Evaporative cooler maintenance: a complete guide

Evaporative coolers are the best solution for cooling large work environments such as industrial warehouses, logistics warehouses, workshops, hangars, and sports and commercial spaces. To maintain their efficiency over time, it is important to perform proper maintenance of the units both during the winter period of inactivity and before the summer season at the time of the first startup.

In this article, we will provide you with some useful tips for the correct maintenance of industrial fixed evaporative coolers. This way, you will be able to keep the environments cool, comfortable, and healthy for your employees.

Table of contents

What is an evaporative cooler?

Evaporative coolers are cooling systems ideal for improving the microclimatic conditions inside work environments during the summer period. Through these systems, it is possible to create ideal operating conditions for employees, allowing them to carry out their activities in a state of psychophysical well-being, health, and safety.

How do air coolers work?

Evaporative coolers operate by harnessing the natural principle of water evaporation, which acts as a natural coolant.

Each unit draws in hot air from the outside, which is filtered and then passed through water-soaked honeycomb pads. The air, pushed by a fan, releases some of its heat to the water contained in the evaporative pads, thus lowering its temperature.
The air is then released into the working environment at more comfortable temperatures.

It is precisely thanks to this principle of renewal that the optimal operation of the adiabatic cooling system occurs with doors and windows open: performance improves due to continuous air exchange, which is also useful in reducing the spread of viruses and bacteria and eliminating odors and dust generated by processes.

While traditional refrigerant gas air conditioners tend to cool the air, making it dry, evaporative coolers enrich it with the right percentage of humidity. This phenomenon allows for the creation of an ideal microclimate, avoiding large temperature fluctuations and throat dryness.

If you wish to delve into the operation of evaporative coolers and the differences with traditional air conditioners, click on the article below.

What are the differences between an evaporative cooler and a traditional air conditioner?

The importance of maintenance

The main purpose of wall-mounted and rooftop coolers is to keep workspaces comfortable and healthy. For this reason, we recommend scheduling two annual maintenance checks for perfect unit operation: one before the start of the seasonal operation and one at the end of the summer period when the adiabatic coolers are taken out of service.

evaporative cooler maintenance calender

The lack of regular maintenance of cooling units can lead to:

  • Loss of cooling efficiency;
  • Breakages or damage to components, resulting in increased management costs due to extraordinary maintenance interventions;
  • Unhealthy and uncomfortable work environments.

Especially in the winter months, when the cooling system is typically unused, if regular maintenance is not performed, the water remaining inside the unit can freeze, damaging the components. If not properly cleaned and disinfected at the end of the season, water deposits can also promote the spread of viruses, bacteria, and molds, which could cause malfunctions and unpleasant odors when the system is turned on in the following season.

Winter weather conditions such as rain, snow, pollution, and wind can lead to a buildup of mineral debris inside evaporative coolers, which over time can damage unit components, reducing performance and the product’s lifespan.

Maintenance procedures for coolers before summer

Pre-seasonal maintenance of evaporative coolers, although a simple operation, should not be underestimated, as it is essential to ensure optimal performance and protect the health of personnel.

Pre-summer maintenance primarily involves two aspects:

  • Cleaning the water tank to remove the accumulation of dirt that can negatively affect the evaporative effect;
  • Sanitization of the evaporative cooler: Clean the evaporative pads using demineralized water to prevent the formation of limescale. Additionally, cleanse the air delivery elements to maintain the efficiency of air-water exchange.
    The type of water used for the system operation affects its performance. In conditions where the hardness of the feed water is particularly high, it is recommended to install a water softener and to check the condition of the evaporative pads more frequently.

Follow these guidelines, and you will be able to prevent any damage to the unit components and achieve maximum efficiency and performance from the water cooler.

Pre-season maintenance procedure for fixed evaporative cooler step by step

  1. Remove the protective cover used to shield the cooler during winter. Ensure it is still intact, clean it with a neutral detergent, and store it dry in a sheltered area. If present, open the air adjustment damper.
  2. Ensure the unit is electrically disconnected and the water valve is closed. Check the integrity of the power cord.
  3. Remove the dust filters and evaporative pads.
  4. Proceed with cleaning the tank and sanitizing the cooler. Wash the filters and replace any unusable pads.
  5. Check that all components inside the unit are intact.
  6. Power the cooler electrically and open the water valve.
  7. Ensure the user interface is operational and start the system in “Cooling” mode.
  8. Ensure all valves operate properly and water is evenly distributed across all evaporative pads, checking for any water leaks from the tank and supply pipe.
  9. Check the proper functioning of the fans.
  10. After a few minutes, turn off the cooler and check the proper operation of the drain valve.
  11. Ensure the tank is completely emptied.
  12. Reposition the evaporative pads and dust filters, then turn the system back on.
preparing the evaporative cooler for the summer season

Maintenance guide for evaporative coolers at the end of the summer season

Let’s now delve into the essential precautions for the maintenance of evaporative coolers after the summer season, to be carried out approximately between the months of October and November.

Post-season maintenance procedure for industrial evaporative cooler

  1. Disconnect the cooler before proceeding with cleaning operations.
  2. Clean the external casing with a soft cloth and a neutral detergent. Avoid using products containing aggressive substances such as alcohol, which could damage it.
  3. Completely empty the tank, removing any water residue and traces of limescale.
  4. Dry it carefully to prevent the proliferation of mold and bacteria during the winter period.
  5. Remove the dust filters and clean any impurities.
  6. Remove and sanitize the evaporative pads using demineralized water to remove dust and deposits.
  7. Decalcify the cooler, ensuring that the internal pipes for water distribution are clean and there are no obstructions in the water distributor to the evaporative pads.
  8. Thoroughly check the proper functioning of all components.
  9. Reposition the evaporative pads and dust filters.
  10. Close any air adjustment damper and cover the cooler with the appropriate cover: this protects the unit from the bad weather and prevents the dispersion of hot air from the building during the winter months.
maintenance of the evaporative cooler at the end of the season

Maintenance of water evaporative coolers should be carried out by qualified personnel who, through targeted actions, can ensure maximum efficiency. For this reason, we recommend that you exclusively seek assistance from experienced technicians.


In conclusion, maintenance of evaporative coolers is a fundamental factor in ensuring proper operation, maximum efficiency, and longevity. Regular maintenance, as described in this comprehensive guide, can bring numerous benefits:

  • Improved energy efficiency: a well-maintained evaporative cooler consumes less water and energy, resulting in savings on utility bills.
  • Increased comfort: a well-maintained cooler provides clean, fresh air free from dust, bacteria, and mold, allowing you to protect the health and safety of your personnel.
  • Extended lifespan: regular maintenance prevents component wear and extends the useful life of the cooler.
  • Prevention of breakdowns: maintenance helps identify and address small issues before they become serious and costly failures.

Rely on our experts for the maintenance of your evaporative cooler!

Our team of qualified technicians is available to perform a comprehensive check of your cooler and ensure maximum efficiency for the entire summer season. Don’t wait any longer, contact us now!