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 = Ó.5 W/mK). On one of the walls, there is one small wooden door with the dimensions of O.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. 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 = Ó.5 W/mK). On one of the walls, there is one small wooden door with the dimensions of O.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. c) If cost of heating is $0.166/kWh, calculate the heating cost per month. Note that 1 kWh = 3600 kJ.

Principles of Heat Transfer (Activate Learning with these NEW titles from Engineering!)

8th Edition

ISBN:9781305387102

Author:Kreith, Frank; Manglik, Raj M.

Publisher:Kreith, Frank; Manglik, Raj M.

Chapter1: Basic Modes Of Heat Transfer

Section: Chapter Questions

Problem 1.40P: As a designer working for a major electric appliance manufacturer, you are required to estimate the...

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