The meaning and difference between G4 and F7 filters

Of course you know that ventilation systems are an essential part of our modern buildings. They not only ensure a continuous exchange of air, but also make a significant contribution to the quality of the indoor air.

But what many may not know: It is the filters in these systems that are largely responsible for the purity and quality of the air.

Typical use of filters

A typical ventilation unit is usually equipped with two filters: one for the fresh air supply and one for the exhaust air. If these filters have the same properties, it makes no difference which one you use for fresh or exhaust air.

But there are differences in filter classification, and it is these differences that are crucial for indoor air quality.

In this guide we would like to discuss the two most common filter types, G4 and F7, and explain what they mean and when which filter type makes sense.

G4 filter

This type of filter is able to filter larger particles such as hair, insects and coarse dust from the air. Its main purpose is to protect the ventilation device from contamination and thus ensure the service life and efficiency of the system.

G4 filters are low-class filters and are ideal for rooms where air quality is less critical, such as basements or garages.

F7 filter

In contrast to the G4 filter, the F7 filter has the ability to remove not only coarse dust, but also invisible fine dust and pollen from the air.

These particles are often not visible to the naked eye, but can cause significant health problems, especially in people with allergies, asthma or other respiratory diseases.

Using an F7 filter in your ventilation system ensures healthy and clean air in your home. It also protects the device from dirt and thus extends its lifespan.

More than two filters?

Sometimes you can find a combination of three filters in ventilation systems. In this case, two low-class filters (often G4) are intended for the fresh and exhaust air, while an F7 filter is used specifically for the supply air.

This combination ensures that the air entering the room is of the highest quality and potential allergens and pollutants are filtered out.

The health risks of fine dust and the importance of F7 filters

The quality of the air we breathe plays a crucial role in our health and overall well-being.

Every day we breathe in thousands of air particles, including those that can be harmful to our health, such as fine dust.

What exactly is fine dust and why should we protect ourselves from it??

Fine dust consists of tiny particles so small that they can penetrate deep into our lungs and even enter the bloodstream.

In the long term, inhaling particulate matter can lead to a number of respiratory and cardiovascular diseases.

The concentration of these harmful particles is often particularly high, especially in urban areas where air pollution is a growing problem.

F7 filter against fine dust and pollen

This is where the F7 filter comes into play, which is also known as a “pollen filter” due to its high efficiency in removing pollen and fine dust.

As the name suggests, F7 filters are particularly effective at filtering tiny pollen particles carried into the home by the wind.

In spring and summer, when the pollen concentration in the air is at its highest, these filters can be a real lifesaver for allergy sufferers.

However, it is important to note that filters, no matter how effective they may be, require regular maintenance.

To ensure optimal functionality and efficiency of an F7 filter (or any other filter in your ventilation system), they should be checked quarterly.

If dirty or particles accumulate, the filter should be cleaned or replaced if necessary. A general recommendation is to replace filters at least once a year to ensure that indoor air is always of the best quality.

So if you want to improve the supply air quality in your home, a filter of class F7 or higher is highly recommended.

Not only does it protect against harmful fine dust and pollen, but it also ensures that you and your family can breathe in a clean, healthy environment.

Installation and maintenance of F7 filters versus G3 and G4 filters

Ventilation systems are essential components of modern buildings and make a significant contribution to indoor air quality.

However, the type of filter you use in your ventilation system can have a significant impact on the system's performance and maintenance frequency. In this section we compare the F7 filter with the more common G3 and G4 filters.

F7 vs G4 filter - features at a glance:

characteristic	G4 filters	F7 filters
Filter class	G4	Q7
scope of application	Coarse dust filter	Fine dust filter
Filter material	Typically synthetic or fiberglass	Typically microfiber or synthetic media
particle size	> 10 μm	0.3 - 10 μm
Efficiency	Low (~60-90%)	Medium (~80-95%)
Common uses	Ventilation systems, coarse material filtration	Indoor air technology, allergy rooms, clean room applications
pressure loss	Less	Higher
lifespan	Shorter (depending on pollution)	Longer, depending on the degree of contamination

F7 filter: higher protection, more frequent replacement

Installing F7 filters in ventilation systems is entirely possible and offers the advantage of effectively filtering out even the finest particles such as pollen and fine dust.

This is a significant advantage, particularly in regions with high pollen concentrations or in urban areas with increased air pollution.

However, the disadvantage of F7 filters is that they need to be changed more frequently due to their finer filter structure. They tend to clog more quickly, which can affect the efficiency of the ventilation system.

Standard in air conditioning technology: G3 and G4 filters 

G3 or G4 filters are most commonly used in indoor air technology. These filters are categorized as coarse dust filters and their main task is to filter larger particles such as hair, sand, insects and other visible particles from the air.

Even though they don't offer the fine particle filtration of F7 filters, they still serve an important role in ventilation systems.

Protection for people and machines 

G3 and G4 filters not only protect people from larger suspended particles, but also protect the ventilation devices themselves.

Filtering out coarse particles prevents them from entering the ventilation system and damaging it or reducing its efficiency.

