Ask Your Question

Angie's List Answers is the trusted spot to ask home improvement and health questions and get answers from service companies, health providers and consumers. For ratings and reviews on companies in your area, search Angie's List.

Top 30 Days Experts
Rank Leader Points*
1 kstreett 240
2 Guest_9020487 110
3 Guest_9190926 105
4 GoldenKid 100
5 ahowell 95
6 KnowledgeBase 95
7 skbloom 80
8 Guest_98024861 70
9 Guest_9311297 70
10 Guest_9400529 70

*Updates every 4 hours

Browse Projects By Category

Question DetailsAsked on 2/17/2014

how long should a dryer vent be

Need to install a dryer vent and wondering what type of hosing to use and how long it should be

Do you have the same question? Follow this Question

4 Answers


Here is an article on that from the NACHI (home inspectors association) that should answer your question -

The "transition" it talks about is the duct piece built into the back of your dryer that come roughly flush with the back of the dryer - its length is not included in the total.

Some communities allow flexible interior ribbed duct - most now do not, and the general IRC (International Residential Code) no longer allows that for new installations.

Note - do NOT use any type of fastener that penetrates the ducting, use two wraps of duct tape on all joints except at the dryer itself (that is a press fit slip-on duct connection), and avoid sags that can accumulate link. Duct should be held in place by blocking or plumbers strapping so it does not break apart in cleaning.

Any run going upward is to be avoided if possible - down into the floor and straight out, or downward and out is preferred. If you do have to go upwards, try to provide cleanout access at the bottom of the upward run to allow removal of lint and grit accumulated there at least yearly, and preferably twice yearly (more often if washing daily as with infants), and the lint and grit will accumulate there.

Answered 6 years ago by LCD


Other then a few newer models, 25 feet is the maximum, count each elbow as 5 feet.

Check this site for things that make venting easier/better, including special elbows that count as 1.5 feet, if you caan't stay under 25 feet. If using a Pro to do the venting, have them check this website first.


Answered 6 years ago by BayAreaAC


Do not use flex line.

I know the spec is not to use fasteners but depending on the run and location, I would prefer to have the line securely together as compared to foil tape alone. I have very non-intrusive rivots used successfully.

That box is awesome BayArea!

I am book marking that for future use.

Answered 6 years ago by WoWHomeSolutions


A couple of things about the DryerBox and similar products:

1) in some areas, you have to allow 6 inches clearance from foam or cellulose insulation from a box like that which contains dryer duct connections, because it is presumed it might be the source of a lint fire. In some cases, that restriction applies only to dryer boxes with covers, some only to plastic boxes, other jurisdictions I have seen it applied as a blanket rule regardless of material constructed of and whether open or covered.

2) check your dryer installation instructions for how close you can put the dryer to the wall - for most models, you cannot put them closer thean 4 inches from the wall, which conincidentally is the diameter of the most commonly used metal ducting. The dryerbox physically allows for near zero clearance, which may be a fire hazard as it does not allow free dissipation of heat accumulating behind the dryer, so check the manual, and put a couple of short pieces (so as to not block floor level airflow under the dryer) of scrap wood blocking behind the base of the dryer to prevent it being pushed closer to the wall than allowed if you use one of these.

3) do NOT confuse this with the dryer "heat recovery boxes" which trap the lint and return the air to the household - those are illegal in most jurisdictions as they accumulate the lint which makes it past the dryer lint trap rather than ducting it to the outside, so can plug up within weeks or even days of heavy use, plus they return the moisture to the house, which is generally a bad thing. The lint also tends to stay damp in many cases, promoting mold growth in the duct.

Answered 6 years ago by LCD

Related Questions

Terms Of Use
Privacy Policy