Roof Surface Temperature Calculation

20 cm of cellular concrete.

Roof surface temperature calculation.

To compute solar reflectance index sri and roof surface temperature based on solar reflectance r and thermal emittance e using astm standard e 1980. 7 cm dead air space ventilation and spacer blocks ignored 3. The house base area is the area of land that the house covers and for more complex shapes can be estimated using the area calculator. The length l times the height h of a triangle is twice its area a2.

The following tools estimate the area of a roof as well as the amount of materials necessary to construct a roof of a given area. The rooftop temperature results from two different properties. Ts to a id is hso a absorption coefficient of outside surface id direct solar radiation on surface. Area is defined as the expanse or measurement of a given surface and there are a few methods for measuring your roof s area.

For the calculation of surface temperature and heat flux the roof figure 1 was approximated by three homogeneous layers figure 2. Input r and e in blue and green cells. You want a roof area calculator that provides accurate estimates to help you order materials such as shingles membrane roofing or ceramic tile. Calculating the surface area of a sloped roof can be time consuming without the right tools.

Start the project with a roof area calculator. 1 roof square 100 square feet. Once you work through the basic triangle we will review a typical roof and how to apply some simple math to calculate how much material you will need for a roof used in our hypothetical example. An approximate equation for the sol air temperature ts of the outside surface of a given wall or roof is.

Our roof calculator uses base length and base width to find the estimated area. Click on the red button to compute sri and roof surface temperature. Ambient conditions and reference surface properties specified in next worksheet. Your job is to calculate and illustrate the temperature gradient through a roof assembly composed of a gravel surfaced built up roof 3 4 inch thick perlite insulation 2 inch thick polyisocyanurate insulation two ply felt and asphalt membrane vapor retarder 1 2 inch thick gypsum board and metal deck.

This calculator produced by lawrence berkeley national labs lbnl allows you to compute solar reflectance index sri and roof surface temperature based on solar reflectance and thermal emittance based on astm standard e 1980.