This is a wiki for a cold storage trailer.
Initially conceived and designed to deal with the need for post harvest storage while ensuring the investment in infrastructure would not be lost if the farm moved locations.
The project took around 1 month to build in the spring, that includes taking care of the typical farm tasks that take place during that time of year.
Basic wiring abilities
Air conditioner (10,000 BTU)
2x4's for framing
5" metal screws
Mold resistant bathroom paint
Eco-friendly lino glue
Carpet knives and blades
Drills and impact driver
Sanders and sandpaper
Remove all the interior plywood
Reroute the wiring and put it into a sheath to protect it from being crushed later one.
Also consider that you may have to access this again in the future, so take care to keep relatively easy to get at.
Another option would be to either keep the wiring on the exterior of the walls. However, this has not been a problem after 5 years of use.
Be sure to mark it's location as you continue with each subsequent layer of insulation and finishing material.. keeping a good photo log also helps
Frame anything that needs to be, such as AC opening
Start fitting insulation between studs.
This can be a painstaking process, and I would recommend using 1" insulation initially as the studs are around that thickness. Followup with another layer of 1", and finish with 2".
Another option is to use a spray insulation for the whole thing... this could be more cost effective, but likely you will have to pay someone to do it.
Once you've insulation spray foam the joints... once dry you can trim with a knife.
Tape all the joints with tuct tape.
Be sure to mark studs and wiring as you cover each layer
Be sure to test the AC in the opening before commencing with this stage.. also remember that the finished size of the opening will probably be close to 1/8-1/4 inch smaller with metal.
Reinstall the wood paneling.
Everything will need to be cut to fit the new interior dimensions of the trailer (ie: you've just added 4" to all four sides of the box)
Start with the ceiling, drilling exit holes for the light wires
Next do the floor.
Next install the wall panels - you may need to scribe some of the joints to get a tight fit (see photo)
Doors - depending on the trailer, you may have to come up with some creative ways to frame and insulate these. take care to factor in the change in heights and widths of the interior.
Sand and fill any woodwork
caulk all joints
paint with a mold resistant bathroom and kitchen paint
Install the linoleum floor
04-07-2017 After thoughts:
5 Years late the farm is still using this tool. It has withstood a lot of wear and tear but is holding up. We have had to replace the AC once, but this tends to be common with coolbot systems that are taxing machines. Properly covering the AC in the off season is a good way to prolong it's life. Though we never got around to it, I think adding some hanging plastic partition between the door and the entrance of the trailer would be a good way to reduce cold air loss when you are opening the door.
On the efficiency of a portable coldstorage: It has been nice overall to have a portable infrastructure, but it does come with drawbacks. Probably the most obvious is the limited dimensions of a trailer and how this can impede getting in and out and quickly reaching different stored crops. The unit maintains a pretty cool temperature in transit and typically is not plugged in at the market, although that is an option that definitely makes it attractive for folks going long distances in hot climates.
Buying a new trailer was the biggest expense for this project, and if you can find a used rig that is in good shape, this is a pretty solid investment.
Feel free to contact me for more questions and triage.