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
1987–88 Montreal Canadiens season four years in a row, sweeping the Bruins in three of the past four seasons, and beating them 3–2 in a best-of-five the other year. This time, the Bruins' defence would wear down Montreal, as Ken Linseman, Ray Bourque and Cam Neely provided the offence to finally conquer the Canadiens. It was the first Bruins' playoff series win over the Habs in 44 seasons. "Boston wins best-of-seven series 4–1" Montreal's draft picks at the 1987 NHL Entry Draft held at the Joe Louis Arena in Detroit, Michigan. 1987–88 Montreal Canadiens season The 1987–88 Montreal Canadiens season was the team's 79th