Shipping Bay: Safety & Reduced Energy Usage Overlap (a Win-Win)

While working as the utilities and facilities manager, to bring on a new major expansion at a large food manufacturing facility, “Safety Always” was part of the culture. The new expansion called for growing from a facility with eight lines of existing production to an immediate addition of sixteen production lines – and targeted to expand to thirty-two lines of production within two more years.

As with most companies, the challenge to continually sustain and search for new ways to reduce energy usage through operations, maintenance, and projects continued to escalate as a business priority.

While the many utilities projects were implemented, one memorable challenge that improved safety results and reduced energy costs pertained to an approach implemented at the plant shipping bay. The utilities staff teamed up with the shipping department staff to address the following problem.

The shipping bay temperature was operated at 0°F and was located between a -20°F freezer taking up a full long wall. Four doors and thirty-one dock doors for truck access were located on two of the other walls. The remaining wall had office windows on each side of an entrance door. The other side of the thirty-one dock doors, where trucks backed up against cushioned seals and dock locks, was directly outdoors and exposed to seasonal ambient temperature. Although the winter months were definitely more favorable for reduced outdoor infiltration and ambient heat-load issues, the hot and humid summer conditions presented the greater peak energy usage challenges that needed to be addressed.

To address these issues a shipping department employee was assigned on each shift to keep watch over the dock doors and to address any findings that would improve housekeeping, prevent unsafe conditions, and reduce energy usage.

The dock manager would monito shipping door attendants, and ensure trucks were backed up and sealed as well as possible before opening the dock doors. They would also make sure the dock door was closed after filling the trucks and before the truck departed the docking station. This cut down on massive air infiltration. There were a couple of shipping door attendants on duty that handled the truck and dock door sequencing from the backup, loading, and the departure.

Housekeeping items were implemented to reduce and prevent potential unsafe conditions such as slips, trips, and falls. This included dock area cleaned of any wood pallet pieces, plastic wrap, cardboard, water, ice, or other types of debris. The removal of these items permitted the dock doors to close and tightly seal, thus reducing energy usage.

Addressing fixed building and equipment issues can offer significant methods to address both safety and energy.

  1. Tighten, repair, or replace any existing door seals that are torn and/or not sealing well.
  2. Install dock-level seals on the sides and below the lifting plate to prevent infiltration.
  3. Replace upper door-cable pulley wheels with larger wheels to reduce time the doors take to open and close and reduce infiltration.
  4. Repair or replace dock door panels that are damaged to ensure proper insulation thickness.
  5. Tighten door rails and door wheel anchor plates and lubricate with low temperature grease to reduce friction loss and energy usage.

Addressing these issues offered significant benefits:

We were able to defrost the dock evaporator less frequently, due to lower frost/ice buildup from air infiltration.

We turned one evaporator into a reheat unit using a hot gas coil that allowed all the evaporators to dehumidify without lowering the dock bay temperature.

Overall, the dock bay area was much cleaner, potential hazards of slips, trips, falls were eliminated, the energy usage was reduced significantly. A few simple changes at the loading dock can improve both safety and efficiency.