Rigifoam investigates the effect of hydro-chlorofluorocarbon (HCFC) on a building’s temperature control and environment.
The Montreal Protocol banned chlorofluorocarbons (CFCs), which were traditionally used extensively in air-conditioners and closed-cell foams as a blowing agent, due to the damaging effects it had on the ozone layer. Hydro-chlorofluorocarbons (HCFCs), a watered-down version of CFCs, were introduced as a replacement for CFCs, despite the fact that it also had ozone-depleting potential (ODP).
Even though HCFCs proved less harmful, the gas formed in the cells are not able to insulate as well as CFCs. SABS/SANS standards still use insulation specifications that were written using CFC technology.
Therefore the Montreal Protocol also saw a majority of first-world countries banning HCFC use in the early 2000s, with developing countries given longer periods to phase out, some up to 2030. Even finished goods that contain HCFCs, such as gas in fridges or air-conditioners and cellular foams, are banned from being imported into Europe, Australia and the United States.
This has led the South African government’s Department of Environmental Affairs (DEA), together with the United Nations Industrial Development Organisation (UNIDO), to impose a ban on the use or importing of HCFC, effective from January 2016. The DEA kick-started the process with its new building, which recently received a six-star green rating from the Green Building Council of South Africa by using amongst other measures materials that have no Ozone Depeting Substances.
Additionally, alternative blowing agent systems for cellular foams have entered the market, with negatives to the performance of its insulation properties and cost. Water blown foams (generate CO₂), for example, reduce insulation performance by up to 20% and have to be applied at an increased density. Formic acid (FA) has the same insulation properties as the above, but affect an individual’s health in the manufacturing process and has a poor shelf life. Methyl Formate (MF) is the cleanest product and the closest to HCFC replacement in terms of insulation properties and density.
Tried and tested, hydrocarbons (HCs) boast zero ODP and proven insulation properties at lower densities for over 20 years in the Polyisocyanurate/polyurethane industry. Ongoing experiments with MF and HC blends have given very good results. These two materials are the only approved replacement materials that have received funding from UNIDO and the United Nations Development Programme (UNDP).
The UNDP notes: “The majority of HCFCs have a high global warming potential (GWP). Their phase-out through the introduction of lower GWP alternatives will therefore contribute significantly to climate change mitigation. Depending on the alternative selected, this contribution can be very significant or can be so deleterious and of such magnitude as to nullify the efforts a country is undertaking via other voluntary actions, such as efficient lighting or appliance replacement programmes to achieve energy savings.”
Product ODP GWP Lifetime (years)
141b (HCFC) Yes 725 9
142b (HCFC) Yes 2 310 17
Formic Acid (FA) No 0 n.a.
Methyl Formate (MF) No 0 n.a.
Hydro Carbons (HC) No 11 n.a.
Although there does not exist a perfectly green solution as of yet, a collective effort can be made to STOP the use of HCFCs, as there are alternatives with far “greener” properties. Efforts to use materials that will save on energy usage in buildings become redundant if these materials contribute to environmental damage in the long run.
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