Skip to main content
U.S. Department of Energy
Office of Scientific and Technical Information

Good roofs save energy-NRCA energy manual

Book ·
OSTI ID:6068427

Procedures have been developed for calculating heating and cooling costs for buildings based on roof components and thermal properties which influence energy conservation. Since the surface area of the roof of a building may be several times that of the wall surface, adequate insulation in the roof is considered one of the most important means of energy conservation. Heat transfer properties are defined in terms of thermal conductivity and conductance, thermal resistance, surface conductance, overall coefficient of thermal transmittance, equivalent temperature difference, and degree days. The energy conservation procedures are directed toward producing comparative designs for various specification alternatives. The estimated efficiencies of various heating systems and the heating values of most fuels are provided, included also is an extensive listing of heating and cooling weather data for US cities and conductance and resistance values for a variety of building materials. The thermal properties of air surfaces and air spaces are reviewed and U values for roofs and ceilings and inflation factors are charted. Sample worksheets are provided for calculating heat loss or gain through a roof, heating and cooling energy savings based on U value, and the net life cycle cost to upgrade roof insulation.

OSTI ID:
6068427
Country of Publication:
United States
Language:
English