How do I calculate the temperature of the wall from exterior to interior

Follow

Ariana Parrish

February 10, 2020 00:21

Hello all, If I am given a wall with the exterior and interior temperature and I'm asked to determine the temperature let's say at the midpoint of the insulation....how do I calculate this? 

 

Thanks!

0

• 

  Erin Cooper February 10, 2020 01:27

  There are two methods, ratio method and a formula.

  Ratio Method: At the point in question, if 80% of the R value is on the inside of the wall, the temp at that point is 20% less than the outside temp.

  Formula: Temp @ point = Temp Outside + [ (R outside / R total) x delta T ]

  I struggled with this one too and delved a lot into it, but the ratio method is what I think is the best because questions on the test will likely be in a simplistic format. 

  0

  Comment actions Permalink
• 

  Robin Tannenbaum February 10, 2020 02:58

  Wow I never know the ratio method but it makes so much sense.  Thanks!  FYI, I believe the Amber videos has a good explanation of the Formula method but really just knowing and practicing the formula above is good. 

  0

  Comment actions Permalink
• 

  Ransolina Sawyerr August 26, 2021 14:42

  Thanks Erin and Robin!

  In the formula method, what is delta T? How do you find the temp at a point on the wall if delta T is not given?  For example, if a question may give just outside temperature and R-value. Any suggestions are appreciated.

   

   

  0

  Comment actions Permalink

Please sign in to leave a comment.