stationary noise feasibility assessment 3071

127 Walgreen Road, Ottawa, Ontario K0A 1L0 T (613) 836‐0934 ● www.gradientwind.com

Stationary Noise Feasibility Assessment

3071 Riverside Drive

Ottawa, Ontario

REPORT: GWE17‐022 ‐ Stationary Noise

Prepared For:

Justin Chubaty Canoe Bay Development Inc.

Prepared By:

Joshua Foster, P.Eng., Partner

Omar Daher, B. Eng, EIT, Junior Environmental Scientist

August 23, 2017

Canoe Bay Development Inc. – 3071 Riverside Drive

Stationary Noise Feasibility Assessment i

EXECUTIVE SUMMARY

This document describes a stationary noise feasibility assessment performed for a proposed mixed‐use

development at 3071 Riverside Drive in Ottawa, Ontario. The development is situated south of the Riverside

Drive and Mooney’s Bay Place intersection. The proposed site plan comprises a mixture of townhouses and

flats, as well as a seniors’ care building and mixed‐use apartment buildings. For reference purposes, the

development is labelled as follows: Townhouses (Blocks A1‐A6), Flats B1‐B3, three‐storey apartments C1‐C2

and the six‐storey retirement and residence building D.

This report summarizes the anticipated noise impacts of the proposed development’s potential rooftop and

at‐grade exterior mechanical equipment on nearby residential noise sensitive areas, as well as on noise

sensitive areas on‐site. The closest points of reception are noise‐sensitive areas on‐site on Springland

Drive, Beachview Private, Bayside Private, and Mooney’s Bay Place. Figure 1 illustrates a site plan with

surrounding context.

The assessment is based on: (i) theoretical noise prediction methods that conform to the Ministry of the

Environment and Climate Change (MOECC) and City of Ottawa requirements; (ii) stationary noise level

criteria as specified by the City of Ottawa’s Environmental Noise Control Guidelines (ENCG); and (iii) site

plan drawings prepared by Roderick Lahey Architect Inc.

Results indicate that, provided equipment selections and locations are similar to the assumptions and

recommendations in this report, noise levels at the points of reception are expected to fall below City of

Ottawa’s ENCG limits. Since the noise levels fall below the ENCG criteria, the proposed development is

expected to be compatible with the existing and future noise sensitive land uses. As this study is based on

assumed mechanical information from experience with other jobs, a detailed study of mechanical

equipment selection and locations should be performed once mechanical information is finalized. Final

mechanical equipment selection and locations should also be reviewed by an acoustical engineer prior to

installation of the equipment.


Stationary Noise Feasibility Assessment ii

TABLE OF CONTENTS

PAGE

1. INTRODUCTION 1

2. TERMS OF REFERENCE 1

2.1 Assumptions 1

3. OBJECTIVES 3

4. METHODOLOGY 3

4.1 Background 3

4.2 Noise Source Assessment and Criteria 3

4.3 Determination of Noise Source Power Levels 5

4.4 Stationary Source Noise Predictions 5

5. RESULTS AND DISCUSSION 8

6. CONCLUSIONS AND RECOMMENDATIONS 12

FIGURES


Stationary Noise Feasibility Assessment 1

1. INTRODUCTION

Gradient Wind Engineering Inc. (GWE) was retained by Canoe Bay Development Inc. to undertake a

stationary noise feasibility assessment of the proposed mixed‐use development located at 3071 Riverside

Drive in Ottawa, Ontario. This report summarizes the anticipated noise impacts of the proposed

development’s potential rooftop and at‐grade exterior mechanical equipment on nearby residential noise

sensitive areas, as well as on noise sensitive areas on‐site. Noise calculations were based on site plan

drawings produced by Roderick Lahey Architects., dated August 14, 2017, and recent aerial imagery.

2. TERMS OF REFERENCE

The subject of this noise assessment is a proposed site plan for a mixed‐use development located south of

the Riverside Drive and Mooney’s Bay Place intersection in Ottawa, Ontario. The proposed site plan

comprises a mixture of townhouses and flats, as well as a seniors’ care building and mixed‐use apartment

buildings. The townhouses are located along the north property line, the flats are located along the east

property line, the seniors’ building is located in the center of the property, and the mixed‐use apartments

are located along the west property line. For reference purposes, townhouses are labelled A1‐A6, flats B1‐

B3, mixed‐use apartment buildings C1‐C2 and seniors’ care building D. Outdoor amenity space is located

throughout the development, specifically to the rear of the townhouses and flats, within several courtyards

associated with the seniors’ building and mixed‐use apartment buildings, as well as within the public park

south of the development.

