nominally 17˚C and 10˚C
at the top and bottom surfaces, respectively. If the concrete has a
thermal conductivity of 1.4 W/m · K, what is the rate of heat loss
through the slab? If the basᴇмᴇɴt is heated by a gas furnace operating
at an efficiency of ηf = 0.90 and natural gas is priced at Cg = $0.01/MJ, what is the daily cost of the heating loss?
2 Answers
-
Q = k × (d)T × Area/thickness
Q = 1.4W/mK × 7(C) K × 88m²/.2m
Q = 4.312 kW = 4.312kJ/s
1 day × 24hr/day × 3,600s/hr = 86,400 s
86,400s × 4.312 kJ/s = .372557mJ/day
.372557mJ × 10/9 (efficiency) × $.01/mJ = 4.13952¢ /day
-
pta nai yar
