Dryer Vent Through Roof

[AJ1978]

While not in the garage I need some ideas:

In my apartments I own, they are on the second floor the dryer is not vented correctly and I want to do it right for obvious reasons:

Add Lint trap in pipe going to attic space
Want to add Dryer Duct booster to vent.
Through the attic (booster mounted)
Vent Through the roof:

Venting through the roof is where I am uncertain, the previous owner had it in some schedule 40 a long horizontal run, and into a now non working roof vent.

I would like to put a pipe straight up directly above the dryer, but I am worried about snowfall blocking the vent. I will be coming out close to the peak, but unsure if a Dryer Jack Zero type vent will work,

OR
Can I run a piece of 4" pipe up maybe 2-3 feet and put a 4 way cap on this

 

[Rookie2]

http://www.garagejournal.com/forum/search.php?searchid=25659332

I installed one of these:
http://www.tjernlund.com/dryer_booster.htm

Into a 18' vertical 4" pvc and a 'T' on top. PVC is not to be used because of static but both metal or plastic collect lint. Without the booster the vent stack had to be cleaned every other month (commercial pet grooming business) , it hasn't needed cleaned in over a year now.

 

[weadjust]

My dryer has a vent through the roof with 90 degree in wall behind dryer straight up through wall, attic, and roof. Straight up section is 13' -14' long. No duct booster needed. Has been like this since 1974 and works fine. No snow to deal with in my location.

I wouldn't add a lint trap in the vent pipe in a rental unit. Doubt tenant would clean it out. I have rental units and provide HVAC filters for tenants and they won't change them. My dryer roof vent cap looks like this.

 

[Showkey]

I would worry with the warm air melting snow and ice making an ice dam further down on the roof.
Home I have......had Radon vent through the roof....... Disaster.........warm air exit caused huge ice dam.
Daughter has the dryer roof vent in Kansas........ice not a problem, but the long run and cleaning the vent pipe has been a huge PIA.
That vent cover picture above in post 3 is the one my daughter has......that vent screen MUST be cleaned often. If it is not the dryer over heats and shuts down.......or worse.

 

[AJ1978]

Rookie2,
Are you Saying the PVC has worked fine? That would be good to know

 

[AJ1978]

My worries was melting the snow and causing problems with ice dams etc. I was thinking of extending the pipe above the roof 2-3 feet and putting a turn down 90 on it etc. OR a TEE with 2 90's dipped downward.

 

[Kaizen]

remember that long pipe will be in cold space so the warm moist dryer air will condense and travel back down. if its not set up to drain back someplace it will fill the pipe eventually.

 

[404]

Why not right out the wall behind the dryer? Shortest distance, no roof leaks.

 

[Rookie2]

Rookie2,
Are you Saying the PVC has worked fine? That would be good to know

It was a PITA because of the high use / moist air collected in the vertical riser but the booster actually moves the moist air out faster and the dryer actually drys faster and I think the exhaust stays warm n dry . Lint does collect but seems to be for the most part exhausted out into the air and some collects on the shingles. The owner has a loose fitting T on top that actually follows the air flow .
I read that on the internet not to use pvc but you might want to look into it more.

 

[weadjust]

Why not right out the wall behind the dryer? Shortest distance, no roof leaks.

My dryer is in the center of the house in a hall. Going through the wall would require going through the kitchen, hall, or a bedroom.

 

[AJ1978]

Going through a wall is not an option here as well. Sits in middle of building, either way if I went down and out, or up and out, it will require a booster. I could go down but I have better access in the attic going straight up

 

[404]

My dryer is in the center of the house in a hall. Going through the wall would require going through the kitchen, hall, or a bedroom.

Oh. Total bummer and my condolences.

 

[weadjust]

Oh. Total bummer and my condolences.

Actually it's quite convenient. Centrally located in the hall. It's not uncommon on older construction in the south to have the washer/dryer outside in the garage or carport storage room.

 

[AJ1978]

I think I will run smooth galvanized pipe up to and through the roof. I am going to look at the alumn stuff and see whats readily available. When I terminate at the top, I am going to use a TEE and some elbows to turn it down. I have pesky black birds that seem to find a way in. AND I DO NOT WANT A SCREEN

I will Then have a secondary lint trap. Then tenants are usually good about taking care of the laundry room as they know I will rip it out and they will be forced to go to the Laundromat.

 

[CNGsaves]

^ ^ That should work.

Use the INSULATED 4" steel pipe in the attic to eliminate condensation problems.

 

[Want2race]

I used to have a roof vented piece but found if I ever used the dryer while raining I would have my thermal fuse blow a few days later.

Turns out wet lint gets stopped and makes a caccoon which blocks the pipe. Since then I just do wall or under the eves!

 

[G McKay]

Why not right out the wall behind the dryer? Shortest distance, no roof leaks.

2nd this. I'd put a dryer vent out through a side wall rather than through the roof. Condensation has no where to go when you are running the pipe vertically. And if you run it across the attic, make sure it doesn't sag down in between the ceiling joists or water will lay there too.

 

[Lugnut64052]

I own a duplex that has both laundry rooms dryers vented through the roof. The vents are about eight feet long, and are terminated like an HVAC vent (short stand of pipe above the roof, with a standard rain cap zip screwed on).

It's worked okay for the most part. The rain caps eventually got plugged up with lint on both of them, but it took 20 years. I had to take them off and clean all the lint out, after which they have worked fine ever since.