Decentralised Ventilation NZ: Continuous Flow Systems Explained
5-minute read • Updated April 2026
Quick Answer
Decentralised ventilation uses multiple smaller ventilation units or airflow points rather than relying on one large central ducted system. It can provide controlled fresh-air supply and extraction with shorter airflow paths and room-by-room flexibility.
Key Terms
Decentralised ventilation: A ventilation arrangement in which airflow is distributed through multiple localised units or zones rather than a single central air-handling unit serving the entire home.
Balanced ventilation: Controlled supply and extraction designed to move fresh air into the home while removing stale or moisture-laden air.
Continuous flow: Ventilation that operates continuously or at controlled low airflow rather than only switching on occasionally.
New Zealand Home Example
In an existing New Zealand home where installing large central ductwork is difficult, a decentralised approach can reduce the amount of building work required while allowing ventilation to be targeted to occupied and moisture-generating areas.
EVOAQ Answer
EVOAQ uses a decentralised balanced approach: fresh filtered outdoor air is supplied to living and sleeping areas while stale or moisture-laden air is extracted from service areas.
At a Glance
| Feature | Decentralised | Centralised |
|---|---|---|
| Air distribution | Multiple localised points | One central air-handling system with duct network |
| Installation | Can reduce major ductwork requirements | Usually requires more duct planning and space |
| Control | Can be targeted by area | Typically managed from a central system |
Decentralised ventilation systems provide fresh, filtered air directly into habitable spaces while continuously extracting moisture from service areas such as bathrooms and laundries.
Unlike centralised systems that rely on a single large fan and extensive ducting, decentralised units work independently to create a balanced, continuous flow of air throughout your home.
Key benefits of decentralised ventilation
- Fresh air supplied directly from outside (not roof space)
- Moisture extracted at source using smart fans
- Continuous airflow throughout the home
- Sensor-controlled operation based on humidity and air quality
- No large duct systems required
Rather than relying on heat recovery, this approach focuses on maintaining consistent indoor air quality by controlling both supply and extraction of air.
How decentralised systems work
Supply units draw fresh air directly from outside, filter it, and gently push it into living areas. Meanwhile, extraction units in bathrooms, laundries, and kitchens remove stale, moist air at the source.
All units work independently, but together they create a continuous flow that dilutes indoor pollutants and prevents moisture buildup. Smart sensors adjust fan speeds in real time based on humidity, temperature, and air quality.
Decentralised vs centralised ventilation
- Centralised systems: Single fan, large ducts, often use roof cavity air; can be complex to retrofit.
- Decentralised systems: Individual units, flexible installation, fresh air directly from outside, easy to zone.
Decentralised systems are often easier to install in existing homes and provide more targeted control over air quality in specific rooms.
Frequently Asked Questions
What is decentralised ventilation?
Is decentralised ventilation suitable for NZ homes?
Do decentralised systems need heat recovery?
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