HELP: Walk-in Cooler Ideas

Evening all,
I am in the process of purchasing a new home, and I have already begun my RIMS system build to be able to produce qty's of beer. My wife and I are pretty excited to buy a house with a good size basement where we can build a full bar / entertainment room. A big part of this build to me is going to be a walk-in cooler. I have wanted one since I was 18, and now I finally have the means and space to construct one. I priced out purchasing an 8'x8' but it was upwards of $4,000.

I decided that I should google "DIY walk-in cooler" and to my surprise HBT was the first link that came up. Specifically John Beere's build. Now that I have read all of that, and all of the other subsequent builds similar to it, I feel that I have a great starting point to work from.

Here is what I have thus far:
- I will be getting my hands on a 10,000 BTU Air Conditioner to use.

- The room will be framed with 2x6 pressure treated wood, and will have a floor built the same (maybe 2x4 on the floor... not sure)

- I live in Buffalo NY where it gets very cold in the winter, so I prototyped, built, and tested a control panel that allows two temp controllers to measure the cooler temperature and the outside temperature. It determines if the cooler needs to be cooled, and if so it will determine if the temperature outside is sufficient to directly pull filtered air, or if it needs to use the AC unit to achieve the desired temperature.

- I have decided that I do not want just a cooler, but also a freezer built inside the cooler.

- I want the total interior space to be 8'x8' or 7'x7' I will have to look at the space that I have available after we settle on a specific property.

Ok, enough blah blah blah background, here are the questions:

If I place a freezer inside the cooler, I will obviously want the AC to be inside of that space. Should I just place a baffled fan on the freezer wall to blow freezer air into the cooler when the temp control in the cooler demands it? Also if that is the case, and the outside air is cold enough to maintain the cooler and not the freezer, should I just pull outside air into the cooler instead of running the ac? Here is a crappy drawing of what I mean:




My biggest concern is the insulation. I can wire a factory to make it automatically, but I have no idea what I am doing with R-Values or what types would be best suited to this application. My boss suggested using the foam sheets nailed to the outside then spray foam to fill between all of the studs then more foam board on the inside (moisture proof stuff). I am not sure if this is the best way to go to achieve a superior R-value. This setup will be in a basement and will have two walls up against the foundation. I will frame out these walls but I am concerned with moisture on my insulation creating mildew.

Any suggestions on how I should approach insulating this thing? Floor, Ceiling and Walls will all have to be taken into account. The actual floor will be tiled or vinyl, most likely tile over a backerboard made for bathrooms. The insulation will have to go under that.

This is all I have for now, I am sure that I will be adding more as this is even more daunting than my RIMS build.

I have never seen a build with a freezer, interesting.This looks like it will be nice!

Posts from one of my forums, they are relevant so I figured I would cross post them.

travisn said:

I would always run the AC. it will draw any moisture out of the air, just make sure the drain is to someplace out side of the room though.

also, walk-ins typically have that fiberglass type of covering on the walls, I am sure sheets like that glued to the walls (think bath tub surround) will keep any extra moisture at bay off of the interior walls/wood.

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tpgsr said:

I plan on using the white sheets as the final layer on the walls. They will be white painted aluminum, and the seams will be sealed with silicone.

Good point on the Moisture in the air, would running a dehumidifier be a good solution to that? I mean, I am trying not to run the AC all of the time, I guess that a dehumidifier is just as bad though. The goal is to get the R-value up high enough so that the BTU loss per hour is very minimal and I will have the AC running very infrequently. The less the AC runs, the less this will cost me per year. I would like to get this to like $20-$30 operating cost per year. (I didn't get that out of thin air.. a guy with a 8'x6' room metered his usage and noticed a total cost of $24/ year)

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travisn said:

a dehumidifier would be exactly the same thing (basically) except it doesnt have a fan to move the cold air, just a coil that pulls the moisture out of the surrounding air. I would use a dehumidifier only if its usage is less than the usage+more cold air benefit of the ac unit.

if you are really doing the logistics on this for energy use, will spending 50-100 on a dehumidifier+ its running costs offset what you would save by running the AC a little less? plus cost/hassle of plumbing the drain (and taking up more of your 64 sq feet) for the dehumidifier too, im sure you wont want to remember to drain the reservoir every so often

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tpgsr said:

True. My other concern was running the AC with temperatures outside in the 10 deg. range. I will be blowing intermittent warm air over the coils to keep them from freezing up, but I am for some reason thinking that the freezing air outside will cause issues with the unit... Am I wrong?



