Keywords: CFC-, 11, ozone depletion, diffusive leakage, heating pipes, insulating foam, refrigeration equipment, rigid polyurethane foam, thermal insulation, Sweden, trichlorofluoromethane, chlorofluorocarbons
Accumulated CFC-11 in polyurethane foam insulation: an estimate of the total amount in district heating installations in Sweden
In rigid polyurethane foam used for thermal insulation, CFC-11 has been the main blowing agent for many years, but is now subject to phase-out regulations. During ageing of this foam, air diffuses into it and blowing agents leak into the atmosphere, resulting in a decreased insulating capacity. Determinations of the cell gas composition and the total content of CFC-11 in foam from district heating installations of different ages are reported in this paper. The total amount of CFC-11 in old district heating schemes in Sweden is estimated at 2000 tonnes. The amount in refrigeration equipment in Sweden is about twice as large.