Dryer vent question
 

We will be coming up to TV to purchase a new home this coming week. The question I have is for those that have noticed the dryer vent pipe looks to be installed with the crimped end on the vent pipe sections facing down instead of upwards toward the roof. I have always had homes with the vent piping installed the crimped ends facing towards the roof vent.....that way allows air to flow freely through the pipe without any obstructions. If the crimped end is facing down....or against the air flow.....the lint would naturally collect on the crimped ends of the pipe sections. I don't know if anyone else has addressed this?......but would love any feedback. I tried to attach a photo.....hopefully it shows up.

Without a completed installation, I am not sure what your issue is. Obviously, you want the air to flow freely through the vent pipe to the roof with no obstructions. In my experience, the flexible duct is installed from the dryer and it connects to the metal duct in the wall. Usually, the flexible duct is attached around the outside of the metal duct and secured with a metal connection collar. The end of the metal duct is usually crimped at the connection end.

The end in the wall box should not be crimped according to code. It should be the smooth end....the crimped end should be on the other end. I will wait to see what others have experienced.

Crimped end is facing the wrong direction.

To prevent lint build up inside the duct run, the crimped end of the pipe should always point away from the airflow source.

Flex hose is designed to fit (very snugly) around the smooth end. Lint would collect in the ridges, creating a fire hazard, in the installation shown here.

Dryer Duct Installation Troubleshooter | Dryerbox

From a quick search for the applicable building code and installation diagrams, retiredguy's reply appears to be correct.

Sometime later today I might pull out my dryer to see what I have. If I remember correctly, my duct looks just like your picture.

No.....his reply is not correct.

Relative to the 90 degree screened roof connection, probably insignificant.

It's wise to have the dryer ducts cleaned from the roof by someone with the right tools every year or two.

The code says that the inside of the duct must be "smooth", but it is somewhat unclear as to whether the end can be crimped. It appears that some installations use a smooth end and others use a crimped end. If you want to make the inside of the vent pipe to be more smooth you can use a plastic transition piece between the flexible dryer duct and the crimped metal pipe. This transition piece will fit inside of the metal duct. But, I tend to agree with Poster No. 7 that it is probably insignificant.

All pictures I can find shows vent crimped end facing up. All vent pipes I find only crimped on one end. IMO don’t look right?


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Why not ask your home inspector at the time of the inspection? I am not sure if an ~inch section of crimp on the end is going to make an issue with accumulation? If you have a smaller home that vents out to the wall then cleaning it should not be as hard as the one that goes through the attic space to the roof.

Just another option....

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These units only require 110V outlet and have no external vent. You program the unit to wash -- and -- dry the clothes. It takes just a bit longer to dry because it uses a heat pump instead of the older electric heaters. But you can program it at night to be finished with warm clothes for your wake up at 7AM. Connects to wifi and phone if you want the advanced features.

That also left room for us to put our second refrigerator inside the laundry room (where the dryer went) instead of out in our hot and humid garage... That left more room in the garage and much more convenient to go to the second frig when cooking.

We looked at the GE all in one unit, but the reviews after 1-2 years were not good. Still something I am considering.

I am not concerned about the one inch....it is about the other connection points going up to the roof. We have built many homes and always did a pre-drywall inspection to verify things were done correctly and to code. These homes are released when they are completed.....so if found to be incorrectly installed.....it will need to be reinstalled.

Common sense (which could be wrong or against code) makes me deduce that the crimped end should be at the far end of a piece of pipe as it goes from dryer to vent. This way, the crimped edge is "going with" the flow of air/lint. Even if caught on the crimped edge temporarily, should eventually free up and blow out the vent.

If the crimped end were toward the dryer (anywhere along the run from dryer to vent), the crimped edge facing the flow of air current would allow lint to get stuck and gather on the crimped edges. Kinda like cholesterol in an artery, it would grow ever larger until blockage occurred.

I am sure your home inspector can review it or even run a scope up it? I think my crimped end is sticking out similar to this. You can always ask for a cleaning as part of the closing inspection?

Per FL code:

M1502.4.2 Duct installation.
Exhaust ducts shall be supported at intervals not to exceed 12 feet (3658 mm) and shall be secured in place.

The insert end of the duct shall extend into the adjoining duct or fitting in the direction of airflow.

Exhaust duct joints shall be sealed in accordance with Section M1601.4.1. Ducts shall not be joined with screws or similar fasteners. Where dryer exhaust ducts are enclosed in wall or ceiling cavities, such cavities shall allow the installation of the duct without deformation.

[url]https://codes.iccsafe.org/content/FLRC2020P1/chapter-15-exhaust-systems[/url


Let us know how it turns out.