The software that I am using to design this is super cool.... Chief Architect

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Its a neat idea, thats for sure.

What kind of AC unit will you be using? I would be surprised if a standard wall unit will get that cold even with a temp contorller hack

I want to use a standard unit, but if after wiring it up it fails to get to my desired temp, I will use it to keep the bar at a comfortable level and go out and buy a real chilling unit.

More cross posts as there is a lot of good information flowing on my board.

LAFENGAS said:

Just a quick word of advice...if you're only doing it yourself to save money, you'll likely find out that will end up costing you more by the time you factor everything in that you didn't think of at first.

DIYing for self satisfaction is a different story though.

My biggest concern with a DIY build on a freezer/cooler would be moisture control. Not the humidity, but long term leaks that get past the walls and floor and now into your furnished basement.

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I am doing it for both reasons. I have read and followed several builds of walk in coolers as DIY and all of them came in right around $1000 dollars. Mine will probably be more based on the fact that I am attempting to place a freezer into the space. I am not too worried if I go over budget, but I really do not want to buy a commercial solution if I can build something comparable myself. I like building things. I will also be sealing up all joints and using adhesive where possible instead of nails. That will help keep the two environments safe. There will be a few areas where conduit has to pass through the walls and I will be sealing those areas up with foam. I have to look into the best means of sealing everything because a leak into my finished basement would be devastating. I would cry if I had to throw out furniture due to mildew.

97FormulaWS-6 said:

For Insulation, I'd suggest the spray-in stuff that one of the guys here used in his upper bedroom he did. That way it will seal up any/all air paths and block any leaks as well as providing a great thermal barrier.

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My boss suggested the spray in foam, but there are lots of different types. That is what I was looking for from here is what type would be the best to use. Open cell, closed cell etc... I was looking at getting something like this to use: http://www.fomofoam.com/HVAC.htm

JayS said:

A few things...

1. I thought air was the enemy with grain storage, not temperature? If so your fresh air cooling is probably going to be a bad idea. You might be better off investing in a decent vacuum sealer and just storing the grain in an unrefrigerated section of your basement.

2. I'm pretty sure any window AC unit you buy is going to ice up if you try to run it in the winter. The way they are designed to just drip the water they pull from the air will likely build up ice in a hurry when it's < 20 degrees outside.

3. I second the idea of 2x6 with R30 fiberglass.

4. I would put both your AC and outside air intakes inside the freezer. Then your two temp controllers can work to keep both areas the proper temp by always pulling the coldest air in through the freezer.

5. You'll probably need more than just a fan to separate the freezer and fridge sections. I think a fan alone will leak too much air and you'll find that your fridge section turns into a freezer. An servo activated baffle door would solve this issue.

6. Like Lafengas said, the 4k for the pre-made one will probably end up being cheaper and better.

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1) Air and temperature. They will be in sealed bags inside of the plastic containers. If I am pulling air from the outside directly with fans, it will make it's way through several filters before entering the cooler. I will probably have filters on the AC box as well to keep the air good. I mean we are dealing with food.

2) The icing up is a concern, and one solution that has been proven effective on other builds is to place a couple small fans blowing "warmer than freezing" air back over the coils to keep them from freezing up. I was also mentioned that this is running so infrequently after it is cooled inside that you can monitor it over the first cool down, and then not really have to worry about it freezing as it is not running long enough to build up much condensation. I will do some more research on this, as it may be a big sticking point.

3) Isn't R30 fiberglass really really thick? like thicker than 6"??

