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.
However, then, as now, the alliance was militarily dominated by the United States. Afghan mission was Nato's first non-European operation. In 1955 the Soviet Union created a counter-alliance called the Warsaw Pact, which dissolved after the break-up of the USSR in 1991.The Czech Republic, Hungary and Poland became the first former Warsaw Pact countries to gain Nato membership in 1999.evelopment. Nato was set up in the post-World War II atmosphere of anxiety, largely to block Soviet expansion into Europe. The collapse of the Soviet Union in 1991 and subsequent demise of the Warsaw Pact, therefore, left Nato with no obvious purpose.