Heating Ventilating and Air Conditioning: Analysis and Design
6th Edition
ISBN: 9780471470151
Author: Faye C. McQuiston, Jeffrey D. Spitler, Jerald D. Parker
Publisher: Wiley, John & Sons, Incorporated
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Textbook Question
Chapter 5, Problem 5.13P
Estimate the unit thermal resistance for a vertical 1.5 in. (40 mm) air space. The air space is near the inside surface of a wall of a heated space that has a large thermal resistance near the outside surface. The outdoor temperature is 10 F (—12 C). Assume nonreflective surfaces.
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1) "Two-by-four" wood studs have actual dimensions of 4. 13 x 9.21 cm and a thermal
conductivity of 0.1 W/m. °C. A typical wall for a house is constructed as shown
below. Calculate: a) heat transfer rate through the wall, b) temperature of inside wall,
outside wall, and insulation material; and (c) temperature drop across common brick.
Disregard any contact resistances at interfaces.
Outside air convection, h = 15 W/m?. °C
Common brick, k= 0.69
8 cm
1.9 cm, k = 0.96
Gypsum
sheath
1.9 cm. k= 048
40.6 cm
Insulation, k = 0.04
2 x 4 studs
Inside air convection, h= 7.5 W/m²• C
Please help me fast.
R Value:
Wall: 0.961m2k/w
Floor: 0.676m2k/w
Roof: 0.7465m2k/w
In a table format show with calculations and research how much money you can save by installing a 115mm layer of insulation (R2.9) in your walls, floor and ceiling over a 5 and 10 year period. Consider the capital costs. Hint: State the current R value of each component. Convert to U value. Calculate new R value of each component (walls, floor and ceiling). Convert to U value. Use Q(W)=A*(change in U)*temperature change. Determine price for installation of new insulation. Determine price saved based on less heat loss through each component separately, then add all values together, and calculate per 5 years and per 10 years. Present all of this information in a table. You do not need to draw any diagrams, simply add the R value in series with your current components R values.
Assume the energy cost is 25 cents kWh
Chapter 5 Solutions
Heating Ventilating and Air Conditioning: Analysis and Design
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