Good morning,
I am currently working through the new PPD videos and watching the HVAC Basics – Heat Transfer Calculations lesson. While following along with the U-factor for walls example, I noticed that when I calculate it on my own, I consistently get 0.568 instead of 0.219 as shown in the video.
I’m not sure whether there may be an error in the video calculation or if I’m misunderstanding a step in the process. Could you please confirm the correct answer? If my calculation is incorrect, I would really appreciate it if you could help me understand where I’m going wrong.
Thank you so much!
Virginia
Hi @mariavirginia.portillo - thanks for writing in! It’s great that you’re doing the math on your own along with the video.
You made an understandable error in your calculation - you missed a zero and used ‘0.485’ instead of ‘0.0485’ as the U-value for the opaque wall. If you add in that zero, the calculation works out to what we show - 0.219.
Again that’s a really common mistake to make, but it’s better to make it now while you’re practicing than on exam day! A good reason to double check your work on the exam, particularly for math questions, if you have any extra time remaining.
Happy studying!
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Whoops, thank you so much!!!
