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HomeMy WebLinkAboutCT 2017-0002; TYLER STREET RESIDENCES; 3337 TYLER STREET NOISE ASSESSMENT IN CARLSBAD CA; 2017-04-03Ldn Consultlng, rnc:. 42428 Chisolm Trail, Murrieta CA 92562 www.ldnconsulting.net April 3, 2017 Elizabeth Lagrua Tyler Street Development, LLC 4459 Hackett Avenue Lakewood, CA 90713 phone 760-473-1253 fax 760-689-4943 APR 1 3 2017 CITY o:~ C ·:l.' /·O Subject: 3337 Tyler Street Noise Assessment in Carlsbad CA The firm of Ldn Consulting, Inc. is pleased to submit the following noise impact analysis for the proposed 3337 Tyler Street residential development in the City of Carlsbad. The purpose of the survey is to determine the estimated exterior and interior noise levels within the outdoor areas of the project site and within the residential structures and recommend mitigation measures for compliance with the California Code of Regulations Title 24 and the City of Carlsbad guidelines and requirements for noise. PROJECT LOCATION/DESCRIPTION The proposed site is located on approximately 0.34 acres and consists of eight (8) multi-family residential dwelling units in two three-story buildings. The proposed project is located at 3337 Tyler Street, west of Interstate 5 in the City of Carlsbad, CA. The primary noise source that affects the site is the San Diego Northern Railway (SDNR) located approximately 205 feet east of the site as can be seen in Figure 1. The project site configuration is provided in Figure 2 below. ACOUSTICAL FUNDAMENTALS Noise is defined as unwanted or annoying sound which interferes with or disrupts normal activities. Exposure to high noise levels has been demonstrated to cause hearing loss. The individual human response to environmental noise is based on the sensitivity of that individual, the type of noise that occurs and when the noise occurs. 4/3/2017 1 1657-05 3337 Tyler Street Noise Report Elizabeth Lagrua Tyler Street Development, LLC 4459 Hackett Avenue Lakewood, CA 90713 4/3/2017 Figure 1: Project Site Location 2 Ldn ConMJ/t/1111, Inc. 42428 Chisolm Trail Murrieta CA 92562 phone 760-473-1253 1657-05 3337 Tyler Street Noise Report Elizabeth Lagrua Tyler Street Development, LLC 4459 Hackett Avenue Lakewood, CA 90713 Ldn CoMu/111111, Inc. 42428 Chisolm Trail Murrieta CA 92562 phone 760-473-1253 Figure 2: Proposed Project Site Plan 4/3/2017 1 r I f I~ i .. ll -.. ' • ' i i I I ' I t j : • l : I I I I j I I · I 1 I 1 I 11 I ii I • I kl I 1 3 '-. R F f,' 'f' I' ' • 1657-05 3337 Tyler Street Noise Report Elizabeth Lagrua Tyler Street Development, LLC 4459 Hackett Avenue Lakewood, CA 90713 Ldn CoMult/1111, Int:. 42428 Chisolm Trail Murrieta CA 92562 phone 760-473-1253 Sound is measured on a logarithmic scale consisting of sound pressure levels known as a decibel (dB). The sounds heard by humans typically do not consist of a single frequency but of a broadband of frequencies having different sound pressure levels. The method for evaluating all the frequencies of the sound is to apply an A-weighting to reflect how the human ear responds to the different sound levels at different frequencies. The A-weighted sound level adequately describes the instantaneous noise whereas the equivalent sound level depicted as Leq represents a steady sound level containing the same total acoustical energy as the actual fluctuating sound level over a given time interval. The Community Noise Equivalent Level (CNEL) is the 24 hour A-weighted average for sound, with corrections for evening and nighttime hours. The corrections require an addition of 5 decibels to sound levels in the evening hours between 7 p.m. and 10 p.m. and an addition of 10 decibels to sound levels at nighttime hours between 10 p.m. and 7 a.m. These