Walk In Cooler!

I was in a home in Waddell, AZ (very west side of metro Phoenix) where the home owner showed my his walk in cooler next to his kitchen. It was a triangular shaped closet converted into a cooler using an AC unit dumping heat to the north side outside. He has a nice thermostat and temperature/humidity reporting display on the kitchen wall. Inside he has a couple of tubs filled with water as his humidity source.

I think they kept it at 40F, though an ideal temp for prolonged storage would be around 32F (+/- 1F) if you could keep it from going below 31F ever.

Such a setup may benefit from small circulating fans pulling cooler air up from floor and not allowing any heavier than air ethylene oxide gas from concentrating in any area.

I would have designed the door to either open out so as to not cover a interior wall–put another way, the door does not allow you to put shelves up against a wall the door needs to open into–or open into the ac area (with a stop) which is already restricted. Plus with a door opening out you can put a curtain in that helps hold the cold air in when you open the door.

This of course envisions vegetable and fruit cold storage. For hanging deer it is not an issue though it requires more space to open the door into the interior.

I’d have the condenser runoff going out to feed a plant (distilled water). In Phoenix, definitely want the exchanger exhaust dumping outside and being in the shade.

NICE PROJECT thanks for sharing.

Mike this looks great! Glad to hear everything is working great! I might hit you up if I have a bumper crop and get into trouble :0)

I have 95% of the trees in there now.



The cooler really has worked good for you through the years. I’m impressed with your setup. If anyone is looking for the parts to put this together it has became more expensive but is still much more reasonable than a walk in cooler. This is your best DIY project yet! All these years later it still looks great.


LOL, I really don’t remember starting this tread at all.

The cooler did turn out to be a good investment. I built it to store Bareroot trees in the Spring but, now it also houses fruit through the Fall and Scion in the Winter.

I would make a few minor changes if I were to build a new one, but the Cool Bot Platform and plans on their site are solid. As @clarkinks said, material cost have gone up (like everything else). But, If you use quality materials, it should last a very long time. Ran a new 100 amp subpanel out to the garage and might add a second coolbot cooler. If I run out of space there, I would look into a used reefer trailer / truck


@clarkinks how does your fruit do on a coolbot room? I’m thinking I need something and unless I can find a used walk in cooler, fairly cheap might go with this.



It is a question best asked to @39thparallel who uses his all the time. It is always pretty cold in there and fruit , scion wood, and new trees keep well.

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@fullplate @clarkinks It works great. The key is insulating well and having a moisture barrier. I have R30 foam walls floor and ceiling Commercial walk in in cooler are big money and probably need 220 service.


We started with a homemade cooler with commercial refrigeration equipment and moved to a cool bot when the compressor died after about 15 years.

Cool bot works great but it does not handle the introduction of large amounts of warm fruit well. It chocked and froze up when we introduced 500 pounds of Peaches at 85 degrees a few years ago.

Also, we could maintain 33 degrees with the refrigeration equipment but low 40’s is the best we can do on a hot day with the cool bot.


We just built a unit about a month ago and it is a true game changer. It’s too bad that we waited so long.

Anyway, ours is about 6x20, but it’s divided into two rooms, 6x8 and 6x12 (or somewhere around that size). We have the Coolbot unit in the 6x8 room and we can open a door so that we have a larger space if we need it.

Also, the outside of the entire unit is it insulated really well, but on the inside, the 6x8 room leaks a little cool air into the other space. This is by design. We put vegetables, mainly tomatoes in that room. It keeps them cool without refrigerating them, so they last longer.


Thanks for all the replies I appreciate it. I could see where sticking 500 pounds would not work I’d imagine even a commercial unit would struggle with that but if I could say put two pounds per 24 hours that would work for me. I’m pretty sure I’ll start thinking and pricing materials, again thank you.


Has anyone recorded KWH usage per month?

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Ours is 10’ x 20’ , 7’ high ceiling. Costs us about $90/ month to run it with only going into it once or twice a day during the summer.


do you know your price per kwh for electricity? I am in Germany and suspect we are paying roughly double most American prices for electricity, so the KWH number is a lot more practical.

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