While the earlier fluorocarbon transitions, from chlorofluorocarbons (CFCs) to hydrochlorofluorocarbons (HCFCs) and then to the fluorinated refrigerants without chlorine (HFCs), were quite straightforward drop-in replacements with environmental benefits. This third paradigm adds some drawbacks and concerns in the efforts to phase in refrigerants with low Global Warming Potential (GWP less than 150 times that of CO2).
The new refrigerants being advocated with low GWP however tend to fall within A2L classification, meaning that they are mildly flammable according to ISO 817:2014 Refrigerants - Designation and safety classification. Other low GWP refrigerants like CO2 (R744) and Ammonia (R717) have other challenges.
With new international regulations, local policies and insurance requirements pending due to the hazard concern, adding A2L leakage detection sensors for controlling mitigation systems and/or shutdowns is a solution.
Senseair, as a global leader in gas sensing technologies, has recently launched robust and long-lifetime NDIR-based refrigerant sensors to implement leakage detection in these systems. Senseair targets the R32 gas concentration in the A2L mixtures, or that of a pure hydrocarbon in the blend, and calculates the air volume concentration of the refrigerant gas and relates it to the avoidance thresholds by levels of LFL (Lower Flammability Limit) or LEL (Lower Explosion Limits). The sensing platform can then communicate an alert or directly engage in mitigation or shut-down procedures.
The Senseair NDIR sensor technology can be installed directly in the cold environment, it is highly selective and immune to disturbance sources and provides a responsive and fast detection of an A2L refrigerant leak for very long and maintenance-free operation (>15 years).
Senseair offers their solutions either as a calibrated sensor module for integration by customer, or as a complete pre-integrated board design with relays and additional features bundled with all the required sensory aspects. Senseair can even design and manufacture the complete enclosed system with cabling and housing and the requirement testing for a product which is ready to install.
Please contact Senseair to discuss your specific needs and requirements to handle the flammability risks of A2L refrigerants, or the challenges with the other low GWP refrigerants.