OVERVIEW

This manual is the result of ASHRAE research project 453-RP, "Manual of Heat Transmission Coefficients for Building Components," conducted by the University of Massachusetts for ASHRAE Technical Committee TC 4.4, Thermal Insulation and Vapor Retarders. The manual provides a single source of measured and verified by calculation, steady-state (no transient behavior is included) thermal transmission coefficients (U-value, U-factor, or overall coefficient of heat transfer) for opaque building components (walls, roofs, ceilings, floors) typical of past, present, and anticipated future construction practices for all climates. Windows, doors, curtain walls, ventilated and unventilated attics, basements, crawlspaces, and slabs-on-grade are excluded. The heat transmission coefficient data sheets of this manual do not cover all the potential building components currently existing. As a result, the manual is in looseleaf form to provide a dynamic publication that can be updated easily.

The layout of the heat transmission coefficient data sheets is similar to Tables 4A through 4K in Chapter 23 of the ASHRAE Handbook, 1981 Fundamentals. The thermal transmission coefficient information provided here is based on experimental data from published and unpublished test results from organizations in the United States and Canada who have a laboratory calibrated hot box (ASTM Standard C 976) or guarded hot box (ASTM Standard C 236). Some of the hot box experimental data examined for possible inclusion in this manual's first edition was excluded because the information was incomplete no calculation could be made to verify the experimental results. An acceptance criterion initially was developed to...