At the time of the study, the mechanical design of the building had not yet been determined; therefore,

mechanical equipment was assumed to be located on the roof and at grade level based on the site plan

drawings and GWE’s experience with similar developments. Figure 1 illustrates a complete site plan with

surrounding context. Figure 2 illustrates the location of all stationary noise sources for the development.

2.1 Assumptions

As mechanical information and drawings for the development were unavailable at the time of the study,

preliminary mechanical information, such as HVAC information, has been assumed based on GWE’s

experience with a similar assessment involving a residential building (File Ref: GWE16‐040). The sound

data used in the present assessment are similar to those used in the aforementioned reference project,

given similar physical characteristics of the building.



Generator information is also based on GWE’s previous experience with similar projects, where the

generator power level is based on 75 dBA at a distance of seven metres. This assessment will be updated

once mechanical equipment information becomes available to reflect the exact equipment used for the

proposed development. A review of final equipment selection and locations by a qualified acoustical

engineer will be required prior to installation of the equipment. The following assumptions have been

included in the analysis:

(i) The locations and quantity of the mechanical equipment have been assumed by GWE.

(ii) Size and sound data of rooftop units, exhaust fan and dry coolers have been assumed by GWE.

(iii) Grade‐level exhaust fan is assumed to operate continuously during the daytime and nighttime

period.

(iv) All rooftop units are assumed to operate continuously during the daytime period and for 30

minutes per hour during the nighttime period.

(v) Specifications for the generator were based on GWE’s previous involvement with similar projects

and MOECC regulations for emergency equipment.

(vi) The generator is assumed to be centered on the rooftop terrace of Building D within a weather‐

proof sound attenuating enclosure.

(vii) The emergency generator will only be tested during daytime or evening hours of (07:00 to 23:00).

(iv) Screening effect of buildings has been considered in the modelling. Parapet height on Buildings C

and D assumed to be 1‐metre above the roof deck.

Equipment considered in the model consists of: (i) S1‐S5: Rooftop Unit (Model Engineered Air FWE163/DJE100/0/MV)

(ii) S6‐S7: Dry Cooler (Model Refrion ER5C 2590.6/2)

(iii) S8: Grade‐level Exhaust Fan (Model Greenheck: SE1‐18‐429‐VG)

(iv) S9: Gas Generator with Class 2 sound enclosure

(v) S10‐S45: Rooftop Unit (York LX Series Model YCS18B21S)



3. OBJECTIVES

The principle objective of this study is to assess the anticipated noise impacts from rooftop and interior

mechanical equipment of the proposed development on nearby residential and on‐site sensitive

receptors, to determine whether the proposed site plan can feasibly operate in the area in compliance

with the City of Ottawa’s ENCG1.

4. METHODOLOGY

4.1 Background

Noise can be defined as any obtrusive sound. It is created at a source, transmitted through a medium,

such as air, and intercepted by a receiver. Noise may be characterized in terms of the power of the source

or the sound pressure at a specific distance. While the power of a source is characteristic of that source,

the sound pressure depends on the location of the receiver and the path that the noise takes to reach the

receiver. Its measurement is based on the decibel unit, dBA, which is a logarithmic ratio referenced to a

standard noise level (2×10‐5 Pascals). The ‘A’ suffix refers to a weighting scale, which represents the noise

perceived by the human ear. With this scale, a doubling of sound power at the source results in a 3 dBA

increase in measured noise levels at the receiver, and is just perceptible to most people. An increase of

10 dBA is often perceived to be twice as loud.

Stationary sources are defined in the City of Ottawa’s ENCG as: “all sources of sound and vibration,

whether fixed or mobile, that exist or operate on a premises, property or facility. The combined sound

and vibration levels of which are emitted beyond the property boundary of the premises, property or

facility, unless the source(s) is (are) due to construction”. The guidelines do not apply to gas stations, and

occasional movement of vehicles on property, such as infrequent deliveries of goods to convenience

stores2.

4.2 Noise Source Assessment and Criteria

The equivalent sound energy level, Leq, provides a weighted measure of the time varying noise levels,

which is well correlated with the annoyance of sound. It is defined as the continuous sound level, which

has the same energy as a time varying noise level over a selected period of time. For stationary sources,

1 City of Ottawa Environmental Noise Control Guidelines, January 2016 2 City of Ottawa Environmental Noise Control Guidelines, January 2016 – Section 3.0



the Leq is calculated on an hourly interval, while for roadways, the Leq is calculated based on a 16‐hour

daytime / 8‐hour nighttime split.

