Heat pump the brand name Freon, a trademark of DuPont. Its manufacture is now banned or severely restricted by the Montreal Protocol of August 1987 because of the damage that CFCs cause to the ozone layer if released into the atmosphere. One widely adopted replacement refrigerant is the hydrofluorocarbon (HFC) known as R-134a (1,1,1,2-tetrafluoroethane). Heat pumps using R-134a replaced R-12 (dichlorodifluoromethane) and have similar thermodynamic properties but with insignificant ozone depletion potential and a somewhat lower global warming potential. Other substances such as liquid R-717 ammonia are widely used in large-scale systems, or occasionally the less corrosive but more flammable propane or
Montreal flood of 1987 of God". In 1988, all the cities on the Island of Montreal, regrouped into the Montreal Urban Community, set up a common "Emergencies Coordination Bureau" ("Bureau des mesures d'urgence"). In 1997, the bureau was renamed "Centre de sécurité civile". Following the Municipal reorganization in Quebec in 2002, most of the cities were regrouped into the greater Montreal and the center became the "Centre de sécurité civile de Montréal". Montreal flood of 1987 The Montreal flood of 1987 happened on July 14 of that year when a series of strong thunderstorms crossed the island of Montreal, Canada, between the noon hour