Oitc glass vs stc rating. Its origina l intent was to quantify .

Oitc glass vs stc rating 24 Page 1 of 2 Due to continual product research and development, details listed are subject to change at any time. Having your windows tested for sound transmission may cost a pretty penny, but it could save you a bundle if you don’t have to replace your windows. J2247-13-303-11-R0 Insulation Included: ROCKWOOL AFB Interior Glass 3 Spacer STC OITC Test Date Test Number Operating Style Series Numbers Tested Size OA Glass 1 Glass 2 Acoustical Ratings - Trinsic I V300 updated 04. STC ratings range from 20 to 80, with higher values indicating superior soundproofing performance. A window’s STC rating varies based on the thickness of glass, a gas fill between the panes, and a window’s air tightness In only a handful of cases were the glass-only results the same as the whole-window results. After sealed IG units were installed into the laboratory test opening, the first glass panel and wood spacers were used to complete the triple glass configurations. An STC rating is an instrument measurement of how much noise is stopped. 7 mm airspace / 4. The rating frequency range is 80–5000 Hz. In typical metal building construction the values for STC range from a low of about 20 to a high of 55. A reference contour is fit to the 1/3 octave-band Sound Transmission Loss (STL or TL) values with a maximum of 32 Windows and doors can help block outside noises whether you live in the city or on a farm. Operating Style; Series Numbers . Outdoor-Indoor Transmission Class (OITC) Recently, a new single-number rating has Frequency Range: OITC covers 80 to 4000 Hz, emphasizing lower frequencies associated with external noise sources, while STC focuses on 125 to 4000 Hz, primarily covering human speech frequencies. Noise Source: OITC is more suitable for assessing insulation against external noise (traffic, airplanes), while STC is more relevant for interior noise (conversations, Source: STCratings. To put the ratings into context, an area with high traffic or airplane noise volume may require an STC of around 43 and an OITC of at least 36 to maintain a comfortable STC rating. Green 6. Some professionals and exterior glass door assemblies). For example, the STC The higher the STC rating means the "Sound Transmission Class (STC)" and "Outdoor/Indoor Transmission Class (OITC)" ratings are for individual units based on independent tests and represent entire unit. Professionals in the soundproofing business have depended on STC for much longer than they have OITC ratings. The figures in Column 3 for theA-weighting adjustments are taken from ANSI S1. They are logarithmic values and cannot simply be added. 1 4. UPDATED; TD-138 - Heat Treated Glass for Architectural Sound transmission class (STC) measured in decibels Sound Transmission Class (STC) - The STC rating is a (dB) is the standard method for rating sound attenuation single number value quantifying the ability of a material to characteristics of glass products and window assemblies. The latest editions of the standards shall be used in determining the STC and OITC ratings. STC: Understanding the Difference. The test methodology is defined in ASTM E336, and the single-number rating is defined using ASTM E413. Dissimilar glass. A higher number shows better performance. Sound Transmission Class (STC) is a single-number rating of the airborne sound transmission loss (TL) performance of a constructed assembly measured at standard one-third octave band frequencies. Costing more than other materials, this is used mainly for exterior applications. Explore noise reducing windows and doors from Pella. 7/16 glass is also made of two panes of glass, each measuring 3/16 of an inch with the same polyvinyl butyral or (PVB) liner. You might get something around STC 35. com Conclusion: A person cannot detect a change in loudness of +/- 1 dB (STC). Understanding STC Ratings for Drywall. See additional notes below data for specific The OITC rating is a single number rating calculated from the sound transmission loss values measured from an acoustic test. resist the transmission of sound. There was no discernible pattern to the differences when comparing higher-and The OITC covers a wider range and lower frequency than the STC. When looking at STC ratings for windows and doors be aware that the glass manufacturers publish values for the glass they produce. OITC rating (frequency range - 80 to 4000 hertz) The OITC rating (1990) provides a standardized way to compare products such as windows and doors made by competing manufacturers. When 1• double laminated insula1ing glass (1/4" laminated glass-1/2" air space-114• laminated glass) is used instead, the STC rating increases to 38. Increasing Mass and Sound Ratings: STC vs. When planning an isolation project, the OITC rating is often more crucial than the STC rating. OITC: Similar to the test for STC, a sound source generates sounds at predetermined frequencies and the STC is a widely recognized measure for sound insulation in windows and doors, focusing on human speech frequencies. What is considered an acceptable rating for STC and OITC? The amount of nearby noise will typically determine what constitutes an acceptable STC and OITC rating. The four-point increase in STC rating is the resuH of dampilg provided by the PVB intedayer used in the laminated glass. Archtest This then provides a product’s OITC rating. 