Noise criteria taken from the ENCG apply to points of reception (POR). A POR is defined under ENCG as

“any location on a noise sensitive land use where noise from a stationary source is received”; this can be

an outdoor point of reception or at the plane of window. A POR can be located on an existing or zoned‐

for‐future‐use premises of permanent or seasonal residences, hotels/motels, nursing/retirement homes,

rental residences, hospitals, camp grounds, and noise sensitive buildings such as schools, places of

worship and daycare facilities. According to the ENCG, the recommended maximum noise level for an

urban (Class 2) environment at a POR is either the lowest one‐hour background noise level due to other

sources, or the exclusionary limits outlined in Table 1, whichever is higher. The site is deemed to be an

urban (Class 2) area as the site is situated near Mooney’s Bay. Riverside Drive (an arterial roadway) and

Springland Road (a minor collector roadway) are the major two roadways within 100 metres, while

Mooney’s Bay is to the west and residential areas occupy the surrounding vicinity. For these reasons, the

site is considered to be situated in a Class 2 urban environment. As mentioned earlier, the stationary noise

criteria used in Table 1 represents generally acceptable criteria for noise levels from the mechanical

equipment.

TABLE 1: EXCLUSIONARY LIMITS FOR CLASS 2 AREA

Time of Day Outdoor Points of

Reception Plane of Window

07:00 – 19:00 50 50

19:00 – 23:00 45 50

23:00 – 07:00 N/A 45



4.3 Determination of Noise Source Power Levels

Table 2 summarizes the sound power levels of each source assumed in our analysis. Source locations are

illustrated in Figure 2.

TABLE 2: EQUIPMENT SOUND POWER LEVELS (dBA)

Source ID

Height above roof

(AR)/ grade (AG)

(m)

Description

Frequency (Hz)

63 125 250 500 1000 2000 4000 8000 Total

S1‐S2 1.8 (AR) Rooftop Air Handling Unit

NA NA NA NA 88 NA NA NA 88

S3‐S5 2.3 (AR) Rooftop Air Handling Unit


S6‐S7 2.2 (AR) Dry Cooler NA NA NA NA 88 NA NA NA 88

S8 1.3 (AG) Exhaust Fan NA NA NA NA 77 NA NA NA 77

S9 1.5 (AR) Gas

Generator NA NA NA NA 100 NA NA NA 100

S10‐S45 0.8 (AR) York LX Roof‐top units


4.4 Stationary Source Noise Predictions

The impact of the stationary noise sources on the nearby residential areas was determined by computer

modelling. Stationary noise source modelling is based on the software program Predictor‐Lima, which was

developed from the International Standards Organization (ISO) standard 9613 Parts 1 and 2. This

computer program is capable of representing three‐dimensional surfaces and first reflections of sound

waves over a suitable spectrum for human hearing. This methodology has been used on numerous similar

assignments, and has been accepted by the Ministry of Environment and Climate Change (MOECC) as part

of Environmental Compliance Approvals applications.

A total of 25 receptor locations were chosen around the site to measure the noise impact at points of

reception (POR) during the daytime and evening period (07:00 – 23:00), as well as the nighttime period

(23:00 – 07:00). POR locations included outdoor points of reception (OPOR) and the plane of windows



(POW) of the adjacent residential properties, as well as sensitive POW and OPOR on‐site. Sensor locations

are described in Table 3 and illustrated in Figure 3. All units were represented as point sources in the

Predictor model with the exception of the exhaust fan at grade‐level, represented as an emitting facade

type. Table 4 contains Predictor‐Lima calculation settings. These settings are typical and have been based

on ISO 9613 standards and guidance from the MOECC.

Ground absorption over the study area was determined based on topographical features (such as water,

concrete, grassland, etc.). An absorption value of 0 is representative of hard ground, while a value of 1

represents grass and similar soft surface conditions. Existing and proposed buildings were added to the

model to account for screening and reflection effects from building façades. Modelling files and outputs

are available upon request.

