Noise Control Study. for. Avalon Public School Portobello Boulevard at Stormwind Avenue in Ottawa, Ontario. Revision 1

Transcription

1 REP N45 Avalon School Traffic Noise Study - R1 Noise Control Study for Avalon Public School Portobello Boulevard at Stormwind Avenue in Ottawa, Ontario. Revision 1 Prepared for: N45 Architecture Inc. Prepared by: State of the Art Acoustik Inc. December 23 rd, 2014

2 REP N45 Avalon School Traffic Noise Study - R1 Contents 1.0 INTRODUCTION BACKGROUND INFORMATION Project Description Site Plan NOISE IMPACT PROCEDURE Procedure Used to Assess Noise Impacts Noise Attenuation Requirements Building Component Assessment (AIF Analysis) Noise Sources and Analysis Road Traffic Information Procedure Used for Roadway Noise Analysis Points of Reception Parameters Used for Analysis Road and Railway Noise Levels and Required Measures Exterior Building Component Analysis Building Components and Room Dimensions Required Overall AIF Initial Calculation of AIF per Wall Component Adjusted Minimum AIF Calulation of Remaining Components Exterior Glazing Requirements Based on Minimum AIF Conclusion Appendix A - STAMSON Calculations

3 REP N45 Avalon School Traffic Noise Study - R1 Page 1 of INTRODUCTION State of the Art Acoustik was commissioned by N45 Architecture Inc. to complete a noise control study as part of a site plan application for the Avalon South Public School in Ottawa, Ontario. This study analyses the predicted road/rail noise impact for the proposed site and provides recommendations in order to meet the regulations set out by the City of Ottawa s Environmental Noise Control Guidelines (ENCG). We have determined that there are no existing stationary noise sources in the area whose impact on the proposed development must be assessed. This study has been completed for all major roadways within 100 meters of the building, all railways or highways within 250 meters of the building and all freeways or provincial highways within 500 meters of the building, as required per the ENCG, section BACKGROUND INFORMATION 2.1 Project Description The proposed building is a public school located at the intersection of Stormwind Avenue and Portobello Boulevard in Ottawa, Ontario. 2.2 Site Plan Figure 1 on the following page shows a site plan view of the proposed school indicating the two road noise sources, the point of reception (POR) and the distances from the POR to the roads used in the noise source models that follow. The POR was chosen as the point on the exterior of the school nearest each noise source.

4 REP N45 Avalon School Traffic Noise Study - R1 Page 2 of meters NORTH 15 meters POR Figure 1 Avalon South Public School, Ottawa, Ontario Site Plan

5 REP N45 Avalon School Traffic Noise Study - R1 Page 3 of NOISE IMPACT PROCEDURE 3.1 Procedure Used to Assess Noise Impacts This assessment uses the City of Ottawa - Environmental Noise Control Guidelines (ENCG), dated May 10, 2006, to assess and mitigate noise from roads, transit ways, railways and aircraft. Summarized in Table 3.1 below are the maximum sound pressure levels for outdoor and indoor living areas taken from table 1.1 of the ENCG. Time Indoor Leq Levels (dba) Class 1, 2 & 3 Areas Road Traffic/Light Rail (dba) 07:00 23:00 45 for rooms inside Schools 23:00 07:00 40 for Bedrooms* Table 3.1 Criteria for Indoor Area Sound Levels for Schools *there are no bedrooms in the school so this limit is not assessed An Indoor Area is defined by the City of Ottawa s ENCG as a Living/dining areas of residences, hospitals, schools, nursing/retirement homes, day-care centers, theatres, places of worship, libraries, individual or semi-private offices, conference rooms, reading rooms, etc. We have therefore based our assessment on the requirements for Living Quarters. The ENCG states that noise control studies are to be prepared when the indoor area is within the following setback distances from the road, highway and railway noise sources: 100m from an arterial road or a major collector 500m from a 400-series provincial highway 250m for a highway or Light Rail Transit system corridor We have considered both Portobello Boulevard and Stormwind Avenue (arterial road or a major collector) for this study since they are less than 100m away from the school. The next two closest roads, Esprit Drive and Brian Coburn Boulevard (arterial road or a major collector) may easily be omitted from this study since they are 300 meters and 405 meters away from the school. The closest 400-series highway is 11.6km to the east and similarly sized Highway 174 is 4.6km to the north. This two roads may be safely omitted from this study. In addition, VIA rail tracks which are located 4km to the south and the new OC-Tranpo Confederation Line which ends at Blair Road over 11km away may both be safely omitted from this study.