4) My concern is that if it is cold enough outside to keep the cooler cold, and not the freezer I will be wasting my energy running the AC to chill the freezer as the cooler is pulling it's air.

5) Everything will be baffled. I just put the fans in there for the concept, but the air will only go in one direction.

6) Better oh yeah, but I really do not need something that is overpriced for my uses. Industrial coolers are expensive as they are built for continual traffic. Mine will hardly ever see traffic and will not need to have the insane cooling power of the commercial units. If I can get my insulation to the same level as a commercial unit then I have nothing to worry about.

travisn said:

also, I rescind what I said about the dehumidifier. I wasnt thinking the air conditioner would be in a separate 'room' away from the refrigerated section. maybe one is needed to keep that section at a desired humidity. the humidity in the freezer room wont be a problem really because its frozen.

and idk if you can get a pre-made unit with separate freezing and refrigeration sections. maybe a pre-built one with a hole cut in the side for a full-size stand up freezer to be glued/sealed into place? (you cant have it just inside the cooler because the coils on the back need fresh air circulation to release the heat it pulls from inside the freezer.)

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When I worked in a kitchen, we had a massive cooler and the freezer was built in to one of the corners. I can not use that cooler as a design example because it had three 2 fan cooling units in the cooler section and one large 3 fan in the freezer section.

I would think that I could run a line from the dehumidifier to the same drain that the ac line is going to be run to. For clarification on the freezing of the drain line on the AC, the pan and the drain line will be wrapped with a heat trace wire up to the point where it goes through the insulation and into the external drain.


Keep the feedback coming, This is getting me thinking a lot! Seems that this project is going to be quite the undertaking.... I wonder how long this will take to build out and get working 100%

Polyisocyanurate would work very well for you. But I worry about the wood studs being the short circuit in this application. A continuous run of insulation board on the inside would help more than you could imagine. A 2x8 has an R-value of about 1. Not a huge deal if they are spaced 24" O.C., but this will detract from the assembly R-value.

6" Polyisocyanurate is about R-43.

The floor would also need to be isolated.

Without reading much more than your first post, here are my thoughts/advice:

- You are going to want a vapor barrier that surrounds the entire outside (walls, floors, and ceiling) of the walk-in. It should go outside of the insulation to prevent moisture from being pulled into the insulation and causing it to degrade.

- You will also want a minimum of R-20 maybe more if you do the freezer to keep the outside surface warm enough to prevent condensation on the outside of the vapor barrier. That water will cause mold to grow in your walls.

- With the addition of the freezer, you make it considerably more complicated. You could provide all the cooling in the freezer and simply leak the air into the cooler as needed to keep it cool. That is how your refrigerator works. But with the circulation of the air, you could end up with smells from your cooler permeating food in the freezer. Additionally, a simple AC unit will no longer work. Once your evaporator temperature drops below freezing, you have to be able to defrost the coil. A simple A/C unit can't do that on its own.

- Using outside air can also provide complications. It must be heavily filtered or you could get odors from outside in. Additionally, look at the fan power you are using and compare it to the compressor power you are saving. You'll find they may be quite close.

Sounds like putting a cheap upright freezer inside the walk in cooler would be easier.

t

Careful with that idea too. Many refrigerator/freezer manufactures don't want their units running in an environment that is too cold. That said, my beer fridge has lasted through many cold Wisconsin winters out in my garage and is still humming along.

tonkota said:

Polyisocyanurate would work very well for you. But I worry about the wood studs being the short circuit in this application. A continuous run of insulation board on the inside would help more than you could imagine. A 2x8 has an R-value of about 1. Not a huge deal if they are spaced 24" O.C., but this will detract from the assembly R-value.

6" Polyisocyanurate is about R-43.

The floor would also need to be isolated.

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This is great. I was looking for some insulation with a high R value. I will look into using a core of foam for the wall and metal sheathing, but I fear that may break the bank, and not be as sturdy. I will have to see.

