When warm humid air from outside enters the store, it leaves its water vapour on the coldest surface it meets: the evaporator fins, the area around the door or cold spots on the ceiling. Icing is therefore a symptom that moisture is getting in rather than a fault in itself. What matters is finding the route the moisture takes, and the place where the ice sits tells you.
| Where the ice is | Likely source | First check |
|---|---|---|
| Door threshold and frame | Door left open too long or a failed seal | Measure open time for a week, test the seal with a paper strip |
| Evaporator fins | Insufficient defrost, moisture entering with product | Review the defrost record and the packaging of new batches |
| Below the evaporator | Blocked drain | Clear the meltwater drain line |
| Ceiling and a wide area of floor | Insulation or under-floor heating problem | Treat it as a structural problem together with the refrigeration service |
When you find ice, photograph it before clearing and log the date and time; note door-open periods, loading and defrost times beside it. A pattern that repeats in the same place shows under which conditions the problem starts and shortens the service inspection.
When clearing ice
Do not scrape the evaporator fins with a sharp tool, because the coil can be damaged; remove the ice with the equipment's own defrost procedure. If ice hanging from the ceiling or building on the floor endangers pedestrians and forklifts, mark the area and open a safe route.
Do not raise the defrost frequency from the look of the ice alone: unneeded cycles put heat into the store and raise consumption and product temperature. Moisture load differs between summer and winter, so reviewing the setting once a year together with the actual load is enough.
