REP Mar Gard Drytech 1015 Dairy Noise Study
Page 1 of 8
2013-12-04
Eric Cameron, P.Eng., LEED AP
Vice President
Mar Gard Limited
92 Bentley Avenue, 2nd Floor
Ottawa, ON K2E 6T9
T: 613-723-1640
F: 613-723-8544
C: 613-218-2112
Mar Gard Limited – 1015 Dairy Drive, Orleans, Ontario
Environmental Noise Control Study
Dear Eric,
This study addresses the stationary sources of noise due to the proposed Industrial warehouse
at 1015 Dairy Drive in Orleans, Ontario. The City of Ottawa Environmental Noise Control
Guidelines give sound level criteria for new potential sources of stationary noise near existing
noise-sensitive land uses, such as the homes which are near the industrial facility. To determine
whether the new building meets the City’s noise guidelines, we have modeled the building and
the proposed mechanical equipment and assessed the resulting noise impact at the locations of
nearby residences.
The guidelines state that at the plane of a bedroom window, nighttime sound levels from new
stationary sources should not exceed 45 dBA. Our simulations indicate that the noise output of
the exhaust fans is sufficiently low to fall within the guidelines. We have also used our
simulations to determine the maximum allowed sound power level for the 3 rooftop units (RTU)
to meet the noise guidelines with and without an acoustical barrier.
As long as equipment is chosen with the sound power levels indicated in this report, no further
noise mitigation measures are necessary to meet the City of Ottawa’s Environmental Noise
Control Guidelines.
If you have any questions about this report, please do not hesitate to contact us.
Sincerely,
Jeremy Thorbahn
Acoustical Consultant
STATE OF THE ART ACOUSTIK INC.
43 – 1010 Polytek Street
Ottawa, ON
K1J 9J3
www.sota.ca
E: [email protected]
T: 613-745-2003
F: 613-745-9687
REP Mar Gard Drytech 1015 Dairy Noise Study
Page 2 of 8
1. Introduction
The site plan drawing dated 2013/11/04 indicates that several of the noise sources on the
proposed building at 1015 Dairy Drive are facing private residences. The City of Ottawa
Environmental Noise Control Guidelines give acceptable sound pressure levels from new
stationary noise sources at the plane of a bedroom window. The guidelines, taken from Table
1.12 of the City of Ottawa ENCG, are given below in Table 1 for Class 1 (urban) and Class 2
(mixed urban and rural) areas:
Time of Day
0700 – 1900
1900 – 2300
2300 – 0700
One Hour Leq (dBA)
Class 1 Area
Class 2 Area
50
50
47
45
45
45
Table 1 - Maximum Values of One Hour Leq or by Time of Day
According to these guidelines, new stationary noise sources such as the rooftop units (RTU) and
exhaust fans (EF) at 1015 Dairy Drive should not cause a sound pressure level in excess of 45
dBA at the plane of a bedroom window during the night.
2. Facility Description
2.1 Site Plan
Figure 1 on the following page shows the site plan for the new building at 1015 Dairy Drive,
including locations of noise-generating equipment considered in this report. The building
consists of a large 2 storey (11m) area and smaller 3 storey (7.3m) areas.
STATE OF THE ART ACOUSTIK INC.
43 – 1010 Polytek Street
Ottawa, ON
K1J 9J3
www.sota.ca
E: [email protected]
T: 613-745-2003
F: 613-745-9687
REP Mar Gard Drytech 1015 Dairy Noise Study
Page 3 of 8
EF2
EF1
RTU1
RTU1
RTU1
RTU3
RTU1
RTU2
RTU1
EF3
RTU1
Figure 1 – Site plan for 1015 Dairy Drive showing locations of noise-generating
equipment
2.2 Noise Sources
The following noise sources are considered in this report. For the exhaust fans, octave band
sound power data has been obtained from the submittals provided to us. For the rooftop units,
we have used the octave band spectra for the units listed in the submittals and applied an
attenuation to determine the sound power level required to meet noise guidelines within a 2-3
dB safety margin. As RTU1 and RTU3 are directly facing the nearby residence, their noise
requirements are more stringent than for RTU2, which is more distant from any homes. If an
acoustical barrier is built in front of RTU1 and RTU3, the units could be slightly louder and still
meet guidelines. This solution is described in section 4.2.
