Panel filters remove solid particles that range from 1 micron to 50 microns.

They include;

• Pollen
• Mold spores
• Mites
• Carpet and textile fibers
• Fabric protectors
• Lead dust
• Milled flour
• Auto exhaust particles
• Humidifier dust
• Legionella,
• Nebulizer droplets
• Spray paint dust,
• Soil dust
• Pet fur among others

The fan suctions the air into the filter media through negative pressure.

When the air comes into contact with the surfaces of the filter medium, it applies different mechanisms that are applied to clean the air.

The filters remove particles that are larger than the pore size of the filter media/fibers through the sieve effects.

The large particles with substantial mass are carried into the filter at high velocity, hit, and stick on the threads through inertial mass effect.

Lighter particles float to the filter media through turbulent flow and get intercepted by the filters.

The filter removes the remaining tiny particles through diffusion.

Also, the particles move through Brownian motion as they approach the fibrous.

They randomly hit each other, which reduces their speed and increases the chances of their capture by the media.

A panel air filter consists of the filter medium and holding frames.

Parts of panel filter

· The Frame Assembly

You can construct the structure using metals such as galvanized steel, aluminum, and cardboard.

Alternatively, you can also use different types of plastic such as polystyrene, polypropylene, polyethylene, and polyvinyl chloride to build the casing.

You can secure the frame using rivets.

The frame assembly holds the filter media in place.

· Filter Media

Normally, they perform the actual sieving of air.

They are held together with corner clips inside the frame.

Besides, they are placed between two wire mesh to keep them in place.

You can use either natural or bonded synthetic materials to make the medium.

Panel filtration system are primarily responsible for protecting the most sensitive components of the system and providing quality breathing air.

If you don’t remove the dirt, they enter and stick on the motor, fans, coils, and sensors.

When they settle and build up inside the ductwork, it compels the fans to perform harder work to overcome the pressure drop resulting from the resistance.

There is also a possible risk of fire explosion when excessive dust settles on the motor and other mechanical parts.

Besides, you will spend more money on secondary replacement filters, which are more expensive because the excess dust loading will drastically reduce their life.

You will get the following benefits from using panel filters:

• Enhanced indoor air quality
• Ease of use and replace
• Cost-effective dust removal devices
• Efficient dust removal equipment
• The non-hygroscopic synthetic media does not support the growth of microorganisms
• Pleated panels have high dust holding capacity
• Protection of sensitive devices downstream

Some panel filters are pleated because the medium material has been folded into an accordion-like pattern to form pleats.

The main differences between the two filters are the sizes of particles they can remove.

Panel filter system

· Primary Panel Filters

The filters can strain course particles ranging from 10 to 50 microns.

Besides, they help protect the secondary panel filters from excess loading, thus improving their service life.

The filters are cleanable.

· Secondary Panel Filters

You can use these filters for removing particles with diameters ranging from 1 to 10 microns.

You use different selective media in making them.

Panel filters are used in diverse industries to remove large particles from the process application.

They are most suited in applications that are not extremely critical such as ventilation, heating, and air-conditioning.

However, they are also used in gold and jewelry industries to retain dust with immense economic value.

They are also essential in protecting and extending the service life of secondary filters.

You will require panel filters in the following industries:

• Automotive,
• Pharmaceutical
• Chemical
• Aluminum manufacturing
• Food processing
• Paint manufacturing
• Warehouses
• Electronics
• Nuclear plants
• Hospitals
• Computer store
• Synthetic fiber manufacturing

What Materials can you use to Construct Filter Elements for Panel Filters?

Your choice of media material will depend on the requirements of your filtration system.

There are numerous materials from which you can select from for manufacturing the filter medium.

You can use synthetic or natural materials.

However, synthetic materials are more suitable because they readily adapt to diverse ventilation systems.

The materials for constructing pleated filters should be able to fold easily without cracking.

They include:

• Polyester
• Cellulose
• Cotton
• Fiberglass
• Paper
• polypropylene
• polyethylene
• Glasspaper
• Wired cloth
• Woven and non-woven fabrics
• Membranes and felts

Yes, you can reuse washable panel filters.

