Allan.pritchard
New member
- Joined
- Nov 3, 2022
- Messages
- 1
Hi All
First time posting so i apologise if the equations are not in the correct format.
This is a bit of a weird issue and I am not sure if I got my workings correct, I'm pretty good with spreadsheets but advanced math is not my strong point. . Background is I am an architectural designer and recently the building codes in New Zealand changed. I now have to calculate thermal conductivity for concrete slabs on the ground. I developed a spreadsheet but I find that part of the equation returns 0 which then results in a divide by 0 issue.
The parameters are
A = Floor Area (m2)
P = Total Floor Perimeter (m)
a = half the floor width (m)
L = half the floor length (m)
k = is the soil conductivity
R = is the floor plus ground thermal resistance
Calculation is
R = [math](\pi*I*x) / (2*k*1n[(1+x)*(1+(1/x)^x])[/math]
where
[math]x = (2 * L * a) / ( I * (L + a) - (2 * A) / (I x P))[/math]
The issue is X becomes 0 if the building is a 6m x 6m square (or any square) by my calculation which means the calculation of R becomes a divide by 0
A= 36
P = 24
a = 3
L = 3
I have also attached the image if the calculation in case I have not interpreted in correctly.
any help would be appreciated to check if x does return 0 for a square
Cheers
Allan
First time posting so i apologise if the equations are not in the correct format.
This is a bit of a weird issue and I am not sure if I got my workings correct, I'm pretty good with spreadsheets but advanced math is not my strong point. . Background is I am an architectural designer and recently the building codes in New Zealand changed. I now have to calculate thermal conductivity for concrete slabs on the ground. I developed a spreadsheet but I find that part of the equation returns 0 which then results in a divide by 0 issue.
The parameters are
A = Floor Area (m2)
P = Total Floor Perimeter (m)
a = half the floor width (m)
L = half the floor length (m)
k = is the soil conductivity
R = is the floor plus ground thermal resistance
Calculation is
R = [math](\pi*I*x) / (2*k*1n[(1+x)*(1+(1/x)^x])[/math]
where
[math]x = (2 * L * a) / ( I * (L + a) - (2 * A) / (I x P))[/math]
The issue is X becomes 0 if the building is a 6m x 6m square (or any square) by my calculation which means the calculation of R becomes a divide by 0
A= 36
P = 24
a = 3
L = 3
I have also attached the image if the calculation in case I have not interpreted in correctly.
any help would be appreciated to check if x does return 0 for a square
Cheers
Allan
