Our architect amd contractor said four bends meet code and the manufactorer’s guidance. I thought that would be sufficient. Is that helpful to know or do you still have concerns @User?

Just met with contractor and configured access from both ends so that cleaning from each end will only involve 2 bends to go around.

Here is my quick sketch of the plan. The vent will be smooth and rigid, with no screws. The rigid part will have two 90 degree bends. The other two bends will be very short and flexible to connect dryer opening to rigid vent and then same at the end to go out the window.

" four bends meet code and the manufactorer’s guidance "

That surprises me that 4 90 degree bends would pass code. Are you sure? And in my mind I see no way to clean if out when needed.

The sensible thing to do is get a condensing dryer. No ducts, no bends, no chase, no ugly out the window venting, no cleaning, no worries.

In an apartment ,I would also consider the condensing dryer. But then I might want a ventilation fan like in a bathroom. I had a condensing dryer and some days it felt like it was going to rain in my Laundry area.

Many apartment units here condense into bucket devices.

I would want at least one access for cleanout on the horizontal part and one on the vertical.

For the typical dryer the maximum vent length is 35 feet with a deduction of 5 feet for each 90 degree bend. so your total duct length is 35-20 = 15 feet, so you need to make sure you don't have more than 15 feet total. They also make Dryer Vent Booster Fans, and they make Long-Vent model dryers for apartment building applications.

We do not have more than 15 feet in length. 7.5' horizontal + 2.5' vertical = 10 feet total. In the pic below the green line is the dryer vent.

I was concerned about condenser dryers and humidity. Oddly, our NYC prewar coop does not allow ventilation fans in windows or elsewhere, but allow a dryer vent. Go figure??? I needed special permission for at W/D. Less than 5% of the units have them.

We will be able to disconnect the vent at the window and behind the unit to go in those ends for cleaning. Does this make sense or seem like a sensible vent cleaining plan? Does to me but maybe I'm missing something.

I'll have it professionally cleaned once a year but would like to do it myself more regularly out of caution. What devices do you recommend for cleaning it? Shop vac with long hose? Those drill attachments with the flexible brushes?

Can you use those smooth long turn elbows for any or all of the bends?

@ci_lantro I've never seen those smooth long turn elbows before. They are nice. I suspect we would really need to drop the chase down quite a bit to make them work and it could get really very wonky.

@ Kendrah -- ETA -- your two latest posts didn't show up in my browser until after I posted this.

Your city may be different, but the code provisions in the towns I'm familiar with will not bar the venting set up you have planned. You've got about 10 feet of ducting from the back of the dryer up over and down to the window, so the four 90° bends are not excessive restriction per the specs of the washtower maker. (Is that an LG Washtower you've bought?) Having the vents cleaned regularly will avoid the kinds of lint build ups that eventually pose the fire risks. (Question, though: is that a gas or electric dryer in your washtower?)

A couple of suggestions about the flexible couplings at either end of the ducting. First, if you haven't already done so, be sure your contractor uses the "semi-rigid aluminum" kind rather than the soft, foil-wrapped accordion-pleated kind. The latter are much more serious major lint collectors and rather fragile. While the semi rigid will tend to accumulate lint faster than rigid ducting, it will do so more slowly than than the soft ducting, will be easier to clean, and will be less likely to suffer damage when being dismounted and remounted for cleaning. Also, if you all don't already know how to mount and dismount the end pieces by yourselves, have somebody show you. That way you can check and clean them yourselves.

As for the cleaning attachments (shop vac with long hose, flexible duct brush): yes, if you have the space to stash them. My dryer vent is about 8 ft. long with two 90° bends. We run about 4 loads a week. A decade or so ago, I would dismount the ends and clean it every year. The brush and shop vac made it easy. I found it hardly ever needs cleaning. YMWV.

Now, if you didn't already have that LG Washtower on hand and didn't already have a contractor already starting work, I might have suggested stacking an LG compact washer with their new ventless compact heat pump dryer model in place of the Washtower. True, the compact stack won't have the centrally located control panel, but it could be a better fit for your little kitchen, would not need you to build the chase, and would not need to rig a vent panel in the window. Heat pump dryers and condenser dryers are both ventless, but heat pump models don't have the rainforest effect that palimpset mentioned for the condenser models. But, maybe you need the full-size capacity of the Washtower to run larger loads so a compact set-up wouldn't work for you?

