• Welcome to the new and improved Building Code Forum. We appreciate you being here and hope that you are getting the information that you need concerning all codes of the building trades. This is a free forum to the public due to the generosity of the Sawhorses, Corporate Supporters and Supporters who have upgraded their accounts. If you would like to have improved access to the forum please upgrade to Sawhorse by first logging in then clicking here: Upgrades

What to do when your dryer duct is too far away to terminate

fiddler said:
Personally I really hate that addition to the code. There is no way to ensure that future owners of the house will have a dryer with the same capacity. Or for that matter when the existing owners replace said dryer.
There is hope, the 2009 requires the developed length of the duct to be permanently labeled by the machine. At lease now there is an OPPORTUNITY to get it right with a dryer replacement. Wooops, already answered by a previous post.Anyway, 5% of fires for just ONE CAUSE is a high number
 
JBI said:
The nailing of kraft paper to the insides of studs is a convenience to the drywallers, but a detriment to the longevity of the building. Air, spelled m-o-i-s-t-u-r-e moves through those spaces causing problems... As infrequently as all other details get done correctly, like cutting around boxes, etc it's hard to get anyone to understand this one.
Yes, I am really starting to have a hard time with it, , , sheetrock and other finish materials have similar vapor retardant properties, why is having an additional vapor retarder necessary in those locations? The PROBLEM is that the building is not ventilated, , , I am getting really sick of this energy baloney. . . can you tell?
 
Booster Fans are allowed now ! , fan tech has a listed approved fan and UL has the standard for it. Please remember to check with UL and the Fan must be listed and approved.It will be in the 2015 code!
 
"Booster Fans are allowed now !"

No, they aren't. Fantech may have received a listing, but they are still not specifically allowed in the 09, or the 12 codes.

"It will be in the 2015 code!"

Interesting comment, since the 2015 code change hearings have yet to even start. There's a long row to hoe there, my friend.

Welcome to the forum, didn't see any particulars in your profile. Where you from, what codes, what is your interest in the codes, your trade????????

Can you please cite your resource on this?
 
Last edited by a moderator:
I just had a contractor give me the specs for a dryer booster fan (sold at a major retailer) and the the specs do not specifically state the fan meets the requirements of the 2009 IRC nor does it give any specs on an assembly (40' with 5 90's, 30' with 2 45's and 1 90..etc.). I had to turn him down, there was not enough documentation to back up the installation.
 
Any pictures as to how they plan to provide access tothat for servicing, replacment, etc. Any type of access panel I can immagine would really look great in a finished ceiling.
 
Big Mac said:
Any pictures as to how they plan to provide access tothat for servicing, replacment, etc. Any type of access panel I can immagine would really look great in a finished ceiling.
Attic Access.....

installation-dryer-vent-booster-fan.jpg


In ceiling, cant say I like the flex line, but

ar12238714542222.jpg
 
local amendment..

access? don't worry about the insulation; the wood will catch fire first..

wouldn't it be nice to replace the fan (with some kind of disconnect) thru an access panel?

toss the dice.. or don't approve it.
 
Just caught up with this thread.

I have seen "UL listed" , according to the documentation, booster fans before. When I looked at the documentation only the motor was listed, the whole fan assembly was not.
 
Agree with those who say boosters are not in the code. It would have to be an approved alternative method.

What is baking my noodle is if that we are looking up at a basement ceiling, that means the basement is outside the thermal envelope, and therefore the basement should be considered unconditioned.
 
I am resurrecting this thread again to see if there is any updated information.

Also, I have a customer that wants to install a booster fan & "new" exhaust

ducting on to their existing residential dryer. Their existing exhaust duct is

an underground pvc duct that terminates below grade oudoors, and fills up

with water when it rains.

The customer is not really interested in any type of approved assemblies

vs. approved motors issues, but DOES seek to have a safe and functional

install. They also do not want to relocate their dryer to an exterior wall!

I will have a licensed electrician install the circuit to the motor.

How does these booster fans activate, ..automatically, ..by the user & a

switch, other?

Any input will be greatly appreciated! Thanks!

.
 
Also, if elbows are part of the length issue you can use long sweep elbows to reduce the deduction of 5' for each 90 (if there is room for them). See 504.6.4.1 of the 2009 IMC. We see these used fairly often, and they do make a difference for distance. We actually allowed them under the 2006 as alternate methods, because the ones we see are ul listed as dryer elbows with an equivalent length of 1' 6".
 
globe trekker said:
The customer is not really interested in any type of approved assemblies

vs. approved motors issues, but DOES seek to have a safe and functional

install. They also do not want to relocate their dryer to an exterior wall!

.
If He really wants a safe installation, he should avoid a booster fan altogether! If it quits working, it becomes nothing more than a lint trap, and it's one of those things that easily becomes "out of sight, out of mind".
 
Continuing some more with this interesting topic..

I have tried to offer some other alternatives to this customer, but they are insistent

on installing a booster fan. They do not want to move the dryer away from the washer,

to an exterior wall and run a "new" exhaust duct & elec. circuit, nor do they want to

create a drainage trench leading away from the existing, below grade termination

point of the pvc duct. This is an older house with a slab-on-grade foundation and

the pvc pipe was installed yrs. ago.

What would you (or ya`ll) do ?

FWIW, "klarenbeek", it's not a He! :D

.
 
klarenbeek said:
If He really wants a safe installation, he should avoid a booster fan altogether! If it quits working, it becomes nothing more than a lint trap, and it's one of those things that easily becomes "out of sight, out of mind".
Require an interlock. Redundant fans. A sprinkler system. Fire watch. Trained Beagle.
 
PVC Pipe Basics

  • PVC pipe was first developed in the 1950s, and its durability, ease of use and resistance to bacteria quickly made its use in plumbing systems very popular. PVC pipe is commonly available in many sizes (diameters) and strengths (schedules), and it is still widely used in residential and commercial cold-water pipes. Because PVC pipe can warp and weaken when exposed to temperatures above 140 degrees Fahrenheit, it is not used for hot-water systems, which tend to consist of copper or galvanized steel.
Dangers of PVC Pipe

  • PVC pipe's sensitivity to heat is a big reason why it is not recommended for use in dryer vents. The exhaust from a clothes dryer can reach temperatures ranging from 120 degrees to 200 degrees Fahrenheit, which could cause the pipe to soften and fail. PVC pipe is also prone to static electricity buildup, which can attract lint and cause it to accumulate inside the pipe. This not only reduces the efficiency of your dryer (which could lead to overheating), but it can also increase the risk of fire and exacerbate condensation issues.
ICC Codes

  • The nonprofit International Code Council (ICC) develops building codes and guidelines for residential and commercial construction. Most cities, counties and states in the United States tend to adopt the ICC codes or to model their requirements closely on ICC recommendations. The ICC code for dryer exhaust ducts specifies the use of smooth, rigid metal ducting
Read more: Types of PVC Pipe Used for Dryer Vents | eHow.com Types of PVC Pipe Used for Dryer Vents | eHow.com

PVC20Dryer20Duct_zps540826f0.jpg


An example why you don't use PVC for a dryer duct
 
It's good to know that the ICC is a nonprofit.

I didn't know about the static electricity.

Wow 200 degrees....I can bake bread while drying underwear.....I can call it sock loaf......talk about loaded with fiber
 
Top