R22
Also known as: R-22, HCFC-22, Freon 22, chlorodifluoromethane
Short definitionThe chlorinated gas (HCFC) of old air conditioners and cold stores. Its production and import have been stopped because it damages ozone; GWP 1,810, ODP 0.055.
In a twenty-year-old store that you go to survey, the unit nameplate will most likely say R22. It is clear why it was liked in its day: it is a single-component gas with no glide, it is content with mineral oil, it is little affected by moisture and it does not burn (A1). Its boiling point is −41 °C. Because of the chlorine in its molecule it was phased out step by step under the Montreal Protocol. Today only reclaimed gas can be found; it is expensive and its purity is not always certain.
The customer is offered three options. A sound plant with no leaks keeps running. After a serious failure the gas is changed: R448A or R449A in cold rooms and frozen stores, R407C in air conditioning. In that case the oil is changed to POE, the drier and gaskets are renewed and the valve is adjusted. The third is to rebuild the unit from scratch; a machine 15–20 years old burns too much electricity, so the investment usually pays back in a few years. The gas removed is not released to the atmosphere; it is recovered.