Blast Freezer Cold Storage Steel Warehouse Building 150mm PU Panel Minus 25

A freezer building is a thermal envelope problem wrapped around a steel frame. The steel is straightforward; the vapour barrier and the thermal break are what decide whether the room holds temperature in year three. This cold storage warehouse uses 150 mm polyurethane panels for walls and 200 mm for the roof, a continuous vapour barrier on the warm side, and a thermal break at every point where the internal steel frame meets the external structure. KXD Steel Structure builds freezer shells for clients who already know their refrigeration supplier, so the interfaces are coordinated from the first drawing.

The most common field failure in cold stores is a cold bridge at the floor to wall junction. We specify an insulated kerb with a 100 mm high density PU block under the wall panel, plus a heated threshold at every door so the slab does not freeze and heave. Panel joints are double tongue and groove with two beads of food grade sealant, fixed with concealed cam locks at 600 mm centres so the panel face stays intact. Ceiling panels are supported by a secondary steel grid independent of the roof purlins, with a design allowance for 0.6 kN/m2 of ice build up on the evaporator platform.

Operation shapes the details more than the drawings suggest. Blast freezer doors get a 500 mm insulated panel leaf with a heated frame and a pressure relief port, because a sealed room at minus 25 degrees will otherwise pull the door shut against its own gasket. Lighting is IP65 with cold rated drivers, and all cable penetrations pass through sealed sleeves so no warm moist air enters the envelope. Antislip floor finish is applied inside the chamber and continued 1.5 m outside the door, where condensate from open doors is heaviest. These details cost a small fraction of the refrigeration plant and prevent most of the call outs in the first winter.

• 150 mm PU wall panel: Polyurethane core with 40 kg/m3 density and a certified thermal conductivity value
• 200 mm insulated roof: Thicker roof core controls heat gain where solar load is highest
• Continuous vapour barrier: Warm side barrier with sealed laps keeps moisture out of the insulation
• Thermal break at frame junctions: PU blocks separate internal steel from external structure to stop cold bridging
• Heated door thresholds: Prevents slab freezing and heave at the highest traffic point
• Independent ceiling grid: Panel support designed for evaporator weight and ice build up allowance

Food processors, seafood exporters, poultry integrators, ice cream producers and pharmaceutical distributors use this shell for blast freezing, frozen storage or temperature controlled docking. It also suits agricultural cooperatives that need seasonal peak capacity for fruit and vegetable freezing. Because the envelope is independent of the refrigeration design, the same building can be split into a minus 25 degree chamber and a chilled anteroom with a single panel wall change.

The envelope test is done before the refrigeration is commissioned. We run a 24 hour temperature pull down test and record surface temperatures at 20 points with an infrared camera, looking specifically at panel joints, door frames and the wall floor junction. Any reading more than 3 degrees above ambient chamber mean is treated as a defect and re sealed. Panels are checked for core density and skin adhesion at the factory, and door hardware is cycled 500 times on a test rig before shipment. Test records are handed over with the as built drawing set.

Panels ship on edge in purpose built racks with protective film on both faces, and corner trims are crated to prevent denting. Refrigeration interfaces, door frames and sealant are boxed by room zone so the installers work room by room rather than opening every crate. Warranty covers 10 years on structure and 5 years on panel integrity, with a joint inspection at 12 months. Share your room temperatures, product throughput and compressor capacity and our engineers will return a thermal calculation with the panel schedule.