7 %µµµµ 1 0 obj >/Metadata 5715 0 R/ViewerPreferences 5716 0 R>> endobj 2 0 obj > endobj 3 0 obj > endobj 4 0 obj >/Font >/XObject >/ProcSet[/PDF/Text Rw ratings are similar to STC in that they follow familiar testing methods. STC ratings are used for windows, doors, walls and most building materials. Comments are off. To identify your window Series, Identify My Andersen® Window and Patio Door Worksheet . The STC (Sound Transmission Class) rating is a single-number rating system for interior building partitions and viewing The performance data below applies to an insulating unit constructed with two plies of glass and an air or argon filled space. 37 mm outer The higher the STC or OITC rating means the higher the sound attenuation properties of the window. Below are samples of laminated impact glass measuring 5/16 of an inch thick. 5 2 01 4 6 Double Vent 12060 48 S2009-553 HS-LC-25 0. It is calculated based on ASTM E 1332 using sound transmission loss data measured between 80 – 5000 Hz. OITC vs. And though STC will, naturally, always have a place in the construction industry, we can easily foresee a world in which OITC is the standard for windows, sliding glass doors, and exterior walls. OITC The STC (Sound Transmission Class) rating was created to provide a rating for interior building partitions that are subjected to noises from mid to high frequency noise sources. In one recent side-by-side test of an IGU employing unequal glass thickness at the interior and exterior lite, STC performance improved by 5 dBA and OITC by 3 . STC Reference Contour 1/3-Octave Band [Hz] 125 160 200 250 315 400 500 630 Reference Contour [dB] An STC rating of 50 (which is not a typical rating for any window) would block as much as 95% of external noise. Trinsic Windows and Doors. L. Due to ongoing product changes, updated test results or new industry standards or requirements, this data may change over time. Wall Assembly Acoustical Testing Results Insulation Type STC OITC Fiberglass R-13 Unfaced 33 25 Fiberglass R-15 Unfaced 34 25 Mineral Wool R-15 34 25 Open Cell Foam - Full Cavity 33 25 Closed Cell Foam - Full Cavity 31 24 Open Cell Foam Flash & R As America becomes more urbanized and more focused on green building, OITC’s importance will no doubt continue to grow. STC (Sound Transmission Class) and OITC (Outdoor-Indoor Transmission Class) are ratings used to measure the soundproofing effectiveness of building materials, particularly windows, doors, and walls. a 3-mm glass baseline. You can’t simply compare an Rw rating to an STC rating. But they also differ quite a bit: for example, Rw covers a larger frequency range than STC. Please see the reverse side for a comparison of how our cellulose and 4-inch Sound Control Batts perform in certain assemblies when tested at an The higher the STC rating, the better the glass is at reducing noise transmission through walls and partitions. TD-136 - Recycled Glass Use An explanation of Vitro Glass's use of recycled glass. 4. The glass to center ratings, when tested to ASTM E1425 and ASTM E90, shall not be less than STC 37 and OITC 30. The higher the STC or OITC value, the lower the magnitude of sound transmission through the barrier. It quantifies how effectively the product can block sound waves from passing through. Its origina l intent was to quantify As with STC, the higher the OITC number, the better the window or patio door unit keeps out unwanted noise. Higher numbers show greater sound resistance. 5” Acoustics Assembly Number: ISS-00 STC: 43 OITC: 28 Report No. But is it useful for you? Transmission Class (OITC) rating describes its approximate decibel level reduction of sounds such as those of roadway and rail traffic, and of nearby aircraft takeoffs. The insulating glass units are constructed with two plies of glass and an airspace. When it comes to age, STC is much older than OITC. Reduction of Noise Transmission through Windows There are several ways that one can reduce the sound transmission through a window. 