DIY Walk in Freezer

Well this is all very interesting as a project just to see if you can make it work type of thing....but if you want serious reliable cooling, I would at least buy the refrigeration unit...and then you have only to match the heat load of the box it was designed for, or you could build the box, determine the heat load and match the ref unit to it...Refrigeration units are very precise in their engineering, trying to match the performance by seat of the pants junkyard ingenuity, is amusing but not practical imo....

An A/C unit would probably work, but for how long. They are cheaply made (China) and not up to the strenous task of keeping temperatures in the freezing zone. What do you do when the unit fails and the frozen foods thaw?

I saw a DIY type freezer unit someone made years ago that in fact did just use an ordinary old style window air conditioner unit for the cooling system. The guy just separated the unit into two parts and had independent fans for the condenser coil and compressor on the outside and the evaporator coil that was inside the freezer shack.

The old air conditioning units built out of copper and steel with R22 freon can easily handle being ran down to 0 F and below without issues. All they need is the factory thermostat bypassed and a proper level of insulation separating the two coil and fan systems.

I say go for it!

Don't forget to insulate the floor.

A good door will be the most difficult thing to fabricate without a proper fabrication facility.

Regarding using a repurposed A/C. That will work. Not something I would bother with though...This is not a commercial solution so knock yourself out.

Not really a typical exterior door around here easily handles our -30 F winter temps while maintaining a comfortable 70+ F inside the house.

Price around $120 - $175 and any home building center or hardware store.

Here's your link to the site that can help you put the whole shootin' match together.

http://www.storeitcold.com/index.php

Great link! Thanks.

A window unit should last longer in a cooler/freezer mode than regular mode if done right.The system has a lot lower pressures overall due to the low temp.I do intend to separate the condenser-evaporator unit and super insulate.The unit will be 80% in-ground, so losses will be minimized.

Thanks for all the help to everyone,the feedback encouraged me to dig deeper into the matter.

Alternatively,I am considering buying a surplus ice cream truck body with cooler unit, but I have to wait for one to come up for auction.Anyone have any leads on this item?

Couple of things

1. the compressor has to have enough capacity ( plus an additional 10-20% "carry-over" ), as determined by Schedule J or other heat load calculations

2. it also must be compatible with the oil and refrigerant type

3. an a/c compressor is typically rated for high temperature refrigeration (air conditioning) and your application will require a low temp. type.

4. furthermore, it must have the adequate temperature rating at continous duty for the environment it is to run in, or it will trip on internal overload

5. there is no 'freezer freon' ; the p/t and azeotropic curves determine this for the subcooling, superheat, design and holding temperature points i.e. -20F to be achieved

I wonder if an automobile unit might be better for you. They are, necessarily, more rugged and with a geared electric motor to drive the compressor at optimum RPM, they should do a good job. The coils are already separate and parts are readily available for them.