bluMartin freeAir 100

the MVHR which requires no plant space,
utilizing an active cascade effect

bluMartin freeAir100 Demand Controlled Cascade MVHR

freeAir 100 MVHR

For smaller dwellings, it is often difficult to find space for an MVHR system. The bluMartin freeAir 100 is a unique MVHR system, specifically designed for smaller dwellings and apartments. It is a continous operating – not oszillating – MVHR system, the worldwide first decentral MVHR unit with Passivhaus certification. It utilizes the cascade principle of ventilation.

Following video explains the workings of a cascade MVHR system without supply ducts:

The Cascade Principle

The concept is simple, but stunning:
A Cascade MVHR is placed in an external wall of a suitable room, often a habitable room or central space.
– Wet rooms and the kitchen are connected to the unit via a short extract duct system, thus creating an air flow path through the dwelling.
– Bedrooms and other habitable rooms tap into the airflow via cascade fans within the internal bedroom wall. As stale air is expelled out of these rooms, fresh air is drawn in through door undercuts or other internal transfer openings.
– The ventilation rate is fully demand controlled according to CO2, humidity and temperature. The active transfer units in the bedrooms are independent, but also fully demand controlled.

Thus the fresh air follows the users in their usage cycle.

Cascade ventilation
Cascade ventilation

Advantages of Cascade MVHR:

1. No Plant Space and Minimal Ducting

The cascade approach comes with a number of advantages, compared to the traditional whole house approach:

There is no plant space needed, as the MVHR unit sits within an external wall. This is especially inmportant for smaller dwelling where every squareinch of floor space is precious. The freeAir 100 MVHR is often installed in a kitchen area, in a central space or living area.

There is also minimal need for ducting. In most cases the cascade MVHR system only needs one or max. two extract ducts to a bathroom or kitchen. The cascade effect eliminates the need for supply ducting in most cases.

Advantages of Cascade MVHR:

2. Demand Control and Optimisation of the Air Flow

The freeAir 100 is fully demand controlled: This means little to no interaction of the user is needed, as the ventilation rate is adjusted according to the indoor air quality (CO2), temperature and humidity. It will try to achieve air quality levels below 1000ppm of CO2. If the air quality is good and humidity levels are normal, the whole system slows down, thus also counteracting over-dehumidification in winter, which can sometimes be an issue with conventional MVHR systems.

It follows the usage cycle between living spaces and bedrooms, as the cascade fans measure the air quality independently from the MVHR unit and speed up, if e.g. a bedroom or study is occupied.

Minimal energy use: Due to their demand controlled operation, the freeAir 100 uses a fraction of energy compared to a standard MVHR. The electrical usage of the system is very low: 4 to 20W.

Cascade ventilation
bluMartin freeAir 100

Advantages of Cascade MVHR:

3. Quiet

One of the problems with smaller, decentral MVHR systems is often their break-out noise, which can be quite disturbing. Therefore often ventilation levels are compromised, to keep sound levels somwhat acceptable.

The freeAir 100 system however, has three tiers of noise attenuation, based on different front panels: The Front Cover III and the Premium Cover, which lowers the noise levels to such a degree that the system can be used in bedrooms.

The freeAir100 cascade fans have also been designed for extreme low noise levels and very little cross-talk.

Advantages of Cascade MVHR:

4. Simple Setup and Monitoring

Simple start-up of the system, due to its demand controlled operation. There is often with no physical commissioning needed.

Monitoring: Advanced control technology allows monitoring of all air quality parameters, if so desired. Excellent data output per free downloadable program (temperatures, CO2, humidity log)

freeAir Connect Software

freeAir Plus Cascade Fans

The freeAir Plus cascade fans are an integral part of the system, distributing the fresh air around the house without ducting. They are installed within internal walls and extract air from the habitable room into a hallway.

Without cascade fans, individual occupied rooms will suffer from deteriorating indoor air quality, if the room door is closed, e.g. a bedroom.

Cascade fans pull air out of the room into e.g. an hallway, creating an influx of fresher air through the door undercut or other transfer opening from other parts of the dwelling. They measure CO2 and humidity in the respective room and speed up accordingly, in order to maintain good air quality levels.

When Is It Recommended

The freeAir Cascade MVHR is ideally suited for apartments, holiday homes and smaller houses. Two or more systems can be used if needed.

One freeAir 100 MVHR would suit following criteria:

  • It can serve a space of up to 70 m2.
  • One storey at a time for one unit. Two storey buildings would need at least two MVHR units.
  • It serves 2 people.

Usually such cascade MVHR can be treated as whole house MVHR system.

The bluMartin freeAir 100 is the worldwide first decentral MVHR unit with Passivhaus certification.

Block of flats with freeAir 100 MVHR
Retrofit MVHR freeAir 100

Retrofit Model of the freeAir 100

The renovation version of the freeAir 100 MVHR is based on the same MVHR unit, but with a 350mm round core through the external wall, instead of one square cut out.

It sits 200mm proud of the wall. It lends itself to be boxed in with a feature cupboard, which could also hide the secondary extract ducts from the top of the MVHR unit, if needed.

Ionisation Module

Imagine standing by a waterfall, breathing deeply in the fresh, invigorating air. We can bring this feeling to your home with freeAir ionic.

Room air contains fewer micro-ions than outdoor air, even when fresh air is introduced into the room. This can lead to fatigue and discomfort. The freeAir ionic module works with the innovative Conductive Air® technology from s-Leit Swissengineering, which restores the natural conductivity of the room air. Unlike conventional ionization, this s-Leit process does not produce nitrogen oxides, ozone, or electrosmog.

Ionisation Module

Further Information

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Technical Info freeAir 100

bluMartin freeAir 100

More technical information on the bluMartin freeAir 100 range of MVHR systems.

Maintenance of the freeAir 100

bluMartin freeAir 100

More information on how to change filters and maintain the freeAir 100 unit.

Retrofit MVHRs: CS50 and CA70

CS50 CA70

Zehnder’s de-central MVHR units ComfoSpot 50 and ComfoAir 70 are ideal for retrofitting, however they are not as powerful as the freeAir 100.

Comparison of Recommended MVHRs

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See what other MVHR units we can recommend.