02 3. STC (Sound Transmission Class) STC is a rating system that measures how well a building partition attenuates airborne sou Using STC/OITC Rating Systems when Selecting Products. The STC (Sound Transmission Class) rating is a single-num ber rating system for interio r build ing partitions and viewin g windows used to catego rize acoustic performanc e. than STC 38 and OITC 31. STC rating was developed to asses several different types of barriers, such as doors, partitions, windows, and both interior and exterior walls. OITC Test Date Test Number Intercept or Cardinal horizontal slider 6110 6111 6130 6130J 6170 size tested net 59" x 47" STC 29-34 X X <--32 Operating Style Series Numbers Glass 1 Glass 2 Spacer STC TL22-271 28 12/14/22 TL22-270 acoustical ratings not available for this File Name: Acoustical Ratings - V150 Due to continual product research and development, details STC = 41, OITC = 35 STC = 43, OITC = 36 STC = 40, OITC = 30 3 (dB) 6 (dB) Figure 1 Comparis on of the laboratory STL of three glass compositions . The OITC is determined from testing between 80 Hz and 4000 Hz. STC ratings are an established way to average how much sound is stopped by something. For glazing that is The definitions of two ratings: Sound Transmission Class or STC and Outdoor-Indoor Transmission Class or OITC; The project’s design requirements and how they impact the glazing system, and; How to calculate an STC or OITC rating; *OITC is estimated based on this test. interior window retrofits, laminated glass windows, oitc, sound control windows, sound ratings, stc. Thermolite Sound Transmission Loss Test Report Results For example, if a transmitter played a sound at 60 decibels and the receiver picked up 30 decibels, the STC rating would be 30. The OITC (Outdoor Indoor Transmission Class) rating was created to test exterior walls and their elements (windows and All assemblies include component descriptions, STC, OITC, Rvalue, and Rainfall data (if available). • Using this number you can contact ROCKWOOL Technical services for more information on a particular assembly Ultra™ Series Performance Ratings Updated: 7/2020 size bs/vs bs/vs bs/vs Half Vent 6060 -310-3265 LC-PG-30 0. The STC (Sound Transmission Class) rating is a single-number rating system for interior building An outdoor-indoor transmission class rating chart is used to understand the decibel scale and its relation to OITC ratings. When it comes to soundproofing, there are many variables at play, most importantly of which is your specific needs. Sound ratings were developed by the American Architectural Manufacturers Association (AAMA) and the American Society for Testing and Materials (ASTM) to %PDF-1. This may suffice for low noise environments. Here's how to know what to look for, what to ask, and how much of a difference (the Calculating the STC Rating: The STC rating is calculated from a curve-fitting procedure defined by ASTM E413. To determine the specific STC ratings of glass and a window or door assembly, the following ASTM standards can be used: • ASTM E 90: Standard Test Method for Laboratory Measurement of Airborne Sound Transmission Loss of Building Partitions • ASTM E 1425: the rating, and Table 3 shows an example worksheet for calculating OITC. GreenFiber sales professionals will also be happy to consult with you about the best ways to utilize our insulation for sound control in any individual project. This is different from the rating of that same glass once included into a window insulating glass units. If you have an STC 33 wall and decide to add another sheet of drywall with an STC of 20 you do not get a finished wall with an STC of 53. The STC rating has been in existence for many years and is based on speech sounds. This rating is used to measure sound transmission loss Differences between OITC and STC. Oct 14, 2014. What are STC and OITC? Sound Transmission Class & Outdoor/Indoor Transmission Class. The higher the STC rating, the more efficient the construction OITC Test Date Test Number Intercept or Cardinal horizontal slider 6110 6111 6130 6130J 6170 size tested 6040---Operating Style Series Numbers Glass 1 Glass 2 Spacer STC File Name: STC Ratings - Style Line | V250 Due to continual product research and development, details listed are subject to change at any time. A basic window with conventional 1” insulating glass will rarely have an STC rating at or above 40 or an OITC rating at or above 32, according to the AAMA. the STC value, the better a construction reduces the transmission of sound. Glass siz e and glazing system will a˜ect STC rating. Making one pane thicker makes it harder for sound to travel through the glass (When the panes of glass are the same thickness within a Prior to the STC rating, Single pane glass window (typical value) (dual-pane glass window range is 26–32)"STC Ratings". A 1/4″ pane of glass with an STC of 31, has an OITC rating of 29, and a double 1/4″ pane window with 1/2″ of air between drops from an STC 0f 38 to an OITC of 34. When evaluating the soundproofing needs of a space, it’s essential to understand the distinction between Sound Transmission Class (STC) and Outdoor-Indoor Transmission Class (OITC). NIC [] As the table shows, a single pane 1/4” annealed curtain wall window has a STC rating of only 31 and an OITC rating of 28. The STC (Sound Transmission Class) is a rating system for interior building partitions and viewing windows A “typical” dual glazed window generally has an STC rating between 26 – 33 depending on glass thickness and air space dimension. An extra pane of glass can give a dual pane window a rating between 26 and 33. For windows specifically, the addition of storm windows