R-numbers are commonly used refrigerant designations, as defined by ASHRAE in their Standard 34, to allow easier understanding than memorising long chemical names, or multiple trademarks. It groups refrigerants into various series depending on their chemical structure. The definitions cover both pure substances, as well as blends (blends being "400" series or "500" series). Refrigerants with the same "number" comprise the same components, e.g. 134 and 134a, however the structure of these molecules are different as signified by the "a". In the same way, the R407 series (R407A, B, C, D, E, F) are all mixtures of the same components (R32, R125 and R134a), but in different percentages of the three named components. ASHRAE's website can be found at
Refrigerant gas sold with a specific trademark, such as SUVA
® or Genetron
®, is produced and supplied to BOC by specific manufacturers such as DuPont, Arkema or Honeywell. Those manufacturers operate high quality production facilities and supply chains to guarantee high quality products. Some products will also be unique to those manufacturers, developed and patented by them. Nowadays, many refrigerants are commonly available and sold by multiple manufacturers, including these companies. To ensure reliable supply, and the best prices for our customers, BOC often sources products from multiple manufacturers. Therefore we offer these products under our own BOC brand, whereby we continue to ensure that we sell only the highest quality product, providing you the same guarantees on quality and reliability.
The Refrigerant Safety Group is identified by two alphanumeric characters, e.g. "A2". The capital letter corresponds to toxicity and the digit to flammability. For toxicity, Class A toxicity signifies no toxicity at less than or equal to 400ppm, Class B toxicity signifies for which there is evidence of toxicity. For flammability, Class 1 indicates that the refrigerant is "non flammable", Class 2 "lower flammability" and Class 3 "highly flammable" all when tested at 60C and 101kPa, with flammability based on the lower flammability limit and heat of combustion. Currently there is discussion on a further new flammability standard "2L" which would sit between 1 and 2.
ODP & GWP are common terms for the environmental impact of refrigerant gases. ODP refers to the Ozone Depletion Potential, a measure of damage to the ozone layer relative to R11=1. GWP refers to the Global Warming Potential, a measure of global warming relative to CO2=1.
There is no formal ISO standard on what a natural refrigerant is, however it is commonly taken to be a gas that can be found naturally within the ecosystem. Common natural refrigerants include R717 (Ammonia), R744 (Carbon Dioxide), R290 (Propane) and R600a (Isobutane). Most Natural Refrigerants offer environmental advantages in having zero ozone depletion potential and low global warming potential.
Recycled refrigerant may or may not undergo a basic rectification process, such as basic oil filtration or removal of moisture using a filter-dryer. This is often done at the point of use. Reclaimed refrigerant undergoes full rectification, normally at a central reprocessing site. The gas is normally reclaimed to "virgin" quality, meeting AHRI 700 or equivalent standards.
The best refrigerant solution will depend on the system that you are operating, the cooling requirements and ambient conditions. Therefore we always recommend consulting the manufacturer's guidelines. However we provide an overview of refrigerants suitable for common applications within our Refrigeration & Air Conditioning Processes section.
The impact of impurities in a system will depend on the type and level of impurity present. In general, impurities will lead to unintended consequences that may impact system reliability, performance and energy efficiency. Most importantly high levels of impurity may create potential hazards for people operating and maintaining the equipment. Further information can be found in the Technical Information section.
No, unless specifically stated to do so. As a general rule, mixing refrigerants in a system will lead to unintended consequences that may impact system reliability, performance and energy efficiency, and most importantly create potential hazards for people operating and maintaining the equipment.
As a general rule, mixing refrigerants in a system is not recommended, unless specifically stated to do so. If you are planning to fill a system with the same blend as previously then topping up may be possible, however doing so will depend on a number of parameters, including the condition of the gas in your system. We recommend that you consult the specific product literature for the gas you are using for more details.
Glide applies to refrigerant blends. This is measured as the different boiling temperatures of the various components of a refrigerant blend. This can lead to a change in the relative components of the blend across a temperature range - fractionation.
In most applications there are alternative gases available if you wish to replace your existing refrigerant due to legislative control, cost or performance reasons. However the choice of gas can be a complex decision. Our Environment and Legislation section provides details of common retrofit options.
Various refrigerants use different oils. Older CFC and HCFC refrigerants tend to use Mineral Oil (MO) and Alkyl Benzene (AB) oils. Modern HFC and HFO refrigerants tend to use Polyolester (POE) oils, although some HFC blends specifically designed as "drop-in" retrofit gases for CFCs and HCFCs may have some tolerance to MO and AB oils. To ascertain whether you can change the oil or not, you will need to refer to the specific refrigerant that you plan to use.
All refrigerants should be disposed of responsibly at the end of life. They should not be vented to the atmosphere, but instead recovered and then either reclaimed or recycled, or destroyed. In many locations, on top of this being best practice, there are legal obligations to follow these rules, e.g. EU f-gas regulations.