Cool story heats up

Food manufacturers are being forced to modify their refrigeration systems in advance of changes that take effect in 2020. But, if they leave it to the last minute, they could face huge cost implications – especially if their systems unexpectedly fail.

It’s all related to the EU’s F-Gas Regulation 517/2014, which is bringing in quota restrictions and causing prices to soar for hydrofluorocarbon (HFC) refrigerants widely used in the sector. Over the past 12 months, the cost of HFC refrigerant R404a, for example, has increased ten-fold.

When looking to futureproof their systems, however, food firms must also consider the impact of rising energy costs and the need for greater operational efficiencies, some refrigeration experts argue.

From 1 January 2020, there will be a service ban on any refrigerant with a global warming potential (GWP) of more than 2,500. It will prevent systems using some HFC refrigerants such as R404a – commonly used in the food industry – from being topped up with new fluid. In 2021, the screw will be tightened even more, as GWP refrigerant quotas are further reduced.

Longer-term, companies are likely to move to very low GWP, ‘natural’ refrigerants, such as ammonia, carbon dioxide (CO2), hydrocarbon (HC) – or even air, for very low-temperature applications. But, in the meantime, interim alternatives are necessary. However, these also present challenges.

One interim option favoured by the industry is to use more environmentally-friendly hydrofluoroolefin (HFO) and HFC refrigerant blends. A new conference on the application of HFO refrigerants is being staged in Birmingham from 2–5 September, organised by the International Institute of Refrigeration and the UK’s Institute of Refrigeration.

One of the problems with synthetic HFO refrigerants is that they are classified as A2L, which means they are ‘mildly flammable’ and care has to be taken in their handling and use.

“People have been working on HFO and HFO blends now for a couple of years. That experience should be shared,”​ says refrigeration expert Professor Judith Evans from the Bristol-based School of Engineering campus of London South Bank University.

Cost manufacturers dearly​

Too many manufacturers left it too late to phase out R22 hydrochlorofluorocarbon refrigerants before they were banned in 2015, and that cost them dearly, says Dr Robert Lamb, group sales and marketing director at Star Refrigeration.

Lessons need to be learnt from that, he warns. “It’s all about prior planning. If you break it down into smaller pieces and plan carefully, what appears to be a very scary problem can be dealt with through a bit-by-bit approach.”​

For a manufacturer operating, say, five refrigeration systems, it might involve replacing the R404a on two systems each year and storing it on site in case there are problems with others in the lead-up to 2020, suggests Lamb.

“If your equipment is suitable in terms of its age, there are a number of interim blends that contain a mixture of HFCs and HFOs,”​ he says. But, as the GWP of these blends gets below 500, they start to become more flammable, he cautions.

“Both the industry and industry bodies are not advising to put these A2L refrigerants into existing systems with A1​ [no flammability] refrigerants, because there are issues around how we deal with the flammability,” ​says Lamb. And that’s where the interim refrigerant blends come in.

But prices for the blends with GWPs of between 1,000 and 2,000 GWP are rising as quotas for the higher GWP components are reduced, he explains.

There are fewer CO2 refrigeration systems on the market. Such systems have primarily been used in retail applications and for cold stores, and they have the disadvantage of operating at high pressures, says Evans.

However, Lamb says that Star has installed three spiral freezers running on CO2 for food manufacturers over the past 12 months, so demand is on the up.

Ammonia-based systems​

Interest in ammonia-based refrigeration systems from the UK food and drink processing sector is also growing, according to refrigeration system expert J&E Hall, a subsidiary of the Daikin Group and a specialist in these systems, although it works on other refrigerant systems too, such as HC and CO2.

Ammonia-based refrigeration systems are mainly used by large food manufacturers. They represent about 20% of new enquiries over the past 18 months, claims J&E Hall managing director Andrew Bowden.

About 60% of J&E Hall’s service and maintenance business is with food and drink, 75% of which is food and 25% beverage, brewing and distilling operations, says Bowden. Around 70% of the food businesses the company works with use ammonia-based systems, he adds.

“We are now receiving more enquiries from food and beverage [companies] where ammonia is being considered,”​ says Bowden.

Rather than clients asking for refrigeration processes that match their favoured refrigerant, they are now asking for the best refrigerants for the type of process they want to use, he adds.

As J&E Hall develops new low-charge ammonia refrigeration system designs, Bowden expects to see them used by smaller players too.

The problem limiting the wider adoption of HC refrigeration systems, meanwhile, continues to be their greater flammability.

This has restricted their use to niche applications, such as for outdoor packaged chillers – where gas build-up does not present a problem – or, more recently, for ‘low-charge’ supermarket chiller cabinets, says Lamb. However, with the right controls in place they can also be made safer to use, claims Bowden.

Air-based refrigeration systems​

Air-based refrigeration systems are not known to be used much in Europe, explains Evans. But, in Japan, Mayekawa has commercialised a model for freezing tuna fish, which is stored at -60⁰C, she adds. There are thought to be about 100 of these refrigerators operating in the country.

“There is no silver bullet for manufacturers when considering F-Gas-free alternatives,”​ concludes Chris Smith, head of temperature control in northern Europe at refrigeration specialist Aggreko.

“Manufacturers have been working to find a refrigerant that ticks all the boxes in a post-2020 future for many years, but have yet to find the perfect fix.”​

This makes it difficult to invest in refrigeration for the long-term, as there is every possibility it will be defunct in several years, Smith claims.

“Currently, the market is looking to the past for suitable alternatives,”​ he suggests. “CO2 and ammonia, which were used long before F-Gases became widespread, are currently seen as the best options as they are naturally-occurring and cheap, and come without the high GWP of F-Gas. However, they have their disadvantages. CO2 works at high pressure, while ammonia is potentially toxic.​

“It’s no surprise, therefore, that companies are unwilling to commit to current F-Gas alternatives for the long-term – there simply is not enough certainty. Counterintuitively, futureproofing a business is more likely to come from short and medium-term systems that provide flexibility and avoid businesses committing large amounts of capital unnecessarily.”​