Food Marketing & Technology - India July 2019 | Page 8

Doors Make the Difference for Cold Storage
A
dvancements in freezer/cooler door technology and
a recent study from the Door and Access System
Manufacturer’s Association (DASMA) now make it easier
to choose which kind of door to use on a freezer/chilled
room in a cold storage distribution center (DC).
Regardless of how official government policy is finally
decided on the issue of climate change, industry has
realized that going green saves money and businesses
have embraced sustainability to bolster the bottom line.
There are major retailers that have encouraged their
supply chain partners to come on board as well.
In most DCs, the building’s interior consists of wide-
open, un-walled spaces. In a cold storage DC the
freezer and chilled rooms have to be their own separate
environments in order to maintain product quality and
prevent food spoilage. Being a low-margin business and
any waste of course comes out of profits.
Confining Cold Air or Letting in Traffic
Cold storage plant managers have been wrestling with
the question of what kind of door works best for a cold
storage room. After all, doors have two uses on this or
any kind of facility – to allow access and to protect the
activities taking place in the room in order to protect
product quality. The two are seemingly in conflict.
The question of covering the opening with a door that
is as thick as the wall itself to prevent heat transfer? Or,
using high-speed doors to prevent traffic back up into
and out of cold storage?
Research Provides an Answer
So how should the management in a cold storage
facility decide when it comes to door selection?
After a two-year project featuring third-party lab
testing, DASMA developed a method to demonstrate
the efficiency of high-speed doors in building envelope
energy calculations. The model for performance testing
and evaluation was a prototypical, high-speed fabric
door.
Overall, DASMA noted that high-speed doors are the
type of product that can significantly help achieve
energy-saving goals.
The DASMA research revealed a new perspective
in evaluating door energy efficiency and took into
consideration common U-factor, air leakage, and motor
horsepower values in a comparison of high-speed
doors to conventionally operating insulated doors.
The study showed that high-speed doors become more
efficient when cycled 55 or more times per day, with that
“crossover” point illustrated below.
The kinds of high-speed doors the study had in mind
have a roll-up design with a heavy-duty plastic fabric
panel. For some measure of heat transfer resistance,
there are models with double panels enclosing a layer of
insulating foam.
Cold Air Stops at the Seal
Along with reducing air infiltration, high-speed roll-up
doors offer a superior seal around the full door perimeter
with side guides covering the vertical panel edges, a
floor-hugging seal, and a brush seal along the top. Roll-
up doors are better designed than solid-panel doors at
sealing the door when closed.
The door’s operating life in an industrial/commercial
setting pretty much involves getting out of the way
of traffic that passes through the opening. Solid panel
doors, being slower, are more likely to be hit by forklifts
and other material handling vehicles. The damage that
results can vary. Panels can be knocked out of alignment,
forming gaps in the seal, have holes punched in them, or
be totally knocked off the wall.
When that collision happens, the result is massive air
infiltration and energy loss. If the door is totally disabled,
the loss of one doorway in a busy cold storage facility can
considerably cripple delivery schedules and wreak havoc
with productivity.
If a high-speed roll-up door is hit and the panel knocked
out of its guides, results are less severe. Most models
have a self-repairing feature; the door is activated to
roll up and then the panel rolls back into its guides. This
design protects both the doorway and the facility’s ability
to meet customer demands.
It’s All About Choice
The introduction of quick-operating sliding doors
combined with DASMA research on suitability of high-
speed doors means that doors can be specified according
to the operation. Now management can make a door
selection and be comfortable with it based on the needs
of the operation.
Whatever the requirements of the facility, industrial door
experts Gandhi Automation’s Pvt Ltd can provide advice
and insight to tailor a door that delivers the performance
and protection every doorway need.