Dryer exhaust duct

[jim baird]

From GA state's 2010 amendments to the '06 IRC:

CHAPTER 15

EXHAUST SYSTEMS

SECTION M1502

CLOTHES DRYER EXHAUST

*Revise Section M1502.6 ‘Duct length’ to read as follows:

M1502.6 Duct length. The maximum length of a clothes dryer exhaust duct shall not exceed 35 feet (10668 mm) from the dryer location to the wall or roof termination. The maximum length of the duct shall be reduced 2.5 feet (762 mm) for each 45-degree (0.79 rad) bend and 5 feet (1524 mm) for each 90-degree (1.57 rad) bend. The maximum length of the exhaust duct does not include the transition duct.

Exception: Where the make and model of the clothes dryer to be installed is known and the manufacturer’s installation instructions for such dryer are provided to the code official, the maximum length of the exhaust duct, including any transition duct, shall be permitted to be in accordance with the dryer manufacturer’s installation instructions. Where exhaust ducts are installed in concealed locations, the developed length of the exhaust duct system shall be indicated by permanent labels or tags installed in an observable location.

(Effective January 1, 2010)

GA amends the building codes every year as part of its adoption process. Usually it is to smooth the path to compliance for the building industry.

All I can tell from this is that my experience the past few yrs has been to see more and more laundry facilities buried deep in the interior of increasingly palatial, McMansionish homes and seeing builders have fits finding a compliant way out.

 

[globe trekker]

Re: Dryer exhaust duct

jim,

Was there a question in there somewhere?

 

[brudgers]

Re: Dryer exhaust duct

Many residential clothes dryers these days blow more than 30' feet.

Particularly the expensive ones.

It's less of an issue in single family homes than in multi-family units where the tenant may supply their own unit...and exterior wall space is at a premium.

But again, many units are rated in excess of 30'.

 

[Coug Dad]

Re: Dryer exhaust duct

I have also been seeing more installations with booster fans in the dryer exhaust.

 

[jim baird]

Re: Dryer exhaust duct

jim,

Was there a question in there somewhere?

Hmmm. No. Just a comment.

Have any here seen trouble with making the maximums?

I have seen Sears dryer spec sheets caliming their dryers will blow 41 feet!

Have also seen vertical ducts that clog up every week or so.

Sadly I have seen more jacklegs trying to get by running that tin-foil type flex connector and calling it a duct.

 

[Mac]

Re: Dryer exhaust duct

HAR! The tinfoil pos is commonly misused...

Flexible transition ducts used to connect the dryer to the exhaust duct system shall be limited to single lengths, not to exceed 8 feet (2438 mm) in length and shall be listed and labeled in accordance with UL 2158A. Transition ducts shall not be concealed within construction.

 

[globe trekker]

Re: Dryer exhaust duct

Coug Dad,

Weren't the booster fans removed from the codes in the 2006 cycle, thereby, disallowing them from use?

jim,

The vertical ducts are required to have a clean out at the bottom of those ducts ( Section 504.3 in

the `06 IMC ), as referenced by Section M1301.1 - SCOPE: in the `06 IRC. "Thanks Uncle Bob!"

.

 

[jim baird]

Re: Dryer exhaust duct

The vertical ducts are required to have a clean out at the bottom of those ducts ( Section 504.3 in

the `06 IMC ), as referenced by Section M1301.1 - SCOPE: in the `06 IRC. "Thanks Uncle Bob!"

[/size].

GT,

I remember when I first saw that IMC Section in the '06 when GA adopted it. My phone call to GA DCA codes consultants got their answer that the IMC did not apply to houses.

I do get your point about the scope and reference there, but have not heard it stretched that way.