(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

i need to find the thickness of the insulating material that is needed to block out the heat that is coming into the room.

the area of the affected wall is 3.3m^{2}the temp in first room is 18 degree celsius while the 2nd room is 45 degree celsius.

the thermal conductivity of the material is 0.0698 W/mK

2. Relevant equations

thermal conductivity, lambda= W/mK

thermal transmittance, U= W/m^{2}K

thermal resistance, R=1/U=thickness/lambda

3. The attempt at a solution

1.find K, the temp difference between the 2 rooms

2.square both sides of equation 1, since im only given area. Find the value of W.

3. subsitute the value of W into equation 2 to find U.

4. substitute the value of U into the third equation to obtain the thickness.

my teacher said the way i dealt with the area was incorrect. Is there any other way to obtain the amount of heat transfer W when im only given the temp difference and the area of the wall?

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# Homework Help: Thermal conductivity and resistance

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