International. In a recent article "Global Emissions of the Refrigerants HCFC-22 and HFC-134a: Unforeseen Seasonal Contributions," published in the Proceedings of the National Academy of Sciences, author Binn Xiang presented the results of in situ observations of R22 and R134a taken following investigations of aircraft flying over the Pacific Ocean over a span of 3 years (2009-2012), in combination with long-term field observations taken from sites on the Earth's surface.
The authors find that R134a emissions are consistently higher compared to inventories since 2000 from the United Nations Framework Convention on Climate Change (UNFCCC), by 60% more in recent years (2009-2012).
They also quantify the latest seasonal emissions patterns, showing that summer emissions of HCFC-22 and HFC-134a are two to three times higher than winter emissions.
According to the authors, this large unforeseen seasonal variation indicates that mechanisms for controlling refrigerant gas emissions are absent from existing inventory estimates.
According to the report, the possible mechanisms that improve coolant losses in summer are as follows:
- Increased vapor pressure in the sealed compartment of the system against high temperatures in the summer.
- Most frequent use and service of refrigerators and air conditioners in the summer months.
The results suggest that engineering (e.g., a stronger sealed system of better temperature/vibration, and a new system design of more compact/efficient components) and regulations (e.g., reinforcing system service regulations) are measures to improve the containment of these gases from working devices that could effectively reduce their release into the atmosphere.
