Hi Pat, you’re right that depending on the thickness of the PVC piping the impacts could be higher or lower. I guess the best way is to do some research and figure out what’s the ‘average/typical’ thickness for PVC ducting. I imagine different countries might have different ‘typical’ thicknesses too based on that country’s standards. If you’d like to adjust the thickness of the ducting for your location, please feel free to clone the template, make the adjustments (rename for clarity) & submit the template for validation ensuring that you include a clear explanation of your assumptions & references to support your update in the template description.