"A cold room" is not one thing. The temperature band decides panel thickness, evaporating temperature, fin spacing, defrost method and how the door is built.
| Room type | Temperature | Typical use |
|---|---|---|
| Blast freezer | −30 to −35°C | Freezing product fast; capacity measured in tonnes per batch or per day |
| Frozen storage | −18°C | Long-term holding of frozen goods; racking layout decides usable tonnage |
| Chilled / fresh keeping | 0 to 5°C | Meat, dairy, fruit and vegetables; humidity and air movement matter as much as temperature |
| Controlled atmosphere | 0 to 5°C | Long-holding fruit; adds gas-tight construction and O₂/CO₂ control on top of cooling |
| Pharmaceutical | 2 to 8°C / −20°C | GSP-style storage; monitoring, alarms and temperature records are part of the scope |
| Ultra-low | −45 to −60°C | Special products and testing; two-stage equipment, thicker insulation, longer pull-down |
| Processing room | 10 to 15°C | Portioning, packing, low-temperature workshops; staff comfort and hygiene drive the design |
Chilled rooms can use thinner panels than frozen rooms, and blast freezers need more again. One thickness everywhere is either wasted money or condensation on the wall.
Roughly 4.5 mm for chilled duty, 6.0 mm for −18°C, 9.0 mm below −25°C. Too tight and the coil ices up fast; too wide and you lose surface area.
Above freezing, off-cycle defrost is often enough. Below −18°C, electric or hot-gas defrost becomes necessary — and it changes both power demand and pipework.
Frozen rooms need underfloor insulation and a vapour barrier against frost heave; chilled rooms usually do not.
Ultra-low and blast duties need two-stage or specially selected compressors, not a larger version of the same unit.
High-traffic frozen rooms need air curtains, fast doors or vestibules — otherwise the coil spends its day removing moisture from the yard.
How to turn these bands into a room list: How to size a cold room. Sector room lists: meat processing · poultry & slaughter.