Total Sound Power Level
(dBA)
Rooftop Unit
RTU1
East Face
92
Rooftop Unit
RTU2 South Face
99
Rooftop Unit
RTU3
East Face
85
Twin City WPB/36E4
East Face
71
EF1
Twin City WPB/21E8
South Face
62
EF2
S&P GED10-1/10
West Face
62
EF3
Table 2 – Allowable noise sources at 1015 Dairy Drive
EQUIPMENT
ID
Location
STATE OF THE ART ACOUSTIK INC.
43 – 1010 Polytek Street
Ottawa, ON
K1J 9J3
www.sota.ca
E: [email protected]
T: 613-745-2003
F: 613-745-9687
REP Mar Gard Drytech 1015 Dairy Noise Study
Page 4 of 8
2.3 Operating Hours
We have been told that the equipment will run according the following schedule:
Summer Season
RTU-1, 2 & 3: Continuous operation on AC mode (i.e. all the fans running)
EF-1, 2 & 3: Continuous operation
Winter Season
RTU-1, 2 & 3: Continuous operation on heating mode (i.e. all the fans except the condenser fans
running)
EF-1, 2 & 3: Continuous operation
Shoulder Seasons
RTU-1, 2 & 3: Intermittent, daytime operation on AC mode (i.e. all the fans running)
EF-1, 2 & 3: Continuous operation
Our recommendations will be made to ensure that noise guidelines are met under the worst
case scenario, i.e. during the summer when all equipment is running continuously.
3. Methodology Used in Noise Impact Calculation
The following section describes the methodology and software used to model the sound
pressure levels at the points of reception due to the noise sources while taking into account
parameters such as source levels, distance, topography, barriers and building geometry.
3.1 Procedure Used to Assess Noise Impact at the Points of Reception
The noise resulting from the major noise sources is predicted at chosen points of reception.
This environmental noise analysis was done using an environmental noise modeling software
called Cadna/A which references ISO 9613. Cadna/A predicts environmental noise through
calculations based on a 3D model which uses geometrical, landscape and topography data,
combined with details of the proposed construction and the noise source power levels.
We created a 3D rendering of the new and existing building at 1015 Dairy Drive and considered
two points of reception at the locations of nearby homes. Noise sources were placed in the
model and assigned the sound power levels given above. Using this information, Cadna/A
predicts the resulting sound pressure levels at the points of reception.
STATE OF THE ART ACOUSTIK INC.
43 – 1010 Polytek Street
Ottawa, ON
K1J 9J3
www.sota.ca
E: [email protected]
T: 613-745-2003
F: 613-745-9687
REP Mar Gard Drytech 1015 Dairy Noise Study
Page 5 of 8
3.2 Other Parameters/Assumptions Used in Calculations
Parameter
Building Reflections
Ground Absorption
Temperature (°C)
Relative Humidity (%)
Value/Condition
On
Default value of 1
20
70
Table 3 – Parameters used in Cadna/A modeling
3.3 Locations of Noise Sources and Points of Reception
Figure 2 below shows the locations of the mechanical equipment (blue crosses) and the points
of reception (black/white spheres) that we considered at the two nearby homes.
RTUs
EFs
POR1
POR2
Figure 2 – Locations of noise sources and points of reception in model
STATE OF THE ART ACOUSTIK INC.
