Glossary
U-Factor
Quantitative measure of heat flow or conductivity, the reciprocal of R-value. While building scientists will use R-values for measures of the resistance to heat flow for individual building materials, U-factor is usually used as a summary metric for the ease of heat transfer through building assemblies
U-Value
(1)The amount of heat that will flow through a square foot of building cross-section experiencing a temperature difference of 1° F. (2) Quantitative measure of heat flow or conductivity, the reciprocal of R-value. While building scientists will use R-values for measures of the resistance to heat flow for individual building materials, U-factor is usually used as a summary metric for the ease of heat transfer through building assemblies
US Army Corp of Engineers Air Leakage Test Protocol
abbr. USACE standard. Airlfow testing procedures developed for testing air tightness of the building enclosure under ASTM test procedure E-779. This test allows for a maximum leakage ratio of 0.25 cfm per ft2 of enclosure area a t pressure differential of 75 Pa. See website : http://airbarriernews.com/industry-news/