Acoustic-Aided Air Filter for Enhanced Filtration and Reduced Energy Consumption

Typically, buildings with centralised air-conditioning have one or more air filters in each of the air handling units. While air filtration plays an important role to improve indoor air quality, it requires a significant amount of energy consumption to achieve high filtration efficiency, which is the extent to which filters remove airborne particles. In a conventional air filter, energy consumption can account for up to 80% of the total lifecycle cost of operating the filter.

Air filters generally remove smaller airborne particles with a lower level of filtration efficiency, and densely packed filter media is typically used to remove these very fine particles, which results in a high pressure drop across the filter. Air filters with densely packed fibre material, such as the High Efficiency Particulate Air (HEPA) filter, are both costly and energy intensive.

While efforts have been made to refine the structure of air filters to reduce the pressure drop, the physical limits of fluid mechanics means that there is a need for a technology that facilitates a further reduction of the pressure drop, especially in high efficiency air filters.

This patented technology greatly enhances the air filter performance while reducing the energy consumption of the filtration process. It utilises acoustic energy to induce the rapid vibration of the particles in the air, which can enhance the filtration efficiency of an air filter from 70% to 90%.

This acoustic-aided air filter uses an enhanced air filtration method with the aid of acoustic (sound) waves, which increases the probability of the particles hitting and attaching to the solid surface of the filter media. Besides the acoustic wave-generating means attached, the air filter may also have a pre-programmed chip to control the frequency of the acoustic waves generated.

Compared to conventional air filters, this technology has demonstrated high efficiency in capturing airborne particles (PM 1, PM 2.5, PM 10) with a low drop in pressure, and also consumes less energy. It has been proven in office buildings, as well as a shopping mall building and international school building. In these use cases, there was 72% maximum energy savings and 42% lower consumable cost compared to the previous air filter system.

This acoustic-aided air filter can be applied in the following ways:

• Buildings with centralised ventilation systems
• Air purifier / air purification equipment
• Vehicle air filtration
• Ventilation and air conditioning equipment
• Industrial pollution control

The current annual global market for air filter and air filtration equipment is estimated to be US$30 billion, and is expected to double in size to US$60 billion by 2022. The Asia Pacific market size is expected to be US$13 billion by 2022.  

Compared to conventional air filter, this acoustic-aided air filter offers:

• Improves filtration performance by 50%
• Lowers pressure drop by 60%
• Improves energy efficiency by 50%
• Lowers consumable cost by 40%
• Can be retrofitted to existing equipment, such as air purifiers and air handling units
• Size is highly customisable