additions are made to account for the increased sensitivity during the evening and nighttime hours when sound appears louder. CNEL values do not represent the actual sound level heard at any particular time, but rather represents the total sound exposure. Additionally, Sound Transmission Class (or STC) is an integer rating of how well airborne sound is attenuated by a building partition. STC is widely used to rate interior partitions, ceilings/floors, doors, windows and exterior wall configurations (see ASTM International Classification E413 and E90). The STC number is derived from tested sound attenuation values found at the 1/3 octave band frequencies. These transmission-loss (TL) values are then plotted and compared to a standard reference contour. Acoustical engineers fit these values to the appropriate TL Curve to determine a single STC value found at 500 Hertz. STC is roughly the decibel reduction in noise a partition can provide, abbreviated 'dB'. If an 85 dB sound on one side of a wall is reduced to 50 dB on the other side, that partition is said to have an STC of 35. This number does not apply across the range of frequencies because the STC value is derived from a curve-fit from the tested 1/3 octave band frequencies. Any partition will have less TL at lower frequencies. For example, a wall with an STC of 35 may provide over 40 dB of attenuation at 3000 Hz but only 15 dB of attenuation at 125 Hz. 4/3/2017 4 1657-05 3337 Tyler Street Noise Report Elizabeth Lagrua Tyler Street Development, LLC 4459 Hackett Avenue Lakewood, CA 90713 NOISE STANDARDS City of Carlsbad Noise Standards Ldn Conllult/1111, me. 42428 Chisolm Trail Murrieta CA 92562 phone 760-473-1253 The City of Carlsbad's General Plan Noise Element requires that all exterior sensitive areas shall limit noise exposure. For noise sensitive residential land uses, the City has adopted a policy which has established a "normally acceptable" exterior noise level goal of 60 dBA CNEL for the outdoor areas and an interior noise level of less than 45 dBA CNEL. However, the City has also established a "conditionally acceptable" policy goal of up to 65 dBA CNEL for residential land uses. For residential properties identified as requiring a noise study, a study shall be prepared by an acoustical professional. This study shall document the projected maximum exterior noise level and mitigate the projected exterior noise level to a maximum allowable noise level. Interior noise levels should be mitigated to a maximum of 45 dBA CNEL in all habitual rooms when the exterior of the residence are exposed to levels of 60 dBA CNEL or more. If windows and doors are required to be closed to meet the interior noise standard, then mechanical ventilation shall be provided per City requirements. California's Title 24 Noise Standards The California Commission on Housing and Community Development adopted noise insulation standards for multi-family residential buildings (Title 24, Part 2, California Code of Regulations or CCR). CCR Title 24 establishes standards, based on the U.S. Department of Housing and Urban Development (HUD) requirements, for interior room noise (attributable to outside noise sources). The regulations also specify that acoustical studies must be prepared whenever a multi-family residential or motel/hotel building or structure is proposed to be located near an existing or adopted freeway route, expressway, parkway, major street, thoroughfare, rail line, rapid transit line, or industrial noise source, and where such noise sources create an exterior CNEL (or Ldn) of 60 dBA or greater. Such acoustical analysis must demonstrate that the residence has been designed to limit intruding noise to an interior CNEL (or Ldn) of