Vertically mounted air curtain proves a valuable retrofit
October 02, 2012 - MMH Editorial
An eastern Ohio food processor sought to curb exorbitant energy losses and icing maintenance costs at the doorway of its 20,000-square-foot freezer. When a traditional air curtain installation was not ideal, the customer found a custom solution that improved safety, cut costs and is on track for a 12-month ROI.
The client had already installed a high-speed, insulated rollup door that reduced infiltration between the -5°F freezer air and the 60°F to 95°F ambient air. But during its hundreds of daily cycles, the door alone could not prevent 8 degree fluctuations in the freezer. Condensation caused ice buildup, resulting in safety concerns and damage to the refrigeration system, floors and fire door roller tracks.
One option was a full-perimeter door that recirculates air horizontally. However, the full perimeter door was cost prohibitive for this company. Instead, the customer opted for a 12-foot-wide, two-speed, 2,304-cfm air curtain mounted above the doorway.
A distributor of loading dock, industrial door and specialty industrial plant products, proposed a vertical installation of the air curtains. This would eliminate the need to cantilever the air curtain away from the high speed door mechanism, but required modified air discharge nozzles.
The air curtain is now up to 80% efficient at separating the two environments. The roll-up door only opens after the air curtain is at full velocity, which takes about one second. The air curtain powers down one second after the door is again closed.
The air curtain installation has reduced an 8 degree freezer temperature fluctuation to less than 2 degrees. Ice maintenance costs have been significantly reduced, equipment sustains less wear and tear, and the potential for slippery floors has been eliminated. The customer is realizing an energy and maintenance cost reduction of thousands of dollars per month, meaning the system will pay for itself within a year.
Read more Casebook 2013.