What is a Coarse Filters?
Coarse Filters, also called Pre Filter or Pre-Filter for HVAC. It is mainly installed in the front of the air filter, mainly to remove coarse particles of pollutants in the air environment. For example:
Grit and dust
Fiber, cotton wool
Insects, pollen
Large particle pollutants in the industrial environment
As the first line of defense in the filtration system, the Coarse Filters effectively reduces system resistance and improves the life of the back-end air filters, reduces maintenance costs, and enhances filtration performance, making it an ideal choice for you to ensure air quality and cost savings.
Types and Constructions of Coarse Filters
Depending on the environment of using system, filtedge Coarse Filters manufacturer can provide you with a variety of constructions of filters.We can also customize your size, efficiency, etc.
Pleated coarse filters increase the effective filtration area by 30%-50% in limited space and are mainly used in HVAC and AHU systems.
With a stable structure, suitable for even the more severe industrial operating working environmental conditions.
Metal mesh coarse filters is suitable for high dust and high fume industrial environments, can be repeatedly reused.
It adopts high-quality Synthetic Filter Media, with stable and smooth airflow and low wind resistance.
Activated carbon coarse filters remove airborne odors and coarse dust, mostly used in commercial systems.
Coarse media pads and rollers can be cut to size, with various thicknesses, can be used in paint booths.
High effective dust holding capacity for industrial HVAC air prefiltration system applications.
Easily washable and reusable, low air flow resistance, suitable for most industrial coarse dust particles.
Types and Constructions of Coarse Filters
Depending on the environment of using system, filtedge Coarse Filters manufacturer can provide you with a variety of constructions of filters.We can also customize your size, efficiency, etc.
Prevent contaminants from entering fans, ducts.
Reduce machine wear and contamination risk.
Reduce the dust load on the medium/ high efficiency air filters.
Extend the replacement cycle of the back-end filters.
Reduced resistance design helps stabilize system differential pressure.
Reduces fan energy consumption and reduces overall energy consumption.
Reduce the risk and frequency of downtime.
Reduce long-term operating costs.
Coarse Filters Media Treatment Process
FiltEdge Coarse Filters manufacturer chooses high-quality filter media in accordance with ISO 16890 standard, which can guarantee you consistent performance of each batch of Coarse Air Filter.
Multi-layer gradient structure design, step-by-step interception, dust is evenly distributed in the filter media, which can solve the problem of rapid rise in pressure loss and easy clogging.
Humidity resistance of the filter material >90% RH, the Coarse Filters can operate stably in a high humidity environment, and the filter material is not easy to soften and fail.
Structural fiber reinforcement, Coarse Filters allows your filter media not to collapse, not bypass side leakage, filtration performance to the optimum.
Automated Pleating Process for Coarse Filters
FiltEdge adopts an automated pleating machine with virtually zero tolerance on pleat spacing, which ensures that the efficiency for each of your Pre-Filter for HVAC is consistent.
The pleat design can increase the effective filtration area by 30%-60%, solving the problem of rapid rise of Pressure Drop and decrease of airflow.
FiltEdge’s enhanced design in pleat molding and support structure provides pleat height stability and prevents the EAF from collapsing.
Sealed Assembly of Coarse Filters Frames
FiltEdge has galvanized steel frames / aluminum frames / paper frames / rimless frames to provide you with a variety of frames that can meet a variety of application scenarios.
The frames are machine cut with no tolerance on size. The problem of difficult installation and sealing failure of Coarse Air Filter can be completely solved.
We use the whole sealing assembly method to prevent airflow bypass.
Quality Inspection of Coarse Filters from the Factory
FiltEdge will carry out dimensional and appearance inspection for each batch of Pre Filter from the factory to ensure the structural integrity and flat edges.
Airflow uniformity check ensures that the airflow passes through the filter material evenly, the airflow is evenly distributed, and the problem of localized high load and localized blockage of airflow is solved.
Why Choose Filtedge Coarse Filters Manufacturer?
Filtedge has been in the Coarse Filters industry for more than 20 years and has accumulated a wealth of experience in solving air filtration problems, so you can eliminate trial and error and reduce the cost of risk.
Filtedge Coarse Filters manufacturer has already owned a 35,00 m² ISO 7 (Class 10,000) purified assembly workshop, equipped with 5 sets of high-end automatic paper folding machines, 4 sets of ultrasonic bag forming machines, 2 sets of gluing systems, 3 sets of high-precision particle detectors, air flow resistance testing stations, etc., which can ensure stable quality and a daily production capacity of tens of thousands of square meters of filtration area.
With several years’ development, we have customers in more than 100 countries, participated in more than 30 important exhibitions, and formed long-term cooperative relationships with different market engineering companies, system integrators and brand customers. Last but not least, we also hope that you can visit our factory and become our important partner.
Application of Coarse Filters
Coarse filters are commonly used in the primary filtration of air systems to intercept large particles of pollutants, reduce the accumulation of dust, reduce the load on the system, and protect the back-end filters and equipment.
Common scenarios in HVAC systems include office buildings, shopping malls, hotels, schools, hospitals, airports, etc. Their incoming air often contains more dust and fiber particles, and if the primary filtration capacity is insufficient, it is easy for the filters to be clogged too quickly, and the differential pressure of the system to rise, which in turn increases the energy consumption of the fans.
