Apartment ventilation during a renovation: what you can touch
You can touch the ventilation during a renovation, but not all of it. The ventilation ducts and shafts of an apartment building are shared: you don't close them off, narrow them or rebuild them on your own decision - what can be changed is decided by building management and, if needed, a design. Inside the apartment, there is work of your own: check the airflow, run the kitchen hood outlet, install bathroom fans, fresh-air ventilators and inlet valves. In the Doma app's route, that's the “Ventilation” stage - before plastering, together with the electrical work and the air conditioning lines.
What's shared and what's yours in an apartment
In an apartment building, ventilation is usually arranged like this: the kitchen and bathrooms have grilles, and behind them are ducts that run through the whole building. Air leaves through them and comes in through windows and gaps. The neighbours' air goes through the same duct, so:
- the duct isn't sealed off completely with a box, a cabinet or tiles;
- the duct's cross-section isn't reduced - a narrow duct takes air away worse for everyone;
- the grille isn't removed altogether or replaced with a blank cover.
Ask building management which parts of the system belong to the building's common property and what needs approval before work. Under the Housing Code, changes to building systems that require the premises' technical passport to be amended count as a rearrangement of building systems (article 25, part 1 - in the app's norms) and require approval; more in Apartment alterations: what you can do without approval.
The requirements for building ventilation are collected in SP 60.13330.2020 “Heating, ventilation and air conditioning”. It's in the app's list of documents, but we don't quote it here: a design engineer will tell you which requirements apply to your apartment.
Where to start: check the airflow
The “Planning” stage of the route has two ventilation items:
- Check airflow in the existing shafts - before designing anything new. The route's hint: hold a sheet of paper to the grille - it should stick to it. If it doesn't, deal with the duct first: that's a question for building management.
- Decide on the ventilation scheme: whether you need a supply air unit, fresh-air ventilators, bathroom extraction. The hint: sealed PVC windows block natural air intake - with airtight windows, air needs another way into the apartment.
The “Ventilation” stage: before plastering
The stage's items:
- Install the air ducts to the design, allowing for ceiling height. Ducts eat up height - check this before the ceilings go in.
- Prepare the kitchen hood outlet at its location, allowing for the kitchen's dimensions. The outlet is matched to the kitchen design before the kitchen is ordered.
- Drill holes for fresh-air ventilators and inlets in the outer wall - before plastering: drilling makes dust and slurry.
- Install the supply unit, if there is one, above the future ceiling together with the ducts - before the ceiling: afterwards it's reached only through a hatch.
- Accept the stage: the ducts, holes and hood outlet are ready before plastering.
The route's hint for accepting the electrical work is a reminder too: plaster only after the wiring and all lines in the walls - air conditioning and ventilation - have been accepted.
If the grille gets in the way of the design
Master Kistya has a tip on this: a ventilation duct can be moved up to the ceiling with a flat duct, and the fan brought out where you need it. It's important to keep the duct's working cross-section and access for maintenance. If it's the building's shared duct rather than your own ductwork, building management comes first.
During the final installation
Fans, ventilators and grilles go in at the end, after finishing:
- bathroom fans - with power; the fan can be linked to the light switch or a humidity sensor;
- fresh-air ventilators and inlet valves - into the holes made before plastering, with power connected;
- grilles and diffusers - and check the airflow after installation;
- check the ventilation works: airflow and noise. The route's hint: noise is the most common reason people switch ventilation off.
What to photograph
Ducts, the supply unit and the hood outlet will end up above the ceiling or in a box. Photograph them before they're covered, with a tape measure in the shot: the “Ceilings” and “Stretch ceiling” stages have photo items for this. With the photo, people will later find where the duct runs and won't drill into it. How to take such photos is in Hidden work: which photos and certificates to keep.
Common mistakes
- The duct was boxed in without a grille - the airflow disappeared for you and sometimes for the neighbours.
- The hood outlet was made before the kitchen design - it ended up not above the hob.
- The holes for the ventilators were drilled after painting.
- The duct wasn't allowed for in the ceiling height - the ceiling had to come down lower.
- The fan is noisy, and people stop switching it on.
Checklist
- Airflow in the existing ducts is checked.
- Building management has said what can be changed in the ducts.
- The ventilation scheme is decided: supply, extraction, ventilators.
- The hood outlet follows the kitchen design.
- Holes and ducts are made before plastering and photographed.
- If there's gas in the apartment, everything is agreed with the gas service.
- After the final installation, airflow and noise are checked.
The neighbouring stages: Apartment wiring during a renovation: how to accept electrical work before plastering and Air conditioning in a renovation: when to run the lines.