GVH_Dan said:

Without reading much more than your first post, here are my thoughts/advice:

- You are going to want a vapor barrier that surrounds the entire outside (walls, floors, and ceiling) of the walk-in. It should go outside of the insulation to prevent moisture from being pulled into the insulation and causing it to degrade.

- You will also want a minimum of R-20 maybe more if you do the freezer to keep the outside surface warm enough to prevent condensation on the outside of the vapor barrier. That water will cause mold to grow in your walls.

- With the addition of the freezer, you make it considerably more complicated. You could provide all the cooling in the freezer and simply leak the air into the cooler as needed to keep it cool. That is how your refrigerator works. But with the circulation of the air, you could end up with smells from your cooler permeating food in the freezer. Additionally, a simple AC unit will no longer work. Once your evaporator temperature drops below freezing, you have to be able to defrost the coil. A simple A/C unit can't do that on its own.

- Using outside air can also provide complications. It must be heavily filtered or you could get odors from outside in. Additionally, look at the fan power you are using and compare it to the compressor power you are saving. You'll find they may be quite close.

Click to expand...

Vapor barrier I got, do i need it on the inside and the outside though?

We are aiming for a R-Value of 40+ and using materials that are mold inhibiting. Mold in my house is the last thing that I want!!

To keep the coils warmer than freezing, I was thinking about taking a run of heat trace through the drip pan so that the water would not freeze and could drain, as well as pulling "warmer than freezing" air over the coils using fans and some ducting or small heaters only when the unit is running. I can go into further detail if this seems confusing, but do you think that would help keep the unit running? I got this idea from the original thread posted by John Beere.

The fan that I am using to pull in the air is a very solid unit. It is very small and has a flow rate of 100 CFM running at .21 Amps. It is made by Hoffman for industrial environments. I may take the fan from the outside and nix it, and just have a fan moving air from the freezer to the cooler.

bonsai4tim said:

Sounds like putting a cheap upright freezer inside the walk in cooler would be easier.

t

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I had thought about doing this as well, but allowing the exchanger on the back of the freezer to breathe outside air....

I have a 20ft. conex that has insulation and an ac unit.

jgardner6 said:

I have a 20ft. conex that has insulation and an ac unit.

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What temperature do you keep it at? What BTU is your AC, and lastly do you ahve condensation issues?

bonsai4tim said:

Sounds like putting a cheap upright freezer inside the walk in cooler would be easier.

t

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I like the idea of using and upright freezer as well. It seems like it would be much cheaper (but certainly less cool looking). The only major installation issue would be to figure out the exhaust system for the hot air the freezer will generate.

tpgsr said:

Vapor barrier I got, do i need it on the inside and the outside though?

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Vapor barrier always on the warm side. That's where the humidity is. You want to block it from being pulled into the insulation.

tpgsr said:

To keep the coils warmer than freezing, I was thinking about taking a run of heat trace through the drip pan so that the water would not freeze and could drain, as well as pulling "warmer than freezing" air over the coils using fans and some ducting or small heaters only when the unit is running. I can go into further detail if this seems confusing, but do you think that would help keep the unit running? I got this idea from the original thread posted by John Beere.

The fan that I am using to pull in the air is a very solid unit. It is very small and has a flow rate of 100 CFM running at .21 Amps. It is made by Hoffman for industrial environments. I may take the fan from the outside and nix it, and just have a fan moving air from the freezer to the cooler.

Click to expand...

What you are talking about is called air defrost. Food plants will do that in coolers and production areas. If you are trying to keep a space at 38F, your coil surface temperature will probably be 10F lower, or 28F. Obviously, this builds up frost as it operates. When the space point temperature is met, the fan will continue to run but the refrigerant flow stops. Since you are blowing 38F air over the coil, it melts the frost and lets it drip away.

You can't do this in a freezer. In a freezer, you are keeping the temperature at 0F or less. To defrost the coil, heat must be added. Heat trace would do it, but you will see it in your electric bill.