6 REP N45 Avalon School Traffic Noise Study - R1 Page 4 of Noise Attenuation Requirements This section outlines the required noise control measures and warning clauses and when to apply them, as stipulated by the ENCG for placement within purchase agreements. If sound levels are predicted to be less than the specified criteria no attenuation measures are required on the part of the proponent. If the predicted noise exceeds the criteria, the City of Ottawa recommends several attenuation measures. These attenuation measures may include any or all of the following: construction of a noise barrier wall and/or berm; installation of a forced air ventilation system with provision for central air; installation of central air; acoustically selected building façade components Where excessive noise levels may adversely affect property or its use, the ENCG requires notices in the form of a Warning Clause to be placed on title in order to alert the buyer or renter of a possible environmental noise condition or a limitation on his/her property rights. The notices on title must be included in the Development Agreement(s) and in the Agreement(s) or Offer(s) of Purchase and Sale. Table 3.4 outlines the noise attenuation measures required for various noise levels predicted at the Plane of Window (POW) of the proposed development (from ENCG Tables 1.8 and 1.10) As the proposed development does not contain any residential units to be rented or sold, we have assumed that no warning clause will apply. Assessment Location Plane Of Inside Room Window (POW), Road Noise Only Leq (dba) Ventilation Requirements Outdoor Control Measures Building Component Requirements Less than 55 None Required N/A Building Compliant with Ontario Building Code Between 55 and 65 More than 65 Forced air heating with provision for central air conditioning Central Air Conditioning N/A N/A Table Outdoor, Ventilation and Warning Clause Requirements Building Compliant with Ontario Building Code Building components (walls, windows, etc.) must be designed to achieve indoor sound level criteria

7 REP N45 Avalon School Traffic Noise Study - R1 Page 5 of Building Component Assessment (AIF Analysis) As mentioned in the previous section and according to Table 1.8 of the ENCG, when noise levels exceed 65 dba at the Plane of Windows (POW) of a indoor area (daytime) or 60 dba at the POW of an indoor area (nighttime) the exterior cladding system of the building envelope must be acoustically designed to ensure the indoor noise criteria is achieved. The City of Ottawa recognizes the Acoustic Insulation Factor (AIF 1 ) method as an appropriate analysis technique. To comply with the City of Ottawa policies, the building envelope will require a minimum AIF rating to provide the indoor noise level required for rooms, offices, classrooms and dining areas inside the school. The City of Ottawa s ENCG outlines the following maximum indoor Leq limits: maximum daytime indoor L eq for areas inside schools should be 45 dba maximum nightime indoor L eq for bedrooms should be 40 dba* *there are no bedrooms in the school so this limit is not assessed The interior of the school is treated as a living space for the purposes of this study. For the overall exterior wall of any room, the required AIF for road and rail transportation noise is: Required AIF = Outside L eq - Indoor L eq (Req) + 2dB (1) When the exterior is built up of multiple components, then the AIF required of each component is determined by the following equation 1 : Required AIF = Outside L eq - Indoor L eq (Req) + 10 log 10 (Number of Components) + 2dB (2) The required AIF is based on the Outside L eq, Indoor L eq required and the total number of exterior façade components. The AIF method allows for the number of components to be reduced if any component significantly exceeds the required AIF 1 : If the AIF of any component exceed the required AIF by 10 or more, the calculation should be repeated for the other components with the total number of components reduced by one. This reduction in the number of components lowers the required AIF for the others. 1 J.D. Quirt, Building Research Note: Acoustic Insulation Factor: A Rating for the Insulation of Buildings against Outdoor Noise, National Rearch Council [Revised June 1980]