Sorry maybe I am stupid but why not moe the dryer to the wall where the window is >

The washtower is electric and we have already purchased it. Thanks for the info about semi-rigid flexible couplings. Does this product work for connecting the machine to the rigid duct and then the other end of the rigid duct to the hole that goes out the window?

https://www.homedepot.com/p/Everbilt-4-in-x-2-ft-Semi-Rigid-Duct-with-Collars-EVER006/313119920?source=shoppingads&locale=en-US&pla&mtc=SHOPPING-BF-CDP-GGL-D26P-026_002_AIR_CIRC_ACC-NA-NA-NA-SMART-NA-NA-NA-NA-NBR-NA-NA-NEW-PMax&cm_mmc=SHOPPING-BF-CDP-GGL-D26P-026_002_AIR_CIRC_ACC-NA-NA-NA-SMART-NA-NA-NA-NA-NBR-NA-NA-NEW-PMax-71700000097492027--&gclid=Cj0KCQiA6fafBhC1ARIsAIJjL8nVzYdusHBAQ28-_q8HXkHYIU9w6K73IplRfbWa6Bh7yzm8cb8_vr4aAhSREALw_wcB&gclsrc=aw.ds

It's an apartment building in NYC prewar, so the plumbing locations are fixed, and really any horizontal plumbing is probably most accessible from the apartment below.

I have never lived in a multi unit building that allowed plumbing to be moved unless it was fully accessible inside your own unit: the basement apartments and some limited changes in multi level units where you could access from below in your own unit.

I just looked at a unit today that had an unusual layout for the building, and when I looked closely at the pictures it was because they raised the floors up in the kitchen and bath to run plumbing changes atop the slab, so as to not disturb the unit below. But I am surprised they were allowed to do even thaty.

They make dryer vent cleaning brushes that are flexible and might be able to go through those bends. Look on amazon. They make different lengths. We have one 90 degree bend in ours and had no problems using a flexible dryer vent brush with the 90 degree bend.

>>>"Does this product work for connecting the machine to the rigid duct and then the other end of the rigid duct to the hole that goes out the window ....." <<<

Yes, that is the kind of stuff you want your contractor to use for those connections.

@vinmarks Thanks for your review of the flexible brushes around a 90 degree elbow.

@Patricia Colwell Consulting - Yep, as @palimpsest noted, the wall where the washtower is located is the wet wall and we cannot bring plumbing over to the widow wall. We looked at having a non-stacked unit with the dryer next to the window and the washer on the wet wall but it really made the space feel insanely narrow plus it made sense to make use of vertical space in a room this small.

No that product from HD is not a good flexible duct - that one is "foil" and if it must be used, is better used as a transition duct (the part connecting the dryer to a permanent duct), not within a built chase.

For the permanent ducts, use 28ga sheetmetal and elbows, just as you were installing HVAC.

Per code, the transition duct can be a max 8' long. And each 90d bend adds 5' of effective length. Typically dryers allow 35ft total duct length (see your installation instructions). I'm sure NYC follows the same restrictions (check) but you're not allowed to be closer than 3' to an opening, so there's that.

Realize you can also get to the dryer vent to clean it from the window too. As long as there are no screws and you clean your dryer lint catcher every load, you shouldn't have too much a problem, unless you only wear wool argyle sweaters.

Plan now that your clothes will take forever to dry.

Also plan DO. NOT. USE fabric softener. You want soft, faster dry? Use a second rinse on the wash cycle. Your sheets and towels will be more absorbent, fluffier and you will gum up the works far less. Buy wool dryer balls, they work well too. Be vigilant with the dryer screen. Plan to have the duct sucked out every three months minimum. Call a pro.

The fewer turns, the closer to an outside wall the better the cheapest dryer on this earth. Blankets, quilts? Out you go to the laundromat and the triple loader washers and dryers.

@3onthetree: are you saying you've found that HD has actually mislabeled some foil ducting to sell it as the semi-rigid transition? That's certainly news to me. Here's a link for the kind of foil ducting which I think you (and I) are warning against. It is a different product. Last time I bought some semi-rigid from Home Depot, it actually was the semi-rigid as represented. Fortunately, Kendrah has a contractor who will know to buy actual semi-rigid and, if sourcing it from HD, should be able to spot mislabeling.

Also, Kendrah was clear that the semi-rigid will only be used for very short transitions and only at the very ends of the rigid ducting and only outside of the chase. To further clarify, nobody was suggesting or planning to use the semi-rigid stuff in the chase much less use any of the foil stuff there.

@JAN MOYER - Why will it take forever for the clothes to dry? Because of the bends? Helpful to know what to expect.

Luckliy, I have never used fabric softener in my life, I'm religious about cleaning the filter with each load, which says a lot as an atheist, and I have an awesome British drying rack that can dry a king size duvet. It dries rather quickly with the vigorous radiator heat they pump out in this building.

That's not only a lot of bends, it's a long distance.

Surely you have other options?

There is a very large building here maybe 20 stories, a block long, almost 500 apartments, and they have in unit washers and dryers.

