Shut the coolroom door, that’s the first and most obvious electricity conserving tip. Ultimately, there’s a knock-on effect taking place inside that freezer or cold storage unit, after all. If there are thermally-based losses inside what should be a sealed chamber, then the refrigeration unit is forced to work harder. Working flat-out, that system part then consumes more electrical power. Like energy-eating dominos, the knock-on effect spreads.
Tip 1. Keep the Coolroom Door Closed
Some folk get so caught up in their duties, they just forget the latest energy-saving memo. Put posters up on the walls, all around the door. If the staff are following the guideline but there are still losses, consider a maintenance check. The door seal, spring-loaded hinges or latch mechanism might require servicing.
Tip 2. Use an Intelligent Stocking Strategy
Wire-formed shelves and freezer-centric furnishings are allowing the cold air to circulate, but the area is half-empty. Nearly empty or nearly full, the coolroom chill can’t cool everything properly if the stock isn’t organized in a manner that facilitates airflow. Stop excess energy consumption here by arranging the stock efficiently.
Tip 3. Energy Auditing
If a professionally conducted system audit is months away, consider a self-audit as a temporary measure. Double check digital thermostats by fixing standard temperature measurement devices inside the enclosure. Infrared cameras and thermo imaging devices might be unaffordable, but a simple mercury-calibrated instrument will do the job just as well.
Tip 4. Regular Maintenance
This step ensures hygiene, but it also serves another purpose. Keeping the system coils free of dirt and grime, the equipment fans and vents obstruction free, and everything else free of icy buildup, the coolroom performs at its best. Otherwise, lots of excess electrical energy gets thrown out because the room’s running costs are out of control.
Tip 5. Use Available Services
There’s a range of products that are expressly designed to aid energy-conscious coolroom managers. Install plastic curtains and make sure their strips are undamaged. The walk-in freezer door will open and close throughout a busy day, but that curtain will minimize open door energy losses. Use energy efficient light fixtures, ones that don’t radiate room-warming heat.
The staff do their part, just by making sure the door is never wedged open, never left ajar. Coming in to check everything, the manager examines the stacking height in the cold room. The stacks are high but not overly tall, so the airflow in the frosty chamber is just right. Incidentally, not only are the chamber lights designed to sip electricity, they can also be built to turn off as soon as the door closes.
Door magnets are added to freezers because cooling equipment has a flaw. Correction, it’s not a system flaw, just a simple law of physics, one that’s not always easy to remedy. A sealed enclosure by design, freezers trap air. Consequently, a positive system pressure develops because of the refrigeration unit. Left unattended, positive pressure causes the dreaded “door pop-open effect.” Door magnets prevent such seal breaking incidents from occurring.
Freezer Door Magnets
Sturdy but simple discrete magnets line a freezer door. There’s a blocky magnetic core, which mates with a flat plate on the swinging door. On another unit, the discrete fittings are replaced by an extruded gasket, a flexible seal that exhibits magnetic properties. Compounded with the flexible plastic during the formulation stage or added as a sintered core, the magnetic gasket holds the swinging panel secure, even when the positive pressure rises.
Why Do Freezer Doors Pop Open?
Well, there are complex air currents flowing in some of these units. Sealed so that the chill air temperature is maintained, it’s not easy to balance the interior pressure against the outer atmospheric pressure. If the refrigeration unit spikes its power output, or if an external door opens elsewhere inside the building, or even if another door on the freezer opens suddenly, a non-magnetized appliance door will open all by itself. In terms of physical laws, which tend to be inviolable, the system will attempt to equalize the pressure, and that attempt will cause the pop-open effect.
Determining the Pop-open Culprits
The refrigeration unit is guilty, but it’s not the sole villain in this tale. There are chemical processes occurring in the perishable items stored inside a freezer. They can alter the pressure differential. Defrosting cycles raise enclosure temperatures. As temperatures rise, molecules become excited. In other words, when the temperature climbs, so does the internal pressure. As mentioned earlier, even if the equipment consistently delivers a balanced volume of air, the opening of an outside entrance could just trigger a pressure equalization incident, so the freezer door comes ajar, just slightly.
Finally, multi-door freezers use door magnet, too. To close the frosty chamber and keep everything safely chilled, the magnets anchor the door. Then, as a door further down opens and closes, the magnetically latched panel stays securely locked. Otherwise, the closing of that second door would be enough to pneumatically drive air forward and into the sealed cooling area, at which point any unsecured doors would open a crack, just enough to cause a serious energy compromising event. Essentially, at the end of the day, unsecured freezer doors can be opened by sudden pressure changes, unless door magnets are fitted.
Asked to design a small coolroom, a sealed chamber that will efficiently store its perishable contents at a consistently low temperature, an installation team swings into action. There are questions to ask, answers to determine, and design principles to rule every decision. Keeping energy expenditure low, the expected cold room load is sought out, probably from the asset manager, the person who’s responsible for the site’s day-to-day runnings.
Standard Operating Procedure (SOF) says the small coolroom will have set dimensional parameters. The size of the refrigeration unit, its fan-assisted throughput and refrigerant cooling power, is rated to work with the cubic space available in a smaller cooling chamber. As a general rule of thumb, however, some overhead is provided, what with a potential busy period causing more system demand.
The first project of the week was a narrow coolroom, which had several glass doors and a single rear-located access door. Consumers pulled items after they opened a magnetically sealed glass door. Behind the racks of dairy products, a stock person refilled items. Towards the end of the week, the design principles and team duties shifted slightly. In this instance, a squat chamber, bereft of glass doors, required a different design approach. Different cooling configurations obviously mandate different design solutions.
Planning Energy-Saving Measures
In a home, people welcome extra space. For coolroom designers, though, wasted space is an undesirable room feature, to say the least. Having said that, the design does optimize available room configurations so that restricted airflows easily reach every corner of a smaller cooling chamber. Wire mesh shelves and open-flow furnishings are preferred here as airflow optimization aids within small coolrooms.
The Multiroom Approach
Instead of packing everything into an overly large cold room, the design principles applied during a project management discussion come up with an alternative solution. Two rooms, not one unevenly filled chamber, are used to store perishable foodstuff. Sized differently, matters such as peak period overflow situations and flexible cold loading scenarios are solved when this approach is implemented properly.
The vents and ducts and powered cooling units require allocation, but only after they’ve been sized efficiently. Multiple cooling chambers are planned out, a small storage room and washing area added to the plan, and there’s even a little space left over for a vestibule area, which connects the two small coolrooms. Circled in ink above the design principles list, two words stand out above all else. Optimization, as applied to the available space, ensures every cubic metre of open space is put to use properly. Functionality comes next, for the design must satisfy its intended application.
C&M Coolrooms can create a custom solution for your specific needs. Talk to one of team members today.