An acoustic monitoring system for detecting a condition of an air filter, the acoustic monitoring system including: a first acoustic transducer upstream with respect to airflow over the air filter; a second acoustic transducer upstream with respect to airflow over the air filter; a third acoustic transducer downstream with respect to airflow over the air filter; a fourth acoustic transducer downstream with respect to airflow over the air filter; a control unit in communication with the first acoustic transducer, the second acoustic transducer, the third acoustic transducer and the fourth acoustic transducer; the control unit configured to determine a filter attenuation value in response to one or more SPL values measured by at least one of the first acoustic transducer, the second acoustic transducer, the third acoustic transducer and the fourth acoustic transducer.

An air filter and a method of air filtration using the said air filter are described. The air filter may comprise a filter media layer adapted to capture and filter one or more impurities from air. The air filter may further comprise one or more acoustic wave generating means attached at one or more sides of the filter media layer. The one or more acoustic wave generating means may generate acoustic waves to be propagated into the filter media layer. The propagation of the acoustic waves into the filter media layer may facilitate the filter media layer to enhance the filtration efficiency of the air filter. The air filter may further comprise a pre-programmed chip to control the frequency of the acoustic waves generated. Further, air filter may comprise a battery adapted to supply power to the one or more acoustic wave generating means and the pre-programmed chip.

A method for detecting particle filter cleanliness includes receiving calibration data for a particle filter. The calibration data represents an acoustic spectrum. The method further includes receiving operational acoustic data from a sensor located in a system comprising a fan and the particle filter, deriving a second acoustic spectrum from the operational acoustic data, comparing at least part of the acoustic spectrum with a corresponding part of the second acoustic spectrum, determining a frequency shift between the acoustic spectrum and the second acoustic spectrum based on the comparing step, and providing an output based on the frequency shift.

A lint collection assembly for a dryer appliance includes a filter housing defining an aperture through which a flow of air exits the drying chamber. A roller assembly includes a supply roller for unrolling clean filter medium over the aperture and a collection roller for simultaneously receiving a used section of the filter medium. A drive mechanism, such as an electric motor is coupled directly to the collection roller or to a separate drive roller for moving the filter medium over the aperture between drying cycles to automatically and conveniently collect filtered lint.

A lint collection assembly for a dryer appliance includes a filter housing defining an aperture through which a flow of air exits the drying chamber. A roller assembly includes a supply roller for unrolling clean filter medium over the aperture and a collection roller for simultaneously receiving a used section of the filter medium. A drive mechanism, such as an electric motor is coupled directly to the collection roller or to a separate drive roller for moving the filter medium over the aperture between drying cycles to automatically and conveniently collect filtered lint.

A particle agglomeration system for improving filtering capacity of an HVAC system is disclosed. The system may include a first plate. The first plate may include a first sound generator. The system may include a second plate. The second plate may include a second sound generator. The system may include a frame. The frame may be configured to position the first plate relative to the second plate. A standing sound wave may be formable between the first sound generator and the second sound generator.

A device with external diaphragm for acoustic cleaning and air purification is provided. The device comprises a housing with a first opening at a top for receiving one or more acoustic wave generating devices each with a diaphragm attached to a coil; and one or more external diaphragm each covering and sealing the diaphragm attached to the coil to facilitated in protecting the acoustic wave generating device as impurities or materials deposit and accumulate on the external diaphragm instead of the diaphragm of the acoustic wave generating device, and easy cleaning as only the external diaphragm needs to be cleaned, which also avoids damage to the diaphragm of the acoustic wave generating device during cleaning.

A particle agglomeration system for improving filtering capacity of an HVAC system is disclosed. The system may include a first plate. The first plate may include a first sound generator. The system may include a second plate. The second plate may include a second sound generator. The system may include a frame. The frame may be configured to position the first plate relative to the second plate. A standing sound wave may be formable between the first sound generator and the second sound generator.

An air filter and a method of air filtration using the said air filter are described. The air filter may comprise a filter media layer adapted to capture and filter one or more impurities from air. The air filter may further comprise one or more acoustic wave generating means attached at one or more sides of the filter media layer. The one or more acoustic wave generating means may generate acoustic waves to be propagated into the filter media layer. The propagation of the acoustic waves into the filter media layer may facilitate the filter media layer to enhance the filtration efficiency of the air filter. The air filter may further comprise a pre-programmed chip to control the frequency of the acoustic waves generated. Further, air filter may comprise a battery adapted to supply power to the one or more acoustic wave generating means and the pre-programmed chip.

An air filter and a method of air filtration using the said air filter are described. The air filter may comprise a filter media layer adapted to capture and filter one or more impurities from air. The air filter may further comprise one or more acoustic wave generating means attached at one or more sides of the filter media layer. The one or more acoustic wave generating means may generate acoustic waves to be propagated into the filter media layer. The propagation of the acoustic waves into the filter media layer may facilitate the filter media layer to enhance the filtration efficiency of the air filter. The air filter may further comprise a pre-programmed chip to control the frequency of the acoustic waves generated. Further, air filter may comprise a battery adapted to supply power to the one or more acoustic wave generating means and the pre-programmed chip.