bathroom Vent

This is entirely the management's problem -- all the potential causes of this problem are under their control. If the exhaust fan is performing as designed there will never be airflow from the duct into your bathroom under a wide range of normal conditions. If there is duct leakage, problems with the exterior wall, fresh air intake duct problems, etc. those are all building management items. And "it just happens sometimes" isn't right.

If you are desperate you can install something called a backdraft damper but that won't always stop all odors. Installing your own fan will move the problem to another apartment without really solving it.

Note that opening a window will generally not increase indoor pressure. Instead the indoors, which is usually designed to be slightly positive in relation to the outside, will tend to equalize with the outside. (Discounting short-term conditions like wind gusts.)

Where are you located vertically within the building? What vintage construction?

Thanks for your help. We are located on the 14th floor (out of 34). The building was constructed in 1968-69 (if that is what you mean with vintage). Let me add that without opening a window we always have air inflow from the vent (24/7); with an open window which creates a draft into the apartment, the vent sometimes works correctly. I would like to ask you two questions if I may. 1) Are you an expert on this matter so that I can use your explanation for future discussion with management?; 2) If they refuse to do anything, are there building codes or guidelines which must be adhered to and if not, report the problem to some city department dealing with these issues? We really appreciate your help, thanks. Nick.

The fact that it happens 'sometimes' and provides you with smoke & other smells also hints that some other that shares your vent pipe may have inappropriately installed their own bathroom or kitchen vent fan, which is messing with the pipe's overall airflow.

I'm on the 15th floor of a 34 story building of about the same vintage (1964-ish), and haven't had any problems yet, with or without windows open. When I open a window, there is often enough pressure difference to hold a piece of paper in place over the kitchen vent, but not always. If I have a window open and open the door to the hall, I get a significant draft for a little while (all going into the hall air vent and the elevator shafts), then it eases up quite a bit.

I agree w/ uptown_joe that this is building management's problem. Are you a rental or an owner?

has this always been the case or did this happen recently?

if recently, then there are 2 instances when this could happen:

1 - one of the fans is not working or was repaired incorrectly.
2 - someone above you made alterations to their bathroom and blocked that exhaust pipe.

I have had this issue a few times - 1950's building, and I am on the 20th floor. In every case, the exhaust fan on the roof that is responsible for continuously drawing air up and out of the vent stack had malfunctioned. Joe is right - contact the super and discuss with him. FYI, if I recall correctly, the NYC building code requires any bathroom or kitchen without a window to have a vent that continuously draws 15cfm of air out of the room.

Would be best if the bathroom had a window, but some people like c0lumbiac0unty don't go for that.

Thanks every one for your help. This is a co-op bldg and we own the unit. Obviously we do not want to create too much trouble although for the last 18 months (when we moved in) we have experienced this problem and is not getting better. If management refuses again to do something then we have to do it ourselves.

Windowless bathrooms have to have a mechanical exhaust of at least 50 cubic feet per minute. In larger/newer bathrooms, you'll see 75.

It's the co-op's responsibility to keep those exhausts running properly. Don't worry about causing trouble. Just call 311, and the city will give the board and management the kick in the butt they seem to need.

Just getting back to this -- glad to see we are all on the same page (CFM quantity variations aside). As others mentioned the building code in effect at the time of the building's construction would specify the required flow rate. As a coop owner you are in a perfect position here -- you have an ownership interest (though a small fraction), and you are also a lease tenant so you get all those types of legal protections too.

And to the earlier inquiry, though the information is solid I'm not a source you'd usefully cite as authoritative (not an engineer, contractor, etc.).

The reason I asked about floor number was suspecting that if you were near the top of the building the stack effect (hot air naturally rising in the shaft) could be combining with another flaw to produce the inflow. At 14 of 34 that specific idea doesn't make as much sense.

Last thought -- in terms of doing it yourself you are limited in the practical options. There is no substitute for the building fixing the problem, and some of the things you could do will just make things worse elsewhere -- try to take the high road and avoid those.

Thanks every one for the help. I know much more now and will discuss with management. If that doesn't work then I will go to the City. As to my claim of doing myself, didn't mean to fix the problem physically. Just take all necessary steps (call 311 etc) to get the problem corrected. Thanks again.

When I was on a board, we had similar complaints. We had to replace the fans and clean out all the debris that blocked the vents. People were stuffing things into the vent to block out foul odors only causing them to be concentrated in apartments below. It took quite a while to tweak this properly and cost a LOT of money.

I just bought a coop floor 12 of 14 1964 vintage building. The vent in the bathroom was designed to be opened or closed but it is now painted open and as far as I can tell it serves no function either blowing or sucking. The kitchen sink plumbing rises through an air shaft and it has a very strong current blowing out through the gap where the pipe comes out of the shaft wall. I assume this gap should really be closed but it's not. I am from California and all of this is so odd to me and I'm even an architect and I can't get me head around the logic of this common air situation. Can one of you explain what's going on?