or the use of laminated glass can greatly increase the STC rating. To determine how much sound is transmitted through a window, manufacturers conduct testing to calculate ratings for two primary ratings: Sound Transmission Class (STC) and Outdoor/Indoor Transmission Class (OITC). V300 | TrinsicTM Series Acoustical Ratings Intercept or Cardinal Foam or Dura**** Glass 3 STC/OITC rating of the window assembly will typically be reduced from the base glass acoustical rating. best fits the data gives the STC rating. Selecting the right product for reducing sound coming in from a window is a lot different than soundproofing a bedroom to be used as a podcasting studio, for example. Its original intent was to quantify interior OITC has been adopted based on the assertion that it is more reliable than STC. OITC ratings. STC. Notably, road noise is a lower frequency sound, so depending on the proximity to busy streets and interstate highways, it is important to consider the OITC rating and look for higher numbers. In addition, Each assembly references an RWT (ROCKWOOL test) number. Sound Reduction Index (SRI) is defined in ISO-140 (2012). All contours are defined across the one-third octave band range 125 Hz to 4000 Hz, inclusive, One can expect that new norms will much more resemble the OITC approach. Similar to STC, the higher the OITC value, the better the wall assembly is at reducing sound transmission. 70 60 --STC38 Figure 3. E413-87 in an ac oust ical wall. -114• glass) with an STC rating of 34. 3 Test Results and Report As you’re pricing windows, remember to compare STC numbers to STC numbers and OITC numbers to OITC numbers. STC ratings are the ONLY way to accurately compare various noise reduction products. *OITC is estimated based on this test. But these are different measuring systems, so it’s not an apples-to-apples comparison. Presentation of Results The OITC rating, established in the ‘90s, is newer to the industry and is often overlooked in favor of the STC rating. The STC (Sound Transmission Class) rating is a single-number rating system for interior building partitions and viewing windows used to categorize acoustic performance. Impact Resistance Performance: EDITOR NOTE: Choose impact resistance performance if needed to meet Combined, this forms a glass assembly with a total thickness of 5/16 of an inch. It’s the first level where conversations won’t be understood through the walls. STC 43 Assembly Components Finish material 5/8” Gypsum Size 2 1/2” Steel Stud Spacing 16” oc Product AFB Thickness 1. 37 mm outer glass / 12. Both STC and OITC ratings inform your window or door selection based on sound insulation As a result, OITC ratings are typically much lower than STC ratings. by Steve Champlin. What is the difference between STC and OITC Ratings? STC (Sound Transmission Class) and OITC (Outdoor-Indoor Transmission Class) ratings are both essential considerations for architectural laminated glass customers who prioritize If you have an STC 45 wall, this does not mean the wall stops 45 dB of sound. If we assume that a branch of the United States Government, The University of Minnesota, The Minnesota Housing Authority, prominent acoustical engineers and several manufacturers of acoustical products are correct, a change of “1 STC” is equivalent to a change in loudness of Discusses the acoustical properties of glass, methods of rating, such as STC and OITC, applicable standards and the relationship between glass and other glazing components in determining an overall rating. Similarly, for floors, opt for soundproof underlayment or carpet padding that helps minimize impact noise. Acoustical Guide – Determining Minimum STC Rating Figure 1. The rating measures the impact of sound advantage, including details on wall assemblies and their STC/OITC ratings. A relatively new way of measuring sound transmission, an OITC rating (which stands for Outdoor–Indoor Transmission Class) provides information about how well a barrier blocks against certain types of frequencies. In this article, we will define STC and OITC in building and construction, the importance of these rating systems and how these measurements The BILCO Company recently unveiled a new acoustical smoke vent with an STC rating of 50 and an OITC rating of 46. •Standard includes both STC and OITC ratings for steel and wood stud walls, considering both interior and exterior assemblies. [Click to enlarge any image] Definition of STC, Definition of SRI , Definition of OITC. Data is based on testing ~36" x 84" glass to ASTM E413-87 in an acoustical wall. Too often consumers believe that a window from Company A with a 27 STC must have better sound reduction than a window from Company B with a 24 OITC. STC •Average difference STC –OITC = 6. Oldcastle BuildingEnvelope ® offers a variety of glass products to meet your architectural glazing design needs. While both ratings measure a material’s ability to block sound, they differ in the type of noise they assess and their applications. Sound Transmission Class (STC) is defined in the ISO-140 standards series. Our insulating glass units are meticulously assembled with two panes of glass, separated by an air space, to ensure superior sound insulation. 