Compare the heat loss (in Watts) from two different windows in a room. One window gas...

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Compare the heat loss (in Watts) from two different windows in a room. One window gas a single sheet of glass 10mm thick whereas the other has two sheets of glass, 5mm each but separated by an air gap of 5mm. The second window is called a thermopane. The windows sizes are Imxlm. The air temperature in the room is 72'F and the outside temperature is 18'F. The thermal conductivity of the glass is 0.9 W/m.K and the average thermal conductivity at of air is 0.03 Wim.K. The convection coefficient inside the room is h= 10 W/m K and outside due to a strong wind is h, = 200 W/m.K. (a) Compare the heat losses between these two windows design, assuming that the air in the gap is stagnant, i.e. heat though the air gap is only transmitted by conduction (b) Consider that in the air gap you also have some radiation and that the radiation coefficient is h, = (T, +T;)(T +T;), using the main equation used for radiation the validity of the %3D expression to estimate h. (c) Assuming thath, = 40T, estimate and compare how the resistance to heat transfer changes when radiation is also considered in addition to conduction alone.. Therefore, you have to estimate the differences in the resistance to the heat transfer considering and without considering radiation in the air gap, and what is the effect in the heat flow? Compare the heat loss (in Watts) from two different windows in a room. One window gas a single sheet of glass 10mm thick whereas the other has two sheets of glass, 5mm each but separated by an air gap of 5mm. The second window is called a thermopane. The windows sizes are Imxlm. The air temperature in the room is 72'F and the outside temperature is 18'F. The thermal conductivity of the glass is 0.9 W/m.K and the average thermal conductivity at of air is 0.03 Wim.K. The convection coefficient inside the room is h= 10 W/m K and outside due to a strong wind is h, = 200 W/m.K. (a) Compare the heat losses between these two windows design, assuming that the air in the gap is stagnant, i.e. heat though the air gap is only transmitted by conduction (b) Consider that in the air gap you also have some radiation and that the radiation coefficient is h, = (T, +T;)(T +T;), using the main equation used for radiation the validity of the %3D expression to estimate h. (c) Assuming thath, = 40T, estimate and compare how the resistance to heat transfer changes when radiation is also considered in addition to conduction alone.. Therefore, you have to estimate the differences in the resistance to the heat transfer considering and without considering radiation in the air gap, and what is the effect in the heat flow?

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