Got this off the ICC website today. Thought I'd post it for your info. ICC answer to booster fans.

Posts: 159
Registered: Jun 2000
posted 03-07-2005 12:55 PM
Well it appears that all of our concerns were shared to some extent. Here is the reply I received today from Larry.
Code Question:

Code Edition: 2003 IMC

Code Section: 504.6

Code Question:

Why is the exception, for a booster fan on the dryer duct, in the IRC and not included in the IMC? I have a R-2 application that was trying to use that exception, which they found in the IRC, and I am not allowing it, because of the absence of it in the IMC. I feel there must be a reason, not just an oversite.

ANSWER: The booster fans have now been removed from the IRC following the 03/04 code hearings. RM6-04/05 attempted to put them back during last week’s code hearings and the IRC committee disapproved the code change. As of now, the booster fans won’t be in either the IMC or the IRC in the 2006 editions.

As Mr. Battles told you, they are different in the 2003 codes because different committees control the content of the two codes. The NAHB has more control of the IRC committee and they approved booster fans for the 2003 code, but the IMC committee disapproved them because no dryer manufacturer permits them in their installation instructions.

I have let the developer know that I am not going to allow them. Thanks for all the feed back.