at least 45 dBA. 4/3/2017 5 1657-05 3337 Tyler Street Noise Report Elizabeth Lagrua Tyler Street Development, LLC 4459 Hackett Avenue Lakewood, CA 90713 ANALYSIS PROCEDURES Exterior Noise Levels Ldn eon.ult/1111, Inc. 42428 Chisolm Trail Murrieta CA 92562 phone 760-473-1253 Noise measurements were taken at the site using a Larson-Davis Model LxT Type 1 precision sound level meter. The noise level meter was programmed in "slow" mode and set to record noise levels in "A" weighted form. The sound level meter and microphone were mounted on a tripod, five feet above the ground and equipped with a windscreen during all measurements. The sound level meter was calibrated before and after the monitoring using a Larson-Davis calibrator, Model CAL 200. The site was monitored in 1-minute intervals or increments so the train activities could be easily identified. The noise measurement was conducted along the Coastal Rail trail between the rail line and the subject property during a train pass-by to determine the noise levels from the train activity. The result of the noise level measurement is presented in Table 1. West of project facing Rail right-of-way Table 1: Measured Train Noise Levels September 22, 2016 77 .7 92.6 48.2 73.3 51.8 48.8 Due to the proximity of the noise measurement to the railroad the overall sound level was found to be 77.7 dBA CNEL for a single event lasting less than 2-minutes. Based on existing train schedules, the peak hourly traffic volume is expected to be four (4) trains per hour. The statistical indicators Ll0, LS0, and L90, are also given. Based on the L90 data, 90% of the time the noise level is below 49 dBA due to very low traffic volumes adjacent to and around the site. The San Diego Northern Railway (SDNR) segment adjacent to the project site is utilized for both commuter trains (Coaster and Surfliner) and a few freight trains. As can be seen from the Lmax data, the train horn at a nearby grade crossing was 92.6 dBA. The noise levels at the site are relatively low but the train noise elevates the overall noise levels above 60 dBA CNEL. 4/3/2017 6 1657-05 3337 Tyler Street Noise Report Elizabeth Lagrua Tyler Street Development, LLC 4459 Hackett Avenue Lakewood, CA 90713 Ldn CoMult/1111, Int:. 42428 Chisolm Trail Murrieta CA 92562 phone 760-473-1253 The worst-case daily train activity is as follows: 50 commuter train and freight trains (Source: NTCD, AMTRAK and SANDAG, 2014). By the year 2030, rail operations are assumed to increase to a total of 98 trains per day due to overall growth, the addition of Metrolink Commuter Service and planned infrastructure upgrades. This would result in a noise level increase of 2.9 dBA CNEL, raising the noise levels to approximately 80.6 dBA CNEL. Hourly noise levels at the proposed building fa~ade would be further reduced due to distance, duty-cycle, and existing and proposed site features. The noise reduction due to distance and a duty-cycle of 8 (minutes) is 4.8 dBA CNEL and 8.8 dBA CNEL respectively, for a reduction of 13.6 dBA CNEL. Additionally, the nearest sensitive outdoor use areas are the proposed ground floor patios facing the railway. An existing 6-foot block wall, located to the west of the site, would provide shielding to the proposed ground floor patio areas. To determine the noise level reductions from the block wall, the Fresnel Barrier Reduction Calculations were utilized. The Fresnel barrier reduction calculation is provided as an Attachment A. Utilizing the Fresnel Barrier Reduction calculations it was determined that the 6-foot solid block wall would provide a 7.0 to 8.4 dBA CNEL reduction. Therefore, the ground level areas would be reduced to 60 dBA CNEL and meet the City of Carlsbad exterior goal of 