I am not sure I understand the bolded part of your quote. Most dryers I have seen come with a flexible duct that wraps around the metal duct and is attached using a metal collar that is tightened with a screwdriver. In that case, the insert end of the metal duct would be pointed against the direction of airflow. Is this a code violation?

Good question?

Apparently that does not apply to transition ducts. The dryerbox manufacturer has directions installing in that manner and the ducts should be joined with clamps or foil tape.

I used this:

DryerFlex(R) Transition Duct

Magvents have been a great solution for some previous very tight/offset installs.

Magvent Dryer Vent - Magnetic Dryer Vent | Dryer Vent Hose Replacement

All the new construction is like that in TV. The pipe exposed has a double crimped end, so in the wall the crimps go in the direction of the airflow. They just have a crimped end exposed for ease of connection.

Thanks Sean.......I was assuming that was the reason since it can be difficult for some to attach the Vent coming from the dryer. I just thought someone currently living there would have the answer. Thanks again.

This is a common installation in the newer sections of The Villages. I am a Licensed, certified, bonded and insured home inspector and I have inspected north of 500 homes in The Villages.

Here is an example from a home on Katie Keith Loop, i.e. "Street of Dreams". I inspected this one in March. This is near Middleton, south of 470.

The older homes have just a smooth opening and people couldn't figure out how to install the pipe so ended up getting a male to male coupler anyway instead of an extender. With periodic maintenance, it won't be an issue.

Finally . A quality response!
 

Yea! Good reply....I was going to say that installing sheet metal duct with crimps reversed downwards was "to keep the rainwater flowing down the pipe into the dryer"....haha

It seems some responders do not understand the problem. Yes your photo shows the crimped end going wrong direction. In your setup each connection going all the way up and out through the roof would become a trapping point for the lint which is flowing up and out. For those that don’t get it, picture a rake; the teeth of the rake grab the grass when pulling towards you. If you turn the rake over and use the back of it the rake will just slide across the grass and catch nothing. That is the same as having crimped connection going the wrong way, the lint will get caught.

Except it's not like that. That piece that is crimped that way is only there. The rest, up through the termination vent, are male into female and taped. They added a male-to-male at the termination point because most people couldn't seem to figure it out.

Vent pipe
 

Vent pipe should always fit over the dryer discharge pipe.

You are correct
 

You are 100% correct. Unfortunately the walls are already closed in so we have no idea what's behind them. The way I understand it is if you buy a "Spec-Home" you don't have much say over what goes on and can't be on site watching the build as you can in the outside world. I certainly hope if it's a custom built home the owner can be on site to see how things are progressing.
Your photo shows what should be an onsite crimp done during installation for the flex vent to attach too and the connections are opposite within the wall and going with the air flow as you described. That crimp appears to be a factory crimp and could be a male to male adapter as mentioned earlier. In the end, who knows? Maintain it by cleaning it every few years with a rotary brush and a shop vac and you should be fine
Good luck with your move.

The county building inspector knows, as this is part of the inspection before the walls are closed in.

That is not the way most dryers are installed. The dryer comes with a flexible duct and a metal band clamp to secure it to the outside of the permanent metal exhaust duct. If you try to put the flexible duct inside of the exhaust duct it is too large to fit, and even if you get it inside, how do you secure it?

Just took mine apart
 

We're getting rid of the original washer/dryer tomorrow so I disconnected everything yesterday. I have what appears to be the exact same vent box setup (i.e. crimped end against airflow) as shown in your photo, and the one from the home inspector. We bought new in 2021. When I disconnected the flexible ducting from the vent box there was some, but not a substantial amount of lint build up.

Ventless all in one washer dryer
 

You may want to look into an all in one washer dryer that is ventless. I would recommend the GE one.

We did this, blocked off the vent. And added a pantry

I clean dryer vents south of rt44 and I have seen it both ways. This female end out is actually better. A 4 inch flexible hose is commonly cut with three slits by installers to fit over the male end. Some hoses are to cheap they rip once past the slits. Or the clamp rips them. But even more common is the installer bending a small v in the house male end to make the circumference smaller and fit inside the 4 inch flexible hose. Great place to rip another hole in the flexible pipe. So, yes I prefer the female end out as the hole goes on square and clamp sits flush on flex pipe.

There is different qualities of flex, some are short and rigid. Some long and like tin foil on a spring. Clamps the villages used need to be tightened to where tabs almost touch, less than 1/16th in between tabs. Better worm clamps have about an inch or more left when snug.

As for lint gathering. Most homes are 8-12 foot of straight pipe. Some 10 models actually have a bend in the pipe in attic area and go 12-14 feet. I find most lint in the lines at the top where the flap box is. The lint in first two feet, it’s pretty even the entire length up, meaning the pipe doesn’t have gathering points. I clean with a brush from bottom to top before going on roof. Villages was recommending every 6 months. I say yearly.

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