8 REP N45 Avalon School Traffic Noise Study - R1 Page 6 of Noise Sources and Analysis The following sections describe the characteristics of the noise sources. 4.1 Road Traffic Information For this study, the major noise sources considered are roads. The sources considered are summarized in the table below. Table 4.1 summarizes the roadway s parameters obtained by Table 1.7, p. 15 of The City of Ottawa Environmental Noise Control Guidelines - Planning and Growth Management Department, Traffic and Road Parameters to be used for Sound Level Prediction for the respective roadway class. Roadway Storm Wind Ave. Portobello Blvd. Implied Roadway Class Annual Average Daily Traffic (AADT) Veh/Day Day/Night Split (%) Medium/Heavy Truck (%) Posted Speed Distance to closest face of School 2-Lane Urban Collector (2-UCU) 8,000 92/8 7/5 60km/hr 30m 2-Lane Major Collector 12,000 92/8 7/5 60km/hr 30m (2-UMCU) Table 4.1 Summary of Major Roadway Noise Sources Considered in This Study 4.2 Procedure Used for Roadway Noise Analysis In order to calculate the road noise impact at the proposed development, we utilized the Ministry of Environment s STAMSON modeling software version This program allows us to input variables of a road or railway such as traffic volume, types of vehicles, speed, barrier locations and topography to find the environmental noise impact at a point of reception a given distance away. 4.3 Points of Reception For a roadway parallel to the building face, the noise impact is uniform along the building face assuming that the road can be treated as quasi-infinite, extending from -90 o to +90 o. We have therefore chosen the point of reception which is on the building face which is closest to both the road to the North (Storm Wind Ave) and to the East (Portobello Blvd.). The POR which represents the worst case noise impact for the entire building will be located at the North-East corner of the school where the school s library is located. Traffic will span the whole surface of the roads, but for our model, we have used the worst case distance from the edge of the road to the North-East corner of the school.

9 REP N45 Avalon School Traffic Noise Study - R1 Page 7 of Parameters Used for Analysis The parameters used in STAMSON to assess the noise impact at POR are below in Table 4.2: Parameter Roadway: Values Used Storm Wind Ave. Time Period 16h/8h Topography Flat/gentle slope with no barrier Rows of Houses 0 Intermediate Surface Absorptive* Receiver Height (m) 1.5 Source Receiver Distance (m) 30m to POR Angle 1/Angle 2-90/90 Parameter Roadway: Values Used Portobello Blvd. Time Period 16h/8h Topography Flat/gentle slope with no barrier Rows of Houses 0 Intermediate Surface Reflective** Receiver Height (m) 1.5 Source Receiver Distance (m) 15m to POR Angle 1/Angle 2-90/90 Table 4.2 Parameters used in STAMSON model *We have determined that the surface between Storm Wind Avenue and the POR to be a lawn and thus will be an absorptive surface. **We have determined that the surface between Portobello Boulevard and the POR to be a combination of grass and concrete which is mostly acoustically reflective. We have chosen to model this as a reflective surface. 4.5 Road and Railway Noise Levels and Required Measures The following table summarizes the predicted sound pressure levels at the point of reception, from the results of the STAMSON environmental noise software (Appendix A). Sound Pressure Levels L eq (dba) due to Road Noise At POR during the DAY At POR during the NIGHT Table 4.3 Predicted Road Noise at the Point of Reception Table 4.3 shows that the predicted sound levels at the building face from road sources exceed 65 dba. According to the ENCG, since the levels exceed 65 dba, it is required to analyze the exterior building components to ensure the indoor sound level targets are achieved.

