Drier vent condensate drain

Pumpguy

My home has a centrally located main floor laundry room. The 4" galvanized direr vent goes down under the floor then runs horizontal about 20 feet or so along the ceiling of a full unfinished basement, then up maybe a foot to the outdoor flapper outlet located just above the top of the foundation.

I'm having a problem with condensate accumulating in the drier vent pipe. We've been here since 2001, and I'm just noticing this now.

Does anyone know of a fitting I can use to attach to the bottom of the drier vent pipe that I can use to pipe this condensate to the basement's floor drain? I'm sure I could come up with something, but maybe there's a special fitting for this purpose that I'm not aware of. Any suggestions what size this condensate drain line should be?

I realize fitting a condensate drain is just treating the symptom. Changing the elevations of the horizontal run and outlet flapper are not an option. Can anyone offer suggestions to prevent this condensate from accumulating in the vent pipe?

Henry

The dryer vent is too long! Most residential dryer vents have a maximum of 16 feet of lenght excluding elbows (normaly 5 feet of lenght per elbow). Due to your lenght, therte is insufficient velocity to keep the water vapour in suspension as well as lint. You should clean your vent as it might help some. A condensate drain will allow lint to accumilate in it as well as obstructing the vent.

Pumpguy

Thanks @Henry,

I'm in the process of cleaning the vent now. I was not aware there was any standard for drier vent pipe lengths, but it is what it is and I'm stuck with it.

I've noticed clothes take longer to dry than they used to, especially several pairs of blue jeans. At this point not sure if it's a problem with the drier itself or lint build-up in the vent. I do clean the lint screen every day, and have cleaned the drier vent connection every so often.

Just have to check one thing at a time and see what I find.

ChrisJ

Pumpguy said:

Thanks @Henry,

I'm in the process of cleaning the vent now. I was not aware there was any standard for drier vent pipe lengths, but it is what it is and I'm stuck with it.

I've noticed clothes take longer to dry than they used to, especially several pairs of blue jeans. At this point not sure if it's a problem with the drier itself or lint build-up in the vent. I do clean the lint screen every day, and have cleaned the drier vent connection every so often.

Just have to check one thing at a time and see what I find.

Henry is in Canada, so that may be another difference.
Can you insulate the pipe? That would also help with condensation.

Fact is, the shorter the pipe and the less turns the better the drier will perform.

Also, not all outdoor dampers are created equal.
https://youtu.be/cFOHGVhmyQA



The 3 blade design is what I'm using shown at 3:30 in the video.

ratio

There are also a number of dryer vent booster fans that may be installed. The ones that I'm familiar with were automatic, they had a pressure switch to bring them on when the dryer started.

N.B. I'm to understand that in my jurisdiction they do not meet the residential code.

HVACNUT

Like @ChrisJ said, try insulating the pipe. Your HVAC supplier might have insulation sleeves that slide over rather than wrap around the pipe. I know they make it for larger diameter pipe, not sure about 4".
For such a long horizontal run, I would clean it twice a year. Pick up a soft bristle 4" soot brush.

Jamie Hall

Also, you mention that it seems that your clothes are taking longer than they used to to dry. You have checked and made sure that the lint screen is clean, yes -- but how about the blower? If lint which gets by the screen has built up on the blower -- some always does, and I've seen it happen -- it can reduce the ability of the blower to blow, which can significantly reduce the air flow. Not that easy to get at -- dryer manufacturers seem to have come up with a variety of ways of making it difficult -- but worth looking at. Your condensation problem, in connection with a long vent line, could be a symptom of something else which needs fixing here.

Pumpguy

Thanks @Henry, your conclusion and recommendations were spot-on accurate!

Cleaned or replaced 4" drier vent pipes as well as drier air blower and internal drier vent ducting.

The transformation in drier performance was miraculous. Clothes now dry in half the time. Lesson learned, that's for sure.

Also thanks to all that replied as well as the opportunity to post this here on HeatingHelp.

I'm looking into a drier vent booster fan, but mounting, wiring, and controls may be a problem.

unclejohn

You need to move your dryer to the basement. You will always trap lint in that riser up to the outside.

ratio

The model I installed was something like this. It just plugged in with a cord, no wiring or controls other than a receptacle, but it does need to be accessible somehow.

kcopp

This question comes up from time to time.... what code is the length of a dryer vent listed? Where is it? Or is it strictly a mfg item?

heathead

Try this kit when dry times inclease. Run in in from outside with dryer on air fluff, no heat. Deflecto Dryer Duct Cleaning Kit, Extends Up To 12'. Just make sure not to reverse drill when using.

HVACNUT

> @kcopp said:
> This question comes up from time to time.... what code is the length of a dryer vent listed? Where is it? Or is it strictly a mfg item?
>
>
> I was wondering the same thing. When my bro in-law lived in a condo, I installed some ceiling fans for him. When I was in the attic, there was lint everywhere. Two stories of vertical vent just dumping in the attic. Did code call for a maximum vertical run? Fire walls every two units, so I couldn't see if they were all like that, but when I looked around outside there weren't any roof penetrations. Weird.

Henry

Each drier can have a different vent lenght. It is writen in the installation manual. Gas fired dryers vent lenghts must be respected as per the certified installation manual. Remember that only smooth pipe is permitted. Not following the manual can lead to dangerous situations such as combustion gases entering the home or even a fire. I have seen a steam dryer in a hospital that caught fire. They had put some turning vanes in the duct work that were blocked with lint.

Gsmith

Check the building code in effect at your location. The requirements for dry ducts in the International Code Council's 2015 Residential Building Code are at section M1502, but these apply only to jurisdictions that have adopted that code, check your specific area building code to be sure.