Low Sound Solutions

Specialists in Heat Transfer Products and Services

The The AAdvanced dvanced TTechnologyechnology Low Sound SolutionsLow Sound Solutions

CONFIDENTIALThis document is the property of EVAPCO, Inc.

It should not be copied or disclosed without prior written authorization.


Same Great AT Features and Benefits

Low Energy Consumption

Low Sound Options

AAdvanced dvanced TTechnology LOW SOUND SOLUTIONSechnology LOW SOUND SOLUTIONS


CTI Test Code ATC-128 (currently in revision process)

Ensures sound data will be measured, evaluated and presented in the same manner. Specifies instrumentation and operating conditions. Defines measurement locations. Describes how to account for background noise in

data reduction. Once adopted, recommended for use in engineering

specifications

Sound Basics Sound Basics

SoundSound


Measuring Sound Pressure Levels. It is important to be aware of testing tolerances. Variables:

Ambient Temperature and Humidity Wind Speed Background Noise Reflectivity Accuracy of Instrumentation

Sound BasicsSound Basics

SoundSound


Uncertainty in Measuring Sound Pressure Levels.


Octave Band Frequency Testing Tolerance* (dB)63 ± 5

125 ± 3250 ± 2500 ± 1.5

1000 ± 1.52000 ± 1.54000 ± 1.58000 ± 2.5

* per ISO standard 3744

SoundSound


Rules of Thumb: Adding two identical sources results in a 3 dB(A) increase

Ex: 73 dB(A) + 73 dB(A) = 76 dB(A)


SoundSound

!


Rules of Thumb: Adding two identical sources results in a 3 dB(A) increase

Ex: 73 dB(A) + 73 dB(A) = 76 dB(A) ±1 dB(A) change in sound level is inaudible +10dB(A) sounds twice as loud Doubling far field distance from a point sound source results

in a 6 dB(A) reduction Ex: 73 dB(A) @ 50 ft (15m) = 67 dB(A) @ 100 ft (30m)

Sound BasicsSound Basics

SoundSound


Features and BenefitsFeatures and Benefits

• Four options to reduce sound levels


EVAPCOEVAPCO®® Induced Draft Products are Induced Draft Products are thethe QuietestQuietest in the Industryin the Industry

– SUPER Low Sound Fan



9 to 15 dB(A) Reduction!SUPER Low Sound Fan –SUPER Low Sound Fan –

9 to 15 dB(A) Reduction!


• Available on all 8.5’ cells• Adds 12” to 21” (330 to 530mm) to cell

height• One piece molded construction, heavy

duty FRP.

• Extremely wide chord blades• Unique forward swept blade profile• Reduced fan speed

• No thermal performance derate!



Dimensional Impact

Construction

Thermal Performance




Just BIGGER!



• Four options to reduce sound levels– SUPER Low Sound Fan



– Low Sound Fan



4 to 7 dB(A) ReductionLow Sound Fan –Low Sound Fan –

4 to 7 dB(A) Reduction!

• Available on all 12’ (3.6m) and 14’ wide cells

• Add 7” (177mm) to overall unit height

• Wide chord fan blades• Aluminum

construction with steel fan hub


Dimensional Impact

Construction

Thermal Performance





– Discharge Attenuation

• Four options to reduce sound levels– SUPER Low Sound Fan– Low Sound Fan


• Available on all standard AT products, except 4’ wide units

• Cannot be used with SUPER Low Sound Fan option

• Can be used with Low Sound Fan option


Up to 10 dB(A) ReductionDischarge Attenuation –Discharge Attenuation –

Up to 10 dB(A) Reduction!


• Straight sided discharge hood• Adds 55” (1400mm) to

standard unit height

• High density fiberglass insulated walls and low pressure drop baffling system

• Self supporting on unit

• Only 2% thermal performance derate


Up to 10 dB(A) ReductionDischarge Attenuation –Discharge Attenuation –

Dimensional Impact

Construction

Thermal Performance




– Water Silencer

• Four options to reduce sound levels– SUPER Low Sound Fan– Low Sound Fan– Discharge Attenuation



• Available on all standard AT products

• No dimensional impact

• Lightweight PVC • Easily removable sections

rest on steel supports• Located in the falling water

area of the cold water basin



EVAPCO Water SilencersEVAPCO Water Silencers

Dimensional Impact

Construction

Thermal Performance



EVAPCO Water SilencersEVAPCO Water Silencers

Measured at 5 ft (1.5m) from air inletMeasured at 5 ft (1.5m) from air inlet

Fans at Full Speed 4 – 7 dB(A) reduction

Fans at Half Speed 7 – 10 dB(A) reduction

Fans Off 9 - 12 dB(A) reduction



Octave Band Sound Analysis – 5ft. (1.5m) dataOctave Band Sound Analysis – 5ft. (1.5m) data

