R-Value question

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    Mark Baker

    Somaya,

    You actually need a lot more information for the question you are asking about.

    It is 2 concepts in 1. 

    1 - is the subject of material R Values.  The ASSEMBLY has a total U Value.  Each item in the wall has its own R value (or K factor).  The combination of all the materials's R values (Thermal Resistance) equals the walls U value (Heat Transmission).

    2. Find the temperature of a given material inside the wall assembly.  This is where you have to take the R value (thermal resistance) and the change in temperature across the wall (you will be given both inside and outside temperature), and figure out the temperature change curve through the wall.  (I want to say Hyperfine has a great sample problem on this).  

    I think that you should spend some more time reading about U-Value, R-Value, and K Factor.  Then look for example problems about temperature change through a wall assembly.

    There are also problems with OVERALL HEAT LOSS through a wall.  This will take the area of the wall multiplied by the R factor to determine how much heat the whole wall loses.  This is an entirely separate problem time from the 2 above. 

    There is a lot of stuff to unpack on this subject. 

    Do yourself a favor and try to learn more about the OVERALL concepts, so that when you are faced with a question related to these, you will better understand what the task you are faced with is.  Or else, you may end up lost in the weeds.

    AND ALWAYS REMEMBER - ONE QUESTION IS ONLY WORTH 1 POINT on the exam.

    Mark

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    Somaya Etemadmoghadam

    Thanks Mark. I am comfortable with topics you've mentioned and I understand them properly. This was a question from somewhere else that I exactly had as much information as I mentioned above to solve it.

     

    You're right, one questions worth one point ... 

     

    Thanks 

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    Mark Baker

    That is an incomplete question that can not be answered. 

    Mark

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