Any specification change must be submitted in writing and approved by the architectengineer, in. Iac has been manufacturing quiet duct attenuators for over 50 years, installing thousands of units each year. Page 3 of 12 a digital attenuators frequency range should be matched to the application of interest. They do their job by utilizing acoustical baffles as means for broadband sound attenuation in hvac systems. To comply with a specified noise level, sound attenuators are added to suitable locations in the ventilation system. As a result, all iac acoustics quiet duct silencers provide a guaranteed acoustic performance. Sa sa sas r ca cb rectangular circularand used for smaterials sound attenuator. Metal forms sound attenuators are manufactured in many varieties, module sizes and materials, designed to eliminate acoustical fill entrainment. Rtqs series rectangular qseal attenuators the rectangular qseal attenuator includes the qualities of the rt series attenuator and incorporates an infill system fully. Iac packless silencers are reactive attenuators with no acoustic infill or lining materials. The silencers may be bent to a maximum radius of 2 x overall. Duct attenuator solutions are available in standard sizes and models, and we can help advise which range is right for your needs. Rectangular silencers noise control price industries. Danish audio connect manufactures a range of highend stepped audio attenuators for hifi, av and proaudio, used by diy audiophiles and audio equipment manufacturers throughout the world.
Noise generated in the silencer and caused by the gas interaction with the silencer. Single duct air terminals b model ezta single duct attenuator dimensional data ezta units with integral sound attenuator ezta units notes. Circular attenuators greenmill ac stocks a range of circular silencers for your current air conditioning or ventilation project. Of course, exceeding a digital attenuators 1db compression point generally results in the generation of elevated output harmonic and spurious signal levels due to the nonlinear behavior of diodes or fets used in digital attenuators. The product suitable for residential and commercial applications including schools and offices, the ventaxia rigid duct attenuator has been developed as a cost effective and compact way of reducing noise within a ventilation system. Products components assemblies imas introduction attenuators. Consult iac acousticss entire quietduct silencers catalogue on medicalexpo. Ac sound attenuator are used in air conditioning system to mitigate excess sound generated by air handling units and air conveying ducts. The choice of attenuators below are all 600mm long, with diameters of 100mm, 125mm, 150mm, 200mm, 250mm, 300mm and 400mm. Lfs silencers are advantageous where low frequency dil requirements are high in hvac systems.
Silencer information and definitions enoisecontrol. Silencers can be fitted to the inlet outlet of circular duct fans or to grilles and louvres as required. Lfs series lightweight flexible silencers pacific ventilation. Available in 100, 125, 150, 200, 250, 315 and 400mm diameter sizes. Welcome to hasco components precision rf and microwave coaxial attenuator section. To satisfactorily select an attenuator the following information is required. Sda small duct attenuators attenuato r typical standard size range model applications width height length sda crosstalk, terminal or duct 150 450mm 150 450mm 600 1800mm mounted attenuation in 50mm increments in 50mm increments in 300mm increments mda duct or equipment 300 2400mm 300,450,600,750,900,1050, 600 2400mm. Quietduct silencers iac acoustics pdf catalogs technical. Moreover, we manufacture duct silencers to specific metal tolerances with controlled acoustic infill flow resistances to achieve consistent results. The sound wave generated by these sources transfer its energy throughout the duct and to the occupants area as shown below. Sound attenuators permit the passage of air while reducing noise in ventilation systems. The combined interior diffuser cone and exterior square jacket casing make these units into aerodynamic regain devices as well as silencers. When low frequencies are controlling, a type lfs selection often results in. Ct2 uses a resistor network built on noninductive smd resistors.
Corporate buildings, industrial, commercial offices material. The light weight, low profile construction also provides corrosion resistance over metal silencers. Model 2608106 fixed attenuator other attenuation values are available to order series 081 for standard flange types and rec om men da tions see pages 118 onwards standard attenuation values suf. Quietduct commercial series silencers iac acoustics. Extreme linearity of fets used in super rf cmos attenuator results its being. The acoustic baffles provide excellent attenuation of speech and unwanted noise while permitting fresh air to circulate continuously.
Iac acoustics rectangular and cylindrical duct attenuators provide effective, predictable noise reduction at substantial savings over other noise reduction. We have standard sizes readily available and are also manufacture to individual requirements. Fixed fiber optic attenuator, also called fixed plug type or fixed buildout fiber attenuator, is used in fiber optic communications to reduce the optical fiber power by a certain level. Sound attenuator without data airmaster equipments emirates. Quiet duct ultra green silencers offer 100% environmentally friendly attenuation solutions. Easily installed, the duct attenuator is used in the system to absorb sound. The iac aeroacoustic laboratory begins offering thirdparty testing services. Sound power level attenuation in an elbow is caused by sound reflection. Triple lock sound attenuator sa the metal core is constructed from perforated and corrugated dead soft aluminum with mechanical interlocking seams the fiberglass insulation is used between the core and outer shell the outer shell is constructed from dead soft aluminum that is corrugated with mechanical interlocking seams to form an air tight, flexible, metal duct.
Iac is the only company in the world that manufactures and sells cleanflow attenuators. Industrial air duct silencers for hvac noise enoise control. Rotary are madebeforebreak the available values are 10k, 50k, 100k, and 250k ohms. The attenuator series, model 777c for example, is avail able in eight standard attenuation values from 3 to 60 db and is calibrated at dc, 4, 8, 10 and 12. Standard models are available in a range of attenuation values from 3 db to 30 db. Single duct attenuator ezta units with integral sound. Attenuators amplifiers and active devices electronics. Rf coaxial attenuators are used for test and measurement applications. For high insertion loss with broadband damping, even in the highfrequency range. Air duct silencers and acoustic louvers are commonly used at the intake and exhaust openings to reduce noise to an acceptable level. Iac has been manufacturing cleanflow attenuators for many years, installing hundreds of units each year. Calculate the attenuation in unlined and lined ducts.