43 – 1010 Polytek Street
Ottawa, ON
K1J 9J3
www.sota.ca
E: [email protected]
T: 613-745-2003
F: 613-745-9687
REP Mar Gard Drytech 1015 Dairy Noise Study
Page 6 of 8
4. Results and Recommendations
4.1 Solution with No Barrier
Using RTUs with the sound power levels given in Table 2, our model predicts the following
sound pressure levels at the points of reception from the RTUs and fans:
Location
POR1
POR2
Sound Pressure Level (dBA)
43.0
42.7
Table 4 – Noise levels at nearby homes
Based on these predictions, the equipment specified in section 2.2 will produce sufficiently low
noise to fall below the City’s noise guidelines of 45 dBA at the plane of a bedroom window,
allowing for a 2-3 dB safety margin.
4.2 Solution with Barrier
If an acoustical barrier is built in front of RTU1 and RTU3, those units could have slightly higher
sound power levels and still meet the noise guideline. An appropriate barrier as described in
Table 5 could provide about 5 dBA of noise attenuation, allowing for units to be chosen with
about 5 dBA greater sound power level. The barrier must be continuous with no gaps at the
ground or between sections. Note that any barrier located close to a building has limited
effectiveness due to reflections from the building that are redirected towards the point of
reception.
Length
Height
Density
20m
3.5m
2
20kg/m
Table 5 – Acoustical barrier properties
With such a barrier in place, the following equipment sound power levels would acceptable:
Total Sound Power Level
(dBA)
Rooftop Unit
RTU1
East Face
97
Rooftop Unit
RTU2 South Face
99
Rooftop Unit
RTU3
East Face
90
Twin City WPB/36E4
East
Face
71
EF1
Twin City WPB/21E8
South Face
62
EF2
S&P GED10-1/10
West
Face
62
EF3
Table 6 – Allowable noise sources at 1015 Dairy Drive if barrier is added
EQUIPMENT
ID
Location
STATE OF THE ART ACOUSTIK INC.
43 – 1010 Polytek Street
Ottawa, ON
K1J 9J3
www.sota.ca
E: [email protected]
T: 613-745-2003
F: 613-745-9687
REP Mar Gard Drytech 1015 Dairy Noise Study
Page 7 of 8
The predicted noise levels with the barrier and the above equipment sound power levels are:
Location
POR1
POR2
Sound Pressure Level (dBA)
42.8
42.7
Table 7 – Noise levels from 5 dBA louder RTU1 and 3 with acoustical barrier
Figure 3 shows the recommended orientation of the barrier relative to RTU1 and RTU3.
POR1
Barrier
RTUs
Figure 3 – Recommended placement of acoustical barrier
4.3 Use of Building as a Barrier
In the case that equipment meeting the sound power level requirements in Table 2 or 6 could
not be found, the only remaining option to meet the noise guidelines would be to relocate the
RTUs to the opposite side of the building, so that the building itself would act as a barrier. This
should result in sufficiently low noise at the points of reception, but we have not modeled this
solution.
STATE OF THE ART ACOUSTIK INC.
43 – 1010 Polytek Street
Ottawa, ON
K1J 9J3
www.sota.ca
E: [email protected]
T: 613-745-2003
F: 613-745-9687
REP Mar Gard Drytech 1015 Dairy Noise Study
Page 8 of 8
5. Conclusion
Based on the equipment specifications (for exhaust fans), typical sound spectra (for RTUs) and
locations provided to us, we have modeled the stationary noise sources at 1015 Dairy Drive and
predicted the resulting sound pressure levels at the locations of the nearby homes. The City of
Ottawa’s Environmental Noise Control Guidelines require that noise from stationary sources at
the plane of a bedroom window does not exceed 45 dBA during nighttime hours. Since
equipment will run continuously through the night, we have based our recommendations on
meeting the 45 dBA guidelines at all times, and have allowed for a 2-3 dB safety margin.
If equipment is chosen with the sound power levels given in Table 2 and at the locations shown
in Figure 1, then noise produced from stationary sources at 1015 Dairy Drive will meet the City’s
guidelines and no further noise mitigation measures are necessary. RTU1 and RTU3 may be
chosen up to 5 dBA louder if an acoustical barrier is added, as described in Tables 5 and 6. If
RTUs with sufficiently low sound power levels for the above solutions could not be found,
relocating the units to the opposite site of the building would reduce noise since the building
would act as a barrier.