Quality criteria of G4 filters 

The quality of G4 filters (and G3 filters too) is measured by various characteristics:

• Filter efficiency: This refers to how effectively the filter removes particles from the air. Higher efficiency means fewer unwanted particles pass through the filter barrier.
• Dust holding capacity: Good dust holding capacity ensures that the filter works efficiently over a longer period of time without becoming clogged too quickly.
• pressure loss: A higher pressure loss can lead to higher energy consumption by the ventilation system. Therefore, it is important to choose a filter with an acceptable balance between filter efficiency and pressure loss.

While F7 filters offer increased protection against fine dust and pollen, G3 and G4 filters are the standard solution in many ventilation systems and offer reliable protection against coarse dust.

Comparison of G3 and G4 filters: separation efficiency, testing procedures and quality assurance

Choosing the right filter for a ventilation system is essential to achieve optimal results in terms of air quality and device performance. G3 and G4 filters are among the most common filter classes in indoor air technology.

Both filter classes offer reliable protection against coarse dust, but there are important differences that should be taken into account when choosing.

Pressure loss and dust holding capacity: similarities of G3 and G4 

Both G3 and G4 filters have similar characteristics in terms of pressure loss and dust holding capacity.

A balanced ratio of these properties ensures that the ventilation system works efficiently and that the filter does not become clogged too quickly.

Degree of separation: the crucial difference 

The degree of separation is the main criterion that distinguishes G3 from G4 filters. A higher separation efficiency means that the filter is able to remove a greater quantity and variety of particles from the air.

In this regard, G4 filters have a clear advantage as they have a higher separation efficiency for coarse dust than their G3 counterparts.

This makes them particularly effective in environments where air quality is affected by increased concentrations of coarse dust particles.

Uniform quality tests according to DIN EN ISO 16890 

To ensure the quality and performance of G4 filters, they are tested according to the DIN EN ISO 16890 standard. This internationally recognized standard specifies uniform quality tests for air filters.

During the testing process, filter efficiency is measured based on the particle size retained. This ensures that G4 filters do exactly what they promise: effectively removing coarse dust particles from the air.

Quality assurance and compatibility with device manufacturers

An important aspect that is often overlooked is quality assurance. Thanks to the strict tests according to DIN EN ISO 16890, consumers can be sure that the quality of G4 filters corresponds to the products of the device manufacturers.

This means that replacing original filters with third-party G4 filters does not represent any compromise in terms of the performance and safety of the ventilation system.

Subtleties of filter technology: G4 vs. F7 in particle filtration

In ventilation technology, it is crucial to select the right filter for the respective application.

The distinction between G4 and F7 filters may seem marginal at first glance, but upon closer inspection you will see significant differences in their ability to filter certain particle sizes from the air.

This is particularly relevant for people who suffer from allergies or live in regions with high pollen concentrations.

Efficiency in filtration of 1 micron particles 

G4 filters have a separation efficiency of only 6% for particles as small as 1 micrometer. In comparison, F7 filters filter out the same particles at an impressive 86%.

This shows that F7 filters are almost 15 times more effective at removing this specific particle size than G4 filters.

Pollen filtration: Larger particles are no problem 

Pollen larger than 10 micrometers is almost completely removed from the air by both filters G4 and F7. . 

This is good news as many of the coarser pollen types are in this range.

The limits of G4 filters for allergens 

Although G4 filters are effective at filtering coarser pollen, they are not specialized pollen filters. In particular, they only filter out around 4% of allergenic pollen particles smaller than 0.3 micrometers.

This means that a large proportion of these finer, allergy-causing particles pass through the filter and can enter the room air.

Optimal breathing air for allergy sufferers: F7 and higher 

The quality of indoor air is particularly important for pollen allergy sufferers. Filters of class F7 or higher quality such as F8 and F9 offer a significant improvement in the air you breathe by effectively filtering out even finer pollen particles.

This reduces the risk of allergic reactions and ensures a more pleasant indoor climate.

Pre-filtration: The key to extending filter life 

A recommended practice in ventilation technology is the use of a pre-filter. In this case, a G4 filter can be used as a pre-filter to efficiently remove larger particles and thus slow down the fouling process of the F7 filter.

This method allows the main filter (F7) to remain efficient for longer and needs to be changed less often.

Frequently asked questions about G4 vs. F7 ventilation filters:

What is the purpose of ventilation system filters?

Ventilation system filters ensure the purity and quality of the indoor air and protect the device from contamination.

What are the two most common filter types and their main functions?

G4 filters remove larger particles such as hair and insects, while F7 filters also filter fine dust and pollen.

For which rooms is a G4 filter best suited??

G4 filters are suitable for rooms where air quality is less critical, such as basements or garages.

What are the advantages of an F7 filter?

F7 filters remove fine dust and pollen, protect against health problems and extend the life of the ventilation system.

Why is air quality important for our health?

Air contains particles such as fine dust that can be harmful to health, especially in urban areas with high levels of air pollution.

How often should F7 filters be serviced or replaced?

F7 filters should be checked quarterly and cleaned or replaced as necessary, but at least once a year.

What differentiates G3 and G4 filters from F7 filters in terms of maintenance?

F7 filters need to be changed more frequently because they filter finer particles and can clog more quickly.

What are the main differences between G3 and G4 filters?

G3 and G4 filter coarse dust, with G4 filters having a higher separation efficiency and being more effective at higher coarse dust concentrations.