Determined to reduce the $7 per week cost associatedwith

Chapter 9, Problem 9.81

(choose chapter or problem)

Determined to reduce the $7 per week cost associatedwith heat loss through their patio window by convectionand radiation, the tenants of 9.18 cover theinside of the window with a 50-mm- thick sheet ofextruded insulation. Because they are not very handyaround the house, the insulation is installed poorly, result-ing in an S?5-mm gap between the extruded insulationand the window pane, allowing the room air to infiltrateinto the space between the pane and the insulation.(a) Determine the window heat loss and associatedweekly cost with the ill-fitting insulation in place.The insulation will significantly reduce the radia-tion losses through the window. Losses will be duealmost entirely to convection.(b) Plot the heat loss through the patio window as afunction of the gap spacing for 1 mmS20 mm.