Asahi Kasei develops gas sensor to detect leaks of highly flammable refrigerants in HVAC systems

Senseair, a Swedish subsidiary of Asahi Kasei Microdevices (AKM), has developed the “Sunlight R290”, a gas sensor with high measurement accuracy and operating range while maintaining minimal heat generation, packaging space and power consumption. Large-scale deliveries of the Sunlight R290 are scheduled to begin in September 2024.

Existing and future regulations regarding PFAS (per- and polyfluorinated alkyl substances, also called “forever chemicals”) and F-gases (fluorinated greenhouse gases) severely restrict the use of conventional synthetic refrigerants in air conditioning, heat pumps and other HVAC systems. The natural refrigerant R290 is propane gas, which is considered a more sustainable alternative to conventional solutions. However, due to its high flammability, reliable and highly accurate leak detection measures are required to ensure safe operation.

Senseair’s newly developed Sunlight R290 gas sensor uses the latest NDIR (non-dispersive infrared) technology, utilizing LED light sources and photodiode sensors. Due to its minimal heat generation, the sensor can be safely operated with R290. In addition, due to the characteristics of the NDIR method, detection is less affected by vibrations or interfering gases, enabling robust and reliable measurements that meet the strict leak detection requirements of the IEC 60335-2-40 safety standard for electric heat pumps, hot water heat pumps and air conditioning systems.

With an operating temperature range of -40°C to 70°C and a relative humidity (RH) range of 0 to 95%, Sunlight R290 can operate stably in demanding environments and covers a wide range of applications including air conditioners, heat pumps, dehumidifiers and panel coolers. When operated under normal ambient conditions, a lifetime of over 15 years can be expected. In addition, the sensor features an automatic baseline correction (ABC) algorithm that enables maintenance-free use over extended periods of time. All this is achieved with a small package size of 34 mm × 21 mm × 12 mm and a power consumption of 94 μA.