When summer temperatures start climbing, keeping a large warehouse or factory comfortable can quickly become a challenge. High ceilings, open roller doors, heat-generating machinery and constant movement of people and equipment can all contribute to uncomfortable working conditions. Industrial evaporative cooling is a popular solution for Australian warehouses, offering an energy-efficient way to deliver large volumes of cooled, fresh air into commercial and industrial spaces. But one of the most common questions we hear at Fanmaster is: “How many evaporative coolers do I actually need for my warehouse?” The answer isn’t always as simple as dividing your floor area by the coverage advertised on a product specification sheet. Getting evaporative cooler sizing right means understanding your building dimensions, airflow requirements, warehouse layout and where cooling will provide the greatest benefit. Fortunately, you don’t need to work everything out yourself. Fanmaster has developed an online Evaporative Cooler Calculator to help businesses estimate their cooling requirements and determine how many industrial evaporative coolers they may need. Here’s what you should consider before investing in a warehouse cooling system.
1. Start With Your Warehouse Dimensions
The first step in evaporative cooler sizing is understanding the size of the space you’re trying to cool. While most businesses know their warehouse floor area in square metres (m²), the total building volume in cubic metres (m³) is equally important when assessing airflow requirements. Consider two warehouses, both measuring 500 m². One has a ceiling height of 4 metres, while the other has a ceiling height of 10 metres. Although their floor areas are identical, the second warehouse contains two and a half times the volume of air. This difference can significantly influence the amount of airflow required, particularly when designing a whole-of-building cooling system. To calculate your warehouse volume: Length × Width × Height = Total Volume (m³). For example:
- Warehouse length: 30 metres
- Warehouse width: 20 metres
- Ceiling height: 6 metres
- Total warehouse volume: 3,600 m³
This provides a useful starting point for estimating how much air your cooling system may need to move. However, warehouse dimensions are only one part of the equation.
2. Understand Air Changes Per Hour (ACH)
One of the key factors in evaporative cooler sizing is Air Changes Per Hour, commonly referred to as ACH. ACH measures how many times the equivalent volume of air inside a building is supplied or replaced over a one-hour period. Unlike refrigerated air conditioning, which generally operates in enclosed spaces, direct evaporative cooling works by continuously introducing fresh, cooled air and allowing warmer air to escape. This makes airflow an important consideration when selecting equipment. The basic calculation is: Warehouse Volume (m³) × Target ACH = Required Airflow (m³/h). Using our earlier example of a 3,600 m³ warehouse:
| Air Changes/Hour | Required Airflow |
|---|---|
| 10 ACH | 36,000 m³/h |
| 15 ACH | 54,000 m³/h |
| 20 ACH | 72,000 m³/h |
These figures illustrate how airflow requirements change depending on the selected air-change rate. They are examples only, not recommended ACH rates for every warehouse. The appropriate rate depends on the cooling objective, local climate, heat loads and building design. A higher airflow rate does not automatically guarantee better cooling. Air distribution, humidity and adequate exhaust openings are just as important.
3. Whole-Warehouse Cooling vs Targeted Cooling
One of the biggest mistakes businesses make when planning warehouse cooling is assuming every square metre needs to be cooled equally. In reality, different areas of a warehouse often have very different cooling requirements. For example, a typical warehouse might include packing and dispatch areas where employees work continuously, high-bay storage aisles with limited staff activity, loading docks with roller doors frequently opening, production areas generating additional heat, and offices or enclosed workspaces within the building. Trying to maintain the same conditions throughout all these areas may result in unnecessary equipment and running costs.
Whole-Warehouse Cooling
Whole-warehouse cooling aims to distribute cooled air throughout a larger working environment. This approach may suit manufacturing facilities, distribution centres and warehouses where employees are spread across multiple areas. Depending on the building, this could involve fixed industrial evaporative coolers with strategically positioned air outlets and appropriate ventilation.
Targeted or Spot Cooling
Targeted cooling focuses on specific work areas rather than the entire building. For example, a warehouse with 1,500 m² of floor space might only have 300 m² of regularly occupied packing and assembly areas. In this situation, strategically positioned portable evaporative coolers may provide a practical alternative to a larger whole-building installation. Portable units also offer flexibility as workstations, staffing levels or operational requirements change.
The key question isn’t simply how large your warehouse is, but where your people actually need cooling.
