fan noise Articles

  • Low cost fan noise attenuation in the power industry

    An article about the application of our Quiet Fan technology (QFt) to reduce the noise from large fans in the power industry has been published in Power Engineering International. The journalist suggests that the widespread adoption of the technology in this industry could reduce both capital and running costs very substantially ...

  • Record breaking formula one fan noise control

    Problem: an extract system fan drone creating a potential environmental noise problem. Solution: aerodynamic engineering instead of silencers – in keeping with the Red Bull Technology ethos. The conventional technique used to reduce fan tones like this is a silencer – a large, palliative silencer that doesn’t tackle the source of the ...

  • Modelling of broadband noise radiated by an airfoil-application to an axial fan

    In this paper, a modelling of the broadband noise radiated by an axial subsonic fan is presented and validated. It is an extension of Amiet's model predicting the broadband noise generated by an isolated airfoil. Two sources are analysed, incident turbulence interaction noise and trailing edge noise. It shows the dominance of the leading edge noise. The broadband noise directivity for axial fans ...


    By Inderscience Publishers

  • Noise Measurement

    Definitions Threshold and criterion levels The threshold level is the A-weighted sound level at which a personal noise dosimeter begins to integrate noise into a measured exposure. For example, if the threshold level on a sound level meter is set at 80 decibels (dB), it will capture and integrate into the computation of dose all noise in the employee's hearing zone that equals or exceeds 80 dB. ...


  • That air conditioner noise is annoying!

    The sound of the HVAC System in your office or factory may be annoying depending on who you ask; the person who has to live with it, or the person who has to pay for it. To measure background noise levels objectively, we use Noise Curves. International standards organizations (ISO, ANSI and ASA) recognize the need to objectify judgements on the amount of ambient noise in enclosed ...


    By NTi Audio AG

  • The Investigation of Noise Attenuation by Plants and the Corresponding Noise-Reducing Spectrum

    As noise pollution is becoming more and more serious, many researchers are studying the noise attenuation effect provided by plants. This article examines six kinds of evergreens as research subjects so as to compare the different arrangements and densities of plants and their effect on noise attenuation. The authors studied the relationship between each of the plant’s characteristics (the ...

  • NASA acts to reduce crawler transporter noise

    The United Space Alliance sought outsideassistance to evaluate and develop noise controlmeasures for NASA’s two CTs at KSC aspart of a modernisation and upgrading program.NASA selected Noise Solutions Inc. (ageneral acoustical contractor) and their subcontractorFaszer Farquharson & Associates ofCalgary, Canada to engage in this project. Thefirst phase of the sound study ...

  • Reducing noise levels through engineering controls

      It"s fairly easy to control personal exposure to noise by limiting exposure time or using hearing protectors like ear plugs or ear muffs.  Engineering controls are usually applied to the machinery that produces noise. Imagine a 200 foot x 175 foot manufacturing facility with a 30 foot high ceiling.  In this building are a variety of cut-off saws, grinders, millers and other ...

  • Filming Low-Frequency Structure Born Noise With Acoustic Camera - Case Study

    Problem An apartment complex consists of five floors, with several apartments over four floors, and an attic on the top floor. In the attic an air circulation system is installed to provide circulation in the bathroms of all the apartments in the building. The circulation system is driven by an air fan distributing air through pipes going to all apartments. The air pipes are cemented in ...


    By Norsonic AS

  • Pinpointing Low Level Sanitary Noise in Apartment Building Case Study

    Problem A newly built apartment building consists of several floors with multiple apartments on each floor. One of the ground floor apartments is disturbed by sanitary noise from the apartment above, which is heard whenever the toilets in the top apartment are being flushed. The sanitary noise is heard in several rooms, and the level was measured to be around 30 to 35 dB, which is above ...


