As a building contractor, you are designing the walls of a house. Each wall is a threecomponent (minimum) composite of plasterboard, insulation, and plywood shown in Figure P4.16. You are to design the wall based on the following information and constraints.

a. Minimum outside air temperature: \(-25^{\circ} \mathrm{C}\)

b. Outside heat transfer coefficient: \(100 \mathrm{~W} / \mathrm{m}^{2} \mathrm{~K}\)

c. Inside heat transfer coefficient: \(50 \mathrm{~W} / \mathrm{m}^{2} \mathrm{~K}\)

d. Inside air temperature: \(20^{\circ} \mathrm{C}\)

e. Maximum heat flux through the wall: \(12 \mathrm{~W} / \mathrm{m}^{2}\)

f. Maximum wall thickness: \(0.175 \mathrm{~m}\)

g. Maximum wall cost: \(\$ 25 / \mathrm{m}^{2}\).

1. Neglecting the vinyl siding, the vapor barrier, and the top and sole plates (boards), design a wall to meet these specifications. You can obtain pricing information for the various components from local home improvement stores. 

2. Suppose you wanted to use metal studs instead of wood. Would you have to add extra insulation to keep your heat flux within specifications?

Transcribed Image Text:

FIGURE P4.16 8 ft. 15 in 4 ft. Sheathing Insulation Drywall Side View