Placing a small freezer in there is looking better. Be careful with poking a hole so the freezer can see outside air. That means a penetration in your vapor barrier and that is hard to seal up. If there is a hole, you will get a lot of moisture in the summer and that could me mold inside your cooler. At the least, it will mean the compressor will have to work very hard to keep up.

bonsai4tim said:

Sounds like putting a cheap upright freezer inside the walk in cooler would be easier.

t

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The other benifit is that when you realize you need more space for more kegs you can move the freezer outside the fridge just make sure the fridge door is wide enough...

CarsonCE said:

I like the idea of using and upright freezer as well. It seems like it would be much cheaper (but certainly less cool looking). The only major installation issue would be to figure out the exhaust system for the hot air the freezer will generate.

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I like the idea, but I would 1000x rather have it as a functional built in freezer within the walk in.

I guess since I only left it like 3'x3' I will not be losing much space by placing a large freezer in there. Ok, back to the drawing board..... Freezer ducted in, and the cooler operating off of an AC unit. I would assume that it will help to keep my freezer from running all of the time having it in such a cold environment.

GVH_Dan said:

Vapor barrier always on the warm side. That's where the humidity is. You want to block it from being pulled into the insulation.



What you are talking about is called air defrost. Food plants will do that in coolers and production areas. If you are trying to keep a space at 38F, your coil surface temperature will probably be 10F lower, or 28F. Obviously, this builds up frost as it operates. When the space point temperature is met, the fan will continue to run but the refrigerant flow stops. Since you are blowing 38F air over the coil, it melts the frost and lets it drip away.

You can't do this in a freezer. In a freezer, you are keeping the temperature at 0F or less. To defrost the coil, heat must be added. Heat trace would do it, but you will see it in your electric bill.

Placing a small freezer in there is looking better. Be careful with poking a hole so the freezer can see outside air. That means a penetration in your vapor barrier and that is hard to seal up. If there is a hole, you will get a lot of moisture in the summer and that could me mold inside your cooler. At the least, it will mean the compressor will have to work very hard to keep up.

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Cool. Vapor on the warm side. Got it.

I am going to just put a freezer in the cooler. What I will do is build the back of the freezer flush with the outside of the frame, and spray foam the **** out of it where it meets up with the walls. I do not have my design program at my office, but I will make up a new drawing when I get home. I just can't wait to get out of my current house and get a fresh slate to make a nice brewing area with a bar and "Man Cave" in the basement.

What exactly do you want the freezer section for? Does it really have to be integrated into the walk-in cooler design?

My 0.02: If you are going to use a refrigerator to cool the freezer unit, why not just go with a chest freezer and keep it separate? It seems like if you get rid of the integrated freezer idea, this project become much easier to work out and more doable.

Yeah, the freezer inside the cooler idea is a cool...but is it absolutely necessary?

That may work for the freezer, but as the saying goes, "Penetration are Problems waiting to happen."

To be honest, you won't be taking a major penalty from having the "hot" air being a load on the cooler. Since the freezer is in the cooler, it won't be a large load, plus the compressor won't have to work very hard to compress refrigerant to discharge to the cool temperatures.

Its almost like single stage vs. two stage vapor compression systems. Wikipedia that to see what I mean. the difference is you are using air between the two refrigerant streams.

I guess I'm a KISS sort of guy. And just paneling up the back wall sounds easier than trying to poke holes, make seals, etc. Plus it would be easy to pull out as was previously mentioned.

Well, I agree with that, and as I have a freezer in my garage, I can test the temperature blowing off of the coils in the winter to see how hot the air it is ejecting is. That will give me and idea of the load that it will be placing on the cooler.

I was going to just frame it in like the door, but I guess that if it dies I would be having to do major remodeling to get another one in the same spot.

Thanks for all of the help thus far guys!! It is sad that I am still just building up a BOM and putting the prints together. I am the type of guy that once the plan is laid I would rather just jump head first in to it. I can't even think about starting this until I sign closing papers... and that is at least 2-3 months away

Oh well, I have the build of my brew rig to hold me over until then!

broadbill said:

What exactly do you want the freezer section for? Does it really have to be integrated into the walk-in cooler design?