4. How Many Evaporative Coolers Will You Need?
Once you’ve established your warehouse dimensions and cooling objectives, you can begin estimating the number of evaporative coolers required. For a preliminary whole-building calculation, the basic formula is:
Required Airflow ÷ Effective Airflow Per Cooler = Estimated Number of Coolers
Let’s return to our 3,600 m³ warehouse. If a preliminary assessment identifies a target of 15 ACH, the required airflow would be: 3,600 m³ × 15 ACH = 54,000 m³/h. If a proposed evaporative cooler could deliver an effective airflow of 18,000 m³/h under the intended installation conditions: 54,000 ÷ 18,000 = 3 coolers. This gives an initial estimate of three units. However, that doesn’t automatically mean three coolers will provide satisfactory cooling throughout the warehouse. The final quantity and positioning must also consider how effectively cooled air reaches occupied areas, the distance air must travel from each unit, obstructions such as pallet racking, partitions and machinery, available ventilation and exhaust openings, heat generated by machinery, roofing and other building surfaces, and local summer temperature and humidity conditions. A correctly sized cooling system needs to do more than move enough air on paper. It must deliver useful cooling where people are working.
5. Take the Guesswork Out with Fanmaster’s Evaporative Cooler Calculator
Not sure where to start? We’ve made the process easier. Fanmaster offers a free online Evaporative Cooler Calculator designed to help businesses estimate the number of industrial evaporative cooling units required for their space. Rather than working through airflow calculations yourself, you can enter your warehouse dimensions and receive an initial estimate of your cooling requirements.
How Does the Calculator Work?
Using Fanmaster’s calculator is straightforward:
- Enter your warehouse length in metres.
- Enter your warehouse width in metres.
- Enter your ceiling height in metres.
- Click Calculate to view your estimated cooling requirements.
The calculator provides a breakdown of your floor area, building volume, air-change calculations, required airflow and estimated number of evaporative coolers. It is designed to help businesses assess their cooling requirements using Fanmaster’s IDDAC-670 industrial evaporative cooling system.
What About Warehouses with High Ceilings?
The calculator uses a 5-metre height basis for its sizing guidance. For warehouses with ceilings higher than 5 metres, additional consideration may be needed to ensure cooled air reaches occupied working areas. This could involve drop-down ducting to direct cooled air closer to employees or alternative installation arrangements, depending on the building.
A Useful Starting Point, Not a Final System Design
While the calculator provides a convenient starting point, every warehouse is different. Factors such as internal heat loads, racking, ventilation openings, local climate and how the building is used can influence the final number and positioning of cooling units. For larger installations, we recommend discussing your results with the Fanmaster team or an experienced installer before making a purchasing decision. Ready to find out how many evaporative coolers your warehouse might need? Try Fanmaster’s Free Evaporative Cooler Calculator. Enter your warehouse dimensions and get an initial estimate in just a few simple steps.
6. Why Warehouse Layout Matters Just as Much as Size
Two warehouses with identical dimensions can require very different cooling arrangements. Consider a relatively open warehouse with minimal internal obstructions. A smaller number of appropriately positioned high-capacity evaporative coolers may be able to distribute cooled air effectively throughout the working environment. Now consider another warehouse of the same size filled with tall pallet racking, machinery and partitioned work areas. Even if the total airflow requirement is similar, the second warehouse may need additional air distribution points or a different equipment arrangement to avoid poorly cooled areas. This is particularly important in facilities with high-bay storage. Airflow needs to be directed towards occupied working zones rather than simply circulating above the racking. When planning your evaporative cooling system, consider where employees spend most of their time, whether equipment blocks airflow, which areas receive direct sunlight and how cooled air will travel through the building. Taking these factors into account early can help avoid purchasing equipment that appears suitable on paper but underperforms once installed.
7. Portable vs Fixed Evaporative Coolers: Which Is Right for Your Warehouse?
Both portable and fixed evaporative cooling systems have a place in Australian warehouses. The right choice depends on the building, budget, cooling requirements and how much flexibility your operation needs.
Portable Industrial Evaporative Coolers
Portable evaporative coolers are particularly useful where cooling needs change throughout the day or where permanent installation isn’t practical. They can be moved closer to workstations, loading areas or production zones as required. Key benefits include flexible positioning as operational needs change, no permanent ductwork installation, targeted cooling for regularly occupied areas, suitability for seasonal and temporary applications, and the ability to add cooling capacity progressively. Portable units are especially useful for warehouses where employees are concentrated in particular locations rather than spread evenly throughout the building.
Fixed Industrial Evaporative Coolers
Fixed evaporative coolers are generally better suited to facilities requiring a permanent cooling solution. Depending on the model and installation design, they can supply cooled air through strategically positioned outlets or ductwork. Key benefits include permanent cooling infrastructure, air distribution designed around the building layout, reduced equipment occupying warehouse floor space, suitability for larger, regularly occupied facilities, and integration with a broader ventilation strategy. For businesses planning a long-term warehouse cooling solution, fixed evaporative cooling can provide an effective option when the system is correctly designed. Fanmaster’s IDDAC-670 industrial evaporative cooler is designed for fixed commercial and industrial cooling applications, providing a solution for businesses looking to manage temperatures across larger working environments.
