Every cooler and freezer has a condenser coil. It gets rid of the heat pulled out of the box: a fan blows air across a block of thin metal fins, and the heat leaves with the air. When dust, lint, grease and flour build up on those fins, air can’t get through and the heat stays in the system.
With the heat trapped, the compressor runs longer and hotter, and the box has a harder time holding temperature, worst of all on hot days. Over months that extra heat wears on the compressor and the condenser fan motor. Plenty of compressor failures trace back to a coil nobody cleaned.
On most reach-ins you can check it yourself in a minute.
Finding the coil
On a reach-in or prep table, it’s usually behind a grille at the bottom front or up on top of the cabinet. Look for a fan and a block of fins that looks a bit like a car radiator. On a walk-in, it’s part of the condensing unit outside, on the roof, or now and then in a mechanical room. Ice machines have one too, unless the machine is water-cooled or uses a remote condenser.
Signs it’s dirty
Sometimes you can just see it, a gray felt of dust across the face of the coil. Otherwise, the unit gives it away by running almost nonstop, pushing hot air out of the grille, or letting the box drift warmer in the afternoon.
What you can do yourself
For dust and lint on a reach-in, turn the unit off at the switch or unplug it, then go over the face of the coil with a soft brush and a vacuum, brushing the same direction the fins run. They bend easily. Bent fins block air just like dirt does.
Skip the pressure washer, and don’t scrape. A coil with greasy dirt on it (common near a fryer or a grill) needs a coil cleaner and a careful rinse, and that’s better left to a tech. Rooftop units are the tech’s job too.
How often to check it
In a kitchen, look at the coils about once a month with a flashlight. Units near the cook line or in a bakery usually need cleaning more often than ones in a cool back room.
A full coil cleaning is part of every maintenance visit we do. If a unit still runs warm after the coil is clean, read our post on walk-ins running warm in summer, or have us look at the compressor and condenser.
