler outdoor temps?...or possibly have the AC facing 'indoors' to recover the heat into the house?)

It's likely most of the typical AC units are too 'dumb' to notice, but you might experiment by making a small box and being sure the unit you intend to use would actually hit refrigerator temps without tripping a low head pressure (or other) fault due to the super cool temps.

The next issue to consider (speaking from walk-in environmental chamber experience) is humidity. If you have a cold box, it is going to want to condense humidity. Especially with 2-3 animals in there - I expect they will be emitting a lot of humidity. So lots of vapor barrier and keep it TIGHT / SEALED. The last thing you want are constantly wet/damp sections of insulation or other construction materials = mold/mildew.

Beyond that, it's just a box, insulation, heat gain, heat load of the animals and capacity of the cooling, etc. Will be interesting to see how it turns out!
 

johneh

Minister of Fire
Dec 19, 2009
3,125
Eastern Ontario
3 years ago when a friend (butcher) retired he wanted somewhere
where he could process wild game. He bought a Sea Container closed
and insulated the back of it and installed this unit
Does the job for him without a big cost
 

MikeK

Member
Oct 12, 2014
34
MN
3 years ago when a friend (butcher) retired he wanted somewhere
where he could process wild game. He bought a Sea Container closed
and insulated the back of it and installed this unit
Does the job for him without a big cost

I have also heard of these: https://www.storeitcold.com/

I think market gardeners use them to build affordable walk-in coolers as well.
 

Isaac Carlson

Feeling the Heat
Nov 19, 2012
433
NW Wisconsin
I have seen the coolbot units, but I don't like the price or the strings of wires or the way they trick the ac unit.
I have an inkbird temp controller for heating and cooling, as well as a johnson/penn thermostat to allow defrosting in the event the fins freeze up. They will be wired direct and will completely replace the factory thermostat control. Total cost was $70.

I am now "net zero" for cost. I helped a friend track/find/process a big buck and he offered to cover the cost of the cooler in exchange for my help and even wants me to build one in his garage when mine is done.

This has been a busy week and I ended up doing a bunch of other things, but will be working on the cooler more tomorrow. I decided to put hardware cloth behind the foam just incase a mouse decides to sharpen it's teeth on my cooler. I do not like rodents in the house.
 
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Isaac Carlson

Feeling the Heat
Nov 19, 2012
433
NW Wisconsin
I finally got back to working on the cooler. The air conditioner is in the wall and the walls are framed in.
I have one layer of foam in the ceiling, with the original r13 batts on top for a total of r25+. I'm thinking about putting another layer of foam up there because it is a flat rubber roof. It gets warm in the sun.

The walls will all be r25+ and the floor is thick concrete and will have r12.5 foam over it along with plywood.
 

Bad LP

Minister of Fire
Nov 28, 2014
1,295
Northern Maine
Next door is a CSA farm. Their walk in cooler is about 14X25, maybe a tad larger. They sprayed 100% closed cell foam on the walls and ceiling. It's cooled using 2 thru the wall AC units and works very well.
 
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Isaac Carlson

Feeling the Heat
Nov 19, 2012
433
NW Wisconsin
I actually got it 905% done and then used some spray foam and it never stopped off gassing. I thought it was the fumes from caulking the foam together, so I have been trying to get it to air out. I ripped the stinky foam out today and all is well. This fiasco actually helped me because I had time to watch the run times and efficiency and was able to make some huge improvements. The blower housing was a huge efficiency killer. It is a giant heat exchanger with the outside air. It was taking over half of my btu's, so I insulated it. Huge improvement.

I have it running right now for the hunt tomorrow and it is runnung for about a minute and stays off for 12 minutes. That time might stretch out a bit more as the internals reach equilibrium. I hope I get a deer.
 
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andym

Member
Feb 6, 2020
233
Hicksville, Ohio
I just recently realized that it is possible to build a cooler this way. I know a guy locally that has one, but don't know any details. I do know that he would let me hang a deer in it tho! I actually have a small buck 'chillin' in my spare refrigerator right now. I keep the fridge around just for that purpose. It's a side by side. I want to fasten some hooks to the ceiling so I can hang the quarters instead of stacking.
 

SpaceBus

Minister of Fire
Nov 18, 2018
4,774
Downeast Maine
What kind of temperatures did you achieve?