What matters at the dock
- Insulated cold store doors with thermal breaks that hold temperature and limit condensation on the warm side.
- Inflatable shelters or dock seals that close the gaps around refrigerated trailers as soon as they dock.
- Leveller position and pit sealing that keep the insulated envelope intact, often by using a loading house.
- Heated seals or frames in frozen areas so doors do not freeze to the floor or jam in their tracks.
- Interlocks that let the door open only when a trailer is docked, keeping open-door time short.
What matters most at a chilled or frozen loading bay?
At a chilled or frozen loading bay the priority is keeping the cold envelope closed for as much of the time as possible, because every open door and every gap around a trailer lets warm, moist air in. That air costs energy to cool, and its moisture turns to condensation and ice.
Chilled and frozen docks behave differently. A chilled dock mainly fights condensation and heat gain, while a frozen dock also has to deal with ice forming on doors, seals and floors whenever moist air gets in.
The main points to control are:
- How long the door stays open for each trailer.
- How well the gap between the building and the trailer is sealed.
- Air leakage around the leveller and pit.
- Ice build-up on door seals, tracks and the dock floor.
Our guide to cold store and chilled loading bays covers layout options in more depth, including where to place doors and levellers.
Which doors and shelters hold temperature best?
Thick insulated cold store dock doors with thermal breaks, paired with inflatable shelters or dock seals, hold temperature best at the dock. Thermal breaks stop cold passing straight through the panel and frame, which limits condensation on the warm side.
In frozen areas, heated frames or seals help stop the door freezing to the floor or jamming in its tracks. For refrigerated trailers of a consistent size, dock seals give a tight fit. Where trailer sizes vary, inflatable shelters close around each one once it is in position. Any vision panels should use insulated glazing so they do not become a weak point, and insulated high-speed doors suit busy internal openings between chilled areas.
In England, Approved Document L sets a limiting U-value of 1.3 W/m²K for vehicle access doors in new and replacement work. Cold store doors are normally specified to insulate much better than that minimum, and we confirm the figure that applies to your nation and project.
Where should the leveller sit in a cold store?
In many cold stores the leveller is best placed outside the insulated envelope, in a loading house, so the door closes onto the warehouse floor rather than onto the leveller platform. That gives a better seal at the door and keeps the leveller pit out of the cold.
Where the leveller sits inside the building, insulated pit edges, brush seals and a door that seals well against the platform help limit air leakage. Interlocks can stop the door opening until a trailer is docked and the shelter is in place. Pit drainage needs checking too, because ice or water in the pit can stop the platform working properly.
A loading house can also be added to an existing building without cutting a new pit into the floor. That suits cold stores where the insulated floor slab should not be disturbed, although planning permission may be needed for the external structure, which we check at survey.
How do you stop ice and condensation causing problems?
Ice and condensation are best controlled by limiting the warm air that enters, keeping seals in good condition and draining water away from the dock. A torn shelter curtain or flattened seal pad lets in damp air, which quickly forms frost on doors, levellers and the floor.
- Check door seals, heater elements and shelter fabrics at every service.
- Keep the door open only while a trailer is docked, using interlocks or traffic light sequencing.
- Make sure drainage in front of the dock is clear, especially at recessed docks.
- Treat ice on the dock floor as a slip and forklift hazard, not only an energy issue.
Ask staff to report a slow-closing door or a torn seal straight away, because a small gap at a frozen dock soon becomes a large ice problem. Repairs to cold store doors and shelters are chargeable, with the price agreed before anyone attends, so planned checks are usually the cheaper route.
Equipment we recommend
Questions
Why do cold store dock doors freeze shut?
Cold store doors freeze when moist air reaches cold surfaces and turns to ice, often along the bottom seal, the side seals or the tracks. Heated frames or seals, good sealing around docked trailers and short door-open times all help. Damaged seals let more moist air in, so ice that keeps returning is a sign the door or shelter needs attention.
Is a loading house better than a pit leveller for a cold store?
A loading house is often the better choice for a cold store, because the leveller sits outside the insulated envelope, the door closes onto the warehouse floor and the pit is kept out of the cold. It also avoids cutting into an insulated floor. Guide prices are £14,500 to £32,000 per house, excluding VAT, and planning permission may be needed.
Do cold store doors have to meet the 1.3 W/m²K U-value?
In England, 1.3 W/m²K is the limiting U-value for vehicle access doors in new and replacement work under Approved Document L, so a new cold store dock door should at least meet it. In practice, cold store doors are specified with much thicker insulation for the temperatures involved. Wales, Scotland and Northern Ireland have their own rules, and we confirm the figure for your project.