The Godden Food Group is a family owned and operated wholesale food distribution business located at Ormeau just north of Queensland’s beautiful Gold Coast. The company supplies a complete range of frozen, chilled, fresh and dry goods to restaurants, caterers and private homes throughout South East Queensland & Northern New South Wales.
In 2019 the lease on the company’s premises came to an end and Jeff Godden, the company’s owner, had to find new premises. Having secured a new home for the business, and built a 27,000m3 insulated store, he needed to fit it out with the most advanced refrigeration equipment, to provide separate rooms for -23°C frozen storage and a chilled area at 2°C - 4°C.
Safety, efficiency and sustainability against the clock
For Godden foods, the key requirements were to have a safe, cost effective refrigeration system that would provide sustainable service well into the future. However, Jeff Godden also had another target in mind: he needed the whole project completed to allow him to be fully operational before his initial rent-free period expired.
Centralized low-charge ammonia with reciprocating compressors
Jeff was recommended to use a centralized low-charge ammonia refrigeration system with four V300 Grasso reciprocating compressors from GEA. Although this was likely to be a little more expensive that a freon system, it was considered to be the best long-term solution for this application because of the significant long-terms savings on energy costs that were possible.
The main benefit of a centralized low-charge ammonia refrigeration system is that it contains very little ammonia, around four to five times lower than a conventional liquid overfeed system. The presence of high-density liquid refrigerant within the wet suction lines and risers is eliminated. Because pressure drops in wet suction lines are up to sixty times higher than in pure vapor lines, the system runs at a much lower refrigerant pipeline pressure drop making it very energy efficient. This is where most of the energy savings are achieved.
The GEA Grasso V300 compressors at the heart of the system were also ideal for the job because of their inherent energy efficiency. The V300 is highly efficient and does not require water cooling that would increase the installation costs and use more energy as water has to be pumped around the system. Not requiring water cooling further reduces energy consumption and makes the installation ‘plug and play’, reducing the time involved and giving the company the flexibility to take the plant with them should they need to move again in the future.
Energy savings and fast pay back
The new plant at Godden Foods was commissioned in May 2020, coinciding with the start of trading from the new premises. Since then it has performed exactly as expected with energy savings of around two-thirds compared with an industry-standard, air-cooled HFC based system. Jeff Godden expects to get back the whole cost of the new plant in eight years well before the expiry of the fifteen-year lease period. The marginal additional cost, compared with installing a new freon plant, would be recovered in half that time. Maintenance costs for the system are forecast at around 2% of the initial capital cost annually, much lower than equivalent freon systems.
A safe system today and in the future
A centralized low-charge ammonia refrigeration system from GEA is also very safe. The operating inventory within the freezer is only 1.5 kg of ammonia so, even if there was a catastrophic leak, the concentration of ammonia within the refrigerated space would be only around 100 ppm. The IDLH (Immediate Danger to Life and Health) threshold is 300 ppm as a comparison.
The result is a new refrigeration plant for Godden foods that is hugely more energy efficient than an equivalent freon system, environmentally sustainable, safe, portable if necessary and, if correctly maintained, will provide 30-40 years of faithful service.