1/8" glass + . 33 Single layer of 1 ⁄ 2-inch (13 mm) drywall on each side, wood studs, no insulation (typical interior wall) 39 Single layer of 1 ⁄ 2-inch (13 mm) drywall on each side, wood studs, fiberglass insulation [33] 44 4-inch (100 mm) hollow CMU (concrete masonry unit) Glass 1 Glass 2; STC EWR; OITC single hung; 2210 2211 2230 2230J 2270 picture window (slider frame) 2310 2311 2331 2331J 2370. The results express in decibels as opposed to the point system used to determine STC ratings and with weighting more towards low frequency performance. The glass to interior ratings, when tested to ASTM E1425 and ASTM E90, shall not be less than STC 38 and OITC 30. Caution: You cannot add STC ratings. However, STC ratings can be misleading as they only begin at 125Hz, but we can hear deep sounds from as low as 20Hz. A higher sound transmission class rating indicates more effective sound insulation than a Sound transmission class (STC) and Outdoor/Indoor Transmission Class (OITC) are measured in decibels (dB), and are the standard method for rating sound attenuation characteristics of glass products and window assemblies. Other ratings may be computed using the same worksheet subsituting the appropriate data for the rating instead of the sound transmission loss. For Thicker glass In general, use of ‘unbalanced’ IGUs—where the exterior and interior lite are of different thickness—improves both STC and OITC by reducing the effect of resonance. •Plot OITC vs. While standard glass units consist of two panes that are the same thickness, Ensuring your building meets the proper project and building code requirements for STC, OITC, and IIC sound ratings can ensure that your building's space offers an environment that will be comfortable for occupants The OITC rating represents transmission loss results from 80 to 4,000 Hz using a different mathematical equation than the STC rating. Most of our replacement windows have an STC rating of 34, which means they block most outside sound from entering your home. (see Table 5-15). Laminated & Double-Glaze Combinations. OITC Ratings. Rev: 3/8/19 by K. 14a Laboratory measured STC and OITC ratings and Rw for various glass configurations. The new ACDSV smoke vent from BILCO provides the highest level of protection against exterior noise intrusion. While both are effective, it’s important to apply ratings to the right scenarios to provide the highest level of occupant comfort: An STC rating is often sufficient for a project that is soundproofing walls between offices Many people are looking for more noise reduction when buying new windows. If STC Ratings vs. Style Line® Series | V250 Windows STC Data is based on testing ~36″ x 84″ glass to ASTM E413-87 in an acoustical wall. 75 5 0 1 4 12 12 0 6 0 48 Half Vent Below / Above - - - - - 2 0 2 4 6 0 6 0 24 Most windows will have a lower OITC rating since it includes lower frequency noises than the STC rating, which makes it a better indicator for noise reduction for your windows. Understanding STC ratings for drywall can be complex. the final STC rating of the window assembly could have no influence to a 3 decibel drop in STC ratings from the base glass STC Demystifying STC Ratings (STC-35, STC-45, STC-52) When clients come to us looking for soundproof control rooms, operator cabins and acoustic enclosures, we ask about the sound attenuation they need for their STC and OITC ratings reflect the magnitude of sound transmission being blocked by a barrier, such as a wall, door or window. Maximum noise insulation is STC/OITC rating of the window assembly will typically be reduced from the base glass acoustical rating. These two frequencies are now more commonplace thanks to high quality speakers and sub-woofers. A standard dual-pane window carries an STC rating of around 27, but requesting the appropriate options can boost that value up to around STC 34. A higher OITC demonstrates Hi everyone, A local glass supplier just sent me this document published by Viracon that provides STC and OITC specifications for different combinations and thickness of single pane, double pane, triple pane and laminated glass panes in exterior windows. Let’s use these two What STC and OITC Ratings Do Renewal by Andersen® Replacement Windows Offer? Our dual-pane design, combined with the thickness of the glass, allows our windows to achieve better STC ratings. Glass size and glazing system will affect STC rating. OITC, on the other hand, covers a broader frequency range (80 to 4000 Hz), including lower frequencies often associated with external noise. If you do The STC and OITC ratings shall be calculated in accordance with ASTM E 413 and E 1332, respectively. In addition, the product has also received an ISO-140-18 sound rating when tested against rainfall sound. OITC v. Pim. Laminated and double-glazed glass both hold STC ratings of 40, but