June 11, 2019
The Impact of Refrigerants on the Ozone Layer
The air conditioning unit is a staple piece of equipment in businesses, institutions, and homes around the world. From large central chiller systems to small window units, air conditioners come in many sizes and configurations. However, they all have something in common: they all use refrigerants to transfer heat to the outdoors.
What are refrigerants?
In the early days of air conditioning, refrigerant options included ammonia, methyl chloride and sulphur dioxide. Methyl chloride and sulphur dioxide are toxic; chlorofluorocarbons (CFCs) replaced them in the 1920s. Sulphur dioxide and methyl chloride were used for decades before discovering the drawbacks.
What impact do refrigerants have on the ozone layer?
In the 1970s, scientists discovered that the ozone layer had been experiencing an overall reduction in concentration by about 4% per decade. In 1985, the British Antarctic Survey thought their instrumentation was faulty because of how dramatically the ozone levels had dropped. The main cause of the depletion was traced back to the rampant use of man-made substances containing CFCs that had been released into the atmosphere from aerosols and refrigerants. CFCs break down in sunlight to release chlorine and bromine, which destroy ozone molecules.
The polar regions are more susceptible to ozone depletion because of the formation of “polar stratospheric clouds” caused by cold temps in these regions. These clouds provide the ideal conditions for the chemical reactions that break down ozone molecules. Therefore, their ozone levels drop to lower levels than the rest of the globe, creating “holes.”
What is the Montreal Protocol?
In September 1987, the Montreal Protocol was introduced to outline the phasing-out of ozone-depleting refrigerants. This treaty defined the timeline for introducing alternatives that would not affect the ozone layer. A total of 197 states signed it, making it the most successful international treaty to date.
Since the treaty was introduced, refrigerants that contain ozone-depleting substances and, more recently, refrigerants that contribute to global warming are much less popular.
What refrigerants are detrimental?
Many older residential air conditioners used a refrigerant called chlorodifluoromethane (R-22). R-22 has a high ozone depleting potential (ODP) and high global warming potential (GWP). R-410A, a chlorine-free refrigerant, also has a high GWP, so other alternatives may become more common in the future.
If you still have a unit using refrigerants that are destructive to the ozone layer, get in touch with Applewood today. We can help you with a system upgrade!