10 REP N45 Avalon School Traffic Noise Study - R1 Page 8 of Exterior Building Component Analysis In this section, we determine if the building complies with the City of Ottawa s ENCG indoor noise requirements based on the currently selected wall and window construction. We compare the required minimum façade AIF to the estimated AIF of the currently selected façade materials. 5.1 Building Components and Room Dimensions The current design of the building façade is made up of 2 components: 1) Glazing 2) W1 Cast-in-place, tilt up wall panel We have assumed that the wall type is at least as sound isolating as CMHC type EW6 (as described in Part 6 of the Canadian Mortgage and Housing Corporation, Road and Rail Noise: Effects on Housing publication) that their AIF can be considered equal: Current Exterior Wall (W1) 76mm Concrete Fascia 100mm Rigid Insulation 152mm Structural Concrete Equivalent to EW6 in CMHC 12.7mm gypsum board Rigid insulation (25-50 mm) 100 back-up block 100mm brick face The calculation of AIF for each building component depends on the ratio of the area of a given component on the exterior to the total floor area of the corresponding interior room. Using drawings supplied from N45, we have determined these dimensions for the library in the North East corner of the school, where we determined the noise impact at the POR. The areas of the exterior wall components and floor area of the unit are given in Table 5.1 below: Values used in CMHC Calculations* Floor Area [m 2 ] Window Area [m 2 ] 68.5 (ratio to floor area) (49%) 50% Wall Area [m 2 ] (ratio to floor area) (88%) 100% Table 5.1 Areas of Exterior Building Components and Floor Area *For any area ratio, we use the next highest ratio in the CMHC tables. The ratio used is shown in the last column of Table 5.1.

11 REP N45 Avalon School Traffic Noise Study - R1 Page 9 of Required Overall AIF Using equation (1), the required overall AIFs for the exterior glazing are calculated as follows, allowing for the possibility of noise-sensitive uses requiring an indoor level of 45 dba during the day and 40 dba during the night at the POR. The maximum estimated outdoor SPL levels are taken from Table 4.3 at the POR (67 dba during the day, 59 dba during the night). Required AIF DAY = 70 (Outside L eq ) 45 (Required Indoor L eq ) + 10log 10 (2) + 2 = 30 (3 DAY ) Required AIF NIGHT = 60 (Outside L eq ) 40 (Required Indoor L eq ) + 10log 10 (2) + 2 = 25 (3 NIGHT ) Thus the minimum required overall AIF for the building façade at this location is 30 as calculated at POR during the day. 5.3 Initial Calculation of AIF per Wall Component The building exterior at the PORs are made up of two components as described in section 5.1. As shown by equation 3 DAY, we calculated that the required overall minimum AIF for the 2- component exterior wall is 30. Using the ratio of wall-area to floor-area (as show in Table 5.1) we used the CMHC guidelines to determined that the AIF of the wall type EW6 (similar to the design wall type) to be AIF 50. This AIF of the wall component of the façade is 20 points higher than the overall AIF requirement of Adjusted Minimum AIF Calulation of Remaining Components If any exterior wall component s AIF is 10 AIF points or more above the minimum overall AIF (in this case 20), then the minimum AIF may be decreased for the remaining components since it can be based on less components as specified in Section 3.3. Since the wall component has an AIF of 50, the number of components can be reduced to 1. We have recalculated the required minimum AIF for the façade with the reduced number of components in equation 4 below: Required AIF = 70 (Outside L eq ) 45 (Required Indoor L eq ) + 10log 10 (1) + 2 = 27 (4) The glazing component of the façade therefore requires a minimum AIF of 27.

