It's OK to vent vertically up to the attic, as long as you are (as you plan to be) carrying on and venting to the outside.

To determine whether your total length of vent and number of 90 degree turns is OK, you'll need to consult your dryer's owner's manual for the data. (Sounds OK to me, but I'm not familiar with your specs.)

But one thing to consider, the horizontal run shouldn't be horizontal, but at as much of slant as you can manage from where it emerges from the attic floor to the point it exits the house. This will ease the constriction of the 90 degree bend as much as possible.

You can buy in-line boost fans (I think Fan-tech is one manufacturer), but you may not need one.

Always use rigid metal piping, not the plastic or metal corrugated stuff. And I prefer to plan on an easy dissassembly point(s), or a clean-out. Make it very easy to sweep the pipe - a couple of times per year is not too often. Cleaning regularly will save you money, decrease dryer time and protect against dryer fires caused by lint in the pipe.

Depending on your typical local storm patterns, you may need to protect the opening with louvers or a hood to avoid having water or snow enter the pipe.

But altogether it doesn't sound like a difficult project.

Molly~

FA,

You know you bring up a good point about the possibility of moisture condensing during the winter and the need for a slight downward slant to the outside on the attic leg.

But I thought the OP was planning on venting in a gable end, that's why I recommended slanting up in order to minimize the constriction of the 90 degree bend. If one slants down, then the constriction is increased, which could decrease the possible total length of run.

I suppose if one wanted to accomodate the possible need for condensate collection problem while still minimizing constriction one could build in a little collection container at the foot of the vertical run just where it exits the dryer. This would make a handy cleanout point, too.

Molly~

I once had to vent dryer from inside wall and someone had vented it up 10 ft. and directly into attic. After awhile the thing must have clogged up and my dryer was taking over an hour to dry just about anything. One day when cleaning out the hose that was severely clogged, which we did frequently, and waiting to get new hose I decided to put an ankle hose, nylon, over the vent on dryer as I was desperate to dry some clothes and immediately that sucker dried stuff in 30 min. or less. Prior to putting sock (hose)over vent, none of my setting seemed to be working as they once had. After disconnecting from the wall vent it completely changed how my dryer worked. Just a clue if you connect this way and eventually have dryer problems.

My "original" venting (when the house was built) went about 8 feet vertical through our attic (in MA, clod in the winter, hot in the summer as it was unheated space)

Well... we moved in in the spring all was fine until the wather got cold.... then the dryer was taking forever to dry the clothes... if it actually did.... so I call service thinking something is wrong with the dryer... turns out they told us to vent the thing differently as the long run in the unheated space is a problem in cold weather....

don't know where yo live weather wise...but you might want to check o this where you are...

This is exactly the set up that is in my house now. How are you supposed to clean the pipe that is in the wall? Dh has been getting into the attic and running a stiff wire with Miracle cloths tied to it. It's really hard to get to the pipe as it comes out under the central heating plenum(sp).

Our dryer vent makes a 90 degree turn where it enters the wall and then goes straight up about 20 feet and exits the roof. It does run straight up through the attic.
When we have the chimney sweep clean our fireplaces, he also cleans out the dryer vent. So far not much has come out of it.
He cleans it from the bottom, and then from the top and then vacuums inside of it.

Marti8A

Try this for DH...I just recently ordered it and I can tell you it works now my dryer doesn't run as long as it did.

The only thing I did was start the dryer on a low setting and started to clean out the exhaust ..OH and tell him to wear a face mask for the dust and stuff that comes out which in my case was a ton.

Worse case if he can't do it from the outside he can do it from the back or the dryer, just needs a vacuum to draw out the garbage.

Good luck
Big Al

http://www.rewci.com/dryerventclean.html

Here is a link that might be useful: Vent cleaning system

If this is in a cold climate the suggestion to have a downward pitch to the horizontal section sounds good. You also need to insulate that section of vent in the unconditioned space to prevent (or dramatically minimize) condensation at all. Lint will build up - that's a fact of life in the best possible situation. With conditions that allow condensation you'll get a lot more lint buildup.

To insulate you'll need fiberglass duct insulation. You'll wrap the rigid vent without compressing the insulation and fasten it together. I've seen HVAC contractors pinch a bit of the ends together and use a special stapler. You can also probably do it with the right kind of tape (duct tape is pretty poor so I'd avoid that). You might have to do some research to find the best tape based on the material used in the facing of the insulation. If you end up using foil faced insulation, there are very good tapes available at HVAC supply houses.

Anything vertical for a dryer vent is basic gravity. the dryer will only lift lint to farz always, always look to vent horizontal and as short as possible. never never bent to unheared areas like attics. your asking for moisture and mold in the winter when you hot air enters the cold attic. plus its illegal to dryer vent vertically in some states like Michigan

replying on a 17 year old thread?

Old threads are included in search results. It's not uncommon they're found. The latest comment is relevant to the subject, so what's the problem?