I have a friend in North Idaho with a problem. The laundry room shares a wall with the garage. The contractor is adamant about not venting the (electric) dryer into the garage, but doesn’t have a clue how to vent it. I suggested one of the water-filled tanks made for condo dwellers, but he’s against that, says the humidity injected into the garage will be too much. It’s an enclosed 2-car garage & the owner only has one car. I also suggested going up through the roof, but he’s worried about the lint buildup at the bend. Apparently the door arrangement doesn’t allow the pipe to be run along the wall to the exterior wall.
She’s single, probably does laundry once a week, or less and with the daytime high temperatures in the low 20’s this time of year, she probably needs all the extra humidity she can get. Anyone have any creative suggestions ? Thanks
Edited 1/1/2009 3:19 pm ET by Ray
Replies
First find out the dryers maximum rated vent length.
Try to determine best/shortest run to vent it outside.
Rule of thumb for 4" duct, IIRC:
For 90° elbows, reduce the allowable vent system length by 10 ft.
For 45° elbows, reduce the allowable vent system length by 6 ft.
My home is pretty much the same situation.
I went through the roof with my vent (mostly rigid aluminum pipe). Flexible aluminum from dryer to where the vent enters the wall, then solid Al until up through the wall and into attic, then transitions to flexible Al about 3 feet before the roof jack fitting.
Flex Al at dryer allows easy removal for inspection / clean out. Flex Al below roof jack allows inspection / clean out there.
Have had this arrangement for about 8 years - about 6 loads per week.
Every now and then the dryer seems to take longer than usual - lint build up generally at the roof jack screen - 1 hose clamp and I am in - no problem.
In your friend's case, I agree that the dryer vent should not exhaust into the garage for humidity reasons.
If his concern is lint build up at the bend: Why not bring rigid pipe through the garage wall, install a T or Y with clean out and then go up (pipe exposed in garage) through the roof? Build an insulated chase if concerned about condensation.
Or, pipe rigid with T or Y inside of existing wall with an access panel for lint clean out.
Keep in mind that in my experience, the lint clogs happen at the roof jack screen - not at the first bend out of the dryer.
Basement or crawlspace? Take the dryer vent down and outside through a side wall.
Jim
If it's an unheated garage, it wouldn't add a significant moisture load.
I would not vent through roof, as it would be difficult to inspect and clean and could even result in a roof fire. The termination is supposed to be out a sidewall and aimed downward, minimum 12" above ground.
What's more important is using the proper duct type (smooth and metallic) and limiting the total length (no more than 25', though that varies with dryer model and vent hood opening). Each 90° elbow counts as 5' of duct (unless the DryerEll long sweep is used - counts as 1½") and each 45° elbow counts as 2½'.
The most air-tight dyer vent cap is the Heartland vertical shuttle cock unit.
http://www.energyfederation.org/consumer/default.php/cPath/30_742_110
Solar & Super-Insulated Healthy Homes
Edited 1/1/2009 4:02 pm ET by Riversong
"If it's an unheated garage, it wouldn't add a significant moisture load."How do you figure that. Since it is heated you might not have that much moisture drive through the walls (not sure about that).But the dryers put out a ton of moisture. You will have rain dripping off the ceiling and water running down the walls..
William the Geezer, the sequel to Billy the Kid - Shoe
FWIW, I've seem a number of dryers vented into garages. Usually with no visible problems. Sometimes (a minority) with obvious condensation problems.
"Ask not what the world needs. Ask what makes you come alive... then go do it. Because what the world needs is people who have come alive."
Howard Thurman
But the dryers put out a ton of moisture. You will have rain dripping off the ceiling and water running down the walls.
You might be right. A load of wash contains about 8 lbs or one gallon of water, which is about double what the air volume of a two-car garage can hold at 40° and 100% RH.
But what's the alternative? Venting through the roof is a no-no. If it means venting indoors otherwise, then I would vent it into the garage. It sounds like there's no way to vent it to an exterior wall.
Riversong HouseWright
Design * * Build * * Renovate * * ConsultSolar & Super-Insulated Healthy Homes
From what I have heard here over the years that while not perfect many people do sucessfuly vent through the roof.My guess it that one of the difference is how close they are to the vent limit. But there are boaster fans specifically for use with dryer vents. With one of those it could be extended almost anyplace..
William the Geezer, the sequel to Billy the Kid - Shoe
...while not perfect many people do sucessfuly vent through the roof.
The risk of fire with a plugged vent is too great, in my mind, to risk venting anywhere there's not easy access for cleaning.
Riversong HouseWright
Design * * Build * * Renovate * * ConsultSolar & Super-Insulated Healthy Homes
Should the failure to account for such venting during construction be considered a weakness of the builder or designer? Or neither?
Should the failure to account for such venting during construction be considered a weakness of the builder or designer? Or neither?
If this is new construction, the both are responsible. If it's renovation or an add-on garage, then it's a matter of doing the best possible with what's there.
Riversong HouseWright
Design * * Build * * Renovate * * ConsultSolar & Super-Insulated Healthy Homes
Contractor is right- at least on principle.
Concentrated humidity in an unheated space can, in some cases, result in condensation, rot and mold issues.
Also, if she uses laundry softeners, other adverse, corrosive chemical effects may occur.
"Ask not what the world needs. Ask what makes you come alive... then go do it. Because what the world needs is people who have come alive."
Howard Thurman
As many have said vent it outside. Could be tricky but keep the bends as few as you can. Maybe build in a "Y" as it leaves the dryer for cleaning. Try keep the outdoor "exit" on the low side for cleaning. My anti-bird cap catches lots of link. I ended up running a new line so I could clean it often.
Ray,
My house is built the same way. When we first moved in the dryer was vented into the garage. I didnt see a big moisture problem, but there was a fine layer of lint that was not captured by the dryer filter. So .....
I ran a duct up to the ceiling, then out to the side of the garage and out through the wall. Its probably about a 6 ft rise up to the ceiling, then 12ft or so out to the outside wall. It has been like that for thirty years. I do have a long dryer vent brush that I run through it every year or two if I remember. I have never had a problem.
Also, I know it is not recommended, but mine is 4" pvc pipe.
Bill Koustenis
Advanced Automotive Machine
Waldorf Md
I cleaned up after a case where the dryer was vented into a garage. No problem all summer then on a good cold day in winter she put a good big load of laundry in the dryer and went to work. When she came back, it looked like it had snowed. She steamed off the paint and texture of the walls and ceiling. Admittedly, this development has rather weak texture with no primer on the drywall but the amount of moisture put out by a dryer has the potential to do real damage.
Thanks for all the suggestions, I spoke to her yesterday, apparently the location of the entry door is the problem for running the pipe along the wall. I suggested running it up 6 feet, then along the wall to exit above the door. The dryer booster fan sounds like a good option for this application.
either vent outside or get a condensing dryer. condensing dryers are more expensive but they solve problems like yours.
Cant you pop through the wall into the garage then run along the wall to an outside wall?
If you do this, you should use insulated duct in the cold garage so you dont get condensation in the vent.
Family.....They're always there when they need you.