The dimensions that drive the layout
- Shelf depth: commercial shelving commonly comes around 450 to 600 mm deep. Deeper shelves hold more but hide stock at the back and slow picking.
- Tiers: four or five tiers are typical in rooms around 2.4 m high inside. Set tier spacing to your tallest common container.
- Bottom shelf: keeping food at least around 150 mm off the floor is common food-safety practice, and it lets you clean underneath.
- Aisle: about 0.9 to 1.0 m is a practical minimum for one person carrying crates; trolleys need more. These are planning figures, not rules.
- Wall gap: a small gap behind shelving, around 50 to 100 mm, lets air move down the walls and stops product freezing to or warming against the panel.
Respect the evaporator's air path
The evaporator, usually high on one wall, throws cold air across the ceiling towards the far end of the room. Shelving or stock stacked right up to the ceiling in that path cuts the throw short, and the far end runs warm. Keep the top tier below the air stream, leave clear space in front of the coil as the maker specifies, and never block the return air at the bottom of the unit.
Place the shelves that hold the most temperature-sensitive product where air reaches them, not in dead corners behind the door.
Worked example: two layouts for one room
Assumptions: internal 3.0 m deep from the door × 2.5 m wide × 2.4 m high; shelving 0.6 m deep with 5 tiers; side runs stop 0.6 m short of the front wall to clear the door; evaporator on the back wall.
| Layout | Shelf runs | Aisle width | Shelf area (runs × 0.6 m × 5 tiers) |
|---|---|---|---|
| Two walls (parallel) | 2 side runs × 2.4 m = 4.8 m | 1.3 m | 14.4 m² |
| U-shape (three walls) | 4.8 m + back run 1.3 m = 6.1 m | 1.3 m | 18.3 m² |
Reading the comparison
The U layout adds about 27% more shelf area in the same room. The cost is two dead corners where the runs meet, and a back run directly under the evaporator, whose top tier may need to be dropped or left free to keep the air path clear. In practice that might mean using four tiers on the back run, giving about 17.5 m² (18.3 m² less one 1.3 × 0.6 m tier). It is still the better layout here, provided the aisle stays wide enough to work in.
If you hold product at about 0.3 m high on each tier, 17.5 m² of shelf holds about 5.3 m³ of product, which at a stack density of 350 kg/m³ (assumed) is roughly 1.8 tonnes.
Shelving materials for cold, wet rooms
- Stainless steel resists corrosion and cleaning chemicals; it costs more.
- Epoxy-coated wire and polymer shelving resist moisture at lower cost; check the coating survives your cleaning routine.
- Plain painted or zinc-plated steel rusts in humid cold rooms, especially near the coast and in the monsoon.
- Ventilated wire or slotted shelves let air pass; solid shelves block it and collect drips.
- Check the load rating per shelf: crates of liquid or meat are heavy, and a sagging shelf is a safety risk.
Working rules that need space
Keep raw meat, fish and unwashed vegetables on lower shelves below ready-to-eat food, label shelves by product group, and rotate stock first in, first out. All of this needs some empty shelf at all times; a room planned at 100% shelf fill becomes disorganised within a week.
Frequently asked questions
- Should shelves touch the cold room walls?
- Leave a small gap. Air needs to move down the walls, and product pressed against panels can freeze in a chiller or pick up heat from a wall that faces a hot space.
- Can I use mobile shelving in a small walk-in?
- Mobile racks on rails can increase capacity by removing fixed aisles, but they are costly, need a level, strong floor, and slow down picking. In most small walk-ins, fixed shelving in a well-chosen layout is the better value.