2.9 Refrigerant Types

1. Chlorofluorocarbons (CFC’s) – Banned Substances (Phased Out)

  • CFCs were some of the most commonly used ODS worldwide, as they were considered to be non-toxic and non-flammable
  • They are also greenhouse gases and contribute to climate change
  • CFCs contain atoms of:
    • Carbon
    • Chlorine
    • Fluorine
  • Were used as:
    • Aerosol propellants,
    • Insulators (foam blowing),
    • Refrigerants
    • Solvents and sterilants
  • All refrigerants have their own unique labelling system to identify the number of carbon, hydrogen, chlorine and fluorine atoms
  • CFCs first evolved in the 1930s as a safer alternative to the highly toxic gases of ammonia (NH3), methyl chloride (CH3Cl) and sulphur dioxide (SO2) being used as refrigerants since fatal explosions resulted from these substances

CFC Usage

Dupont Canada, formerly the largest CFC producer in Canada, ceased production of CFCs in 1993 – three full years before the mandatory phase-out under the Montreal Protocol.

Under Canadian federal law (the Ozone Depleting Substances Regulations), after January 1, 1999 no person is permitted to manufacture or import into Canada a product that contains a CFC, unless a special exemption is granted.

Despite strict regulations in Canada, the Montreal Protocol allowed for developing countries to produce CFCs for a period of ten years after January 1, 1999 to meet the basic domestic needs of that country.

This led to a black market for illegally obtained CFCs (particularly CFC-12), smuggled from developing countries using a number of creative methods.

In 2004 one Canadian company was charged $25,000 for illegally importing 3,090 CFC- containing bar fridges into Canada in 1999.

1.8 ounces of CFC-12 per fridge – a total of 158 kg CFC-12 imported.

Industry Usage of CFC’s

During wide spread usage:

2. Hydrochlorofluorocarbons (HCFC’s) – Restricted Usage

  • HCFCs were designated as one of the key replacements for CFCs under the Montreal Protocol
  •  Although not as harmful to the ozone layer as CFCs, HCFCs have a significant global warming potential (GWP) that contributes to climate change
  • HCFCs were used extensively in the refrigeration, air conditioning and foam blowing sectors, and most commonly include HCFC-22 as a refrigerant and HCFC-141b as an insulator in foams
  • In Canada, as prescribed by the Montreal Protocol, the production and consumption of all HCFCs will be phased out by January 1, 2020, with the exception of HCFC-123 which will be phased out by January 1, 2030
  • The latest adjustments were made at the 19th Meeting of the Parties to the Montreal Protocol in 2007
  • At future meetings of the Parties to the Montreal Protocol, one can anticipate further attempts to accelerate the phase-out timetable for HCFCs, which may be a necessary action needed to meet ozone protection, climate change and energy efficiency objectives
  • An accelerated phase-out of HCFCs would likely advance the replenishment of  the Antarctic ozone hole by 2055 and offset nearly 22 gigatons of CO2 equivalence between 2010-2050
  • An accelerated phase-out of HCFCs would likely advance the replenishment of  the Antarctic ozone hole by 2055 and offset nearly 22 gigatons of CO2 equivalence between 2010-2050

3. Hydrofluorocarbons (HFC’s) – ODS Replacement

  • Hydrofluorocarbons (HFCs) were originally developed as long-term replacement products for CFCs and HCFCs
  • HFCs are substances that contain:
    • Hydrogen
    • Fluorine
    • Carbon
  • These substances do not contain any chlorine and their ODP is zero
  • HFC’s are potent greenhouse gases (GHGs)
  • Present, the most widely used HFC refrigerants on the market are HFC-134a because it has thermodynamic properties similar to that of CFC-12 and R410A with the restrictions placed on R22 January 2010
  • HFC’s first appeared in the early 1990s as a replacement for CFC-12 & HCFC-22 primarily used as a refrigerant in domestic refrigeration & mobile air conditioning systems and residential and light commercial air conditioning systems
  • Present, the most widely used HFC refrigerants on the market are HFC-134a because it has thermodynamic properties similar to that of CFC-12 and R410A with the restrictions placed on R22 January 2010
  • HFC’s first appeared in the early 1990s as a replacement for CFC-12 & HCFC-22 primarily used as a refrigerant in domestic refrigeration & mobile air conditioning systems and residential and light commercial air conditioning systems
  • HFCs have such common utility that every industry sector can relate to them
  • HFC-134a has expanded its role to other applications including sterilization, propellant and insulator for foam blowing
  • Research over the past 15 years has shown the accumulation of HFCs in the atmosphere is significant
  • HFC-134a is one of the seven basket gases under the Kyoto Protocol
  • HFC’s in general are powerful greenhouse gases with GWPs ranging from 140 (HFC-152a) to 11,700 (HFC-23) compared to CO2 over a 100-year period
  • The overall performance of HFC’s has also been taken into question and has prompted some European countries to move towards other environmentally friendly alternatives
  • Early indication is that HFC-based appliances may be significant energy users and have poor performance records in higher temperature situations compared to systems using hydrocarbons
  • Technology innovations in engineering are likely to advance performance in future for the various alternative applications

US EPA’s: Significant New Alternatives Policy (SNAP)

SNAP was developed by the United States Environmental Protection Agency (EPA) to evaluate and regulate Class 1 (ODP > 0.2) and Class 2 (ODP < 0.2) substitutes for ODS under the Clean Air Act.

The purpose of the program is to smoothly transition from ODS to alternatives that offer lower risks to human and environmental health.

In the RAC sector, HFC-134a was been identified as an acceptable substitute for various CFC, HCFC new and retrofit applications including:

  •  Chillers
  •  Industrial refrigeration and air conditioning
  •  Cold storage
  •  Automobile and mobile transportation
  •  White goods

In addition, HFCs are being used within other sectors, such as domestic appliances, foam blowing, cleaning solvents, aerosol propellants, and fire and explosion protection.

4. Hydrocarbons – The Future

  • These are natural, non-toxic, non-ozone depleting and low GWP replacements for CFCs, HCFCs and HFCs
  • They are chemical compounds composed of hydrogen and carbon atoms and have a very short atmospheric lifespan of only weeks to months where they eventually break down into their component parts of carbon dioxide and water
  • Some examples of hydrocarbons used as refrigerants or foam blowing agents include pentane, butane, ethane and propane
  • These gases have been in use since the late 1800s and have begun to re-emerge in new equipment manufacturing processes as concern over the environment has grown significantly.  Hydrocarbons have been used in a wide variety of applications that include fuels, lubricants, plastics, chemicals and propellants

5. Carbon Dioxide – The Future

  • Due to advances in technology, particularly the manufacture of thin and strong aluminum tubing, carbon dioxide refrigerants have the potential as replacements for halocarbon-based refrigerants
  • Despite being a global warming gas, releases of carbon dioxide would be insignificant compared to the same amount of HFCs
  • Small lightweight systems, such as portable air conditioners, are the most effective for carbon dioxide because the high operating pressures let the refrigerant pass through small-diameter tubing, allowing for the design of compact systems
  • In addition, the most significant property of carbon dioxide as a refrigerant is the low critical temperature of 31.1°C