FiltEdge Coarse Air Filter adopts synthetic fiber filter material and reasonable dust holding structure design, and its filtration efficiency can cover the range of G3-G4 (MERV 5-8) under normal HVAC working conditions, and the initial resistance is generally controlled at about 30 Pa. In actual operation, it can effectively intercept large suspended particles and slow down the accumulation of dust in the back-end filter, Back-end filters typically last approximately 30%-50% longer and are replaced 40%-50% less frequently, helping you reduce overall operating and maintenance costs.
Commercial air handling systems usually have long operating hours, low start-up and shut-down frequencies, frequent filter replacement, and relatively high operation and maintenance costs. Some common primary filters are prone to short life and rapid efficiency loss under continuous operation.
For the characteristics of commercial environments, FiltEdge Coarse Filters can be used for about 3-6 months under the working conditions of regular office buildings and shopping malls. FiltEdge Coarse Filters can remove dust, pollen and other common particles with an efficiency of over 80%, and the efficiency level covers G4 / MERV 7-8. Coarse Filters are available in standard sizes and can be customized to fit mainstream commercial equipment, reducing the frequency of change-outs and typically lowering your annual replacement costs by approximately 20-30%.
Industrial application scenarios are usually manufacturing workshops, processing plants, cement factories, steel mills, power plants, spraying, machining, etc. Ventilation systems are often in a high dust and high load operating environment, and filters are prone to clogging due to the excessive accumulation of dust, or even structural deformation, which affects the stable operation of the equipment.
FiltEdge Coarse Filters are designed for high dust conditions by adopting thickened filter material and high-strength frame structure. In actual application, its dust holding capacity is significantly higher than that of ordinary structure products, and can be about 50% higher under some working conditions. Even in high dust concentration environments, the operating resistance of the system can still be maintained within 50 Pa. This design helps to protect your fans and internal components of the equipment, extends maintenance intervals, and is suitable for plant fresh air and all types of industrial ventilation systems.
The general scenario of AHU system is clean room, laboratory, pharmaceutical, factory centralized air supply, etc., which requires high requirements on filter size matching, sealing performance and resistance stability, and if there is bypass leakage, it will easily lead to the accumulation of dust inside the unit, which will affect the heat exchange and operation efficiency.
Our Coarse Filters for AHUs are specially designed in terms of dimensional tolerances and sealing structure to ensure a good match with the unit. Under common operating conditions, the initial resistance is usually maintained at 25-35 Pa, and the filtration efficiency covers G4 / MERV 7-8. Based on real-world project feedback, FiltEdge Coarse Filters can help you reduce coil and cabinet dust buildup by up to 40% from uncontrolled coil buildup, helping to maintain stable unit operation over the long term.
Coarse Filters Class and Performance Standard (ISO 16890) Parameter Table
- Coarse Filters Class and Performance Standard (ISO 16890) Parameter Table
| Item | Parameter range |
| Filtration class | Coarse 50% / 60% |
| Corresponds to EN 779 | G2 / G3 / G4 |
| Main filter particle sizes | 10–20 μm |
| Coarse particles capture efficiency | 85%–95% |
| Applicable air speed | 1.5 – 3.0 m/s |
Coarse Filters are most commonly used in HVAC systems as Pre Filters, and are often referred to as Coarse Air Filters or Pre-Filter for HVAC.
In practice, these names are often interchangeable, and the key lies in the filtration level and structure to match the system requirements.
Yes, they are. In HVAC air filtration, G2, G3, and G4 Air Filters are typical Coarse Filters and are often used as the first filtration stage of a system. filtEdge’s G3 and G4 grades are the most common choices for commercial and industrial applications.
Without Coarse Filters, large amounts of dust can enter the AHU, contaminating not only the coils and fans, but also prematurely disabling the MEP or HEP filters. From the perspective of System Protection, Coarse Filters are the most cost-effective, yet the most neglected, filter.
Properly designed Coarse Filters are inherently low pressure drop. In FiltEdge’s product design, we pay more attention to the initial resistance and resistance growth curve to ensure that there is no significant impact on airflow and system efficiency in actual operation.
Yes, by controlling pressure loss and minimizing equipment contamination, Coarse Filters can reduce fan loads and, in the long run, help improve the overall energy efficiency of an HVAC system.
In most HVAC systems, Coarse Filters are installed at the air intake of the air handling unit as the first stage of HVAC air filtration to protect the entire system.
Coarse Filters under ISO 16890
Coarse Filters belong to the ISO Coarse class of ISO 16890, which corresponds to the G2 / G3 / G4 classes of the conventional EN 779 standard.
Typical performance range:
– Particle size: 10-20 μm.
– Coarse Particle Capture Efficiency: Approx. 85% – 95%.
– Design goal: low initial resistance, stable differential pressure
ISO Coarse filters are widely used in the pre-filtration phase of HVAC, commercial and industrial systems.
Coarse Filters Maintenance and Replacement Recommendations
– Normal environments: check every 3-6 months
– High dust industrial environments: every 1-3 months
– Replace when differential pressure approaches recommended final resistance.
