Calculating Heat Transfer in a Brick Wall: Homework Question Explained

AI Thread Summary
To calculate the heat transfer through a brick wall, the relevant equation is Q* = (T1 - T2) * k * A / X, where T1 is the inner temperature, T2 is the outer temperature, k is thermal conductivity, A is the area, and X is the thickness. For the given wall dimensions, the area A is 24 m², and the thickness X is 0.3 m. The thermal conductivity of the brick is 0.8 W/mK. It's important to note that to convert watts to joules per hour, one should multiply by 3600 instead of dividing. Proper notation is crucial, as the caret symbol (^) typically indicates exponentiation.
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Homework Statement



Consider a brick wall, 4.0 m high, 6.0 m wide and 300
mm thick, where the thermal conductivity of the brick
is 0.8 W.m-1.K-1. During a particular one-hour period,
the temperatures of the inner and outer surfaces were
measured to be T1 14oC and T2 6oC respectively. The average
rate of heat transfer

Q*=Rate of heat tranfer (i think)

Homework Equations



The equation that I am trying to use is Q* = (T1-T2)*(k)*(A)/^X not sure if correct.

The Attempt at a Solution



^X is just the thickness of material
A is 4*6=24m^2
k = 0.8W/mK

so i filled in and the divided by 3600s to get an answer in joules, i know i have can wrong can someone help me out with what formulae to use for this question?
 
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You are using the correct formula. A watt is 1 joule/second so you should not divide by 3600. To get joules/hr, multiply by 3600.
 
Last edited:
Careful with the use of ^. It means exponentiation to most people.
 
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