Master-Bilt® Refrigeration News & Product Information
Refrigerated Warehouses 101
Refrigerated warehouses fit a wide range of applications from frozen food storage to testing chambers. Designing one from the ground up requires a clear plan upfront. Many people think of a refrigerated warehouse as just a very large walk-in and, starting out, the design process is similar. Specifications such as size, temperature level, number of compartments and refrigeration load must be determined first. However, after the fundamental specs are resolved, other considerations come into play such as loading docks, roof support, doors and structural flooring. Adherence to local building codes is another factor. Some regions, for example, require structures to meet certain seismic qualifications. In other areas it may be necessary for roofs to meet snow load conditions. There’s a lot to keep track of when building a cold storage warehouse and this article will introduce you to the basics. If you have further questions, please contact us at 800-647-1284.
Wall And Ceiling Panels
Typical polyurethane foamed-in-place panels, which fit together by cam-locks, are four inches thick and provide excellent energy efficiency. See this webpage for more advantages provided by polyurethane foaming. Five-inch and six-inch panels provide even greater insulation efficiency and structural support. In fact, some manufacturers can supply up to a 23 ft. long ceiling panel in 6-inch thickness with no additional panel support required. Additionally, there are numerous options in interior and exterior metal finishes to match your design scheme or durability requirements.
Special consideration must be taken when specifying a refrigerated warehouse floor, especially if it’s a freezer. The design can get complex, usually involving a slab of polyurethane insulation sandwiched between a top layer of concrete and a lower concrete subfloor. Beneath the subfloor there’s frequently a gravel bed measuring a foot deep. A treated wooden thermal break lines the perimeter of the floor to prevent the transfer of cold air through the concrete. Plastic visqueen vapor barriers are also installed between the insulation slab and the concrete subfloor to block moisture coming upward from the ground.
Underfloor heating is also necessary as a shield against the upward expansion of frozen water in the ground beneath the sub slab. This heating, or defrosting, is accomplished in several ways. One of the most popular is to install PVC piping in the floor allowing warmer ambient air to act as a defroster. Other ways include electric heating and glycol pumping.
Ceilings And Roofs
Depending on the size, location and complexity of a warehouse, there are different ways to design the roof or ceiling.
If the structure is housed within a larger building, it may be possible to have a self-supporting ceiling. With this type, walk-in panels are connected to overhead steel beams by self-support clips. Pallet racks inside the structure may also be used to support roof panels.
Due to the size of most warehouses, walk-in ceiling panels require extra support to span the greater distances. That’s where a suspension ceiling comes in. Structural steel angles are connected to the building roof by steel rods and to the ceiling panels by support clips.
In outdoor warehouses, walk-in ceiling panels are bolted to horizontal steel beams beneath them. The beams are supported by columns to which the wall panels are attached. Optional galvalume roofs and flat or sloped membrane roofs are a good way to extend the life of the roof and further protect contents inside.
Docks And Doors
Loading docks are a necessity if the warehouse is to be used as a distribution point. The number of docks will, of course, be determined by the available space and shipping volume. With docks come additional considerations like weather seals and vinyl curtains. Weather seals fit on the outside of the dock and seal the perimeter of a trailer to help keep inside cold air from escaping. Vinyl curtains fit over doors and entrances also blocking out warmer air.
Warehouses usually require doors that are large enough for forklifts and other vehicles to pass through. Depending on budget and personal preference, there are a wide variety of choices including manual or electric sliding doors, bi-parting doors and overhead sectional and vertical lift doors.
Refrigerating a large space like a warehouse requires a robust refrigeration system. The temperature range and refrigeration load are decided by the contents stored and their temperature when placed in the warehouse. Frequently, parallel rack systems are designed to support the refrigeration load required. Parallel systems are a more energy efficient solution as they match refrigeration capacity to the actual load. These systems also allow remote monitoring and diagnostics as well as interfacing with existing building controls. In addition, they offer a level of redundancy for safety. See our parallel rack refrigeration system webpage for more information.
This article has touched on some of the main considerations regarding refrigerated warehouses but, as previously noted, there are many others. With all the construction details, it’s a good idea to find a single source supplier who can provide design assistance as well as panels, refrigeration systems and other components.