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panchoandlefty_gw

Venting: highest CFM for 9' duct, internal blower)

14 years ago

My sales guy sold me a 48" Vent A Hood Pro Island Liner. My carpenter is building a custom wood hood for it.

It arrived yesterday. All the installers were talking about what sixze duct to use since it wanted 12" but in my ceiling, because of some existig copper pipe, I only have room for 9' duct, tops.

The acted like this was no big deal. They use smaller than required duct all the time, blah, blah... however, from GW I knoew this would be a problem. Not only would I not get the 1200+ CFM i PAID FOR, it would be noisy as the motor worked over-hard to push air through a restricted space,

I called VAH who verified this thought. They recommended I back down to the "regular" island model, with 550 CFM (8" duct)

If I have to go back to the drawing board ANYWAY, I am curious if anuyone, off hand, has a high CFM internal blower with 8-9" duct correctly installed, per manufacturers specs.

From this experience, I am willing to guess that many of you who THOUGHT you bought effective, quiet systems, but have found them loud and unruly may have more issues with your ducts than with the appliance.

Neither my salesman, nor the installers would have mentioned to me that they were modifing the system to fit the smaller pipe. In fact, not only were they discussing using smaller pipe, they were considering using flexible duct, which in aslo a VAH no-no.

If I hadn't looked it up myself, after install, I would probably have just assumed that, indeed, VAH made a loud vent.

Just something to consider.

Any thoughts on high CFM with 8-9" duct? Must have a internal blower. Island install.

I know, I'm, calling Modern Aire as soon as the West Coast wakes up. Other ideas?

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