The sums don't quite add up for the problem we looked at earlier. The two calculations for compound insulation give a slightly different answer.
You can see the calculations with my terrible handwriting here. Or just go straight to the video below, which is much lighter on maths.
This is the calculation looking at parts of the wall in parallel first.And this is how to calculate looking at the parts of the wall in series first.
We don't get the same answer. Here's why and what we can do about it.
