R-value (insulation) contain no trapped CFCs or HFCs (e.g., half-pound low density foams). On certain brands, twenty-year tests have shown no shrinkage or reduction in insulating value. This has led to controversy as how to rate the insulation of these products. Many manufacturers will rate the R-value at the time of manufacture; critics argue that a more fair assessment would be its settled value. The foam industry adopted the LTTR (Long-Term Thermal Resistance) method, which rates the R-value based on a 15-year weighted average. However, the LTTR effectively provides only an eight-year aged R-value, short in the scale of a building that
Ministry of Construction of Heavy Industry Ministry of Construction of Heavy Industry The Ministry of Construction of Heavy Industry of the USSR (Mintyazhstroy; ) was a central government institution charged with leading the heavy industry of the Soviet Union. It was established in 1946 to replace the several successor Commissariats to the People's Commissariat of Heavy Industry of the USSR, dissolved in 1939. After liquidation in 1953, it was reactivated from 1967 to 1986. The ministry headquarters was one of the Seven Sisters built during the last 10 years of Stalin's life, also known as the Red Gate building owing to its proximity to the Red