8. Don’t Forget Ventilation and Exhaust Air
One of the most important considerations in evaporative cooler sizing is often overlooked. Where will all the air go? Direct evaporative cooling works by drawing warm outside air through water-saturated cooling media. As water evaporates, it absorbs heat from the incoming air, reducing its temperature while increasing its moisture content. The cooled air is then delivered into the building. For this process to work effectively, sufficient air must be able to leave the building. Without adequate exhaust or relief openings, indoor humidity can build up and cooling performance can deteriorate. Depending on the facility, this may involve:
- Open roller doors or appropriately sized ventilation openings.
- Wall-mounted exhaust fans.
- Roof-mounted exhaust fans.
- Mechanical extraction designed to support the incoming airflow.
The required exhaust arrangement depends on the system design and building conditions. It’s also important to remember that evaporative cooling is generally most effective in hot, dry conditions. Performance becomes more limited as outdoor humidity increases. In humid environments, refrigerated air conditioning or an alternative cooling strategy may be more appropriate.
9. Common Evaporative Cooler Sizing Mistakes
Investing in warehouse cooling without properly assessing the application can lead to disappointing results. Here are six common mistakes to avoid:
- Mistake 1: Choosing equipment based only on floor area. Square-metre coverage figures can be helpful for an initial comparison, but they don’t account for ceiling height, building layout or heat loads.
- Mistake 2: Assuming one large cooler is always better than several smaller units. A single high-capacity unit may deliver substantial airflow, but that doesn’t guarantee even distribution throughout a large or obstructed warehouse.
- Mistake 3: Ignoring exhaust and ventilation requirements. Evaporative cooling requires adequate air relief. Without it, the system may struggle to perform effectively.
- Mistake 4: Overlooking humidity. Evaporative cooling performance is influenced by local weather conditions. A system suitable for a hot, dry inland location may not provide the same results in a humid coastal environment.
- Mistake 5: Cooling areas that don’t need it. Focusing on occupied work zones can sometimes deliver a more practical and economical solution than attempting to cool an entire warehouse.
- Mistake 6: Relying entirely on an online calculation. An evaporative cooler calculator is an excellent starting point, but it cannot fully account for every building characteristic or operating condition.
For larger or more complex installations, professional advice can help ensure the system is correctly selected and positioned.
10. When Should You Get Professional Sizing Advice?
For smaller applications, selecting a portable evaporative cooler may be relatively straightforward once the work area, available ventilation and cooling objective are understood. However, for larger warehouses or permanent installations, a more detailed assessment is recommended. This is particularly important where multiple evaporative coolers are required, the warehouse has high ceilings or extensive racking, significant heat is generated by machinery, cooling must reach multiple occupied zones. fixed ductwork or mechanical extraction is involved, and existing ventilation systems need to be considered. An experienced installer can assess the building, review equipment positioning and help determine an appropriate installation arrangement. Fanmaster also has a network of installers who can assist customers with their project requirements. If you’re planning a permanent cooling installation, our team can help you explore suitable equipment and connect you with an installer.
11. Plan Your Warehouse Cooling Before Summer Arrives
Warehouse cooling is easier to plan before temperatures begin climbing and equipment becomes urgently needed. Taking the time to assess your building, cooling requirements and available options can help avoid purchasing unsuitable equipment or making costly changes later. Before choosing your evaporative coolers, make sure you can answer these five questions:
- What is the total volume of your warehouse?
- Are you cooling the entire building or specific work areas?
- What airflow is required for the intended application?
- How will cooled air be distributed and warm air exhausted?
- Would portable or fixed evaporative cooling provide the best solution?
With these answers, you’ll be in a much better position to select equipment that suits your workplace. And remember, you don’t need to do all the calculations yourself. Fanmaster’s online Evaporative Cooler Calculator provides a simple way to get started.
Ready to Cool Your Warehouse This Summer?
At Fanmaster, we’ve been helping Australian businesses manage industrial and commercial cooling, heating and ventilation requirements for over 26 years. We understand that every warehouse is different, and choosing the right equipment involves more than simply matching a product to a floor area. Whether you’re looking for portable cooling for a busy packing area or a fixed evaporative cooling system for a larger facility, our team can help you explore suitable options. Start by using our free Evaporative Cooler Calculator to estimate how many units your warehouse may require. From there, explore our industrial evaporative cooling range, visit our Warehouse Cooling solutions page or contact Fanmaster on 1300 900 345 for assistance with product selection and installation options.
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