300 Ton Cooling Tower

Conditions: 900 gpm, 95/85/78(300 Nominal Tons)

Selection: (1) AT 19-6128.5’ x 12’ plan area(1) 20 HP Motor



Octave Band Sound Analysis – 5ft. (1.5m) dataOctave Band Sound Analysis – 5ft. (1.5m) dataModel AT 19-612

Standard Sound Data

20 HP (15kW)BAND END SIDE TOP

63 Hz 78 78 80

125 Hz 81 81 86

250 Hz 81 81 86

500 Hz 75 76 80

1k Hz 72 73 75

2k Hz 69 71 73

4k Hz 72 72 71

8k Hz 73 73 68

dB(A) 80 81 83

Model AT 19-612

with Water Silencers


63 Hz 78 78 80

125 Hz 81 81 86

250 Hz 81 81 86

500 Hz 74 76 80

1k Hz 67 70 75

2k Hz 62 66 73

4k Hz 63 64 71

8k Hz 64 65 68

dB(A) 76 77 83

80 – 76 = 4 dB(A)

72 – 63 = 9 dB



Model AT 19-612

SUPER Low Sound Fan


63 Hz 74 77 74

125 Hz 70 72 79

250 Hz 68 66 69

500 Hz 69 69 66

1k Hz 71 71 66

2k Hz 69 70 65

4k Hz 72 71 63

8k Hz 73 73 65

dB(A) 78 78 72

Model AT 19-612

Standard Sound Data


63 Hz 78 78 80

125 Hz 81 81 86

250 Hz 81 81 86

500 Hz 75 76 80

1k Hz 72 73 75

2k Hz 69 71 73

4k Hz 72 72 71

8k Hz 73 73 68

dB(A) 80 81 83


83 – 72 = 11 dB(A)



Model AT 19-612

SUPER Low Sound Fan

& Water Silencers


63 Hz 74 73 74

125 Hz 70 76 79

250 Hz 68 69 69

500 Hz 63 68 65

1k Hz 63 67 65

2k Hz 61 65 64

4k Hz 63 63 62

8k Hz 64 65 63

dB(A) 70 73 72

Model AT 19-612

Standard Sound Data


63 Hz 78 78 80

125 Hz 81 81 86

250 Hz 81 81 86

500 Hz 75 76 80

1k Hz 72 73 75

2k Hz 69 71 73

4k Hz 72 72 71

8k Hz 73 73 68

dB(A) 80 81 83




Model AT 19-612

SUPER Low Sound Fan & Water Silencers


63 Hz 74 73 74

125 Hz 70 76 79

250 Hz 68 69 69

500 Hz 63 68 65

1k Hz 63 67 65

2k Hz 61 65 64

4k Hz 63 63 62

8k Hz 64 65 63

dB(A) 70 73 72

Octave Band Sound Analysis – 5ft. (1.5m) dataOctave Band Sound Analysis – 5ft. (1.5m) dataInduced Draft

Brand “B”Induced Draft

EVAPCOModel 3333A/Q

Crossflow Unit with Low Sound Fan


63 Hz 63 56 55

125 Hz 63 65 73

250 Hz 68 68 80

500 Hz 68 71 74

1k Hz 70 74 76

2k Hz 67 73 77

4k Hz 60 66 74

8k Hz 54 61 70

dB(A) 73 78 82



Model LSTA 8P-125

Standard Sound Data

50 HP (37kW)BAND End Fan Side TOP

63 Hz 77 79 77

125 Hz 74 77 77

250 Hz 69 76 76

500 Hz 69 77 78

1k Hz 68 75 74

2k Hz 65 73 71

4k Hz 62 70 71

8k Hz 57 66 71

dB(A) 73 80 80

Model AT 19-612

SUPER Low Sound Fan & Water Silencers


63 Hz 74 73 74

125 Hz 70 76 79

250 Hz 68 69 69

500 Hz 63 68 65

1k Hz 63 67 65

2k Hz 61 65 64

4k Hz 63 63 62

8k Hz 64 65 63

dB(A) 70 73 72

Octave Band Sound Analysis – 5ft. (1.5m) dataOctave Band Sound Analysis – 5ft. (1.5m) dataForced Draft Induced Draft



