DIY Flower Cooler from an Existing Structure | Keeping Flowers Fresh

If you’re entering into the world of cut flower business, a flower cooler is something that you’ll likely be investing in, to grow your business and give your cut flowers the most bang for their buck! Let me show you how you can easily DIY one from, even the smallest corner of your garage.

Flower Coolers (aka floral refrigerators or floral coolers) keep the humidity high and the temperature low to keep your flowers fresh. Thankfully, you can look no further than your own home to create a DIY Flower Cooler!

After 5 years of growing cut flowers on our farm, our business flourished (pun intended) to a point where a flower cooler was the next step we needed to take. This wasn’t a snap decision – I had been pondering where to put a flower cooler for years, until I realized that our small utility shed where we keep our family bikes and other storage- would be a perfect spot, until the farm would need it to it’s full capacity.

With the shed, I already had the structure on hand (no need to buy a new cooler), it has a great walk-in size to fit multiple flowers, and it would only need to be used in the summer months (the rest of the year it could serve it’s original purpose of storage). So? Problem solved!

Building this utility shed into a flower cooler has been a major win for our business! This welcome addition has given me the space to lay out large arrangements, vases of flowers, centerpieces, and install items. With our own walk-in cooler, we have been able to handle our first funeral and two more weddings – talk about growth!

Let’s get to building our walk-in flower cooler!

How to build your own Flower Cooler the video

Why You’ll Love Having Your Own DIY Flower Cooler

  • This DIY Flower cooler provides a cost-effective way to lengthen the lifespan of your fresh flowers
  • This cooler can be built from any structure around your house – it’s a creative way to use (or reuse!) items you already have!
  • A Floral Refrigerator can make the difference between a hobby and a business. You never know when your cut flower business might go from, setting up a roadside stand to needing to create a large install or funeral piece that simply would never fit into your standard garage refrigerator.

Materials you’ll need to build your DIY Flower Cooler

  1. 3-4′ foam insulation (Rigid foam is recommended). The higher the R value of insulation, the lower your electricity bill will be. R25 is recommended (You can layer: two layers of R10 and one layer of R5 to achieve this). *Do not use fiberglass
  2. Caulk and/or spray foam insulation
  3. CoolBot (Check out: “Questions People are asking about”) Our coolbot has saved us about 40% on energy costs too, as opposed to running a traditional cooler.
  4. Air Conditioner compatible with CoolBot
  5. Paneling to cover the insulation (optional)

Total Cost (I personally spent) for materials = $700

coolbot in flower cooler

Steps to make your DIY Flower Cooler

  1. Pick a structure (This can include a variety of sizes. For us, it was our walk in utility shed)
  2. Clean out entire structure
  3. Cut a hole in one of the walls to fit the air conditioner
  4. Hook up CoolBot. What is a CoolBot? Check: “Questions People are asking about this topic”.
  5. Fill any small gaps including between sheets of insulation and under every door/corner with caulk or spray foam insulation to ensure air tightness. Or just place your pieces of insulation over top of the studs. Use spray foam insulation around your air conditioner as well. *Do not use Caulk and Spray Foam insulation together in the same spots – they do not work together and can counteract each other over time.
  6. Add insulation to the inside walls of the structure.
  7. Optional: add paneling over the insulation. For sheathing our interior, we went with a thin fiberglass reinforced plastic (FRP) which durable, sanitary, and easy to clean.
  8. Personalize cooler space to your needs! Shelves, etc.

For more specifics check out “Helpful Tips!”

flower cooler room

Questions People are asking about DIY Flower Coolers

How do flower coolers keep flowers fresh?

Flower coolers keep flowers in a high-humidity and low-temperature environment (the optimal temperature range is anywhere from 30 – 40 F degrees). This slows down the blooming process in different parts of flowers (cell growth, respiration, and sugar consumption). This allows them to stay fresh for a longer amount of time and have a longer shelf life.

Can I buy a flower cooler?

Yes, you can buy commercial flower fridges. However, one look online will show you floral refrigerators cost anywhere from $1,000 to $7,000 – eek!

What is CoolBot and how does it work?

CoolBot is an electronic device that connects to an air conditioner. It allows your air conditioning unit to go cooler than usual by tricking it into thinking the room is warmer than it actually is. For example, it allows the AC unit to cool a room down to around 38 degrees F. The ideal temperature we keep our flowers at is around 38 – 40 F / 3.33-4.44 C degrees.
Learn more about CoolBot here:


Helpful Tips!

  • Do not use Fiberglass Batt insulation. Even with the right vapor barrier, the humidity levels in your cooler can make this a moldy mess and can allow cold air to leak out. This uses more and costs more in electricity.
  • If possible, keep your cooler out of direct sunlight (this will save construction and operating costs). If not possible, put twice as much insulation on the roof as the walls.
  • With studs, it is optimal to put the insulation over (outside of) them and not in between them. Insulation between studs can shrink and cause gapping over time. If you do install insulation between studs, make sure that you also put some over them as well.

More information/specifics for how to build your walk-in cooler: here

Pin this for later!

Other Helpful Builds + Gardening Posts

hearty sol signature

Affiliate Disclosure & Content Disclaimer

This post may contain affiliate links from a paid sponsor, Amazon or other program. When you use these links to make a purchase I earn a small commission at no extra cost to you. This allows me to continue creating the content that you love. The content in this article is created for information only and based on my research and/or opinion. 

Emily T.

Leave a Reply

Your email address will not be published. Required fields are marked *


it's hip to be square!