What size cool store do I need? Are there recommended cool store sizes for onions and potatoes? What is the best height?
On-farm cool storage facilities are the next big thing in the horticulture industry, especially for onion and potato growers. But just how big do they need to be? Read on to find out!
Cool stores for onions and potatoes are growing in popularity, with labour restraints, rising off-farm storage costs, and supermarket contract demands some of the factors driving this trend.
If you are looking to gain more control over quality, increase productivity and reduce operating costs, then a cool store shed can be a smart investment. It allows you to store produce on-farm for longer, and can be cost-efficient to run too. For example, Tolsma units such as the Quadro Compact Cooler have hatches that open when the outside temperature is low enough, reducing the need for active refrigeration.
Like any shed, size is an important consideration for cool stores.
Poorly planned dimensions can create logistical headaches, while a lack of storage capacity may limit your ability to scale production or achieve the return on investment you are aiming for.
So, in this article, we walk you through the steps to choosing the right size for your cool store.
We also provide recommended dimensions and shed sizes based on common storage volumes for potatoes and onions.
Let’s get started.
7 Steps To Deciding Cool Room Sizes
1
Budget
Your budget is often the starting point when planning a cool store shed. There are a few general rules of thumb to help you get the most value for money:
- A longer shed is usually more cost-effective than a wider one.
- Including a “roof-only” section can provide a cost-effective area for short-term storage and improve access and airflow.
Smart budgeting and planning will ensure your cool store works for your current requirements and can be easily and cost-effectively extended in the future.
2
Site Restrictions
Consider whether there are site restrictions such as limited access or existing infrastructure that will shape the size, configuration and footprint of your cool store shed.
3
Capacity
Storage capacity is arguably the most important factor when determining your cool store size.
Consider:
- How many tonnes do you plan to store?
- Whether the shed includes an airing area
- How high do you intend to stack boxes or bins?
These factors will shape decisions around:
- The number of cool rooms
- Bay spacing
- Clearance heights
You’ll find best-practice recommendations for each of these later in this article.
4
Shed Access
Safe and efficient access is critical for day-to-day operations and should be factored in early.
Start with your site layout—is there enough room for trucks and forklifts to safely turn or reverse? Then look at the shed itself:
- Shed width, height, and bay spacing all influence access – refer to the Cool Store Size Recommendations section.
- An open gable can provide cost-effective wide access, especially compared to options like girder trusses, which involve removing a column between bays.
- Consider the machinery and equipment that will be accessing the shed, such as your forklift size and lifting height.
Remember, inefficient access and slower loading/unloading aren’t just frustrating, they cost you money.
5
Cool Room Fitout
The quantity, size and layout of the cool stores will directly shape the overall size and configuration of your shed.
For example, column placement will be planned and even varied throughout the shed to ensure the columns don’t interfere with cool room doors, external vents or refrigeration units or hatches
Structural columns will also need to be engineered to suit suspended cool room panelling.
Coordinating your shed layout and cool room design from the start will save on retrofits and inefficiencies later.
6
Ventilation & Airflow
The dimensions of your cool store shed can influence the amount of natural ventilation and airflow through the facility.
This is an important consideration if your shed includes a short-term storage area. For example, a roof-only section is a popular inclusion for airflow (and easy access) when moving boxes in and out of storage.
7
Future Plans
Cool stores are tipped to become important infrastructure for growers by opening up market opportunities and helping you to keep ahead of the game. So, it is important to ensure you aren’t limiting future growth with your cool store size.
- Consider current requirements and future production goals. Is a shed ever too big?
- Choose a site with space for additional cool rooms or a roof-only extension
- Avoid design choices that box you in or are difficult to change. For example, it is difficult to increase the height of a shed once it has been installed.
This is a great way to future-proof your shed and ensure it continues to deliver value as you grow.
Cool Store Size Recommendations
What Is The Best Cool Store Height?
To ensure that there is adequate clearance, the shed height needs to allow for the depth of the roof trusses.
Typically, if you are stacking six boxes high in your cool room, a seven-metre-high ceiling is required.
The overall shed height (eave height) varies between span widths. For example, a 30-metre span has a roof truss depth of one metre. As a result, an eave height of around 8.25 metres is required.
What Is The Best Cool Store Length?
The cool store length is determined by the bay spacing that works best for your cool store and the number of bays that are required.
Our building consultants work closely with cool room specialists on details like bay spacings to ensure that the column placement doesn’t interfere with the cool room doors, external vents or refrigeration units or hatches.
It is worth keeping in mind that most potato and onion boxes are approx. 1.8m (W) x 1.2m (D). This is handy to know when determining the best bay sizing in airing areas and cool room sizes.
What Is The Best Cool Store Width?
The best cool store width will depend on the configuration of your cool store facility.
However, there are several popular standard span sizes for cool stores, including 24m, 27m and 30m.
You can learn why we recommend using a standard span size here – What Are The Standard Spans For Farm Sheds?
So, what size should you build? What cool store sizes work for your storage requirements?
Our building consultants have provided some suggestions below based on popular storage capacities.
Standard Cool Store Size Suggestions
Please note that these assume standard stacking height and typical bin/box configuration.
- 15m (L) x 24m (W) x 8.25m (H) stores approx. 650 tonnes of potatoes or onions (single room)
- 18m (L) x 30m (W) x 8.25m (H) stores approx. 1,050 tonnes of potatoes or onions (two-room layout)
- 21.6m (L) x 30m (W) 8.25m (H) stores approx. 1,550 tonnes of potatoes or onions (three-room layout)
We trust these cool room sizes and advice have been helpful! Looking for more ideas and inspiration? Check out the gallery below!
Useful Resources
- How Much Does A Potato Cool Store Cost?
- Euston Park’s Cool Store Saving Time & Money
- What Is The Leadtime For A New Shed?
That’s a wrap on cool room sizes for potatoes and onions!
Ready to capitalise on the benefits of on-farm cool stores? Book a project consultation today—call us on 1800 687 888. We’d love to work with you.
