Automated Interior Reefer Door Cuts Fuel Use

A new electronic system saves fuel by reducing how long trailer doors are open during temperature-controlled deliveries. The MD2000 automated interior door from Assa Abloy Entrance Systems replaces inefficient reefer “curtains”— those heavy strips of plastic hung vertically behind reefer door openings.

Instead of pushing cargo through a barrier, the electronically controlled door “opens with lightning speed, electronically senses the presence of workers and cargo passing through, and quickly closes once the passage is clear,” according to John Zimmerman, Assa Abloy’s sales manager for high-performance doors.

“With the push of interior- and exterior-mounted buttons, the door opens and closes automatically within seconds, once the system’s electronic photo eye confirms that the passage is clear,” he added.

Zimmerman said that by reducing the number of defrost cycles, the door can deliver fuel savings of up to 40%. The automatic door can be installed or retrofitted on the face of a reefer’s interior wall. Specifically designed for freezer applications, the door has been tested and validated to operate at 0 degrees Fahrenheit.

Along with aiding fuel efficiency, the door is designed to help streamline food deliveries while ensuring a constant temperature and humidity barrier for reefer interiors. The manufacturer stated that, when compared to the MD2000 door, plastic-strip curtains are a porous barrier at best, and create friction points for workers, significantly reducing the working dimensions of the opening. The strips are also prone to swing, striking workers and dislodging cargo, making trips with heavy pallet jacks and hand trucks both difficult and frustrating.

“During field research, we observed that workers tied or otherwise lodged the strips out of the way, leaving the door without any atmospheric barrier during unloading,” Zimmerman said. “Or the curtains had been compromised by being cut back or cut off altogether to make passage less cumbersome, thereby exposing cargo to the outside environment and potential contaminants.”

The door’s closing cycle can be programmed to between 0 and 90 seconds and the flexible door retracts if it encounters resistance. Once closed, the secure barrier only opens for authorized personnel to prevent theft and intentional adulteration of cargo.

The flexible interior door features a large clear window panel and a soft bottom edge, and retracts if it encounters any resistance, protecting delivery workers and eliminating potential damage to cargo. A breakaway design allows the door to be pushed open in case of emergency or an accidental collision; the door can be placed back in operational position in moments.

According to the company, the MD2000 door can be easily installed on the face of a reefer’s interior wall by OEMs or retrofitted on existing trailers within just a few hours, and Assa Abloy will send technicians to train qualified customers on proper installation and service techniques. The system comes with its own plug-and-play modular wiring harness kit, and all cables and connectors remain accessible at the point of use for easy service and maintenance.    

Red LED light strips are mounted on both sides of the MD2000 interior door frame and remain on when the door is closed to help orient workers orientation in low-light conditions. The lights turn off when the door is open and begin flashing to signal when it is preparing to close.

The manufacturer stated that the door effortlessly reduces interior temperature variability during frequent stops, keeping food safer. By significantly reducing the time it’s open, the door also prevents humidity from entering the refrigerated space, inhibiting condensation, vision-diminishing fog, and dangerous surface ice from forming on floors.

In addition to ensuring product control and integrity, according to Assa Abloy, the MD2000 automated reefer will also improve a fleet’s bottom line. “Formal studies have proven fuel savings of up to 40% by adding a high-performance door to the temperature-controlled food delivery process, by reducing the number of defrost cycles,” the company stated.