CMV filters

Filters are essential components for CMVs. Inspection, cleaning, and regular renewal of filters are more than necessary to ensure optimal operation and performance of the ventilation system.

What is the role of your CMV's filtration?

CMV filters have two main roles: to protect the equipment from premature clogging and the inhabitants of the home.

In addition to protecting the ventilation device from clogging, the treatment of the air by the filters prevents all kinds of bacteria from entering your home. In fact, the air will be significantly healthier and free of all substances and other elements that can harm your health.

The filtering capacity of a filter is evaluated according to the structure of the medium and the size of the mesh (fine or coarse).

The life of a filter also depends on several parameters: the type of housing, the airflow rate, and of course the location. It is important to ensure that these are renewed regularly both for the quality of the indoor air but also to ensure a long life for your ventilation.

The different types of CMV filters

There are two types of filtration:

• The insufflation filters: They are there to filter particles and to guarantee a healthy and purified incoming air. They are therefore found at the air inlets. They block dust, dust mites, an important part of fine particles, not visible to the naked eye and allergenic substances (pollens, ...)
• The extraction filters: They protect the exchanger from dust, prevent clogging, and guarantee the performance and longevity of the installation. They are present at the extraction vents.

Classifications of CMV double flow filters

Filter classifications are based on a European or global standard. It should be noted that many of the filters currently sold in the market still have NF EN 779 (European) as a reference although this was replaced in 2018 by ISO 16890 (global).

European classification of EN 779 filters

For the European classification of EN 779 filters, each specific model is indicated by a letter (G= coarse, M= medium, F= fine, H= absolute) and a number determines its filtering capacity (from 1 to 16 and the higher the value the stronger the filtration class). There are mainly 4 classes of filters with different levels of efficiency on each of them:

• G= 1 to 4 with an average efficiency below 40%

• M= 5 and 6 with an average efficiency between 40% and 80%

• F= 7 to 9 with an average optimum efficiency of over 80%

• H= 10 to 16

Detail of a G4 universal filter

Those concerning double flow CMVs for dwellings are the classes:

• G4: serving as a prefilter for class 9 fine filters or as a heat exchanger.

• M5: basic filter for fresh air.

• F7: Ultra fine filter for fresh air, allowing to filter very fine particles such as pollens from plants, germs or dust.

Example G4 and F7 filter

New ISO 16890 standard

The new ISO 16890 is the globally updated and currently applied standard. It brings all international standards together to be more understandable and to ensure better health protection. It subdivides the different classes of filters according to their efficiency on the 3 standard dimensions of fine particles used by the WHO and international environmental agencies to measure pollution.

• ISO ePM 1: filter, with a fine mesh, effective on particles whose size is < 1µm (=0.001mm).

• ISO ePM 2.5: filter, with a fine mesh, effective on particles whose size is < 2.5µm (=0.0025mm).

• ISO ePM 10: filter, with a fine mesh, effective on particles whose size is < 10µm (=0.01mm).

Notation: PM is from English "Particle Matter"/ e for "Efficiency".

Here is an excellent video from the Passive House Platform (Belgian site):

When should you change your single flow CMV filters?

The single flow CMV does not have filters per se as it does not need them. It is therefore not necessary to plan for the replacement of any filters. As a reminder, the main role of a single flow CMV is only to expel the stale air from the house to the outside. However, it is possible to add filters on the air inlets located in the living rooms of your house, but they will have to be made to measure at the risk of creating pressure losses which will unfortunately not be compensated by the device. Filters should generally be changed once a year.

It has, among other things, air vents and grilles that are very easy to maintain.

Price of a single flow CMV filter

As there are no specific filters for single flow CMV, if you decide to go for a custom-made one, as an indication filters for double flow models are from 7€.

When do you have to change your CMV filters?

The life span of CMV double flow filters depends on the type of dwelling, the level of pollution and the air flow rate through it. Logically, replacement should be done once the filters are out of order.

In fact, for a good efficiency of the double flow CMV, its filters need to be in good condition throughout the year. We recommend periodic inspection and maintenance, at least every 3 months after its first use. If after periodic inspection of the equipment on visual observation of the condition of the filters, the filters are sufficiently dirty or deteriorated, then replacement should be done, especially after the pollen season.

In a normal setting where the use of double flow controlled mechanical ventilation is not intensive, its filters need to be replaced at least once or twice a year.

Price of a double flow CMV filter

As an indication, the price of cheap entry-level items varies between €7 and €30, but among others you can find replacement CMV filter kits at higher prices that can easily reach a hundred euros. The price of a CMV filter depends on the product range. Moreover, it is different from one brand to another, from one model to another.

To save money, we advise you to buy your filters in sets.

How to change your CMV double flow filters?

Changing CMV filters is not a complex operation. It is a task that anyone can do without worry, it just requires a little dexterity as the filters are dedicated to be replaced with ease. The first thing to do is to remember to stop the system temporarily. Then get protective gloves and a mask. Remove the protective caps from the filters. Remove the used filters from their place and install the new ones.

To go further on this topic, also find our complete article on the maintenance and maintenance of your CMV. You must also take into account your entire installation (duct, exchanger, register) for an optimal life span.

What are the main CMV filter manufacturers?

We'll find the ventilation manufacturers: Aldes, Atlantic, Unelvent, S&P, Brink, etc. We distribute some of the products, with many references in stock.
Note that there are also filter holders: This is a frame in which you directly position the filter cut to the dimensions of your machine. They are sold as a frame + 1 filter kit. I invite you to look carefully at which CMV it will be compatible with. We can also provide you with filters to be cut directly at your place.

What filter for my Brink CMV?

To find the reference of your filter, refer to the maintenance sheet you got when your machine was delivered.

Feel free to check out all the articles on ventilation in our Advice area as well as indoor air pollution. There, now you know everything about CMV filters. Don't hesitate to also visit the ADEME website about ventilation.