One critical maintenance task for a walk-in cooler utilizing an air-cooled condenser is regularly cleaning its condenser coil. On a maintenance inspection or repair, most technicians check the condenser coil to see if it needs cleaned, as they should. However, many times they overlook checking the evaporator coil to see if it needs cleaned.  

This is generally not an issue, as evaporator coils do not require the same cleaning schedule as condenser coils. They are located in a cleaner environment, and regular defrosting keeps the coils cleaner. However, over time, they can develop a layer of dirt that should be removed in order to keep the system operating efficiently. The frequency of cleaning depends on the environment, but they should always be inspected during a maintenance or repair visit to see if cleaning is required.  

Cleaning an evaporator coil is generally much harder and requires more time and planning than a condenser coil, because it is usually located in an area that is harder to access. Shelving full of food products is generally stored right under the evaporator. This shelving is generally not on wheels but built in place with more shelving on both sides, making moving the shelf very difficult at times. You may need to work with the shelving in place and move the food product in order to access the coil. Some shelves are built so close to the evaporator that it makes the cleaning process very difficult. Be careful when handling the food — you do not want to contaminate or damage the product. It’s probably best to get an employee to move the food for you.   

I was once working at a high-end restaurant on a walk-in cooler that needed its evaporator cleaned. Under the evaporator was a shelf full of product and, as I was moving the product, a large container of soup spilled onto the floor. I cleaned it up and went on to clean the evaporator. Someone from the restaurant came into the walk-in looking for the soup — apparently, it was for a special business luncheon the restaurant owner was hosting that afternoon. When I told them it had spilled, they were quite upset. Not sure what happened at the luncheon, but I quickly finished cleaning the coil and got out of the kitchen.  

When cleaning evaporator coils, it is probably best to avoid using any chemical cleaner. A soft nylon brush and a spray bottle filled with water are best, because it would be very problematic if any coil cleaner were to get into the food product. You also need to be careful how the dirt falls off the coil during the cleaning. Move and cover any food product that has the potential for contamination from the cleaning process, and work with the kitchen staff to have them cover or move the food as needed. Also, be aware that fins may start to crumble as you’re cleaning the coil. This is a separate issue and may require the coil to be replaced.  

Cleaning evaporator coils is rarely an easy or quick process. You should consult with the kitchen staff or owner of the equipment to come up with a plan to safely and efficiently clean the coil. It is best to plan carefully and avoid rushing a job that will cause more issues than needed.