Walk-in coolers
What the parts do, what temperature the box should hold, why a cooler that worked fine last summer struggles this one, and the four things worth checking yourself before the stock is at risk.
Four parts, one loop
Every walk-in is the same refrigeration circuit as your home fridge, scaled up and split across the building.
The compressor raises the pressure of the refrigerant. The condenser — the coil with the fan, usually outside or in a plant room — dumps that heat to the air. The refrigerant passes through a metering device that drops the pressure, then into the evaporator, the unit cooler mounted inside the box, where it absorbs heat from the air and the product. Then back to the compressor.
Everything that goes wrong is a disturbance to that loop: not enough refrigerant in it, not enough airflow across one of the coils, or a control telling it the wrong thing.
What it should be holding
Most walk-in coolers run between +2 and +4 °C. That is cold enough to keep product safe and warm enough that the coil is not fighting a frost problem all day.
A few things worth knowing about that number:
- Air temperature and product temperature are not the same thing. Product lags behind.
- The reading at the controller is one point in the box. Corners behave differently.
- A box swinging a couple of degrees through a defrost cycle is normal.
- A box that climbs steadily all afternoon is not.
If you keep temperature logs for inspection, the pattern in them is diagnostic. Bring them to the conversation.
Sizing or replacing a box?
Work out roughly what capacity it needs from the box size, the temperature, the door traffic and what goes in it.
Estimate a walk-in cooling load
A starting point for the conversation, not a design. Real equipment gets a site visit.
Four things to check before you call
None of these need tools, and any of them might save you a callout. If the box is warming right now, call first and check while you wait.
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Is the condenser blocked?
Find the outdoor or plant-room unit and look at the coil. Flour, grease, dust, cardboard stacked against it, a plastic bag sucked onto the face — all of it stops the system rejecting heat, and all of it is common. This is the single most frequent cause of a cooler that cannot keep up.
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Is the door sealing?
Close it and look for light around the gasket. Check the gasket for tears and the hinges for sag. A door that no longer pulls itself shut, or one that staff prop open during a delivery, will beat any refrigeration system in the building.
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Is the evaporator iced up?
Look at the unit cooler inside the box. A light frost is normal between defrosts. A coil packed solid with ice is not — it blocks airflow, and the box warms up even though the system is running hard.
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Has anything changed?
New product lines, a bigger delivery, a prep table moved in front of the evaporator, a hot summer week. Coolers that have been fine for years often start struggling because the job changed, not because the equipment failed.
Box warming right now?
Call 672-762-7877. Refrigeration failures are covered on the 24/7 line. Keep the door shut, move what you can to a working box or onto ice, and read the controller rather than opening the door to check.
What usually turns out to be wrong
- A dirty or obstructed condenser. Cheap to prevent, and the most common cause of a box that will not pull down.
- A refrigerant leak. The system cools poorly and runs constantly. Topping it up without finding the leak just delays the same call.
- Defrost faults. A failed timer, heater or termination sensor leaves the coil iced and the box warm.
- Door and gasket failures. Torn seals, dropped hinges, broken closers, a frame that sweats.
- Fan motor failures. Either coil. The system looks like it is running and is moving almost no air.
- Controls out of calibration. The box holds a temperature, just not the one you think it is holding.
Deciding whether a tired unit is worth another repair? The refrigerant on the nameplate is usually the deciding factor. Work through repair or replace.
Questions we get on the phone
How often should a walk-in be serviced?
Twice a year suits most kitchens, with condenser cleaning more often in a greasy or dusty environment. The economics are simple: a planned visit costs a fraction of an emergency callout plus a load of spoiled stock. See maintenance plans.
Why is there water on the floor?
Usually a blocked or frozen condensate drain line backing up, or a door sweating because the seal has gone. Both are repairable, and both are a slip hazard before they are a refrigeration problem.
Can you convert a cooler into a freezer?
Sometimes, but it is rarely as simple as swapping the equipment. Freezers need more insulation, a different defrost strategy, and floor protection the box may not have. Tell us about the box and we will tell you honestly whether it is worth doing.
Do you install new walk-ins as well as repair them?
Yes — new box installation, replacement condensing units and evaporators, controls and monitoring. See what refrigeration work we cover.
Are there rebates for refrigeration upgrades?
BC Hydro and FortisBC both run business programmes that cover refrigeration equipment upgrades, with conditions on the site and the contractor. Where to check.
Tell us what the box is doing.
Describe the symptom and the equipment on the phone. If you can read us the nameplate, better still.