These filters are economical to use and will help you save a lot of money.

The filters are suited for applications with high dust contamination levels.

You can install them in vents and air conditioning systems.

Depending on the type of filter, you can clean them 20 times before you can replace them with new ones.

Also, the frequency of washing will depend on the rate of dirt accumulation though up to 3 cleanings in six months can be done under normal filtration conditions.

You can clean the panel filters through reverse jet cleaning at 19 mw.g or 100 PSI water pressure.

Some filters require spraying with filter cleaners and soaking for some time to remove the dirt.

Ensure that you consult the manufacturer’s instructions on how to clean the panel filters before settling for any method.

The frequency of filter element replacement or cleaning will depend on the level of air contamination, flow rates, type and grade of the filter.

You can install an automated differential pressure gauge with a timed alarm to signal when the filter elements are due for replacement.

Visual inspection alone can be erroneous since the eye can only detect dirt of up to 40 microns.

Similarly, some high rated filters may visually appear dirty, yet they haven’t reached the optimal efficiency levels.

Most disposable filters can last between several days/weeks and up to six months, depending on the filtration conditions.

Pleated air filter

Panel filters are rated depending on the size of particles they can remove from the air.

Different rating systems provide a relative measure of filter efficiency.

Panel filters are usually rated through the minimum efficiency reporting value, traditionally abbreviated as the MERV system.

The rating system has a scale running from 1-16, where the lower values grade filters that remove large sized particles and higher grades for those that restrain small size particles.

Since panel filters are spread across different classes, they can capture particles ranging from 1-50 microns.

MERV 1-4: These are mostly primary panel filters and will remove particles above 10 microns in diameter.

You will use them in residential window AC units.

MERV 5-8: The majority are secondary panel filters and remove particles that range from 3-10 microns.

You can use them in industrial workplaces, commercial and residential buildings.

MERV 9-12: The panel filters remove particles between 1 and 3 microns.

They are suitable for hospitals, laboratories, businesses, and superior residential buildings.

Another rating system, EN 779, was introduced in Europe in 2012 and operated up to 2018.

According to the system, primary panel filters range from G1 to G4, while secondary panel filters range from M5 to F9.

Different countries have developed different standards that must be complied with by manufacturers within their territory.

The standards also vary from one industry to the other.

For example, ISO 16890 provides standards for testing and rating filters based on their ability to remove the most harmful particles to human health.

ISO 5011:2014 standards provide guidelines for testing, conditions, reporting, and comparison of panel filters used in combustion engines and compressors.

The standards are for filters used in industrial and automotive applications.

There are two main types of panel filters, the flat panel filter, and pleated panel filter.

· Flat-panel Filter

They are the most basic and cheapest air filters.

You can construct them from flat panel fibrous medium enclosed in a metal or cardboard frame.

They can only remove large particles from the air entering the system.

The majority of the flat panels comprise synthetic fibrous/porous material.

· Pleated Panel Filters

Pleated filters have a medium that is bent in accordion-like pattern and enclosed in the frame.

The bending pattern enables it to fit inside the frame without increasing the size of the filter.

Besides, the pleats increase the surface area and dirt holding capacity of the filters, which makes them more efficient than flat panel filters.

Moreover, the higher surface area ensures maximum filtration potential and minimum airflow resistance.

Also, the depths of the pleats correspond to that of the holding frame.

The pleats can be spaced at any length dictated by the filtration requirements and can assume narrow U shape or wide V shape.

When installing these filters, ensure that you expose all the medium surface to the air for filtration.

For filters with narrow pleats, perpendicularly install spacer sheets between the medium fold.

The spacers will prevent the screens from pinching together and losing surface area for filtration.

Cardboard disposable and metal V- shape panel filters are the most used.

In fact, the medium consists of a cotton-polyester blend or a synthetic material.

Many manufacturers produce ready-made standard size panel filters.

These sizes vary from one manufacturer to the other.

You can also place an order for custom-sized panel filters to suit your installation requirements.

However, customized filters will cost you more compared to standard size filters.

The cost of panel air filters varies greatly.

