A construction crew is building an ice rink. A wall 10 m high by 30 m...
A construction crew is building an ice rink. A wall 10 m high by 30 m long separates the cold rink (40◦F) from the nice warm locker (75◦F) room. The wall has two layers of drywall that are 0.5 inch thick each and have a thermal conductivity of 0.17 W/m K. What should the R-value be of the insulation between the walls to keep the rate of heat transfer to a maximum of 40 W?
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A construction crew is building an ice rink. A wall 10 m high by
30 m...
A wall in a building has a width of 15 m and a height of 3...
A wall in a building has a width of 15 m and a height of 3 m. It is made of several layers — a layer of motionless air with an R value of 0.12 K m2/ W, a 12.4 mm thick layer of gypsum board with a thermal conductivity of 0.17 W/m K, a layer of brick with an R value of 1.7 K m2/ W, and another layer of motionless air with an R value of 0.12 K...
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1.3 127 5.3 3.(10 pts) A cold storage room (10 m x 10 m x 10...
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Consider a 4 m high, 6 m wide and 0.17 m thick wall whose thermal conductivity is k = 0.8 W/m.oC....
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Heat Transfer Problems 1. A window pane (1/8 inch thick) in an old house owned by...
Heat Transfer
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1.3 127 5.3 3.(10 pts) A cold storage room (10 m x 10 m x 10 m) is being maintained at 2 °C using a vapor compression refrigeration system that uses R-134a. The evaporator and condenser temperatures are -20 and 40°C, respectively. The walls and ceiling of the storage room is constructed of 15 cm thick concrete (thermal conductivity-1.37 WIm K]) and 4.3 cm thick insulation (thermal conductivity-0.04 W/[m K). The outside insulation surface temperature of the walls (or ceiling)...
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