12 REP N45 Avalon School Traffic Noise Study - R1 Page 10 of Exterior Glazing Requirements Based on Minimum AIF The minimum AIF of 27 dictates the overall window construction. If this minimum AIF is met, the building façade construction will be adequate to meet the indoor sound level requirement for noise-sensitive land uses at all points at the school. In order to determine the type of windows that have an AIF of at least 27 we used the ratio of window-area to floor-area (as show in Table 5.1). We have summarized in Table 5.2 below, the minimum recommended double glazing compositions that the CMHC guidelines say have a minimum AIF of 27. Glass Thickness *Inter-plane Spacing AIF for 50% window area to floor area 2mm & 2mm 18mm 27 3mm & 3mm 13mm 27 4mm & 4mm 6mm 27 Table 5.2 Double Glazing with AIF of at least 27 *Note: The inter-plane spacing is the size of the air space between panes If one of the glazing types above or better is chosen, then the areas in the school most impacted by traffic noise will meet the City of Ottawa s ENCG requirements for indoor sound levels. If glazing with a minimum AIF of 27 is used on all windows, it can be assumed that all rooms at the Avalon School will meet the minimum required AIF for indoor sound level requirements specified by the City of Ottawa s ENCG. A proposed glazing construction for the building was sent to us in an dated December 19 th, 2014 from N45 Architecture Inc. All the glazing for this project is from AGC and will have a minimum glazing construction as follows: 6mm glass 13.5mm inter-plane spacing 6mm glass This glass has a minimum AIF of 29 which will meet the requirements of at least at least AIF 27.

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14 Appendix A STAMSON Calculations

15 STAMSON 5.0 NORMAL REPORT Date: :31:08 MINISTRY OF ENVIRONMENT AND ENERGY / NOISE ASSESSMENT Filename: por1new.te Description: Time Period: Day/Night 16/8 hours Road data, segment # 1: StormWind (day/night) Car traffic volume : 6477/563 veh/timeperiod Medium truck volume : 515/45 veh/timeperiod Heavy truck volume : 368/32 veh/timeperiod Posted speed limit : 60 km/h Road gradient : 0 % Road pavement : 1 (Typical asphalt or concrete) Data for Segment # 1: StormWind (day/night) Angle1 Angle2 : deg deg Wood depth : 0 (No woods.) No of house rows : 0 / 0 Surface : 1 (Absorptive ground surface) Receiver source distance : / m Receiver height : 1.50 / 1.50 m Topography : 1 (Flat/gentle slope; no barrier) Reference angle : 0.00 Road data, segment # 2: Porobello (day/night) Car traffic volume : 9716/845 veh/timeperiod Medium truck volume : 773/68 veh/timeperiod Heavy truck volume : 552/48 veh/timeperiod Posted speed limit : 60 km/h Road gradient : 0 % Road pavement : 1 (Typical asphalt or concrete) Data for Segment # 2: Porobello (day/night) Angle1 Angle2 : deg deg Wood depth : 0 (No woods.) No of house rows : 0 / 0 Surface : 2 (Reflective ground surface) Receiver source distance : / m Receiver height : 1.50 / 1.50 m Topography : 1 (Flat/gentle slope; no barrier) Reference angle : 0.00

16 Results segment # 1: StormWind (day) Source height = 1.50 m ROAD ( ) = dba Angle1 Angle2 Alpha RefLeq P.Adj D.Adj F.Adj W.Adj H.Adj B.Adj SubLeq Segment Leq : dba Results segment # 2: Porobello (day) Source height = 1.50 m ROAD ( ) = dba Angle1 Angle2 Alpha RefLeq P.Adj D.Adj F.Adj W.Adj H.Adj B.Adj SubLeq Segment Leq : dba Total Leq All Segments: dba

17 Results segment # 1: StormWind (night) Source height = 1.50 m ROAD ( ) = dba Angle1 Angle2 Alpha RefLeq P.Adj D.Adj F.Adj W.Adj H.Adj B.Adj SubLeq Segment Leq : dba Results segment # 2: Porobello (night) Source height = 1.49 m ROAD ( ) = dba Angle1 Angle2 Alpha RefLeq P.Adj D.Adj F.Adj W.Adj H.Adj B.Adj SubLeq Segment Leq : dba Total Leq All Segments: dba TOTAL Leq FROM ALL SOURCES (DAY): (NIGHT): 59.57