# Ductwork surface area calculation problem

• Apr 25th 2012, 06:32 AM
tibor
Ductwork surface area calculation problem
Hello,

I have a major in economics and I am creating an excel spreadsheet for quotations of sheet metal ductwork as my final thesis. I need to calculate weights for various types of ductwork produced in the company I chose for my thesis. In order to calculate weight, I need to know the surface area of ductwork parts. For many parts (pipes, elbows,etc.) I have figured out the formula for surface area myself, resp. found it on the internet. But there are some pieces I am not able to figure out how to get the surface area based on the input parameters.

You will find the pictures of the parts in the pdf attachment for which I need to get the formula for calculation of the surface area (in metric units). I would be very thankful if anyone of you could help me with finding the correct formulas.

Thank you very much for your time, help and effort.

Sincerely,

Tibor
• Apr 25th 2012, 07:31 AM
HallsofIvy
Re: Ductwork surface area calculation problem
Those are too many questions to answer here but all the formulas you need can be found at
Surface Area and Volume Formulas - Three Dimensional Shapes
• Apr 25th 2012, 08:02 AM
tibor
Re: Ductwork surface area calculation problem
Thank you for the reply, I know about those basic formulas, but my shapes are asymetrical and / or need to calculate area under the curved line (integration), so these basic formulas will not help me.
• Apr 28th 2012, 01:50 PM
HallsofIvy
Re: Ductwork surface area calculation problem
I can only answer based on what you give. The only "curved lines" in the figures you show are circles. All the figures are made from basic cylinders, spheres, and prisms that you can apply basic formulas to.
• Oct 3rd 2012, 04:41 AM
chvega
Re: Ductwork surface area calculation problem
I am working on the same thing for my brother's sheet metal company. How did you calculate the surface area of the elbows? HELP PLEASE!!
• Oct 3rd 2012, 08:22 PM
Wilmer
Re: Ductwork surface area calculation problem
Go elbow your way through these: