Cold and Frozen Storage
Cold and frozen storage warehouses combine combustible insulated panel envelopes with refrigeration plant whose refrigerant can itself be a fire or health hazard if it leaks, requiring a dedicated fire protection concept.
Hazard picture
The building envelope of cold and frozen storage warehouses is usually built from sandwich panels with a polyurethane or polystyrene core, which can release heat rapidly and generate toxic smoke in a fire; at the same time, the insulating effect hampers early fire detection from outside. Many facilities also operate ammonia refrigeration plant, whose refrigerant is itself flammable and strongly irritant to toxic if released, meaning a refrigeration plant failure represents both a property and a life-safety risk.
Protection measures
Sprinkler design in freezer areas must use dry or antifreeze systems, since wet-pipe systems would freeze below zero; alternatively, low-temperature loops with antifreeze solution are used. Ammonia refrigeration systems require a dedicated gas detection system, emergency ventilation of the machinery room, and physical separation from the actual storage area. The combustible insulated panels of the building envelope should be additionally protected through classified building elements or sprinkler protection sized for the facade and roof surfaces.
Insurance relevance
Because of the combination of a high fire load in the building envelope, low operating temperatures and potentially hazardous refrigerant, cold and frozen storage warehouses are treated as a distinct risk category requiring heightened survey scrutiny. Insurers typically require evidence that sprinkler design and refrigeration plant safety function independently of each other, so that a refrigeration plant failure does not simultaneously compromise fire protection.