STATE OF THE ART ACOUSTIK INC.
43 – 1010 Polytek Street
Ottawa, ON
K1J 9J3
www.sota.ca
E: [email protected]
T: 613-745-2003
F: 613-745-9687
Air Cooled Screw Chiller
Performance Specification
Provided Features
Acoustic Package
Acoustic Condenser Fan Stacks – Field Installed
Acoustic Louvers
Acoustical Compressor Enclosure
Acoustical Compressor Jackets
Testing Package
Quality Assurance Inspection
Warranty
Limited Warranty on Fisen Provided Parts
Field Installed Items
(16)Acoustic Condenser Fan Stacks
JCI Provided Vibration Isolation *Must be sized for revised weights
Job Name:
Date:
Job:
PreSubmittal
Ver.
1.1
York Contract No.:
Performance
Page 1 of 8
Air Cooled Screw Chiller
Performance Specification
Construction Details
Sound Attenuation Package - The chiller shall be provided with several sound absorbing means to minimize the
radiated sound from the unit. Sound ratings listed in the performance tables reflect average sound levels that would
be expected if a random sample of production chillers were tested. Some uncertainty in the sound levels may be
expected due to measurement method uncertainties, varying site conditions, and slight variations in the installation of
components.
Sound Attenuation Package – Acoustic Condenser Fan Stacks – Field Installed - The unit shall be equipped with
acoustic condenser fan stacks. The stacks shall be fabricated out of a minimum of 16 ga. galvanized sheet metal. All
exposed sheet metal visible from the exterior of the unit shall be painted with an exterior grade paint to match the unit.
The inside of the stacks shall be lined with acoustic absorbing foam fabricated from tough urethane foam in a 1” thick
media. The acoustic liner shall be faced with a foil aluminized material. Reduction of acoustic levels is indicated in the
performance tables. The fan stacks shall be shipped to the jobsite for field installation onto the top of the unit. All
necessary hardware for attachment of the stacks to the unit shall be provided along with detailed installation
instructions.
Acoustical Compressor Enclosure - The unit shall be equipped with an acoustical compressor enclosure. The
enclosure shall be fabricated of 18 ga. galvanized sheet metal. All exposed sheet metal visible from the exterior of the
unit shall be painted to match the unit with an exterior grade paint. The inside of the enclosure shall be lined with
acoustic absorbing foam. Reduction of acoustic levels is indicated in the performance tables.
Acoustical Compressor Jackets - The unit shall have all compressors wrapped in a sound absorbing material. The
sound absorbing material shall be of a composite design utilizing multiple layers to maximize sound absorption and
minimize transmitted noise. The jackets are then shrink wrapped in a UV resistant polymer to provide an additional
level of weather resistance.
Sound Attenuation Package – Acoustic Louvers - The unit shall be equipped with sound absorbing acoustic
weather louvers. The louver design shall incorporate insulated acoustical blades and high free area to provide
maximum resistance to sound transmission, rain, and weather while providing minimum resistance to airflow. The
louvers shall be constructed with heavy gauge formed aluminum frame and blades mechanically fastened together.
The louvers shall be acoustically insulated with a fiberglass insulation. All exposed surfaces visible from the exterior of
the unit shall be painted with an exterior grade paint to match the unit. The acoustic louvers located over top of the
rigging attachment locations may need to be removed prior to rigging to ensure that the rigging straps do not cause
permanent damage to the unit or louvers. The acoustic louvers may need to removed for access underneath the
chiller. Provision will be made in some of the exterior louvers (as shown in the drawings) for the chilled water piping to
penetrate. The installing contractor is responsible for running any pipe and fittings required from the chiller barrel to
the exterior of the louvers.
