Surface Temperature Of Roof

The average temperature difference through the day was about 2 degrees f.

Surface temperature of roof.

Also primary importance of venting is to avoid ice damage by keeping roof surface sub freezing in high snowfall areas. Plot the calculated temperature gradient values for top surface of each material on the roof assembly drawing. An approximate equation for the sol air temperature ts of the outside surface of a given wall or roof is. Those are the recommended temperatures if you really need a need roof as long as you get 2 or more days above 30 f.

Ts to a id is hso a absorption coefficient of outside surface. A 0 4 instead of 0 9 the surface temperature would be 130 f instead of 190 f. Z where 3 q heat flux heat flow towards inside is positive t temperature. If the roof considered in figure 2 had a white instead of black surface i e.

The difference between the maximum temperatures of black and white vertical surfaces is about 50 f degrees compared with 60 f degrees for horizontal surfaces. Inside air temperature was steady ranging between 23 and 24 c. Department of energy. Y 2 qi to.

The results suggest that roof sheathing plywood and roof truss lumber temperatures which are the primary factors that influence thermal degrade of fr treated materials are primar. The biggest temperature difference was about 9 degrees fahrenheit which occurred around noon. The temperature of a vegetative roof at its surface is actually cool to the touch on most days it s in total shade with a conventional roof surface protected under a dense canopy of vegetation. On a hot sunny day the temperature on the surface of a traditional black roof can be more than 50 degrees fahrenheit 10 degrees celsius warmer than the surrounding air temperature source.

Response factor method for calculating heat flux the temperatures and heat fluxes at the surface of a roof are related by the response factor sets. Sheathing temperatures recorded were 168 f 76 c for black shingled roofs and 147 f 64 c for white shingled roofs. Draw a line from the winter interior dry bulb design temperature to the next value and continue to connect the dots until you reach the winter exterior design dry bulb temperature.