A small storage room has the dimensions of 20 m X 20m X 3m high. The walls of the storage consist of three layers; Drywall (thickness = 0.5 inch, K = 0.5 W/mK), • Fiberglass (thickness = 2 cm, K = 0.1 W/mK), and • Brick (thickness = 8 cm, K = 0.5 W/mK). On one of the walls, there is one small wooden door with the dimensions of 0.9 m X 2 m and thickness of 3 cm. The thermal conductivity of wood is 0.4 W/mK. The inside temperature of the storage room is to be maintained at 20°C, while the temperature outside is 0°C. The rate of heat lost through the roof is 30 kW. Heat loss through the floor can be ignored. a) Calculate the total heat loss from the storage room (kW). b) Determine the temperature at the inner wall of the brick (°C). c) If cost of heating is $0.166/kWh, calculate the heating cost per month. Note that 1 kWh = 3600 kJ.

A small storage room has the dimensions of 20 m X 20m X 3m high. The walls of the storage consist of three layers; Drywall (thickness = 0.5 inch, K = 0.5 W/mK), • Fiberglass (thickness = 2 cm, K = 0.1 W/mK), and • Brick (thickness = 8 cm, K = 0.5 W/mK). On one of the walls, there is one small wooden door with the dimensions of 0.9 m X 2 m and thickness of 3 cm. The thermal conductivity of wood is 0.4 W/mK. The inside temperature of the storage room is to be maintained at 20°C, while the temperature outside is 0°C. The rate of heat lost through the roof is 30 kW. Heat loss through the floor can be ignored. a) Calculate the total heat loss from the storage room (kW). b) Determine the temperature at the inner wall of the brick (°C). c) If cost of heating is $0.166/kWh, calculate the heating cost per month. Note that 1 kWh = 3600 kJ.

Elements Of Electromagnetics

7th Edition

ISBN:9780190698614

Author:Sadiku, Matthew N. O.

Publisher:Sadiku, Matthew N. O.

ChapterMA: Math Assessment

Section: Chapter Questions

Problem 1.1MA

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