Case studies by Scantec show significant energy savings and quick payback for low-charge NH3 systems versus conventional HFC-based systems.
Stefan Jensen, managing director of Australia-based Scantec Refrigeration Technologies, presented performance data from five recent industrial installations running on NH3 at the 7th IIR Ammonia and CO2 Refrigeration Conference in Ohrid, Macedonia, held on 11-13 May.
The energy data, collected over one year, reflected the performance of medium-sized refrigerated distribution centres, currently in operation in Australia. Four facilities were serviced by low-charge NH3 systems whereas one other facility runs on a conventional single stage NH3 system. The low-charge NH3 systems significantly outperformed the conventional NH3 system in terms of energy efficiency.
“The result is 2-2.5 times lower specific energy consumption for the low-charge NH3 systems,” said Jensen, discussing the actual performance data.
The five facilities shared the same owner, thus the differences in modes of operation and products stored between the different warehouses were negligible.
Additionally, there were minor differences in climatic conditions between the various sites.
“Nothing beats ammonia when it comes to operating efficiency, but it has to be designed properly.” – Stefan Jensen
Based on this case study, Jensen demonstrated that state of the art low-charge NH3 systems, when applied correctly, are quickly becoming energy and cost competitive when compared to HFC-based systems.
“The differential investment between our low-charge NH3 system and industry-standard HFC systems is usually returned in 3 to 4 years,” remarked Jensen.
Jensen, however, emphasised the importance of system design for achieving optimum performance.
“Nothing beats ammonia when it comes to operating efficiency, but it has to be designed properly.”
“Why do we bother with synthetic refrigerants if low-charge ammonia systems can offer better energy performance, as registered from existing installations, than standard HFC systems?,” he concluded.
Stefan Jensen is a registered Professional Engineer in Queensland, Australia and is a member of the Board of Directors of the International Institute of Ammonia Refrigeration (IIAR) in Washington, USA.
His presentation was one of the highlights of the 7th International Conference on CO2 and Ammonia Refrigeration Technologies, which took place in the Balkan lakeside resort of Ohrid, Macedonia on 11-13 May, under the auspices of the International Institute of Refrigeration.
A total of 150 participants attended the event, which combined keynote speeches from experts with technical presentations on work related to CO2 and ammonia systems.