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Whole-house ventilation vs extractor fans
Ventilation ranges from a single extractor fan in a bathroom to a whole-house system serving every room. As homes get more airtight, individual fans are often no longer enough. This guide compares room-by-room extractor fans with whole-house ventilation and explains when each is appropriate.
By VentRight Editorial · Last updated 2026-07-08 · Impartial · Sourced
What is the difference between whole-house ventilation and extractor fans?
Extractor fans are intermittent and room-by-room, fitted in a kitchen or bathroom and run when needed. Whole-house ventilation systems, such as MEV, dMEV and MVHR, serve every room and run continuously. Extractor fans deal with moisture at a single point on demand; whole-house systems ventilate the entire home all the time.
The two sit at different points on a scale. At one end is a single bathroom fan plus trickle vents in an otherwise naturally ventilated home. At the other is a fully ducted MVHR system supplying and extracting across the whole house. What is appropriate depends mostly on how airtight the home is.
Are extractor fans enough on their own?
In older, leakier homes, intermittent extractor fans in the wet rooms plus background ventilation, such as trickle vents, can meet the requirements. But as homes get more airtight, that combination is no longer enough, because there is not enough natural airflow to bring in fresh air, and a continuous whole-house system becomes necessary.
The move away from relying on extractor fans tracks the tightening of homes. A draughty house has plenty of incidental fresh air, so fans dealing with moisture at source can be sufficient. A sealed modern house does not, so it needs deliberate whole-house ventilation, not just spot extraction.
When do I need whole-house ventilation?
You need whole-house ventilation when the home is airtight enough that natural airflow and extractor fans cannot supply enough fresh air. That means new builds and deep retrofits, which use MEV, dMEV or MVHR. Leakier, older homes can often still rely on intermittent extract plus background ventilation, though better ventilation still helps.
Airtightness is the deciding factor. If you are building or deeply renovating, you are almost certainly in whole-house territory. If you have an older home with a condensation issue, a whole-house approach such as PIV or continuous extract may still be worthwhile even if fans would technically comply.
Is MVHR a whole-house system?
Yes. MVHR, along with MEV and dMEV, is a whole-house continuous ventilation system, serving every room. A bathroom or kitchen extractor fan, by contrast, is a single-room intermittent system. MVHR goes furthest of all, both supplying fresh air and extracting stale air across the whole home while recovering heat.
So the progression from a single extractor fan to full MVHR is a progression in scope and continuity: from one room on demand, to the whole home all the time, to the whole home with heat recovery. Our guide to the four system types and the selector help work out where a given home sits.
Questions
- Do I need whole-house ventilation or just extractor fans?
- It depends on airtightness. Airtight new builds and deep retrofits need a whole-house system. Leakier older homes can often rely on intermittent extractor fans plus background ventilation.
- Are extractor fans enough for a new build?
- No. A new build is too airtight for extractor fans and trickle vents to supply enough fresh air, so it needs a continuous whole-house system such as MEV, dMEV or MVHR.
- Is MVHR better than extractor fans?
- They do different jobs. Extractor fans handle moisture at a single point on demand; MVHR ventilates the whole home continuously and recovers heat. MVHR is the right choice for an airtight home, not a leaky one.
- What is whole-house ventilation?
- A system that ventilates the entire home continuously, rather than a single room on demand. MEV, dMEV and MVHR are whole-house systems; a bathroom extractor fan is not.