I live in an apartment on the top floor. It's the dream apartment for me except for the heavy cooking smell from neighbors entering the unit. I believe the main culprit is the bathroom fan without manual control, it has a motion detector and runs for hours whenever sees any light or movement. The smell was tolerable the summer since we kept our windows open, fresh airflow.

It's now winter, and we keep the windows closed. When the bathroom fan runs, it creates suction, pulling air into the unit from wherever it can.

I detected two sources of air coming in:

  • The breaker box in the entrance (on the shared wall with another unit)
  • Range hood duct (poorly sealed, duct shares a common "box" on the rooftop with other units)

The smell does enter through the range hood duct even when the bathroom fan is off. So far maintenance only interested in hood duct exit, and installed a second flap to prevent air from coming into my unit to that said box, no difference. There were talks about installing a backdraft motor on the rooftop as well, but at this point, I'm pretty sure I'm being ignored and not confident to press on this since "smell" is hard to prove.

Since I'm on a rented property, I want to address these with light, reversible modifications. My ideas are:

  • Breaker box:
    • Use a thin rubber seal around the inner gap of cover. A snug fit should work, the cover is rarely opened.
    • Use clear silicone to fill the gaps around the frame.
  • Range hood:
    • Modify it to use the ductless recirculation mode.
    • Remove the duct connection, place a duct cap, and seal with foil tape.

Does this sound like a good plan to you? Are there any fire/safety codes that I'm missing, or some alternative that would work better?

Attached images of the breaker box and range hood duct. Pictures of breaker box on a wall from different angles Range hood extraction duct connection inside cabinet

  • What type of cooking gas or electric? Sealing the breaker box will probably end up not working at only the Sheetrock to box each cable penetration will also need to be sealed. I have used a fire stop foam to seal the clamps in a box before, kind of messy and hope that you don’t ever need a new circuit but it is code legal where other sealants may not meet code requirements. 1 can of fire seal foam will do the bottom of the box.
    – Ed Beal
    Nov 25, 2020 at 6:15
  • @EdBeal Stove is electric, and it is a low profile microwave range hood on top of it. For the box lid, I'm thinking of cutting out a rubber sheet to seal the contact points. Hoping that with the bottom sealing, all paths of the leak will be eliminated. imgur.com/Pf4d7ZI imgur.com/4ZWRzFz
    – bariscc
    Nov 25, 2020 at 8:09
  • Run your vent hood any time you smell odors coming in. That should create enough pressure to force the smelly air from other's apartments out, instead of letting it swirl and come into your apartment.
    – FreeMan
    Nov 25, 2020 at 14:29
  • @FreeMan that's what I have been doing all summer, open a window, run the vent, cleared in 5 minutes. Doing this now with low 40s outside isn't practical. Vent alone seems to struggle clearing the air without makeup air, smell gets stronger when it's run, and takes hours to get rid of the smell. It makes me think it pulls and pushes the air within the same duct.
    – bariscc
    Nov 25, 2020 at 17:19

2 Answers 2


Every residence, excluding the ISS, submarines and similar special cases, needs a certain amount of makeup air. Newer buildings tend to let in far less air as a way to improve energy efficiency, but there is always some air coming in or else you would end up with too much CO2 and not enough O. See Apollo 13 or a report of a mine disaster for details.

That being said, if the problem is excess draft caused by the bathroom fan, stop the bathroom fan! Since this is a rental, you can't replace the motion sensor without permission. But a piece of duct tape over the sensor will fix that problem really quickly. Alternatively, you could tape some sort of flap over the sensor so that you could turn it on/off as needed in order to ventilate moisture from the bathroom after a shower or bath. Much like many people place a removable cover over their laptop camera and remove it when they actually want to Zoom.

  • 1
    I really like this idea. Initially I thought of installing a pull chain on the fan (it's on the ceiling) but this more practical and simple. That should solve the breaker box draft problem which is only triggered by the fan. On the other hand, even with the fan off smell comes in through range duct, so I can't avoid sealing that part.
    – bariscc
    Nov 25, 2020 at 18:09

With an electric stove I don’t see a safety issue with blocking your vent off. Using a fire block spray foam on the bottom inside of your breaker panel may be the most effective place to seal, on commercial jobs I have had to seal multi floor access points and fire rated spray foam was the best method I found to seal clamps going into gutters and panels.

  • Instead of spraying foam, maybe a custom fitted piece of rigid foam sheet.
    – DaveM
    Nov 25, 2020 at 17:06
  • If the bottom has 10+ circuits a seal will be impossible unless duct seal is pressed into each clamp or fire rated foam the foam although expensive is much easier (never use regular foam fire rated is normally red/pink and an inspector will flag non fire rated in a heartbeat.
    – Ed Beal
    Nov 25, 2020 at 17:19
  • I was referring to the stove vent.
    – DaveM
    Nov 26, 2020 at 5:32

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