The EU-funded LIFE FRONT project, which aims to remove barriers to adoption of hydrocarbon refrigerants within the refrigeration, air-conditioning and heat pump (RACHP) industry, has published a new report, its last one, which provides a risk assessment of flammable refrigerants in two heat pumps and a refrigerated cabinet.

The free report – “Quantitative Risk Assessment of Flammable Refrigerants to Validate the Level of Safety of Proposed Mitigation Measures for Minimising Flammability Risk” – is available here. (shecco, publisher of this website, is a participant in the LIFE FRONT project.)

The report offers a quantitative risk assessment to provide manufacturers “tools to analyze potential risks, hazards and resulting consequences as well as to assess the potential effect of risk mitigation measures in hydrocarbon equipment,” said Pauline Bruge, Project Coordinator in shecco’s Market Development team. “It can thus demonstrate the level of safety of a product, which then can be gauged against other relevant hazards to determine the acceptability of a risk.”

Identified hazards for the three studied appliances show that “these often arise from human errors or misbehavior,” said Daniel Colbourne, Engineer at German Consulting Firm HEAT GmbH, and Lead Technical Expert of the LIFE FRONT project. 

Consequently, Colbourne added, detailed and easy-to-understand instruction manuals and well-trained technical personnel for installation, commissioning and decommissioning “are seen as effective mitigation measures to reduce identified risks.” In addition, hermetically sealed leak-tight systems “are also seen as essential to prevent the formation of an explosive atmosphere within and surrounding the appliance in case of a leak,” he said. 

While training for safe handling of hydrocarbons is currently available in Europe, it is not consistent, the report noted, adding that apart from the ATEX Workplace directive, mandates at a national level are vague. Therefore, the report said, raising awareness of this directive – especially its Annex II(A) – is recommended, since it was found in meetings of interest groups that the majority of stakeholders and practitioners seem to be largely unaware of it.

The risk assessment report built on lessons learned from a field study and laboratory tests summarized in a previous LIFE FRONT report, “Recommended leak hole size and mass flow rate by system and application characteristics”and in two databases, the “Refrigerant Leak Size Database”and the “Concentration Database.”

Improving product design

Work on the risk assessment report focused on improving product design by making modifications to accommodate for the use of larger hydrocarbon charges and evaluating options for passive and active risk-mitigation measures.

Tests were implemented on a prototype from each of the industrial partners of the LIFE FRONT project: AHT, AiT and NIBE. Prototypes included a commercial refrigeration cabinet, an indoor packaged air-to-water heat pump, and a ground-source heat pump derived from an existing catalogue product that had been specifically designed and modified to function with propane (R290).

In the tests, the effectiveness of the specific design in mitigating the risk and preventing the creation of an uncontrolled explosive atmosphere was assessed, and a “robust and reliable methodology” for evaluating the safe usage of a product using flammable refrigerants was defined, the report said. Results of this were discussed in an internal project workshop on quantitative risk assessment.

The LIFE FRONT risk assessment report summarized the results of the workshop (workshop slides available here), providing an overview of relevant information on risk assessments for flammable refrigerants in Chapter one. Chapter two provides more concrete guidance for RACHP companies by presenting three risk assessments for the R290-based appliances, refrigerated display cabinet, ground source heat pump and an air/water heat pump.

In general, based on the work under this project and also within the wider literature, it is seen that the flammability risk presented by the use of hydrocarbons is low compared to the fire risk associated with other comparable equipment and appliances, the report said. For instance, the example of the display cabinet described in the report illustrates that the flammability risk can be several times lower than the background or residual risks (such as from electrical fires, etc.). This also needs to be taken into account when revising RACHP safety standards, the report advised. 

The LIFE FRONT project led such risk assessment “to fulfill its goal to remove barriers posed by standards for flammable refrigerants in RACHP applications,” said Bruge. “It strives to improve system design to address flammability risks and encourage thereby wider uptake of climate-friendly alternatives to fluorinated gases.”

LIFE FRONT has also published “Impact of Standards on Hydrocarbon Refrigerants in Europe – Market Research Report,” which provides a detailed explanation and breakdown of relevant safety standards and associated barriers related to RACHP equipment.

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