TABLE 3: RECEPTOR LOCATIONS

Receptor Number

Location Height Above Grade (m)

R1 POW – 724 Mooney’s Bay Place – 2nd Storey 4.5

R2 POW –15 Bayside Private – 2nd Storey 4.5

R3 POW – Holy Cross School – 2nd Storey 5.5

R4 POW – Holy Cross School – 2nd Storey 5.5

R5 POW – 41 River Garden Private – 2nd Storey 4.5

R6 OPOR – Public Park 1.5

R7 POW – Block A2 – 2nd Storey 5.5



R10 POW – Building Flat B1 – 3rd Storey 9



R13 POW – Building C1 – 3rd Storey 9

R14 POW – Building C2 – 3rd Storey 9

R15 POW – Building D West façade – 6th Storey 18





TABLE 3: RECEPTOR LOCATIONS(CONTINUED)

Receptor Number

Location Height Above Grade (m)

R18 OPOR – Building D Northern courtyard 1.5

R19 OPOR – Building D Southern courtyard 1.5

R20 POW – Building D West façade step‐in – 6th

Storey 18

R21 POW – Building D West façade step‐in – 6th

Storey 17

R22 POW – Building D North façade – 6th Storey 18

R23 POW – Building D East façade – 6th Storey 18

R24 POW – Building D East façade – 6th Storey 17

R25 POW – Building D South façade – 6th Storey 17

TABLE 4: CALCULATION SETTINGS

Parameter Setting

Meteorological correction method Single value for C0

Value C0 5.0

Default ground attenuation factor 1

Ground attenuation factor for roadways and paved areas

0

Temperature (K) 283.15

Pressure (kPa) 101.33

Air humidity (%) 70



5. RESULTS AND DISCUSSION

Noise levels produced by HVAC equipment at all outdoor points of reception and other plane of window

receptors fall below the ENCG criteria. Equipment operations were assumed to be continuous during the

daytime, evening and nighttime for all sources except the rooftop units, which were assumed to operate

at 50% of the time during the nighttime period. The nighttime period has the more stringent criteria. The

results for noise levels due to HVAC equipment are presented in Table 5 and noise contours 1.5 metres

above grade are illustrated in Figures 4‐5.

For emergency equipment, Section B7.3 under NPC‐300 states that the sound level limits are defined as

5 dB greater than the sound level limits otherwise applicable to stationary sources3. Therefore, since this

development is classified as a Class 2 area with a daytime limit of 50 dBA, the generator limit is 55 dBA.

Generator noise levels were found to be below the ENCG criteria. The emergency generator was evaluated

separately from other sources of noise4 (See NPC‐300 C4.5.3). Noise level results for the emergency

backup generator are presented in Table 6 and the noise contours 1.5‐metres above grade are illustrated

in Figure 6.

The development is expected to be compatible with the existing and future noise sensitive land uses,

provided that the assumptions are consistent with Section 2.1 and 4.3 with respect to mechanical

equipment.

3 MOECC, Environmental Noise Guidelines, NPC 300 – Part B, Section 7.3 4 Environmental Noise Guideline “Stationary and Transportation Sources – Approval and Planning” NPC‐300



TABLE 5: NOISE LEVELS FROM HVAC EQUIPMENT

Receptor Number

Receptor Location

1‐HR LEQ (dBA) ENCG Criteria (dBA) Meets ENCG Criteria

Daytime / Evening

Nighttime Daytime/

Evening Nighttime

R1 POW – 724 Mooney’s

Bay Place 34 32 50 45 Yes

R2 POW –15 Bayside

Private 40 37 50 45 Yes

R3 POW – Holy Cross

School 40 37 50 45 Yes

R4 POW – Holy Cross

School 41 38 50 45 Yes

R5 POW – 41 River Garden

Private 37 35 50 45 Yes

R6 OPOR – Public Park 37 34 50/45 ‐ Yes

R7 POW – Block A2 34 32 50 45 Yes

R8 POW – Block A3 34 32 50 45 Yes

R9 POW – Block A5 41 39 50 45 Yes

R10 POW – Building Flat B1 43 40 50 45 Yes



R13 POW – Building C1 40 37 50 45 Yes

R14 POW – Building C2 41 39 50 45 Yes

R15 POW – Building D West

façade 47 44 50 45 Yes





R18 OPOR – Building D Northern courtyard

38 35 50/45 ‐ Yes

R19 OPOR – Building D Southern courtyard

39 37 50/45 ‐ Yes



TABLE 5: NOISE LEVELS FROM HVAC EQUIPMENT (CONTINUED)