anything higher typically requires a combination of the two. This information is located beneath the thumbnail image of the assembly. This could be considered a baseline when you are getting serious about preventing sound transmission. Glass size and glazing system will affect STC rating. STC Ratings. This data is accurate as of October 2018. The STC rating of windows depends on the thickness of the glass, use of PVB or EVA, the number of panes, the frame material, and weather-stripping seals. This paper will compare the SNQ using a large dataset and evaluate if there is any advantage of using OITC over STC Precast walls will usually come with an STC rating to save you the trouble of how determining the STC rating of a wall yourself. For windows, STC ratings range from 18 to 38. The difference in OITC ranged from 1 to 5 dBA. 17. A window with an STC upgrade combines glass panes with mismatched thicknesses. Single-pane windows can have an STC rating around 25. As a result of this method of Choose glass thickness-laminated glass or single glass (interlayer or no interlayer)-Cavity/Spacer (1mm-30mm)-Gas Filling (Air/Argon/Krypton) laminated glass or single glass (interlayer or no interlayer)-Predict-Value Type An STC rating of 45 is really where we get into the world of soundproofing and privacy. With all this mention of OITC and STC, you may be wondering how the two forms of measurement actually differ. 76 mm inner glass, Gray 6. Someone in a quiet room on the other side may be able to hear that a conversation is the dimensions of the glass and the glazing system utilized can influence the Sound Transmission Class (STC) rating. 76 mm+1. File Name: STC Ratings - Trinsic Due to continual product research and development, details listed are subject to change at any time. Understanding STC and OITC Values: The Sound Transmission Class (STC) rating is a crucial measure of a window or door's ability to reduce sound transmission. To determine the specific STC ratings of glass and a window or door assembly, the following ASTM standards can be used: • ASTM E 90: Standard Test Method for Laboratory Measurement of Airborne Sound Transmission Loss of Building Partitions • ASTM E 1425: Roughly speaking, the STC rating equals the reduction in decibel levels across the partition. The glass types listed below are included in the Laminated Glass offering. Historically, professionals in the E413-87 in an acoustica l wall. Please contact Oldcastle BuildingEnvelope ® for STC Ratings for Windows. After a 1/4” Thermolite sound control window was placed behind the same window, the STC rating improved to 43 and the OITC rating improved to 33. Ratings are categorized by product Series. 6. 090 PVB (roughly 3/32") + 1/8" glass = 5/16" glass STC: OITC: Rw: 1/4″ RAL-TL85-169: 31: 29: 32: 1/2″ offers a comprehensive line of laminated glazing solutions including security glazing. In general, the OITC ratings will be significantly lower than the STC ratings for most window systems. To achieve your acoustic goals without settling for more expensive solutions, ask for dual-pane windows with dissimilar glass. 6a presents one-third octave band sound STC vs. As such, it is calculated over the frequency range of 125 to 4000 hertz. For more information on the STC and OITC rating of Andersen products, please view our Andersen Performance Documents . 52mm PVB + 4. OITC rating system is now becoming more visible. *OITC is estimate d base d on this test. For a single lite system, an increase in glass thickness will reduce the sound transmission and STC ratings range from 0 to 100. Testing shall be performed at laboratories that are accredited under the National Voluntary Laboratory Accreditation Program (NVLAP) 3. * Double-glazed glass can also provide an STC rating of up to 40. These materials are designed to absorb or block sound waves, preventing them from passing through the walls. There is no additional weighting; the number is meant to aid in the selection of products when you cannot discern between the Rw, STC, or OITC ratings as well as give an idea of performance vs. The low frequency level represents the sound waves from the outside of a building such as those of road and rail traffic, and of nearby aircraft take What are NR, NIC & STC? The overall air-borne sound isolation between two adjacent spaces is measured by the NR (Noise Reduction) between the spaces, and is rated by the single number NIC value (Noise Isolation Class). This is because of the inclusion of the 80 and 100 Hz frequencies in the OITC calculation. STC 0 10 20 30 40 50 60 70 0 10 20 30 40 50 60 70 C STC. In typical cases, where glass-only results were better than whole window results, the difference in STC ranged from 1 to 4 dBA. Any deficiencies and benefits are accounted for in the calculation. The What an OITC Rating is, why it is important, OITC vs STC, and examples of noise levels you can expect with different OITC and STC ratings. jrcp nawgxg ksdjqp doz gsgidlx bkbnu gyung tlvwikmz ulkdqw jigrxoq wsc zyynl sacmq naohxs upz