Tight buildings still move air
Apartment buildings put up in River North over the last decade or so are typically wood-frame residential floors on top of a concrete podium of parking and retail. Energy codes push them to be airtight, so the building has to bring in fresh air mechanically. Common designs supply conditioned air to the corridors, which then leaks under each apartment door, while bathroom and kitchen fans pull air out of each unit. Some buildings use energy recovery ventilators, called ERVs, that exchange heat between outgoing and incoming air.
Each of these systems creates pressure differences, and smoke follows pressure. If a neighbor's unit is slightly positive compared with the corridor, their smoke leaks into the hall and then under your door. If your bathroom fan runs constantly, your unit is slightly negative, and it pulls air from whatever gaps it can find, including the space around pipes and outlets shared with the neighbor. In stacked units, vertical shafts and chases can carry odor up several floors.
This is why the smell often seems to come from nowhere, comes and goes with the weather or time of day, and sometimes is strongest in a closet or bathroom rather than near the shared wall.
Common paths in newer buildings
- Under the entry door
- Corridor air, often supplied on purpose, carries hallway smoke in
- Bathroom and kitchen exhaust
- Constant fans pull air from neighbors through gaps
- Plumbing and electrical penetrations
- Gaps around pipes under sinks and behind outlets on shared walls
- Vertical chases
- Shafts for ducts or plumbing link stacked units
- ERV or central ventilation
- Rare, but cross-leakage is possible if equipment is misadjusted or shared
Matching the pattern to the likely path
Keep a few days of notes on when and where you smell it before you contact management.
- IfSmell is strongest just inside your entry and in the hallwayThenThe corridor is the likely carrier. Management can check corridor pressurization and door bottoms, and add door sweeps.
- IfSmell is strongest in the bathroom or under the kitchen sinkThenLook at gaps around pipes and the exhaust path. Sealing penetrations is often a small maintenance task.
- IfSmell gets worse when your bath fan or range hood runsThenYour unit is being depressurized. Try running it less or opening a window slightly and see if the pattern changes.
- IfSmell is in the closet or along one shared wallThenOutlet boxes, cable penetrations and the base of the wall are candidates for sealing.
- IfSeveral neighbors on different floors smell it at onceThenA vertical shaft or central system may be involved. That is a building-level issue for the manager or HOA.
What to ask the property manager
- Is corridor air supplied mechanically, and is it balanced to keep units from pulling hallway air in?
- Does my unit have its own ERV or ventilation unit, and when were its filters last changed?
- Can maintenance seal gaps around plumbing and electrical penetrations on the shared walls?
- Is the building smoke-free by lease, including cannabis, and how are complaints handled?
- If treatment is done in a neighboring unit, will anything be done to keep it from reaching mine?
General information for RiNo, not a quote or professional advice. In an emergency, call 911.