In Focus: Natural Refrigerants

“This is the decade of natural refrigerants, when they become the dominant force across multiple sectors,” declared Marc Chasserot, Founder and CEO of ATMOsphere, at a discussion hosted by Güntner at Chillventa 2022. He was referring to the rapidly increasing use in the refrigeration and cooling sector of natural alternatives to synthetic refrigerants, which have been shown to be damaging to the planet and to human health.

Güntner has long been a champion of the use of natural refrigerants, in particular carbon dioxide, ammonia and hydrocarbons. “Almost half of the products that we sold in 2022 were for use with natural refrigerants, and we expect that proportion to increase rapidly in the future,” says Michael Freiherr, Managing Director of Güntner. “And this can only be a good thing for our planet.”
Here we look at the many benefits of natural refrigerants.

THE RISE AND FALL OF SYNTHETIC REFRIGERANTS

Successive man-made refrigerant gases have proved to be harmful.

In 1937, American engineer Thomas Midgley Jr was awarded the American Chemical Society’s Priestley Medal for distinguished service in the field of chemistry. His achievement was to have developed Freon, the first of many chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs) and hydrofluorocarbons (HFCs) – non-toxic and non-flammable gases that could be used as refrigerants. In the decades that followed, they became widely used in industrial, commercial and home refrigeration.

However, history would prove to be a less enthusiastic judge of Midgley’s work. In the 1970s, scientists discovered that CFCs were causing significant damage to the Earth’s ozone layer, which protects it from ultraviolet radiation. In 1987, the Montreal Protocol effectively banned their use. HCFCs, which similarly damage the ozone layer, but to a lesser degree, have now also been almost completely phased out around the world.

This leaves HFCs, currently the most commonly used synthetic refrigerants globally. While they do not harm the ozone layer, they are greenhouse gases that are hundreds to thousands times more potent than carbon dioxide in terms of their global warming potential (GWP).

A recently developed synthetic alternative to HFCs is hydrofluoroolefins (HFOs), which have only 0.1% of the global warming potential of HFCs. However, both HFCs and HFOs produce trifluoroacetic acid (TFA) as they degrade, which many scientists believe is harmful to the environment, marine life and humans.

REASONS FOR CHANGE

A variety of factors are powering the switch to natural refrigerants.

REGULATION
Unsurprisingly, the harmful effects of today’s synthetic refrigerants have led to strict regulations governing their use. In 2016, 197 countries adopted an amendment to the Montreal Protocol committing to cut the consumption and production of HFCs by more than 80% over the next 30 years. However, countries and regions have also introduced their own, more stringent regulatory measures. In Europe, for example, the EU’s F-Gas regulation intends to reduce emissions of fluorinated gases, which includes HFCs, by two-thirds by 2030. The EU’s REACH regulations, which govern which chemicals can be manufactured and used within the EU, may also lead to bans on certain HFCs.

“The F-Gas regulation is the most important piece of legislation worldwide for the refrigeration and cooling industry when it comes to encouraging the use of natural refrigerants,” says Chasserot. “It’s being seen as the model to follow in other parts of the world, especially the US.”

In the US, the American Innovation and Manufacturing (AIM) Act, enacted by Congress in 2020, aims to phase down production and consumption of HFCs in the country by 85% by 2036. Proposals by the country’s Environmental Protection Agency will prohibit the manufacture, sale and import of products containing certain HFCs within the next few years.

As research into the harmful effects of HFOs continues, it is likely that regulations will also be introduced to curtail their use.

ESG CONCERNS
Environmental concerns now dominate corporate thinking. According to a recent survey by financial services company Morningstar, nine out of ten companies currently have or are developing a formal strategy to manage their environmental, social and governance practices. In particular, they are aware of their responsibilities in relation to the Paris Agreement on climate change regarding the need to hugely scale back greenhouse gas emissions.

Since the Covid-19 pandemic, companies have also seen a significant increase in both shareholder and consumer concern about the state of the planet. Research by Boston Consulting Group found that almost three-quarters of 3,000 respondents across eight countries were now more aware that degradation of the environment threatens humans. A similar proportion said environmental issues are as concerning as – or more concerning than – health issues.

For this reason, companies are concerned not only about carbon emissions but also about their impact on the planet in general. “The fundamental principle is ‘do no harm’,” says Andreas Hermelink, a Director at consulting firm Guidehouse who specialises in energy and sustainability. “It’s not just about greenhouse gases, it’s also about avoiding solutions that can do damage.”

ECONOMICS
The financial sector is playing a growing role in the transition to natural refrigerants, as both lending and investment decisions increasingly take environmental factors into account. The Net-Zero Banking Alliance, for example, representing more than 40% of global banking assets, is committed to aligning its lending and investment portfolios with net-zero emissions by 2050. Direct emissions from refrigerants are increasingly being seen as part of this equation.

There are also financial reasons for avoiding assets that could become subject to future regulations. “Of course, you can invest in HFO solutions, but then you must be aware that in a few years, depending on where it is in the world, they could be banned, and then you obviously have a problem,” says Hermelink.

Chasserot agrees: “There's a real risk associated with investing in these kinds of solutions, which could end up meaning you're going to have to replace them very soon,” he says.

THE NATURAL WAY FORWARD

The future lies in natural refrigerants.

Natural refrigerants avoid all of the pitfalls associated with synthetics. They produce either negligible or no greenhouse emissions, offer no environmental risks and are future-proofed against regulation and costly refits. Their use supports four of the United Nations’ Sustainable Development Goals: sustainable industrialisation, safe and sustainable cities, climate action, and the safety of the oceans.

Güntner has been developing energy-efficient solutions using natural refrigerants for many years, and was one of the first recipients of the ATMOsphere label, a stamp of approval for best-in-class manufacturers of solutions using natural refrigerants. We also have our own state-of-the-art lab for CO₂ and ammonia solutions, where we do testing, research and development, enabling us to deliver trustworthy and reliable application data.

“In recent years we’ve done a lot of work in particular on reducing the refrigerant inventory within the system, developing new tube geometries,” says Ian Runsey, Chief Technical Officer in North and Latin America in Güntner. “And especially with ammonia, we’ve been looking at ways to optimise the feed methodology into the evaporator, and thereby using far less refrigerant.”

Advances in technology are also making systems using natural refrigerants more competitive in terms of cost compared to those using synthetics. In an increasing number of cases, particularly in large ammonia installations, natural refrigerants now prove cheaper. This is another factor driving their growth.