My 0.02: If you are going to use a refrigerator to cool the freezer unit, why not just go with a chest freezer and keep it separate? It seems like if you get rid of the integrated freezer idea, this project become much easier to work out and more doable.

Yeah, the freezer inside the cooler idea is a cool...but is it absolutely necessary?

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I do not think that the freezer is making it hard at all. What is making it hard is deciding how to cool the freezer and draw from it. I could easily go out and buy a freezer blower and condenser unit, but where is the fun in that. The challenge here is to push the limits of what has been done, what can be done and how it can be done. The freezer section will be used to store food, hops, and bodies. I actually am just as excited to have a large freezer where I can store meat and Sams purchases as I am for having a keg cooler. Just wait until I attach another addition to this with more louvers and fans for a fermentation chamber!!

I actually found a commercial cooler on craigslist that is $800, and I may just buy that. I am waiting to hear back if it includes the blowers or not. Even if I buy that, I am still going to have to DIY some of the build which makes me happy. The walls on this unit are really tall, and will have to be cut down to fit my space. The condenser is also mounted on the roof of the cooler and mine would have to be mounted on the side. Either way I cut it, this animal is about $1000 and that is not too shabby for a giant fridge. (the freezer not included in that price!)

GVH_Dan said:

..."Penetration are Problems waiting to happen."...

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True in many aspects of life...

Here is a pretty big update to the prints... I based them off of the suggestions and a quick drawing one of the guy on my board posted. I am still concerned that the ac unit should be exhausted to the outside of the house, but that can always be changed for a few dollars even after the build is done. I also have plenty of time to ponder this before I can even begin work so maybe I will figure out my balance between the positives and negatives.

On to the images:

Overview of the room:



View looking left from the door:



View looking from the front left corner:



Birds-eye view of the whole thing. You can see how thick the walls are in this one (ignore the right corners... it is a program thing I can not figure out.):

I got a lot more feedback from the other board, and this is what we came up with in the end:

Here is What I came up with after taking a measurement of my current basement and assuming that my new house will be pretty close to the same width.

EDIT: Damn... The dimensional overview image is corrupt and on my home computer... oh well, 3d overviews gives enough of an idea for now.

This is the layout of the rooms up against the concrete of the foundation:


Here is a shot of the unfinished bar, and it will not look like this at all, this is for illustration purposes. I am going to build it using nice woods and either pounded brass or copper. Notice the sliding window that reaches into the cooler so that we can store bottles of beer on that shelf and have easy access to them!


The brewing room. There is still more to go in there as well, but the program didn't really have all of the images I need so I will have to create them.


And the cooler which is virtually unchanged except for the window and the door moving from the front to the brew room.


I will probably update this sometime over the weekend with my final revisions and a full Bill of Materials with cost.

THANK YOU ALL FOR YOUR HELP!!! I would have never gotten this project to this point without all of the great input here. I can not wait to create the build thread in a couple of months when we start putting all of this craziness together.

Still not sure why your stuck on the idea of having the freezer open into the cold room, especially the way you have everything laid out. Why not have the freezer sitting in that corner of the brewery but opening into the brewery. This keeps you from having to open the cold room door(and letting a lot of cold fall out) just to get something out of the freezer. It also makes more "wall space" inside the cooler where you could put more kegs/shelves/stuff without really giving up much space in the brewery.

Also it's not clear in the mockup, will there be a part of the bar that hinges up, or will the bartender have to leap the bar to get back there?

I want the freezer in the cooler so that I can pull things out of it and into the fridge to defrost. I also think that it works out a lot better in the cooler aesthetically. I really will not need any more shelf space in the cooler as I already have more than actually necessary.

As far as the bar, I tried for like 15 min to get the bar built how I wanted in the drawing.... It was not happening so I drew a cabinet, threw a top on it and called it a bar. The actual bar will be much nicer and will have a hinged gate on the right side so that we can get behind it. That or we are considering a walkthrough between the brew room and the back of the bar.