A house located in Boulder, Colorado (40° N latitude), has ordinary double-pane windows with 6-mm-thick glasses and the total window areas are 8, 6, 6, and 4 m2 on the south, west, east, and north walls, respectively. Determine the total solar heat gain of the house at 9:00, 12:00, and 15:00 solar time in July. Also, determine the total amount of solar heat gain per day for an average day in January. The shading coefficient of a double pane window with 6-mm thick glasses is SC = 0.82. The incident radiation at different windows at different times are given as in the table.

Consider a cuboidal furnace (l = 5 m, b = 4 m, h = 3 m), whose surfaces closely approximateblack surfaces. The base, top, and side surfaces of the furnace are maintained at uniformtemperatures of (1040) K, (840) K, and (540) K, respectively. Determine (a)the net rate of radiation heat transfer between the base and the side surfaces, (b) the net rate ofradiation heat transfer between the base and the top surface, and (c) the net radiation heattransfer from the base surface.   Steam in a heating system flows through tubes whose outer radius is r1 = (3) cm and whosewalls are maintained at a temperature of 127 °C. Circular aluminum fins (k = 180 W/m K) ofouter radius r2 = (6) cm and constant thickness t = 1 mm are attached to the tube. The spacebetween the fins is 3 mm. Heat is transferred to the surrounding air at 27 °C, with a combinedheat transfer coefficient of 60 W/m2 K. Determine the increase in heat transfer from the tubeper meter of its length as a result of adding fins

A copper ball of 20 cm diameter is kept outside open to sky during summer. The ball is capable of receiving and emitting heat by radiation. Identify the satisfactory conditions from the following to treat the ball as a block body. I)    the emissivity and absorptivity of the ball should be equal to one II)   the reflectivity and transmissivity of the ball should be equal to zero III)  the ball should emit lesser the heat absorbed I only II only I and II only II and III only I, II and III