Both are undercounter units, one is on one side of the kitchen and one is on the other. I have no idea how they are vented, but if it is horizontally out through the ceiling of the unit the total run is more than 25 feet. because they are on the interior of the building.

The vertical space could be use for something else over the units, it could be countertop, it could be storage.

I think in those apartments a lot of them have a wall oven over the dryer and a DW next to the washer, obviously with counterspace over those. (Not recommending a wall oven in a small kitchen just saying what they have.

I would not recommend getting single unit, anyway, I would get two stackable. If something goes wrong with one in a combo then you have to replace both.

A condenser dryer also takes forever to dry clothes, I had one.

Our buidling was built in 1938 and the pluming cannot handle the volume of water discharged from a heavily used kitchen sink, dishwasher, and washing machine. Therefore, no unit is allowed to have a kitchen and washing machine, period.

Laundry is only allowed if you own two apartments and remove the kitchen from one and turn it into laundry. We are in the lucky few who can afford this and purchased a studio apartment down the hall from us for a song.

I really considered ventless dryers but we generate a tremendous amount of laundry and I was so discouraged by how long a drying cycle takes. Plus, I was concerned about the humidity issue with no exhaust fans allowed.

@palimpsest Maybe all of the dryers in the building near you are 24" deep and ventless? A typical vented dryer is 30 minimum plus 4-6 " in the back for venting. That makers for a super deep counterspace and hard to reach cabinets or shelves above. This is one reason we did put a separate dryer next to the window.

@jwvideo if you click on the link Kendrah provided you can read their own product description right towards the top: "aluminum foil ensures durability". So if you actually go to the store, you will see the "flimsy wire" foil ones that you followed up with a link; however, this one Kendrah is asking about is also "foil," just a little less "flimsy," that you can easily crush/dent by squeezing with your hand. Although acceptable for a transition duct, make sure you don't have some tight bends where it can pinch. There are other flexible ducts made from actual sheetmetal, you can't just look in the dryer section at the big box store, you have to move into the HVAC section.

Also, in the same comment that Kendrah posted the link, she said ". . . and then the other end of the rigid duct to the hole that goes out the window?" So the intent is to use it for the last two 90d turns within a built chase. So, I think my interpretation of the thread and advice is correct, I don't need to call Home Depot, and the best method of the permanent ductwork should be 28ga HVAC sheetmetal when in chases.

And if @palimpsest is reading, for some reason your comment on effective length wasn't showing for me, so I thought I was introducing new pertinent info, but you already had it covered.

Actually the building I am talking about was built in 1960 and touted as luxury, meaning it had a washer and dryer and DW. (And VCT tile in all areas and very utilitarian baths, so it's interesting what luxury meant here in 1960). Much of the apartment stock at that time --and to the 90s really-- was 19th c. house conversion, early 20th c. apartments that may not have even had laundry in the building, and a few modern midrises that had some amenities. My first apartment, in the early 90s, had no air conditioning, no laundry in the building, no dishwashers, and it was considered a nice building. A positive point for the realty was that all their buildings were on the Same Block as a laundromat.

They aren't condensing dryers but they are very small counterdepth units where I think you can only dry a few things at a time.

@3onthetree --- by golly, you are right about product confusion at Home Depot. Turns out that HD is offering two similar sounding versions of the Everbilt 4 in x 2 ft. vent duct with collars. This one is what I had used previously. It is called "Semi-rigid Aluminum Dryer Vent Duct with Collars" and sells for $15.97. The "aluminum foil one" is this one, which was the one in Kendrah's link, and is slightly less expensive at $15.38. It is called "semi-rigid duct with collars." Slightly different name but similar enough to catch the unwary.

@Kendrah -- note the above if shopping for the dryer vent duct parts at Home Depot.

Thanks @jwvideo. My contractor gets his materials from a local distributor. But, this has been useful for me to better understand the terminology about what to ask for.

Don't use flexible pipe! Hard pipe it, using two 45's instead of a 90 wherever possible for a gentler radius, or those nice large radius elbows shown above. Flex pipe both impedes airflow and collects lint; a bad idea in your situation. You can also poke through it with a cleaning brush. Strongly consider upsizing the pipe-- if it's 4" use a 5" pipe instead. Lots of tight bends are really bad for flow.

Kendrah -

2 suggestions Install a dryer booster fan if the setup allows.

Regardless, the dryer duct cleading rods WILL be able to sweep those bends. I've done similar bends and you have some distance between the 90's....

Be prepared for oopsies. One time I was cleaning a semi weird run with 3 90s in a very short distance. There was some resistence but the drill was spinning....Ended up losing the head. And had to remove the duct, mastic on the seams, etc to find the head. ##iT happens I suppose