60 dBA CNEL. At the upper levels, the existing three-story residential complex to the south would partially break the line of sight to the rail line providing a minimum 3 dBA CNEL reduction. Therefore, the worst-case building fa~ade is expected to be as high as 64.0 dBA CNEL. Based upon these findings and the instantaneous peaks from the train operations, interior noise levels need to be reduced to meet the CCR litle 24 and City of Carlsbad requirements. Interior Noise Levels The methodology used to determine the resultant interior noise levels is based upon the exterior noise level minus the sound transmission loss as identified in the American Society of Testing and Materials (ASTM) guidelines: E413 &E90. The exterior noise levels at the proposed structures calculated in terms of dBA are converted to the six octave band sound pressure levels between: 125 Hertz -4000 Hertz. Acoustical modeling of the proposed project dwelling units was performed in accordance with the above guidelines and included combining the transmission loss for each of the building components that will reduce the interior noise levels. Building components typically include the windows, exterior doors, and exterior walls. The total noise reduction is dependent upon the transmission loss of each building component, 4/3/2017 7 1657-05 3337 Tyler Street Noise Report Elizabeth Lagrua Tyler Street Development, LLC 4459 Hackett Avenue Lakewood, CA 90713 Ldn eon.ult/1111, Inc. 42428 Chisolm Trail Murrieta CA 92562 phone 760-473-1253 their subsequent surface area, quality of the building/construction materials, a building fac;;:ade and angle correction. The interior noise level is also dependent on the acoustical energy absorbed within the room based upon the Noise Reduction Coefficients (NRC). NRC is a scalar representation of the amount of sound energy absorbed upon striking a particular surface and the arithmetic value average of sound absorption coefficients indicating a material's ability to absorb sound. The absorption coefficients for individual surface areas such as carpet, drywall and furnishings are used to calculate the interior room effects. The calculated building noise reduction includes both the room absorption characteristics and the transmission loss from the exterior wall assembly. The interior noise reduction calculations were performed using Ldn's interior noise model. The model converts the exterior sound level to octave band frequencies and accounts for the transmission loss, correction factors and room absorption. The floor plans used for this analysis were provided by TRE Architects received January 2017. The following construction details were utilized for each of the building assemblies to determine the noise reduction characteristics: Exterior walls and roof assemblies must have a Sound Transmission Class (STC) rating of 46 or better. Exterior walls with this rating consist of 2"x4" studs or larger, spaced 16" o.c. with R-13 insulation minimum and an exterior surface of 7/8" cement plaster (stucco). Interior wall and ceiling surfaces shall be at least 1/2" thick gypsum or plaster. Roof assemblies should have a minimum of ½" sheathing, R-30 insulation and sealed to prevent noise leaks. Glass assemblies should be dual-glazed and acoustical sealant applied around the exterior edges. The window assemblies are generally the weakest noise reducing component but are the most convenient and cost effective elements to change if additional attenuation is needed. The STC ratings for the glass assemblies was calculated in the interior noise model and provided in the findings below. Bathrooms, kitchens, closets and corridors are not required to meet the 45 dBA CNEL standard and therefore were not