Exhaust-Only Ventilation Exhaust-only ventilation is the reverse of supply-only ventilation; stale air leaves the building from a known location (through exhaust fans ducted to the outdoors) and outdoor air enters the building from an unknown location.
In the 1960s, the Soviet Union began to prepare the Warsaw Pact for its internal function of keeping the NSWP member states within the alliance. The Soviet Union took a series of steps to transform the Warsaw Pact into its intra-alliance intervention force.
Greece, Turkey, and West Germany later joined NATO, but in 1966 France withdrew, citing American violations of the 1949 treaty. In 1955, the Warsaw Pact, a Soviet-led Eastern European alliance, was established to counter NATO. In 1994, three years after the end of the Cold War, NATO engaged in its first military action as part of an international effort to end two years of fighting in Bosnia-Herzegovina. Poland, Hungary, and the Czech Republic, which all left the Warsaw Pact upon its dissolution in 1991, joined NATO in 1999.