Replies

1. 
   David_Thomas | Jul 01, 1999 11:23am | #1

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   I'm with Fred. Your contractors are claiming each product to be the better one. Actually, they are selecting what they find to be easiest. There's no way the weaker flex duct with its greater pressure drop is better than rigid, smooth, metal duct. You'd have to go up at least one size to get the same flow through flex as rigid and in many spots (through joists, etc.) you can't go any bigger. Not that anyone who spec'd such material would putting much effort into sizing the system properly. Can you get another bid from someone else to put in rigid duct? -David

1. 
   FredB | Jul 01, 1999 12:35pm | #2

   *I assume you are using flex vs rigid to keep the demolition and reconstruction costs down.If not I join the crowd, can't think of a reason to use them.If so, maybe you should rethink if flex is worth it. Rigid is s-o-o much better. It has more efficient air flow, is easier to insulate, traps less dust and foreign objects...

1. 
   Walter_R | Jul 08, 1999 08:30am | #3

   *How about noise? On my last house replaced 6" round branch ducts with flexible ducts and found noise to be significantly reduced with no discernable loss in system performance.

2. 
   Gary_Gallaher | Jul 08, 1999 08:30am | #4

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   We are having our heating/AC ducts replaced. One contractor recommends Wire Flex, another recommends Aluminum Flex. Both seem to feel very strongly that their's is better. The wire flex would have a smoother surface inside, but it is plastic. Wouldn't that break down sooner due to heat? Which would withstand more abuse from people clawling around and under them?