modeled. The sensitive rooms were considered to have tile or hardwood flooring. These rooms were modeled to determine the interior noise reductions. If the modeled interior noise levels were found to be higher than 45 dBA CNEL in the habitual areas with the minimum assembly requirements described above additional modeling was performed to determine the minimum STC rating for the glass assemblies to further reduce interior noise levels below the acceptable interior threshold of 45 dBA CNEL. 4/3/2017 8 1657-05 3337 Tyler Street Noise Report Elizabeth Lagrua Tyler Street Development, LLC 4459 Hackett Avenue Lakewood, CA 90713 FINDINGS Ldn eon.ult/1111, Int:. 42428 Chisolm Trail Murrieta CA 92562 phone 760-473-1253 The worst-case building fa<;ade noise levels were determined to be 60 dBA CNEL for the first floor areas and 64 dBA CNEL for the upper floor levels. Basic calculations show that a windows open condition will only reduce the interior noise levels 12-15 dBA CNEL and not provide adequate interior noise mitigation. To meet the 45 dBA CNEL interior noise standard, an overall minimum interior noise level reduction of 19 dBA CNEL is needed for the proposed project. Therefore, a closed window condition is required to reduce interior noise levels to comply with CCR Title 24 and City of Carlsbad requirements. The windows closed condition requires that mechanical ventilation is installed to move air within the structure and control temperatures. The mechanical ventilation must meet the jurisdictional requirements for these dwelling units. The building fa<;ade noise level of 64 dBA CNEL was utilized for all proposed sensitive rooms to determine the minimum STC ratings of the assemblies. It should be noted though; maximum sound levels due to rail operations could reach instantaneous peaks of up to 90 dBA due to signaling and warning devices. Although these peak noise levels may only occur for 1-2 seconds, operation of such devices during evening or nighttime hours could result in a nuisance to sensitive receptors. The necessary Sound Transmission Class and transmission losses for all glass assemblies are provided in Table 2. To meet the minimum requirements, all glass assemblies facing or having a direct line of site to the railroad tracks should be dual-paned and acoustical sealant applied around the exterior edges having an STC 28 rating. The modeled results with an anticipated interior noise level of 45 dBA CNEL or less are provided as an Attachment Bto this report. Table 2: Minimum Sound Transmission Class Ratings STC Octave Band Transmission Loss (Hz) Assembly Rating1 125 250 500 1000 2000 4000 Windows 28 19 20 22 32 37 38 Fixed Windows 28 21 15 25 35 41 28 Glass Doors 28 19 17 26 33 39 29 1 STC Ratings used in Model Although, STC 28 rated window and glass assemblies are needed to meet the 45 dBA CNEL standard. Due to the ra il operations, it is recommended that interior noise reduction methods 4/3/2017 9 1657-05 3337 Tyler Street Noise Report Elizabeth Lagrua Tyler Street Development, LLC 4459 Hackett Avenue Lakewood, CA 90713 Ldn Conallt/1111, Int:. 42428 Chisolm Trail Murrieta CA 92562 phone 760-473-1253 (i.e., dual-paned glass treatments) for the window and glass assemblies installed having line of sight to the rail alignment be increased to a minimum sound transmission classification (STC) rating of 31. This would assist in remediating instantaneous noise levels from the train activities. If you have any questions, please do not hesitate to contact me directly at (760) 473-1253 . Jeremy Louden, Principal Attachments: A -Fresnel Barrier Calculations B -Interior Noise Model Calculations 4/3/2017 10 1657-05 3337 Tyler Street Noise Report TYLER-1 Incoherent Line Source Source