Customer Challenge:
Frost Build up in freezer room
Our customer has a freezer room for the storage of finished, packaged produce. Ingress of moisture laden ambient air when the doors were open produced a constant build-up of frost on all surfaces within the store, including product.
Health and safety
Traditional PVC strip curtains had been installed at the doors to minimise air movement, however they were not effective in controlling temperature and were prone to becoming covered in frost which reduced visibility. The frost that fell from the curtains as personnel entered the freezer posed a slip hazard.
Temperature/energy
The set point temperature in the freezer was difficult to maintain due to the loss of cold air and ingress of warm air. The evaporator chiller system needed to operate at full capacity to compensate for the temperature losses. The temperature differential between floor and ceiling of the freezer meant the highest shelves in the room could not be used.
Production quality
Finished product quickly became covered in frost which damaged packaging when thawed.
Maintenance costs
Ice build-up on the chiller evaporators meant they were operating at full capacity with frequent service requirements. Full repairs were necessary when the build-up of ice jammed the fans.
Typically the room required a 6 weekly shutdown and defrost.
Enershield solution:
Installation of a vertically mounted DSH 120 Enershield air barrier.
Enershield air barriers create a smooth laminar air flow across an opening to create a virtual door and form up to a 90% seal which separates the environments on either side.
Result:
The freezer temperature losses and the ambient air ingress were eliminated. The ice/frost issue then dramatically reduced and the PVC strip curtains were removed. No further freezer room defrosts were required. Personnel were able to access the room without any restrictions and safety hazards were eliminated.
Additional Benefits:
Reduced chiller use
On completion of the installation the client’s evaporator units unexpectedly began cycling on and off. Alerted by this, the client contacted the maintenance company who advised that the units were now able to maintain the set point temperature and were in fact functioning correctly.
The maintenance and running costs of the evaporators has reduced with associated financial savings.
Temperature
The Enershield air barrier recirculates the freezer room air. In doing so it effectively de-stratifies the room air and equalises the room temperature. As a result the storage capacity in the freezer increased as the highest shelves of the storage racking could now be used.
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