From building services hvac systems to industrial discharge stacks, duct attenuators control noise. Cda circular duct attenuators uk cda2 1 of 2 caice internal diameter external diameter pod o d length octave band static insertion lossdb weight kg e d rn gd etail s 63 125 250 500 1k 2k 4k 8k n d p. Rectangular and circular duct silencers, as well as acoustic louvers, control the noise generated by air moving equipment. Fixed attenuators in circuits are used to lower voltage, dissipate power, and. Furnish and install quiet duct elbow style silencers of the types and sizes shown on the plans andor listed. The iac type lfs quietduct silencers provide superior low frequency attenuation. Elbow attenuators are available in three models for horizontal or vertical applications requiring broad band noise reduction when space for straight attenuators is not available.
Performance data is provided for eight centerline lengths 36, 48, 60, 72, 84, 96, 108, and 120. Sound attenuation in duct elbows engineering toolbox. Single duct attenuator dimensional data ezta units with integral sound attenuator ezta units notes. Duct attenuator acoustic attenuator ventilation airmatic. Please contact to our sales for other customized values. Refer to the rtqs series for applications where moisture may be present in the air stream. Attenuation certification for this series of attenuators is. Attenuation in lined and unlined ducts at different sizes and frequencies are indicated in the table below.
Noise control measures, such as silencers, allow the air to flow freely from the necessary generators without the addition of any unwanted sound. Model 779 is available in 15 standard attenuation values from 1 to 60 db and is calibrated at dc, 4, 8, 12. Attenuation due to end reflection is entered below. Airflow in the silencer is in the opposite direction to the noise propagation. Maximum insertion loss l balanced performance m ultralow pressure drop h construction type. Rectangular silencers are intended for silencing noise in rectangular ductwork and a wide range of design options allow them to be integrated into any hvac system with ease. Section 01 33 23 shop drawings, product data, and samples c. Series 081 model 2608106 features full waveguide band low frequency sensitivity the fixed attenuators, series 081, are low vswr devices suitable for operating over the full waveguide band.
Typical attenuation values are between 1 and 30 db. Weights are approximate and will vary based on selected options, insulation type, etc. Circular duct attenuators specialist ventilation services. It is convenient to discuss them along with decibels. The iac acoustics quietduct silencers meet stringent design requirements from acoustical consultants, consulting engineers, owners and contractors. Attenuators reduces the amplitude or power of a signal without distorting its waveform.
Testing was conducted in accordance with astm standard e4772006a, entitled standard test method for measuring acoustical and airflow performance of duct liner materials and prefabricated silencers and adc test code fd 72r1, entitled flexible air. The ventaxia rigid duct attenuator is suitable for residential and commercial applications including schools and offices. This includes noise on the inside of buildings and noise radiating outside to the surrounding neighbours. Dvac sound attenuators are designed to achieve the required performances as set out in the astm standards e47706a for prefabricated attenuators. Supply and sound attenuator duct model key available models wh general the aluminum supply tubing and sound attenuator are insulated flexible air ducts. Thank you for your enquiry, someone will be in touch soon. Iac acoustics quiet duct silencers acoustical solutions. Attenuators weaken or attenuate the high level output of a signal generator, for example, to provide a lower level signal for something like the antenna input of a sensitive radio receiver. Ncs acoustics design, manufacture and install many types of attenuators, including.
Rectangular attenuators shall be of the rt, r3t or rtqs series as designed and manufactured by fantech pty. Duct silencers acoustic louvers oneill engineered systems. Fixed attenuators in circuits are used to lower voltage, dissipate power, and to improve impedance matching. If the duct is located inside the conditioned building envelope, use the standard insulation which is. Insertion loss is considered part of the fixed performance of the system path in which the step or variable attenuator is located. Hasco stocks an extensive selection of rf and microwave attenuators. Offering excellent sound reduction over a range of frequencies, the rigid duct attenuator is available in two lengths depending on the noise suppression requirements. Manufactured in galvanised sheet metal with 50mm rockwool sound absorption material. Digital step attenuators offer precision and linearity. A wide variety of sound attenuator ducting options are available to you, such as hvac systems, air conditioning. Sound power and sound pressure are different in that sound power is a measure of. Cross talk attenuator introduction cross talk silencers are designed to maintain sound transmission ratings in low velocity air transfer between adjoining spaces. The design of the cleanflow quiet duct silencers is suitable for air handling systems requiring the ultimate in cleanliness and hygiene. It comes in two sizes and four different insulation thicknesses.
In the lower frequencies, such as 125 hz, even greater lengths of duct lining would be required to achieve the 10 20 db insertion loss typically achievable by many of the broad range of iac silencers including the lfs series. Acoustic attenuator insertion loss data for the attenuators to be derived from tests in accordance to bs4718. The attenuation from the terminal to the room is 5 db. The sound attenuators should have adequate silencing capabilities, low air resistance and be as small as possible. In ventilation systems, noise stems from a variety of components such as the fans or the fire dampers. Iac acoustics designs d duct diffuser silencers dds for installation at the outlet of vane axial fans. It is only in larger ducts and at higher frequencies the attenuation is considerable.721 1275 1358 1427 1508 990 430 690 184 987 1038 772 364 1359 227 1090 1403 12 1216 1031 306 732 579 370 949 1145 375 490 226 515 151 328 693 781 850 218