Posted by GoodCooling Team
Rising energy prices and ever hotter summers confront businesses with an important question: how can you create a pleasant indoor climate without the electricity bill exploding? Anyone comparing different cooling systems quickly comes across very different figures for consumption and costs – manufacturers advertise best-case values under laboratory conditions, while actual consumption in everyday business operation often looks different. In this article we show you how to calculate the actual running costs of evaporative air coolers and conventional air conditioners yourself, and provide a clear worked example for everyday business use.
Why an Accurate Comparison Is Worthwhile
Especially with larger areas or a business with several cooling units, seemingly small differences in power consumption add up over a whole summer season to noticeable amounts on the electricity bill. If you work out realistically in advance what costs to expect, you avoid nasty surprises and can justify the investment in new cooling technology properly to management or controlling.
How Does the Cost Calculation for Cooling Units Work?
The formula for the electricity costs of any electrical appliance is basically simple:
Power consumption (kW) × operating hours × electricity price (€/kWh) = electricity costs
The key variable here is the power consumption, because this is where evaporative air coolers and air conditioners differ fundamentally. While an evaporative air cooler essentially runs a fan motor and a small water pump, an air conditioner has to drive a compressor that actively cools the air down. This is reflected directly in the wattage.
Evaporative Air Cooler vs. Air Conditioning: The Figures Compared
The following table shows typical guide values as are usual for commercially used units. The actual values always depend on the specific model, the room size and the ambient conditions – the order of magnitude, however, remains comparable.
| Unit type | Typical power consumption | Operation (8 hrs/day) | Cost per day* | Cost per month (26 days)* |
|---|---|---|---|---|
| Evaporative air cooler | approx. 60–200 watts | 8 hours | approx. €0.14–0.48 | approx. €3.70–12.50 |
| Portable air conditioner | approx. 800–1,500 watts | 8 hours | approx. €1.92–3.60 | approx. €50–94 |
| Split air conditioner (commercial) | approx. 1,200–2,500 watts | 8 hours | approx. €2.88–6.00 | approx. €75–156 |
*Calculated using an assumed commercial electricity price of €0.30/kWh. Use your own tariff as a guide – it may differ depending on contract, region and time.
Why the Difference Is So Large
An evaporative air cooler cools on the principle of evaporative cooling: water is passed over a cooling medium (usually a cooling pad), and a fan draws in air, which absorbs moisture and cools down in the process. No refrigerant is actively compressed – the energy required is essentially limited to the motor and pump. An air conditioner, by contrast, actively extracts heat from the air via a refrigeration circuit, which physically requires considerably more energy. This explains why the electricity consumption of evaporative air coolers is in practice often 80–90% lower than that of comparable air conditioners.
A Worked Example for Your Own Business
To work out the costs for your specific situation, we recommend the following approach:
- Determine the power consumption: You will find the wattage on the rating plate or data sheet of the unit in question.
- Set realistic operating hours: Over what period is cooling actually needed – e.g. during opening hours or work shifts?
- Insert the current electricity price: You will find your commercial energy rate (cents/kWh) on your electricity bill.
- Apply the formula: Power consumption in kW × operating hours × electricity price = daily costs.
- Extrapolate to the billing period: Daily costs × operating days gives the monthly or seasonal total costs.
This gives you a reliable estimate in a few minutes, tailored to your actual circumstances, instead of relying on general manufacturer specifications.
Don't Forget the Hidden Costs of Air Conditioning
For a fair comparison, in addition to pure electricity consumption you should also take into account further cost items that arise with permanently installed air conditioning:
- Installation by a specialist firm, including structural work
- Regular maintenance and inspection of the refrigeration circuit
- Refrigerant top-ups and legally required leak tests
- Higher repair effort due to more complex technology
An evaporative air cooler generally needs no installation, has no refrigerant circuit and can be cleaned and maintained in a few simple steps – an aspect that is underestimated in many calculations.
Typical Mistakes in Cost Calculation
In practice, a few recurring errors of reasoning lead to cooling units being compared incorrectly. A common mistake is to look only at the purchase cost and ignore the running costs over the entire service life – especially with units that are in use over several summers, this quickly reverses the picture. A second mistake is to calculate with unrealistically low operating hours: if a unit is actually run all day, even small differences in wattage add up to noticeable amounts over the season. And third, the current electricity price is often not taken into account, with outdated or flat-rate values used instead – a look at your latest electricity bill quickly brings clarity here and makes any worked example considerably more reliable.
Frequently Asked Questions
How much electricity does an evaporative air cooler actually use per hour?
That depends on the particular model and the fan setting chosen, but for most commercially used units it is in the range of roughly 60 to 200 watts – well below what a comparable air conditioner requires.
Can I calculate the electricity costs of my air conditioner in the same way?
Yes, the formula presented (power consumption × operating hours × electricity price) applies in principle to any electrically operated cooling unit. With air conditioners, you should also bear in mind that the compressor does not run continuously at full power but may cycle depending on the controls.
Is an evaporative air cooler worthwhile at very high outdoor temperatures too?
Evaporative air coolers noticeably lower the perceived temperature through air movement and evaporative cooling, but for physical reasons they do not reach the same very low target temperatures as an air conditioner. For most commercial applications where noticeable cooling and air circulation are the priority, this is sufficient in practice.
How does humidity affect the cost calculation?
Evaporative air coolers work by evaporation and therefore slightly increase the humidity in the room. In very humid climates this can somewhat reduce the perceived cooling effect, but it does not change the fundamentally lower power consumption and thus the lower electricity costs compared with an air conditioner.
Conclusion
The electricity cost comparison shows clearly: for many commercial use cases – from the workshop through hospitality to the warehouse – an evaporative air cooler is an economically attractive alternative to conventional air conditioning, especially when very low target temperatures are not required. Work through your individual scenario using the steps above to get a well-founded basis for your decision.
In our range for hospitality, events & workshops and in the industry & large areas section you will find evaporative air cooler models for different room sizes and areas of application.