to Receiver Horizontal Distance (ft)= Source to Barrier Horizontal Distance (ft)= Barrier to Receiver Horizontal Distance (ft)= Source Height (ft) = 5.00 Receiver Height (ft)= 4.00 Barrier Height (ft) = 6 .00 210.00 200.00 10.00 Distance Source to Receptor (ft) d = Distance Source to Barrier top (ft) dl = Distance Barrier top to Receiver (ft) d2 = 210.00 200.00 10 .20 Frequency (Hz) = 8000 Attenuation (db) = 13.3 Fresnel Frequency (Hz) = 4000 Attenuation (db) = 11.6 Fresnel Frequency (Hz) = 2000 Attenuation (db) = 9.9 Fresnel Frequency (Hz) = 1000 Attenuation (db) = 8.4 Fresnel Frequency (Hz) = 500 Attenuation (db) = 7.0 Fresnel Page 1 N = 2.813 N = 1.407 N = 0.703 N = 0.352 N = 0.176 INTERIOR NOISE CALCULATIONS Project Name: Building (s) Floor Level Arch Plan: Room Type: 3337 Tyler Street All 1 All Den Exterior Noise Levels Exterior Assembly Stucco Windows Fixed Window Glass Doors Exterior Door Source NBS W-50-71 Milgard Milgard Milgard NBS Monograph 77 Room Absorption {RA) Interior Characteristics Source Carpet Army TM 5-805-4 Furnishings Army TM 5-805-4 Drywall Netwell Overall Absorption Factor (Furnished Room) Noise Reduction Area 261 so 0 40 20 Noise Reduction from Absorption based upon Floor Area Noise Level Increase for Defects and Exposed Surface Area STC 46 28 28 28 26 NRC 0.28 0.45 0.07 0.8 Overall Reduction from Tranmission Loss + Room Absorption -Surfa Building Fa<;ade Noise Level (dBA CNEL) 125 250 27 42 19 20 21 15 19 17 16 14 125 250 0.15 0.17 0.32 0.29 0.09 0.08 0.56 0.54 125 250 -20.6 -20.6 18.5 18.5 ce Exposure Ldn Consulting, Inc. Date: 1/23/17 Project # 16-57 Transmission Loss {dB} Frequency {Hz.} 500 1000 2000 4000 44 46 49 54 22 32 37 38 25 35 41 28 26 33 39 29 23 30 36 26 Absorption Coefficients Frequency {Hz.} 500 1000 2000 4000 0.12 0.32 0.52 0.30 0.42 0.58 0.60 0.48 0.05 0.03 0.06 0.09 0.59 0.93 1.18 0.87 500 1000 2000 4000 -20.6 -20.6 -20.6 -20.6 18.5 18.5 18.5 18.5 17.1 62.0 Resultant Interior Noise Level (dBA CNEL) 45 * Corrections for Fa~ade Level was accounted for In the modeling. INTERIOR NOISE CALCULATIONS Project Name: Building (s) Floor Level Arch Plan: Room Type: 3337 Tyler Street All 2 All Family/Dining Exterior Noise Levels Exterior Assembly Stucco Windows Fixed Window Glass Doors Exterior Door Source NBS W-50-71 Milgard Milgard Milgard NBS Monograph 77 Room Absorption {RA} Interior Characteristics Source Carpet Army TM 5-805-4 Furnishings Army TM 5-805-4 Drywall Netwell Overall Absorption Factor (Furnished Room) Noise Reduction Area 819 144 0 96 0 Noise Reduction from Absorption based upon Floor Area Noise Level Increase for Defects and Exposed Surface Area STC 46 28 28 28 26 NRC 0.28 0.45 0.07 0.8 Overall Reduction from Tranmission Loss + Room Absorption -Surfa Building Fac;ade Noise Level (dBA CNEL) 125 250 27 42 19 20 21 15 19 17 16 14 125 250 0.15 0.17 0.32 0.29 0.09 0.08 0.56 0.54 125 250 -26.9 -26.9 18.5 18.5 ce Exposure Ldn Consulting, Inc. Date: 1/23/17 Project # 16-57 Transmission Loss {dB} Frequency {Hz.} 500 1000 2000 4000 44 46 49 54 22 32 37 38 25 35 41 28 26 33 39 29 23 30 36 26 Absorption Coefficients Frequency {Hz.} 500 1000 2000 4000 0.12 0.32 0.52 0.30 0.42 0.58 0.60 0.48 0.05 0.03 0.06 0.09 0.59 0.93 1.18 0.87 500 1000 2000 4000 -26.9 -26.9 -26.9 -26.9 18.5 18.5 18.5 18.5 20.7 62.0 Resultant Interior Noise Level (dBA CNEL) 41 * Corrections for Fa~ade Level was accounted for in the modeling. INTERIOR NOISE CALCULATIONS Project Name: Building (s) Floor Level Arch Plan: Room Type: 3337 Tyler Street All 3 All Master Bedroom Exterior Noise Levels Exterior Assembly Stucco Windows Fixed Window Glass Doors Exterior Door Source NBS W-50-71 Milgard Milgard Milgard NBS Monograph 77 Room Absorption {RA} Interior Characteristics