    By Norsonic AS

  • 5 New Features for Trojan Noise Nuisance Users in NoiseTools v1.6.1

    We’ve added a number of new features and functions to NoiseTools v1.6.1 to help make analysis and reporting easier for our Trojan Noise Nuisance Users. Take a look at these 5 new features and learn some handy tips for upgrading. NoiseTools v1.6.1 for Noise Nuisance Users ...


    By Cirrus Research plc

  • The experimental study of the effect of air conditioning system on internal noise within high speed train

    With the increasing requirement for the travelling comfort of high speed train, the reduction in interior noise becomes very important. Noise source identification is a prerequisite to the decrease in the interior noise. To study the effects of air conditioning system on the noise inside the high speed train, the comprehensive measurement of noise and vibration was made for different carriages of ...


    By Inderscience Publishers

  • DuPont LoWave Acoustic Material with Low-Frequency attenuation case study

    A major U.S. manufacturer of laboratory equipment was concerned that one of its newest pieces of equipment would not gain widespread acceptance in the marketplace due to its high overall noise level and unpleasant sound quality. Company officials needed to improve the sound signature of the equipment improving the comfort level of people working around it, without altering product design in a way ...


    By NEVA Associates

  • Gas Monitoring for Ventilation Control and Energy Management

    The growing demand for underground and enclosed parking and maintenance garages (resulting from limitations on land availability) has increased the awareness and need for proper ventilation and control systems. In addition, increased health and safety programs have only added to the concerns of toxic and combustible gases in confined or enclosed spaces. Historically, ventilation and make-up air ...


    By Arjay Engineering Ltd.

  • How to certify aero engines

    Aircraft Engine Noise Certification PowerJet, formed as a joint venture between Russian OAO NPO Saturn & French SNECMA (SAFRAN Group), have designed and built the new SaM146 turbofan engine selected by the Sukhoi Civil Aircraft Company to power its Superjet 100 aircraft family. The Sukhoi Superjet 100 is a medium-haul airliner developed in collaboration with Alenia Aeronautica (Italy), and ...

  • Clean and fume free environment for students

    The challenge A new facility was erected at the Vredenburg Campus (South Africa) in December 2008. Ventilation was not considered in the development stage of the facility and was, therefore, very poor with only natural air flow through open doors and windows and some ‘whirlybirds’ in the roof of the ...


    By Plymovent Group BV

  • Waste Transfer Station Odours - Case Study

    Application Greenstar Ltd. who operate the large waste transfer station at Ballyogan needed to ensure working conditions inside the building were acceptable to the workforce and that the surrounding area did not suffer from odourous emissions. An early part of the design process called for an efficient extraction system to draw air from the Reception Hall and the Baling Hall to meet these ...

  • Holcim Ste. Genevieve Cement Plant - Case Study

    Big and beautiful The new cement manufacturing facility of Holcim (US) at Ste. Genevieve with a production capacity of four million tonnes per year went on stream mid-2009 and is one of the most environmentally-efficient cement plants in the Holcim Group. It is 40 percent more energy-efficient than the Holcim (US) plants that were closed in 2009 and emits 10 to 25 percent less ...

  • NoiseNews Round-Up: Noisiest Dogs, Pokémon Go, Cinema Snacks & Opera

    Yes, it’s me – The Noise Doctor. I’m back with the NoiseNews Round-Up. I’ll be bringing you some of the latest and quirkiest noise-related news stories from around the world. In this edition, I’m looking at the top 10 noisiest dogs, Pokémon Go, cinema snacks and opera. Let’s get started. Ssssh! – Silent Snacks are Heading to the Big Screen at ...


    By Cirrus Research plc

  • Innova`s race against time; the sonic mystery

    What began as a puzzling mystery in the semi-arid scrub-land of Colorado, ended as a race against time for the acoustic specialists of INNOVA (formerly ATCO Noise Management). The Olathe Compression Station, operated by Kinder Morgan’s TransColorado Gas Transmission, is located on a plateau in isolated, canyon-cut Colorado countryside, three km from the nearest ...


    By Innova Global Limited.

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