Surface Temperature Of Roof

Department of energy.

Surface temperature of roof.

The average temperature difference through the day was about 2 degrees f. Those are the recommended temperatures if you really need a need roof as long as you get 2 or more days above 30 f. 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.

The average daily summertime temperature of the black roof surface was 75 c 167 f but once retrofitted with a white reflective surface it measured 52 c 126 f. Y 2 qi to. 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. 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.

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. 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. In hot weather for easiest handling temperatures should be below 90 f.

Sheathing temperatures recorded were 168 f 76 c for black shingled roofs and 147 f 64 c for white shingled roofs. 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. 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. If the roof considered in figure 2 had a white instead of black surface i e.

Inside air temperature was steady ranging between 23 and 24 c. Ts to a id is hso a absorption coefficient of outside surface. The biggest temperature difference was about 9 degrees fahrenheit which occurred around noon.