shipping container flower cooler with coolbot
We’ve been in need of more cooler space for a while. For those of you who are newer to our story- when we purchased our farm it had zero farming infrastructure. It didn’t even have a garage. I guess there was shed, but it was rotten beyond repair and it definitely wasn’t a place you could store anything that wouldn’t soon be inhabited by rodents or hornets. We chose a comfy home for our uprooted family over the farming set up of my dreams. Oh well! On the bright side- I’ve been able to grow our infrastructure to meet our needs specifically.
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I modified a Carry-All trailer during my first season to serve as a flower cooler. It is about 5ftx5ftx8ft. It is fully insulated with spray foam (even the underside) and I added a small A/C unit with a Coolbot.
Our walk in “cooler” serves a couple of purposes. In the warmer months it does exactly what you’d expect- it’s a flower cooler for hydrating and holding freshly harvested blooms until they are ready for sale or design work. We can also dry store peonies and tulips there. But in the winter we use it as a root cellar- so it really needs to be minimally heated in our cold climate. We’ve been using that modified Carry-All trailer for these purposes for the last several years. But we’ve outgrown that space.
My plan has been to allocate part of small barn that will be built here to serve as our cooler. We planned to construct our own cooler inside that space. But unfortunately our builder expressed a number of concerns about our plan and it became clear that they weren’t confident in our plan. We went back and forth a few times, and after explaining several times to them that their alternative idea (to purchase a ready made cooler and put it inside the barn) would be cost prohibitive and too small a space for us, I scrapped the plan all together, and took “cooler space” off the contractor’s plate. I resolved to solve the problem on my own.
What I found is that I could create the most cooler space for the lowest cost by using a shipping container. We decided to buy an insulated “reefer” (refrigerated) cooler because we knew it would be fully outfitted with surfaces that could be easily cleaned and disinfected if needed. But we didn’t want to use the 2-stage diesel powered cooling unit in regular reefer units and we didn’t want to pay twice as much for a single stage electric one, either. The best choice for us was to purchase a broken diesel unit and modify it with Coolbot units to serve our needs. We were able to save a little money in purchasing a broken unit, too. The cooler cost me $7600 delivered.
Coolbot customer service will recommend to you how many units and how many BTUs you should employ to reach your desired temps in an insulated container. That amount is going to depend on your climate and intended purpose. They suggested about 4800 BTUs for us (which could be met with 2 really large LG A/C window air conditioners) and two Coolbot units for controlling them. Given that we were entering the fall and would need less cooling this fall and that we have some electrical constraints this season (we plan to upgrade to 400 AMP service for our farm next year), we decided to add 3,000 BTUs this fall via two, 1500 LG A/C units. This is the largest size A/C that could still safely run on the two 240v outlets available to the container for this project. It’s really important to know what kind of electrical you will need when you’re putting together these Coolbot systems so you don’t overburden your outlets/breaker box.
If we determine that we aren’t able to keep our cooler cold enough next summer, we’ll add a third 1500 BTU unit and that system will get us really close to the recommended amount of 4800 BTUs. For now, our cooler will run for a few weeks and then we will switch to minimally heating the container with a space heater to maintain temps above freezing. It is having no trouble maintaining 40 degrees right now.
Some things we learned when modifying our container:
-There are I-beams located within the walls that are exponentially harder to cut through than the areas between them. We hit one I-beam when cutting the first hole for the first A/C unit and then knew what visual clues (seams) indicated the placement of others. We drilled pilot holes to start our cuts and used a reciprocating saw to cut the holes for the A/C units. We added some stainless steel L-brackets to the outside of the container to help support the weight of the A/C units. Once installed, we sealed the small gaps around the A/C units on the inside of the container with some insulation tape. We sealed the gaps on the outside with some expanding foam.
-Insulated shipping container doors (ours at least) can be real jerks to open. I don’t know what our long term solution will be for this problem. We have tried greasing them and we’ve ground down the rust we saw on the frame. Now we’re tossing around ideas like installing a regular door or removing the container’s swinging doors and replacing them with an insulated roll up garage door. For now, we roll up our sleeves and muscle them open.
Having this new climate controlled space on our farm is a game changer. We have space to accommodate the growth of our bulb forcing program and lots of room for the cut flowers that were clogging up the design studio last summer. Its a relief to have it here and set up, and we already consider it to be part of our integral/necessary infrastructure. (It’s almost filled up already!)
Have questions about modifying shipping containers to turn them into coolers? Let me know in the comments and we’ll do our best to answer or we’ll try to refer you to someone who can help.
Best,
