A one-story house is heated with natural gas, which gives off 3.890 107 J of ene

Question

A one-story house is heated with natural gas, which gives off 3.890 107 J of energy for every cubic meter of gas burned. Take the average temperature difference between the inside and outside for the 120-day heating season to be 12 degree C. In the diagram below h1 = 5.00 m, W = 8.00 m, L = 10.0 m and h2 = 3.00 m. If the walls, windows, and roof have an average thickness of 22.0 cm and the thermal conductivity (including the windows) is 0.48 W/(m · degree C), determine how many cubic meters of gas is used up during the 120-day winter season? Assume air infiltration and heat loss through the ground is negligible.

Explanation / Answer

(a)the energy is E = 3.890 x 10^7 J

the time is t = 120 day = 120 x 24 x 60 x 60 seconds

the power is P = (E/t)

the temperature difference is dT = 12 oC

the average thickness of walls,windows and roof is S = 22.0 cm = 22.0 x 10^-2 m

the thermal conductivity is k = 0.48 W/m.oC

let A be the area of the house

we know from the relation

P = (k x A x dT/S)

or A = (P x S/k x dT)

the volume of gas used up during the 120-day winter season is

V = A x (h1 + h2)

where h1 = 5.00 m and h2 = 3.00 m

Related Questions

Navigate

• Browse (All)
• Browse A
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.