# Homework Help: Conductive heat transfer through basement wall

1. Dec 10, 2012

### omc1

1. The problem statement, all variables and given/known data

In an electrically heated home, the temperature of the ground in contact with a concrete basement wall is 13.8oC. The temperature at the inside surface of the wall is 20.8oC. The wall is 0.118m thick and has an area of 9.43m2. Assume one kilowatt*hour of electrical energy costs $0.10. How many hours are required for one dollar's worth of energy to be conducted through the wall? 2. Relevant equations q=KAdeltaT/L 3. The attempt at a solution (1.7)*(9.43)*(20.8-13.8)/0.118=950.99 W$1=10000Whr
10000/950.99=1052 hrs....not working though???

2. Dec 10, 2012

### mpreds

Where did you find your k value? And is it in the correct units?

-Mark

PS: You did mean to write 10.52 hrs I hope?

3. Dec 10, 2012

### omc1

yes i mean to write that, I got 1.7 from online source, but someone else also used 1.5 but neither of those works?

4. Dec 10, 2012