Job Name:
Date:
Job:
PreSubmittal
Ver.
1.1
York Contract No.:
Performance
Page 5 of 8
Air Cooled Screw Chiller
Performance Specification
Rigging
*** CAUTION ***
DEPENDING ON THE RIGGING EQUIPMENT AT THE JOBSITE, THE ACOUSTIC LOUVERS
LOCATED OVERTOP OF THE ATTACHMENT LOCATIONS MAY NEED TO BE REMOVED
FROM THE UNIT PRIOR TO RIGGING. A SPREADER BAR OF A LENGTH GREAT ENOUGH
TO PREVENT THE RIGGING STRAPS FROM PUSHING INTO THE SIDE OF THE LOUVERS
OR UNITS IS REQUIRED TO PREVENT PERMANENT DAMAGE.
Fan Stacks
Job Name:
Date:
Job:
PreSubmittal
Ver.
1.1
York Contract No.:
Performance
Page 6 of 8
Air Cooled Screw Chiller
Performance Specification
Field Connections
Field connections are detailed in the factory IOM or Technical Guide other than those listed in this document. Refer to
the factory provided documents for detailed instructions on high voltage electrical connections. Failure to follow the
instructions in that document as supplemented by the instructions in the Fisen IOM addendums or any other IOMs may
result in equipment damage or personnel injury.
FIELD WIRING
1. UNIT MOUNTED DISCONNECT
2. WIRE PER NEC AND LOCAL CODES
3. SUITABLE FOR 60° AND 75° CONDUCTORS
4. DASHED LINE INDICATES FIELD WIRING
STANDARD FIELD POWER WIRING
DETAIL ML
Acoustic Louver
Electrical Connections
Note: The installing contractor is responsible for running the chiller water piping from the
chiller barrel to the above penetrations in the louvers to the exterior of the chiller.
Hydronic Connections
Job Name:
Date:
Job:
PreSubmittal
Ver.
1.1
York Contract No.:
Performance
Page 7 of 8
Air Cooled Screw Chiller
Performance Specification
Acoustical Condenser Fan Stack
ACOUSTICAL CONDENSER FAN STACK
1.
2.
3.
4.
SHEET METAL CONSTRUCTION WITH
MECHANICAL FASTENERS.
18 GAUGE G90 STEEL
PAINTED SIMILAR COLOR TO BASE UNIT
MULTI-LAYER ACOUSTICAL ABSORBING
MATERIAL OF VARYING DENSITY TO
REDUCE REFLECTED NOISE.
1.
2.
3.
4.
5.
6.
INSTALLATION KIT INCLUDES:
STACK SIDES
5/16" TEK SCREWS FOR ASSEMBLY
3/8" TEK SCREW FOR ATTACHMENT
FOAM GASKET
FOIL TAPE
SHIPPING AND INSTALLATION
HFUBͲ025Ͳ050
HFUBͲ025Ͳ100
HFUBͲ050
HFUBͲ100
¼
¼
½
1
1
1
1
1
1
1/
1Ͳ¼
½
1
A=Decoupler Thickness
B=Vinyl Barrier Thickness
C=Absorber Thickness
D=Nominal Thickness
Acoustical Barrier Data
BRD HUSH FOAM polyurethane acoustical foam is manufactured to exacting specifications of a partially reticulated cellular
structure. This controlled porosity of the nominal 2 lbs./ft.3 density UL-94/HF1 foam results in maximum acoustical absorption.
Product categories include type HFU (absorber only), type HFUB (barrier composites), type HFUD (damping composites) and type
HFQC (quilted composites). To protect the foam in applications that require resistance to water, grease, dust, oil and other
contaminants, film facings can be applied to the material with minimal impact on acoustic performance because of the
diaphragmatic action transferring sound energy to the internal construction. Here acoustic energy is dissipated by means of friction
in the form of heat.
Job Name:
Date:
Job:
PreSubmittal
Ver.
1.1
York Contract No.:
Performance
Page 8 of 8