The application requirements, rating, material of construction, among other factors, determine the price of a panel filter.

Generally, pleated secondary panel filters cost more compared to flat filters and primary filters.

For example, a simple panel air filter made of cardboard frame for conditioning system will cost between $2 and $10 apiece.

In contrast, a medium efficiency industrial panel air filter can cost up to $ 120 per piece.

Metal air filter

Panel filter comes in diverse sizes, models designs.

Ensure that you consider all requirements that suit your filtration needs to maximize the filtration capacity.

The following factors will affect the effectiveness of your panel air filter:

• Environmental conditions of your operations: This includes the temperature and flow rate of the air.

The acceptable pressure drop will also influence the choice of your filters.

• Quality of construction material, including the support frame, media, and bonding material.
• Nature of contaminants: Combustible and hazardous contaminants require higher filtration efficiency.
• Filtration requirement: The nature of contaminants will influence the type of panel filter you purchase. You also need to know how often the process produces pollutants.
• Rating of filters: Higher rating filters are more efficient and costly.
• Budget allocation: Consider both initial purchase cost and operation cost.
• Installation requirements: You must mount the filters accurately to avoid bypass air. Consider the dimensions of your mounting surface and available sizes in the market.

There are numerous designs of panel air filters constructed to suit specific filtration requirements.

Below are some of the conventional designs or models that you can consider for your filtration needs:

• Glassfibre panel filters
• ProPleat S Coarse 60%
• ProPleat S Coarse 60%
• Wireframe filter
• AirPleat Coarse 70%
• Mesh filters
• V-Form panel filter
• Metal washable panel filters
• Rod frame panel filters
• Polyfoam washable panel filters
• Pad holding frames
• MiniCell High-performance panel air filters
• Synthetic panel filters

There are three more types of air filters based on EN 779 and EN1822 standards of air filter classification.

These include semi HEPA filters, HEPA (High-Efficiency Particulate Air) filters, and ULPA (Ultra Low Particulate Air) filters.

All these filters can achieve higher filtration efficiency than panel filters.

For instance, you can use semi HEPA filters between grades E10 to E12 to remove particles that are above 0.5 microns at 99.5% efficiency.

You will use HEPA filters when you want to achieve a filtration efficiency not lower than 99.995% for particles that have greater than 0.3-micron diameter.

ULPA filters have the highest filtration efficiency and can remove particles above 0.3 microns at 99.99995%.

Some ULPA filters can remove particles as small as 0.12 microns.

Because of the high filtration efficiency, HEPA and ULTRA screens filter the air in very sensitive applications such as pharmaceutical industries.

They are also fundamental in the construction of biosafety cabinets and the manufacturing of electronic goods.

Panel filters allow higher airflow rates compared to HEPA and ULPA filters.

In contrast, HEPA and ULPA filters require more energy to move a similar amount of air through the screen as a result of high filter resistance.

HEPA and ULPA filters are more expensive than panel filters.

Care and servicing for panel air filters is very simple, although it varies with the type of application.

Ensure that you routinely carry out proper maintenance to maintain clean ductwork.

Without proper maintenance, the mold can reproduce in the ductwork if the humidity reaches the dew point.

You can observe the following tips to ensure the appropriate function of the filters:

• Label the filter casings with relevant information referring to the type of filter, date when they were last changed, and the pressure drop.
• Immediately change damaged, collapsed, wet, and old infested filters.
• Use access door with quick release and hinged access doors to ensure easy access to the filters for servicing.
• Schedule filter service period out of the regular working hours. This scheduling will help you avoid disruption of the provision of clean air or dispersion of contaminants to the personnel.
• If you must do servicing during regular working hours, ensure that you switch off the fans.
• Clean the entire filter area during maintenance.
• Use a clean piece of cloth to wipe out dirt from the filter casing.
• Avoid spilling dirt into the ductwork when changing the elements.
• Record all maintenance operations for future reference and planning
• Keep the dirt content of washable filters below 50% to increase the lifespan of interior devices by almost double time.

With the information in this guide, certainly, you can choose a suitable panel filter for your applications.

However, in case you have additional questions on these filtration systems, contact FilSon Filters team.