Airedale International Air Conditioning, which recently selected R-32-based BITZER Orbit 8 scroll compressors for its latest generation of Azure DeltaChill chillers, reports an estimated 7 percent increase in European Seasonal Energy Efficiency Ratio (ESEER) compared with its previous R-410A range.
The UK manufacturer ran comprehensive tests over several months on prototypes with various compressor options. BITZER supported the development team with access to advance performance data for the refrigerant and visits to the company’s UK R&D facility by James Cullen, global Director Scroll Product Management.
Callum Teahan, Airedale’slead mechanical engineer,who headed up the product development team, said: “The forerunner to Airedale’s DeltaChill R32 was based on the R410A version of BITZER’s scroll, so it made sense to trial the R32 version in order to minimise design changes to the platform. In addition, model variants available, such as the GSU Orbit + and Economiser compatibility, made it attractive in terms of meeting future change sunder Ecodesign Tier 2 (2021) efficiency targets.”
Prototypes included different evaporator technologies, as well as Airedale’straditional choice of condenser. Tests were carried out at standard rating conditions and at the extremes of the operational envelope to check performance and reliability.Other measures included tests for ESEER, Ecodesign SSCEE, oil return tests in worst-case conditions (low mass flow), and high and low supply water temperature.
“We initially faced some challenges in relation to oil management,” says Callum Teahan, “asR-32 has a lower density and mass flow compared with R410A. Throughout the testing process Bitzer were very helpful and provided technical support and expert assistance on site to enable us to resolve the issue.”
This included the supply of special versions of compressors fitted with oil sight tubes, enabling the development team to monitor conditions within units during testing.
Having not only proven the reliability of R-32 technology but established that it yields a valuable efficiency advantage, Airedale is now rolling it out across its new generation of packaged DeltaChill chillers, available in cooling capacities from 450kW to 1MW.
It includes training for installers in the safe handling of R-32, as part of Airedale’s BESA-accredited flammable refrigerant training courses.
Kevin Glass, managing director of BITZER UK, says: “The Orbit 8 scroll is well established technology, and has proven very reliable on outgoing R410A. Our own tests alongside those of Airedale show that the new R-32 version is just as reliable, and delivers a significant efficiency improvement on what was already a highly efficient product. With pressure on to further reduce running costs for end users and improve systems’ environmental performance, this has to be a welcome addition.”
