Electrostatic Air Filter: Everything You Need to Know
- Jennifer Crowley
- Dec 18, 2023
- 5 min read
Updated: Jul 8, 2024
The importance of indoor air quality and the benefits of maintaining a clean air environment has become a major concern for indoor spaces. These benefits range from our mental and physical health improvements to better HVAC system efficiency and lower electricity costs. As a result, many large, public indoor spaces like offices, schools, buildings, and medical centers that we visit daily are required to pay greater attention to air quality for the safety of everyone.
But often, finding the right indoor air quality solution that is both economically sound and effective can seem daunting and overwhelming. With so many different types of HVAC filters and so much information to digest, how do you know the best choice?
If you want to save money and time while enhancing your air quality, electrostatic HVAC filters may be an excellent solution for your facility. In this blog, we will be going over the different types of electrostatic air cleaning filters, which one is most effective and how they differ from the industry standard filters.
What is an Electrostatic Air Filter?
An electrostatic filter is a form of air purifying technology commonly used in larger indoor spaces – specifically for commercial or industrial purposes. These units can be used in portable air cleaning devices or installed in the ductwork of HVAC systems.
The main idea of electrostatic filters is to utilize static electricity to attract and trap particles on the charged fibres and carbon paths. So instead of getting pulled through and being blocked by filter material like standard filters, the particles are attracted to the filter media.
Types of Electrostatic Filters
You will encounter two standard electrostatic technologies when searching the different types of electrostatic filters. In this article, we will be comparing the two:
Electrostatic Ionized Technology
Electrostatic Polarized Technology
Let’s look at the two technologies in a little more detail.
Electrostatic Ionized Technology
Ionic electrostatic filters give a charge to airborne particles passing through the filter. The electrical charge allows the particles to be pulled and entrapped by plates (precipitators) of the opposite charge.
Are Electrostatic Ionized Filters Effective?
Electrostatic ionizing filters effectively remove large particles, such as dust and pollen, from the air but cannot filter the air of all particles at the same level of efficiency. The filter’s efficiency depends on the contaminant’s size; smaller particles in the mid-range within 0.1 to 1 micrometres are not charged as effectively and, as a result, are not collected thoroughly on the plates.
The Effect of Ionization on Health
One of the most significant issues with electrostatic precipitators is the potential creation of ozone as a byproduct. If breathed in at ground level, ozone is proven to be hazardous to one’s health. There is a potential risk of experiencing:
Decreases in lung function
Aggravation of asthma
Throat irritation and cough
Chest pain and shortness of breath
Inflammation of lung tissue
Higher susceptibility to respiratory infection
Electrostatic Polarized Technology
Unlike Ionizing technology, polarized particles are referred to as bi-polar, meaning that each molecule has a positive charge at one end and a negative charge at the other. Let’s take the example of a magnet; polarized technology works similarly to how magnets’ positive and negative sides attract each other. Electrostatic polarized filters combine three major scientific principles to filter air and trap unwanted particulates.
Steps of the Filtration Process
Impingement – Commonly referred to as a pre-filter, the impingement process traps dust by using the media placed in the path of oncoming airborne particles to stop it.
Polarization is the process of inducing an electrostatic charge to any particulates that pass through the air cleaner. This allows pathogens to be easily removed from the air with oppositely charged fibre media that act like magnets.
Agglomeration is an advanced stage of polarization. The already charged polarized particles attach with other polarized particles as they collide in the air – this is called a “polarized field.” This field binds the submicron particles that standard filters otherwise let pass, deactivates the viruses/bacteria, and traps them in the filter, allowing the air cleaner to capture even the smallest particles.
Why Are Polarized Electrostatic Filters More Effective?
Unlike the more common ionizing technology found in most electrostatic air filters, polarized-media air cleaners do an exceptional job of removing sub-micron (<1 micron in size) particles without the efficiency loss associated with precipitating electronic air cleaners. In addition, as each particle attaches itself to the fibre strands it, in turn, becomes part of the collection process, thereby increasing the effectiveness of the filter as it loads. Polarized media also produces no ozone – making the filter better in performance and for human health.
To summarize, here is a table demonstrating the difference between the two types of electrostatic filters just discussed.
Ionizing Technology | Ozone | Harmful to health | Not effective on small microns | Messy cleanup |
Polarizing Technology | No Ozone | No harm to health | Effective on all sized microns | Hassle-free maintenance |
Traditional Filters (MERV)
Until now, we have established that electrostatic polarizing technology is far more effective than electrostatic ionizing technology in indoor settings. But how exactly does it compare to the regular standard filters – that we find in most HVAC systems today?
All traditional air filters are differentiated according to their MERV (Minimum Efficiency Reporting Value) rating, which denotes their efficiency. The higher a filter’s MERV rating, the more effective it is at capturing airborne particles.
MERV 13 and below are considered to be HVAC-system-grade filters for residential, commercial and general hospital use. MERV 13 filters are able to filter particles closer to the 0.3 microns size, which includes contaminants such as:
Pollen
Mould
Dust
Dust Mites
Bacteria
Pet Dander
Smoke
Virus carriers
Exhaust fumes
Electrostatic Filters vs Standard Filters
When comparing electrostatic polarized filters, specifically the Blade Electrostatic Polarized Filter, to MERV 13 and MERV 8 filters, we see the Blade Electrostatic Polarized Filter has greater filtration performance, filtering at 0.007 microns and maintaining a lower pressure drop. Pressure drop refers to the amount of electricity it takes to push the air through a filter. A low-pressure drop rating means pushing the air through the filter takes less power.
Learn about other Types of HVAC Filters and how they compare to electrostatic filters.
Blade’s Electrostatic Polarized Filters
The Blade Electrostatic Polarized filter provides HEPA-Class and MERV-rated filtration while lowering your building’s energy consumption and maintenance time. Our electrostatic filters are the best option in HVAC systems and facilities where enhanced air quality is required, but a HEPA filter is not practical.
Blade electrostatic polarized filters remove micro-particulates 40x smaller than traditional HVAC filters, enhancing your indoor air quality.
Blade’s electrostatic polarized filters remove harmful particulates, even as small as 0.007 micrometres, that traditional filters do not, making them the ideal filtration solution. Utilizing active polarization fields binds the tiny submicron particles together that standard filters and electrostatic ionic filters let pass.
When compared to traditional standard filters, Blade is proven to provide enhanced air quality and longer-lasting filters and lowers your energy consumption. In addition, the filter’s innovative design uses low-density media, reducing the strain on your HVAC system compared to traditional filters and high-efficiency systems.