Source Carpet Army TM 5-805-4 Furnishings Army TM 5-805-4 Drywall Netwell Overall Absorption Factor {Furnished Room) Noise Reduction Area 243 24 0 40 0 Noise Reduction from Absorption based upon Floor Area Noise Level Increase for Defects and Exposed Surface Area STC 46 28 28 28 26 NRC 0.28 0.45 0.07 0.8 Overall Reduction from Tranmission Loss + Room Absorption -Surfa Building Fa<;ade Noise Level (dBA CNEL) 125 250 27 42 19 20 21 15 19 17 16 14 125 250 0.15 0.17 0.32 0.29 0.09 0.08 0.56 0.54 125 250 -21.2 -21.2 17.3 17.3 ce Exposure Ldn Consulting, Inc. Date: 1/23/17 Project # 16-57 Transmission Loss {dB} Frequency {Hz.} 500 1000 2000 4000 44 46 49 54 22 32 37 38 25 35 41 28 26 33 39 29 23 30 36 26 Absorption Coefficients Frequency {Hz.} 500 1000 2000 4000 0.12 0.32 0.52 0.30 0.42 0.58 0.60 0.48 0.05 0.03 0.06 0.09 0.59 0.93 1.18 0.87 500 1000 2000 4000 -21.2 -21.2 -21.2 -21.2 17.3 17.3 17.3 17.3 20.5 62.0 Resultant Interior Noise Level (dBA CNEL) 41 * Corrections for Fa~ade Level was accounted for in the modeling. INTERIOR NOISE CALCULATIONS Project Name: Building (s) Floor Level Arch Plan: Room Type: 3337 Tyler Street All 3 All Bedroom 2 Exterior Noise Levels Exterior Assembly Stucco Windows Fixed Window Glass Doors Exterior Door Source NBS W-50-71 Milgard Milgard Milgard NBS Monograph 77 Room Absorption {RA} Interior Characteristics Source Carpet Army TM 5-805-4 Furnishings Army TM 5-805-4 Drywall Netwell Overall Absorption Factor (Furnished Room) Noise Reduction Area 198 28 0 0 0 Noise Reduction from Absorption based upon Floor Area Noise Level Increase for Defects and Exposed Surface Area STC 46 28 28 28 26 NRC 0.28 0.45 0.07 0.8 Overall Reduction from Tranmission Loss + Room Absorption -Surfa Building Fac;ade Noise Level (dBA CNEL) 125 250 27 42 19 20 21 15 19 17 16 14 125 250 0.15 0.17 0.32 0.29 0.09 0.08 0.56 0.54 125 250 -19.7 -19.7 15.7 15.7 ce Exposure Ldn Consulting, Inc. Date: 1/23/17 Project # 16-57 Transmission Loss {dB} Frequency {Hz.} 500 1000 2000 4000 44 46 49 54 22 32 37 38 25 35 41 28 26 33 39 29 23 30 36 26 Absorption Coefficients Frequency {Hz.} 500 1000 2000 4000 0.12 0.32 0.52 0.30 0.42 0.58 0.60 0.48 0.05 0.03 0.06 0.09 0.59 0.93 1.18 0.87 500 1000 2000 4000 -19.7 -19.7 -19.7 -19.7 15.7 15.7 15.7 15.7 23.0 62.0 Resultant Interior Noise Level (dBA CNEL) 39 • Corrections for Fa~ade Level was accounted for in the modeling. \ INTERIOR NOISE CALCULATIONS Project Name: Building (s) Floor Level Arch Plan: Room Type: 3337 Tyler Street All 3 All Bedroom 3 Exterior Noise Levels Exterior Assembly Stucco Windows Fixed Window Glass Doors Exterior Door Source NBS W-50-71 Milgard Milgard Milgard NBS Monograph 77 Room Absorption {RA) Interior Characteristics Source Carpet Army TM 5-805-4 Furnishings Army TM 5-805-4 Drywall Netwell Overall Absorption Factor (Furnished Room) Noise Reduction Area 279 52 0 0 0 Noise Reduction from Absorption based upon Floor Area Noise Level Increase for Defects and Exposed Surface Area STC 46 28 28 28 26 NRC 0.28 0.45 0.07 0.8 Overall Reduction from Tranmission Loss + Room Absorption -Surfa Building Fa91de Noise Level (dBA CNEL) 125 250 27 42 19 20 21 15 19 17 16 14 125 250 0.15 0.17 0.32 0.29 0.09 0.08 0.56 0.54 125 250 -20.7 -20.7 16.2 16.2 ce Exposure Ldn Consulting, Inc. Date: 1/23/17 Project # 16-57 Transmission Loss {dB} Frequency {Hz.} 500 1000 2000 4000 44 46 49 54 22 32 37 38 25 35 41 28 26 33 39 29 23 30 36 26 Absorption Coefficients Frequency {Hz.} 500 1000 2000 4000 0.12 0.32 0.52 0.30 0.42 0.58 0.60 0.48 0.05 0.03 0.06 0.09 0.59 0.93 1.18 0.87 500 1000 2000 4000 -20.7 -20.7 -20.7 -20.7 16.2 16.2 16.2 16.2 21.6 62.0 Resultant Interior Noise Level (dBA CNEL) 40 * Corrections for Fac;ade Level was accounted for In the modeling.