Receptor Number

Receptor Location

1‐HR LEQ (dBA) ENCG Criteria (dBA) Meets ENCG Criteria

Daytime / Evening

Nighttime Daytime/Evening

Nighttime

R20 POW – Building D West façade step‐in

44 43 50 45 Yes

R21 POW – Building D West façade step‐in

46 45 50 45 Yes

R22 POW – Building D North façade

38 35 50 45 Yes

R23 POW – Building D East


R24 POW – Building D East


R25 POW – Building D South façade

40 38 50 45 Yes

TABLE 6: DAYTIME NOISE LEVELS FROM EMERGENCY BACKUP GENERATOR

Receptor Number

Receptor Location 1‐HR Leq(dBA) ENCG Criteria (dBA) Meets

ENCG Daytime Daytime

R1 POW – 724 Mooney’s Bay

Place 25 55 Yes

R2 POW –15 Bayside Private 35 55 Yes

R3 POW – Holy Cross School 37 55 Yes

R4 POW – Holy Cross School 36 55 Yes

R5 POW – 41 River Garden

Private 31 55 Yes

R6 OPOR – Public Park 30 55 Yes

R7 POW – Block A2 30 55 Yes



R10 POW – Building Flat B1 36 55 Yes



R13 POW – Building C1 44 55 Yes



TABLE 6: DAYTIME NOISE LEVELS FROM EMERGENCY BACKUP GENERATOR(CONTINUED)

Receptor Number

Receptor Location 1‐HR Leq(dBA) ENCG Criteria (dBA) Meets

ENCG Daytime Daytime

R14 POW – Building C2 44 55 Yes

R15 POW – Building D West façade 39 55 Yes



R18 OPOR – Building D Northern

courtyard 40 55 Yes

R19 OPOR – Building D Southern

courtyard 41 55 Yes

R20 POW – Building D West façade

step‐in 55 55 Yes

R21 POW – Building D West façade

step‐in 55 55 Yes

R22 POW – Building D North

façade 33 55 Yes

R23 POW – Building D East façade 35 55 Yes

R24 POW – Building D East façade 36 55 Yes

R25 POW – Building D South

façade 32 55 Yes



6. CONCLUSIONS AND RECOMMENDATIONS

Our stationary noise assessment for the proposed mixed‐use development at 3071 Riverside Drive

indicates that, provided equipment selections and locations are similar to the assumptions in this report,

noise levels on‐site and on nearby residential areas are expected to fall below the City of Ottawa’s

Environmental Noise Control Guidelines (ENCG). Therefore, the proposed development is expected to

be compatible with the existing and future noise sensitive land uses. As this study is based on assumed

mechanical information from GWE’s previous experience with similar projects, final mechanical

equipment selection and locations should be reviewed by an acoustical engineer prior to installation of

equipment.

To ensure compliance with the ENCG sound level limits, the following design considerations should be

considered:

Majority of the equipment should be located on rooftops

Parapets should extend above the roof surface to provide shielding of the equipment

Rooftop units for Buildings C and D should not exceed a sound power level of 88 and 91

dBA (referenced to one picowatt) respectively, unless additional noise control measures

are considered

Dry Coolers should not exceed a sound power level of 88 dBA, unless additional noise

control measures such as roof screens are considered

Where necessary, silencers or acoustic barriers may require consideration if equipment

selections exceed recommended sound power.


Stationary Noise Assessment 17

FIGURE 4: HVAC DAYTIME AND EVENING NOISE CONTOURS (1.5 METERS ABOVE GRADE)

80 – 85 dB

75 – 80 dB

70 – 75 dB

65 – 70 dB

60 – 65 dB

55 – 60 dB

50 – 55 dB

45 – 50 dB

40 – 45 dB

35 – 40 dB

0 – 35 dB



FIGURE 5: HVAC NIGHTTIME NOISE CONTOURS (1.5 METERS ABOVE GRADE)

80 – 85 dB

75 – 80 dB

70 – 75 dB

65 – 70 dB

60 – 65 dB

55 – 60 dB

50 – 55 dB

45 – 50 dB

40 – 45 dB

35 – 40 dB

0 – 35 dB



FIGURE 6: GENERATOR DAYTIME NOISE CONTOURS (1.5 METERS ABOVE GRADE)

80 – 85 dB

75 – 80 dB

70 – 75 dB

65 – 70 dB

60 – 65 dB

55 – 60 dB

50 – 55 dB

45 – 50 dB

40 – 45 dB

35 – 40 dB

0 – 35 dB

stationary noise feasibility assessment 3071

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