Whilst assisting to reduce energy consumption and carbon emissions of a building, thermal insulation and pre-insulated panels can impact on climate change and ozone depletion if they are not manufactured in a responsible way.
CFCs, HFCs, HCFCs & PIR Insulation
Blowing agents are typically used to enhance the thermal performance of PIR insulation, by filling the cells within the insulation with a low thermal conductivity gas. This gas can be released into the atmosphere through various channels, such as during the manufacture of the product, during transit or after the product is ceased to be used.
Blowing agents used in the manufacture of PIR insulation products, such as CFCs HCFCs and HFCs, can accelerate climate change and ozone depletion if they are released into the atmosphere.
A blowing agents’ impact on ozone depletion and climate change is characterised by its Ozone Depletion Potential (ODP) or Global Warming Potential (GWP).
What is Ozone Depletion Potential (ODP)?
CFCs, HCFCs and other substances released into the atmosphere can react with the ozone layer in a negative way. A molecule of chlorine can react with the ozone and catalyse the conversion of ozone molecules into oxygen. One chlorine atom has the potential to destroy more than 100,000 ozone molecules! This is the process of ozone depletion and has already caused a substantial amount of damage to the ozone layer.
ODP is the ratio of ability of a substance to degrade ozone, to that of chlorofluorocarbon-11 (CFC-11), which therefore, has a value of 1. HCFC-141b has an ODP of 0.11,10 times less degrading than CFC-11. Other substances, such as Pentane, have an ODP of zero., i.e. they do no harm to the ozone layer.
What is Global Warming Potential (GWP)?
Global Warming Potential is causing our ice caps to melt. GWP is the ratio of ability of a substance to trap heat in the atmosphere, to that of carbon dioxide. The more heat the gas traps, the bigger its potential to contribute to global warming. A GWP is calculated over a specific time interval, commonly 20, 100 or 500 years. CFC-11 has a GWP, over 100 years, of 4,750, HCFC-141b has a GWP of 725, HFCs 134a has a GWP of 1,300 [1], other substances such as Pentane have a GWP as low as below 5.
Reference:
[1] Global-Warming-Potential-Values