Question

QUESTION 7- HEATING AND COOLING LOAD CALCULATIONS 7.1 What is sol-air temperature? 7.2 Determine the sol-air temperature for a flat roof if the direct radiation normal to the sun's rays Dx) is 893 WIm2 and the intensity of scattered radiation normal to the roof (,) is 112 W/m. Take the absorptivity of the roof for direct and scattered radiation as 0.9, the heat transfer coefficient of the outside surface as 34.4 W/m2, the outside air temperature as 37 C and the solar altitude angle as 80°C If the time lag of the roof structure is zero and its decrement factor is unity, calculate the heat gain to the room beneath the roof if the U-value of the roof is 0.5 W/m K and the room temperature is 25%.

can I please to have a clear hand written answer for the above question, your help is appreciated, thanks.

Answer 1

Component I_Self mmy ABCD 20 times 300^3/12 = 45 times 10^6 EFGH 360 times 20^3/12 = 24 times 10^4 IJKL 20 times 300^3/12 = 4.5 times 10^6/90,240,000 x^bar = Sigma_ax/Sigma a = 150 mm Moment of Inertia about y-y prime I_x y = Sigma I_self + Sigma a g^2 I_y - y prime = 522,240,000 I_y - y prime = I_y y + Sigma a x^bar^2 522,240,000 = I_y y + 423 times 10^6 [I_y y = 90,240, m m^4] = Ans