Getting the Most Out Of High-Ceiling Facilities With High-Speed Doors
Michael Watkins | Food Manufacturing
In a growing number of food processing plants and DCs, things are looking up -- at least 40 feet or more. Facilities are expanding vertically as owners look to reduce both fixed and variable operating costs. While these operations raise their roofs, high-speed doors enable these buildings to keep product moving and help minimize energy loss.
Over the past 15 years, these facilities have been growing taller. An April 2014 article that appeared on the Food Manufacturing website (Building Up, Not Out), established that vertical expansion of existing facilities is an affordable and practical solution for improving productivity and profitability.
First, there is the issue of land costs. Food processing is a low profit-margin business, so companies want to be based outside of large cities where land costs are cheaper. In cities like Chicago, as developers are gobbling up property for high-end hotels, apartment complexes and offices buildings, old-line food manufacturers are exiting.
Yet, no matter where a facility is located, land is not cheap. Doubling the height doubles the volume of the facility while maintaining the same footprint.
Minimizing the footprint also minimizes the ceiling area. Energy costs in a refrigerated DC typically account for 25 percent of the operating budget. Because most heat gain occurs through the roof, a smaller footprint means reduced energy loss for the warehouse.
Creating a taller facility, whether through expansion or new construction, means that automated and multi-level pick modules can be integrated into facilities to improve order fulfillment efficiency. For operational and budgetary reasons, many low-temp operations with tall facilities must choose between using forklifts to handle and store product before it goes to market, or investing in an automated storage and retrieval system (AS/RS). If the facility goes with forklifts, doorways up to 16 feet high are needed to accommodate the high masts.
Of course, a higher ceiling puts unique demands on an operation. These can be addressed by using high-speed doors that enable cold room access, and which are capable of opening at a speed of 60 to 100 inches per second. Here are three ways high-speed doors maximize the benefits of high ceilings.
Downtime -- The smaller footprint means less linear wall space, so these rooms have minimal doorways. Downtime becomes a big issue with minimal access points.
Palermo's Pizza is one of the country's fastest growing pizza makers under its own brand name and private label. The company was one of the first to open a plant in Milwaukee's Menomonee River Valley, a location chosen because of its proximity to its existing workforce. Just a few short years later, Palermo's needed more space. Rather than relocate to an area farther from the workforce, 64,000 sq. ft. was added to the existing operation, including a 40 foot high ceiling in the freezer storage room.
The smaller footprint means less aisle distance for faster access to the product. But the reduced overall linear wall distance also means fewer doorways -- just five in the case of Palermo's.
High-mast forklifts requiring 18 feet of clearance at Palermo's can go through these doorways hundreds of times a day. The extreme cold and the high demand to meet short deadlines mean drivers move quickly. A slow-opening door is a target for forklifts, because drivers can misjudge if the doorway is clear and might clip the bottom of the door as it rolls up. Losing even one doorway due to a vehicle collision can severely disable the operation's tight schedules and strain client relations.
However, fast doors make collisions nearly impossible. The fastest doors can provide a clear doorway in less than two seconds, allowing unimpeded traffic access for even the tightest approaches to the doorway.
According to Palermo's facilities engineer Steve Daniels, "our guys are going back and forth through that freezer all day long, taking raw materials to the line. If we can't keep that flow going, we're shut down."
In the very rare case the door does get hit, most models have a breakaway/fast reset feature that has the door back in operation in just seconds. Consequently, door repair crews -- a common sight in many operations -- seldom have to pay a visit to the facility except for an occasional tune-up, saving repair costs.
When it comes to routine door maintenance, advanced electronics in the high-speed door controller enable adjustments to door operation to be made at floor level, a real benefit when doors are 18 feet tall. The man-lift stays parked.
These systems offer total digital control and self-diagnostics to minimize maintenance surprises. The AC drive enables soft starts and stops, while providing smooth motion at the door's high speeds for longer component life. High-speed doors can further reduce maintenance by eliminating the coil cords usually attached to the bottom bar and instead communicate wirelessly and continually with the controller -- wherever the controller is mounted -- to continuously track door operation and provide greater safety.
Sustainability -- Between the freezer room and the chilled dock there can be a temperature differential of approximately 40 degrees. A high doorway typically has about 160 square feet of exposure area. A considerable amount of frozen air can escape the freezer room when these high doors are open.
In low-temp environments, high-speed doors reduce air infiltration with fabric panels that cover the doorway. Some models even feature insulated panels that provide additional R-value.
Recent research also has found that the high speed more than compensates for the doors' insulation deficiencies. When a door is used more than 55 times a day, a high-speed door starts to save more energy than a standard door. In a busy facility, 55 cycles can occur in just a matter of a few hours.
When closed, a high-speed door does an excellent job of sealing the doorway along all four sides of the perimeter. Along the side of the panel, its guides envelop the panel edge to stop energy from escaping the room. Combined with a floor-hugging gasket and brush gaskets along the header, cold air is contained.
For the Palermo's operation, with freezer storage near production, there are both sustainability and productivity issues. Daniels notes that with their freezer at minus-15 degrees, "every time the door opens I'm losing refrigerated cold air to my production space."
Daniels has no quantifiable figures on the energy savings from the doors, but says," I can see a change in my compressor usage."
He also points out his employees are much more productive because they are not exposed to as much super cold air coming through the open doorway.
Faster Traffic Flow -- In a busy operation where low-temp doorways are accessed hundreds of times a day, seconds count. A high-speed door can be opened and accessed in less than five seconds, saving hundreds of accumulated worker-hours a year just waiting for the door to open. This allows for better utilization of human resources and investment in equipment.
Recent Advancements -- Technological advancements in high-speed doors include the recent introduction of solid panel doors capable of opening at 125 inches per second. Traditional solid panel doors that lumbered along at a slow speed were appreciated for their heavily insulated panels, but were hit routinely by forklifts. Now low-temp operations can have both rapid operation and higher R-values, plus the design of these new doors enables them to withstand accidental impact.
The information contained in this publication is intended for general information purposes. No representation is made that the information or references are complete or remain current. Click here for Grainger's full legal disclaimer.