This patent application covers design and modular manufacturing techniques for an economical air handler and exhaust fan product line that delivers better energy performance, acoustical performance, space utilization, and operational efficiency than is available in today's marketplace. An axial fan is positioned within airflow guides designed to minimize turbulence to reduce acoustics and energy consumption. The specific arrangement of air filters, heating and cooling coils, airflow guides, sound attenuating surfaces, fan modules, control panels, backdraft dampers and isolation dampers enables the stacking of modular units to meet air handler capacity requirements with inherent redundancy. In some configurations, the air handler described provides complete redundancy for a no-shutdown system that will reduce HVAC energy requirements to a lower level and provide a greater operating range than is available in today's market.

A sound suppression apparatus for installation inside a gas transport duct is provided. The sound suppression apparatus comprises a resistive sound-absorbing element (110) and a housing providing a reactive sound-attenuating element (130) communicating with a surrounding of the apparatus via opening in an outer surface of the housing. An outer surface of the sound suppression apparatus comprises an outer surface of the resistive sound-absorbing element and the outer surface of the housing. A gas transport duct comprising the sound suppression apparatus is also provided.

A windband for an exhaust fan system. The windband comprises an elongate housing receivable about a exit nozzle of the exhaust fan system, an air inducer formed from a perforated material and positioned adjacent the bottom portion of the elongate housing, and a discharge sleeve positioned adjacent and secured to the top portion of the elongate housing. The discharge sleeve is formed from a perforated material and forms a passageway through which gas from the nozzle and induced ambient air passing through the elongate housing are discharged. The perforated air inducer and discharge sleeve together assist in the minimization of a pressure differential between an upwind side of the windband and a downwind side of the windband when the windband is subjected to wind striking the windband at an angle.

A sound attenuating baffle device used in a duct receiving a gaseous flow in a flow direction therethrough, includes a baffle casing supported within the duct and a fibrous sound absorbing material occupying the hollow interior of the baffle casing. One or more perforated sheet members at least partially defines the exterior of the baffle casing across which the gaseous flow of the duct is arranged to be directed. A liner sheet of a non-eroding, sound absorbing foam material is supported within the hollow interior of the baffle casing against an interior surface of the perforated sheet member(s) so as to span across each of the perforations and prevent direct communication of the fibrous sound absorbing material with the perforations to prevent erosion of the fibrous sound absorbing material into the gaseous flow through the duct.

A modular fan housing configured to hold an array of motors and fans is provided. The modular fan housing is configured for use in an air-handling system that delivers air to a ventilation system for at least a portion of a building. The fan housing comprises a plurality of modular units configured to be stacked adjacent to one another in at least one row or column to form an array. The modular units each include an interior surface and have a front end and a back end that define a chamber. The chambers are configured to receive the motors and fans. Sound attenuation layers extend along at least a portion of the interior surface of the corresponding chambers. The sound attenuation layers are positioned between at least some of the adjacent chambers.

The invention relates to a sound-absorbent element for an air outlet, said air outlet comprising a housing with an air outlet opening and a connection to an air supply shaft, at least one sound-absorbent element being mounted in said housing and/or a housing of the air supply shaft, and said sound-absorbent element comprising a carrier that is connected to at least one layer of sound-absorbent material. Said at least one layer of sound-absorbent material comprises activated carbon, or at least one additional layer of activated carbon is applied to this layer of sound-absorbent material.

An acoustic metamaterial noise control system of embodiments of the disclosed technology combines acoustic metamaterial principles with absorptive materials, with a result of a significant reduction in sound radiation within, or emanating from, an HVAC duct. Sound waves that impinge on the noise control system placed at the end (terminal opening of an air duct to ambient space within a room/building), or at a predetermined place on the duct, cause the sound waves to reflect back to the start of the noise control system and also to be absorbed by sound waves within the absorptive core. This is accomplished by way of the use of micro-perforated panels (MPPs) placed in periodic manner with absorptive layers and air gaps to achieve anisotropic conditions to reflect and absorb sound waves for optimum sound reduction.

A drying apparatus for a water damaged floor structure having an intermediate layer between a surface layer and a subfloor, which drying device comprises a suction blower for, from an outlet opening in the floor structure, drawing humidified process air from the intermediate layer and heating the humidified air, and a sorption dehumidifier to receive the heated process air from the suction blower, convert it to heated dry air and, through an inlet opening in the floor structure, separate from the outlet port, force the heated dry air to the intermediate layer, where the heated dry air accumulates moisture from the floor structure and is converted to new process air which is again sucked up and heated by the suction blower in a closed process. According to the invention, the dryer has a PTC element for a sorbent block in the dehumidifier, a common housing for the suction fan and dehumidifiers, and a sound and heat insulation in the housing.

According to various embodiments, a mesh assembly may be provided. The mesh assembly may include: a first mesh including a plurality of first holes arranged according to a pattern; a second mesh including a plurality of second holes arranged according to the pattern; wherein the second mesh is provided on top of the first mesh; and wherein at least one hole of the plurality of first holes is at least partially obstructed by the second mesh.

A silencing device, an air purifier, and a method for producing the same are provided. The method includes that: a sound wave spectrum when an air purifier to be silenced performs operations is acquired; a frequency value, which exceeds a sound wave frequency limit for the air purifier, of the sound wave spectrum is calculated; and a silencing device adapted to the air purifier to be silenced is produced according to the frequency value. At least one structural parameter of the silencing device is configured according to the frequency value. The silencing device is configured to reduce a sound with the frequency value exceeding the sound wave frequency limit.