Model LSTA 8P-125 @ 50HP

Unit Price with:

• Standard Product

Price (ex-factory) = $ 16,500

Model AT 19-612 @ 20HP

Unit Price with:

• Water Silencers

• SUPER Low Sound Fan

Price (ex-factory) = $ 18,000

Life Cycle Cost ComparisonLife Cycle Cost Comparison

$ 1,500

$ 7,050

Annual Energy Savings

Total Fan Power Cost / yr = $ 4700 Total Fan Power Cost / yr = $ 11,750

$0.09 / kWh and 3500 hours per year (40% usage rate)



SUPER Low Sound Fan(s):

Suggested Mechanical SpecificationSuggested Mechanical Specification



Specify Sound Data 5’ above Fan Discharge at Full Speed


Verification of Supplier Data

45°

5’

Microphone Position





• Verification of Supplier Data





45°5’

Verification of Supplier Data

5’

Not Here

Property Line

Not Here

Microphone Position





• Verification of Supplier Data

• Sound Quality

• Sound Frequency

• Acoustical Shadow




Sound Quality• Sound Frequency

• Acoustical Shadow*

High FrequencySelf Attenuating

Not Here

Microphone Position

Low-Mid Frequencies


Property Line

*Seelbach & Oran, What to do about Cooling Tower Noise, Industrial Acoustics Co., Inc., 1998.

Not Here


Replacement Projects Consider EVAPCO Induced Draft AT Style Units First!

Low Energy Low Sound Simplified Maintenance

Retro-Fit ApplicationsRetro-Fit Applications

SoundSound

Replacement Sections / Retro-fits All Low Sound Solutions can be Retro-fitted

into existing EVAPCO Induced Draft Units!


Success StorySuccess StorySuccess Story



BACKGROUND:• 500,000 Sq.Ft. Office Building in Boston

•Noise related complaints from tenants – shaking windows •Building Owner hired sound consultant•Sound Consultant recommended 14 dB reduction in 250 and 500Hz octave bands

• Building owner contacted Evapco to inquire about possible solutions to address sound consultant recommendation.


Success StorySuccess Story


Two Cooling Towers: 8’x24’ and 8’x18’ - 4 Fans Total - 20 Hp EachTwo Cooling Towers: 8’x24’ and 8’x18’ - 4 Fans Total - 20 Hp Each



• Towers end to end

• Sound reflecting off the building walls and windows

BACKGROUND:


SOLUTION:• EVAPCO proposed replacing the standard fans with

EVAPCO SUPER Low Sound Fans

• EVAPCO Guaranteed:• 18 dB sound reduction in 250 Hz Octave Band• 15 dB sound reduction in 500 Hz Octave Band

• Building owner loved the idea!•Requested identical replacement units withEVAPCO SUPER Low Sound Fans installed.




• Independent sound consultant was hired to record “before” and “after” sound measurements to verify guaranteed reductions.



Cerami & Associates – New York, NY


RESULT:Cerami & Associates, Inc. Acoustical Engineers, Project # 14810Cerami & Associates, Inc. Acoustical Engineers, Project # 14810


REDUCTION – 5ft Above Top

Tower: 8’x24’ 8’x18’

BAND 5 ft. 5 ft.

63 Hz 14 11

125 Hz 14 21

250 Hz 18 19

500 Hz 19 25

1k Hz 14 21

2k Hz 12 16

4k Hz 17 15

8k Hz 13 9

dB(A) 15 21


INITIAL SOUND – 5ft Above Top

Tower: 8’x24’ 8’x18’

BAND 5 ft. 5 ft.

63 Hz 92 93

125 Hz 91 98

250 Hz 89 92

500 Hz 87 93

1k Hz 83 90

2k Hz 79 82

4k Hz 73 75

8k Hz 64 67

dB(A) 89 94


• Four options to reduce sound levels– SUPER Low Sound Fan– Low Sound Fan– Discharge Attenuation– Water Silencers

• Sound Reduction from the top, sides and ends

• No capacity derate in most cases• Low Energy• Overall sound pressure levels available in

EVAPCO’s selection software


EVAPCO® Induced Draft Products are the Quietest in the Industry

ConclusionsConclusions




TakingTaking

QualityQualityandand

ServiceServiceto ato a

Higher Level . . .Higher Level . . .

EVAPCO, INC.EVAPCO, INC.

Business

Low Sound Solutions