I am doing some research on ducting and not living in the US I want to know where to look and what to look for. I need to work out if it is cheaper to use PVC or steel ducting in the US and where are some sites I could do some comparison costings from for both. I would also appreciate any comment between the two as in ease of install, problems etc. I know the old problem of static in the PVC but has it any other issues you have found or has the steel ducting got any. It is the steel I am totally unfamiliar with so any info on that would be much appreciated.