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 (What the Fuck Is Going On?) Run-D.M.C. type of old-school rapping"; and "The Penguin Price Guide for Record & CD Collectors" called "1987" an "entirely brilliant example of the art of disc-jockey-as-producer". Giving another retrospective review from across the Atlantic, "Trouser Press" described "1987" as "energetic" and "a loopy dance album that isn't unlike a lot of sampled records, but proceeds from an entirely different cultural understanding." Bill Drummond and Jimmy Cauty were responsible for the concept and production of "1987", its lyrics and the TR-808 beatbox rhythms. Drummond provided rap, and an additional rapper introduced as 'Chike' appears on "Don't Take Five (Take What You