Consider a building with 3200 ft² of walls. Assume the ceiling is well-insulated and compute the energy loss through the walls based on the following materials, assuming an indoor temperature of 70 ^?F and an outdoor temperature of 30 ^?F:?

(a) walls are composed of 4" thick hard wood;?

(b) walls composed of 3/4" of plywood on the inside and outside, with 8" of fiberglass insulation between;?

(c) same as (b) but with 18 single-pane R-1 windows (US units), each with area 0.7m² (remaining area is surrounded by walls as in (b)). Take thermal conductivities and/or R-values from?

Tables 6.1

?and Table 6.3.

Transcribed Image Text:

Thermal Thermal diffusivity conductivity k Material a (10-7 m²/s) (W/m K) Air (NTP) 0.026 205* Argon (NTP) 0.018 190 Кrуpton (NTP) 0.0094 100 Xenon (NTP) 0.0057 61 Water 0.57 1.4 Hardwood (white oak) 0.18 0.98