A platform for research: civil engineering, architecture and urbanism
A platform for research: civil engineering, architecture and urbanism
Practical correlation for thermal resistance of low-sloped enclosed airspaces with downward heat flow for building applications
The 2009 ASHRAE Handbook—Fundamentals (Chapter 26) provided a table that contains the thermal resistances (R-values) of vertical, horizontal, and high-sloped (45°) enclosed airspaces. This table is extensively used by modelers, architects, and building designers in the design for the R-values of building enclosures. The effect of the airspace aspect ratio and the inclination angle (θ) of 30° on the R-values are not accounted for in the ASHRAE table. However, previous studies showed that the aspect ratio of the airspace can affect its R-value. In this article, the previous studies that focused on determining the R-values for vertical, horizontal, and high-sloped enclosed airspaces are extended to investigate the effect of the aspect ratio on the R-values of low-sloped (θ = 30°) enclosed airspaces under downward heat flow for different airspace thicknesses and having a wide range of values for the effective emittance, mean temperature, and temperature differences across the airspaces. Thereafter, practical correlation is developed for determining the R-values of low-sloped enclosed airspaces for future use by modelers, architects, and building designers.
Practical correlation for thermal resistance of low-sloped enclosed airspaces with downward heat flow for building applications
The 2009 ASHRAE Handbook—Fundamentals (Chapter 26) provided a table that contains the thermal resistances (R-values) of vertical, horizontal, and high-sloped (45°) enclosed airspaces. This table is extensively used by modelers, architects, and building designers in the design for the R-values of building enclosures. The effect of the airspace aspect ratio and the inclination angle (θ) of 30° on the R-values are not accounted for in the ASHRAE table. However, previous studies showed that the aspect ratio of the airspace can affect its R-value. In this article, the previous studies that focused on determining the R-values for vertical, horizontal, and high-sloped enclosed airspaces are extended to investigate the effect of the aspect ratio on the R-values of low-sloped (θ = 30°) enclosed airspaces under downward heat flow for different airspace thicknesses and having a wide range of values for the effective emittance, mean temperature, and temperature differences across the airspaces. Thereafter, practical correlation is developed for determining the R-values of low-sloped enclosed airspaces for future use by modelers, architects, and building designers.
Practical correlation for thermal resistance of low-sloped enclosed airspaces with downward heat flow for building applications
Saber, Hamed H. (author)
HVAC&R Research ; 20 ; 92-112
2014-01-01
21 pages
Article (Journal)
Electronic Resource
English
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