Neil Roberts, Technical and Business Development Refrigerants EMEA at Chemours UK Ltd says an “apples and apples” comparison of new low global warming potential (GWP) HFO blends with CO2 and hydrocarbon systems in commercial refrigeration clearly shows how this new technology can give up to 20% reduction in life cycle cost with the minimum CAPEX in new retail refrigeration installations.
With the approaching ban on high GWP hydrofluorocarbons (HFCs), such as R404A, coming in 2020 under the F-Gas regulations, it brings the choice of what to use for new commercial refrigeration installations under great scrutiny. In conjunction with this, the reduction in F-Gas quota pushes industry to use much lower GWP products than have been used in the past. The question is how to do this without sacrificing the benefits that HFCs have provided for many years?
When we look at the benefits of HFC systems to retailers we see this is well known technology which simplifies installation and maintenance while minimizing capex costs. They are robust and dependable operation which reduce retailer downtime and maximize trading hours: and they are safe and energy efficient with the right designs and when maintained correctly.
The big issue is the high global warming potential of traditional HFCs like R404A that causes an environmental concern when systems leak which has driven the restrictions in the F-Gas regulations. The good news is that new technology is now being piloted that seeks to keep the benefits of HFC technology while complying with the F-Gas regulations in the long term.
Retailers must consider their options carefully. UK retailer ASDA looked at the options available to ensure the business remained compliant and sustainable under the F-Gas changes.
ASDA noted the urgency with the next phase-down step approaching at the end of 2020 and the need to use low GWP – ie below 300 – refrigerant options across a variety of applications, including Commercial Refrigeration, as shown in figure 1.
A crucial factor was to choose a solution that not only had a lower GWP but also tat least maintained the performance of the products it replaced, with the energy efficiency being particularly important, as increased indirect emissions from increased power consumption will greatly reduce any net gain of lowering the refrigerant GWP. ASDA was also looking for similar operating characteristics to the common HFCs such as R404A, as well as the mid GWP HFO (hydrofluoro-olefin) blends such as Opteon™ XP40 (R449A) being used to retrofit existing systems.
A recent report by independent consultants Wave, winners of the RAC Cooling Business of the Year 2018) shows that low GWP HFO blends such as Opteon™ XL refrigerants can give the lowest emissions and up to 20% lower life cycle cost per kW of cooling capacity over 10 years when compared to other F-Gas compliant solutions.
Figure 2 shows the comparison for a typical supermarket of c.2000 m2 but the trend is relevant for store sizes from c. 300 m2 upwards:
These Opteon™ XL refrigerant blends are specifically designed for use in commercial refrigeration in new equipment. Opteon™ XL20 (R454C) with a GWP of 148 and Opteon™ XL40 (R454A), with a GWP of 239 are well below what is needed to meet future F-Gas restrictions.
The products do have a mild flammability (known as A2L) but this can be handled safely, as has been shown by the study below.
From Pilot Study…
ASDA trialed one of the candidates in an existing system in the ASDA Merchandising Centre of Excellence (MCE) in Leeds over a six-week period in early 2018. The results from this trial were excellent. Following this, individual risk assessments were performed, from design and manufacture, to installation/ decommissioning, maintenance and normal usage stages.
…to New MCE trial and upcoming go-live in 2019
The trial in the new MCE commenced in February 2019 with two purpose built packs by Hubbard using compressors supplied by Emerson and approved for use with HFO blend refrigerants. The packs delivered <40kW and contained approx. 50kg of refrigerant. One pack was run on R448A, an A1 HFO blend, and the other on Opteon™ XL40 (R454A). As well as a test of the performance of the A2L refrigerant, the set up was used as a test bed for the risk assessments, and specifically of the measures to mitigate risk in such a system. These included ventilation, leak detection and developing a response protocol should a leak be detected.
Learnings from this pilot study will be utilized in the first ASDA live supermarket to adopt the Opteon™ XL HFO blend technology to be completed later in 2019.
ASDA, with the help of Chemours, has developed a commercial refrigeration system that proves the viability of this technology and gives a better option where other solutions are not favourable on cost and/or performance grounds. It is commercially competitive as it uses similar components to traditional HFCs, which also simplifies installation and maintenance giving better uptime and reduced loss of trading hours.
This meets the challenges of the F-Gas phase-down and bans on the use of high GWP refrigerants and provides a long term, sustainable solution to small pack commercial refrigeration applications.