Towards more energy-efficient cold storage

With a continuous global effort to reduce our carbon footprint, refrigeration manufacturers are being pressured to develop more energy-efficient products.

Today, the industry is meeting this environmental challenge, urged on by new Refrigeration Minimum Energy Performance (MEPS) requirements to accommodate higher energy-efficient star rating refrigerators. And nowhere is this more important than in refrigeration systems for food storage.

Retrofitting cold storage units

Craig Parker, technical manager for Patton Australia/NZ, says although environmental motivation is high, the challenge is to remain cost effective and competitive. As a result, Parker says refrigeration products need to be designed in a way that makes them adaptable to retrofit energy-efficient components.

“It’s interesting times in the refrigeration industry and comforting to know the developments for cold food and beverage storage today are the cornerstones for the wellbeing of the environment into the future,” he said.

Patton’s J Series coolers have just been released in Australia and New Zealand and are being used as large cool store complexes for the kiwifruit industry in NZ.

Importantly, the coolers have options to configure for water defrost. With any low-temperature system a defrost cycle is required to clear ice from the coils. The benefit of water defrost is that it replaces the need to have high energy using electric heater elements. With a water system the site can have a holding tank and re-circulate the water time and again.

“Water defrost appears to be making a strong comeback in popularity as the awareness and concerns over energy usage or wastage increase,” Parker said.

Frost-free storage

Creating a frost-free environment is a constant challenge for cold storage solutions. The Munters IceDry dehumidifier features an Desiccant Wheel, which dries the air to a dewpoint temperature, eliminating the need for an airlock.

It also features reduced defrost cycles. By delivering air at lower dewpoint temperatures, desiccant dehumidification systems enable the existing cooling-based equipment to defrost less frequently (often reduced from four times to once a day). This saves energy while reducing the amount of re-entrained water vapour that is inherent to defrosting of cooling-based systems.

In addition, desiccant dehumidifiers specifically target moisture (latent) loads, which allows the operator to decouple the latent and sensible loads in their facility. Sensible loads are addressed by the system’s cooling equipment while the desiccant section tackles the latent component of the total load. All of this reduces the overall refrigeration load.

Ice making

Energy efficiency also extends to cold storage issues such as ice making.

Maree Garner, sales manager for Coast Distributors, explains that there are many ice makers on the market, but buyers are increasingly looking for energy- and water-efficient products.

“Our Ice Maker machine, which produces nugget ice, saves up to 30% on energy uses. In order for this machine to produce 46 kg of ice, it uses just 50 L of water and 5.1 kW of power,” Garner explained.

“By comparison, traditional ice cube machines use 84 L of water and 6.2 kW of power to produce the same amount of ice.”

Unique to the design is the ability to pump ice up to 20 m through a tube. This allows for remote installation of the ice machine and the convenience of having ice delivered to where it is needed.

Sue Falcke, exhibition manager of the Air Conditioning, Refrigeration and Building Services Exhibition, commented that the quest for energy-efficient refrigeration solutions for food and beverage storage just keeps on growing.