Air-Conditioning, Heating and

Refrigeration InstituteRefrigeration Institute

What is AHRI?

� National trade association representing manufacturers of more than 90% of North American produced central air-conditioning, heating, and commercial refrigeration equipment.

� A major voice for the HVACR industry offering its members � A major voice for the HVACR industry offering its members a forum to solve common challenges and a variety of services and benefits.

� ARI merged with the Gas Appliance Manufacturers Association (GAMA) in 2008 to form the Air-Conditioning, Heating, and Refrigeration Institute (AHRI).

� Is one of the nation’s larger trade associations

– Representing 311 HVACR and water heating manufacturers

across 39 product sections

� Promotes policies beneficial to industry

� Represents the industry domestically &globally

� Establishes international standards

What does AHRI do?

� Establishes international standards

– Over 100 industry standards and guidelines

� Administers rigorous certification programs

– 39 Certification Programs

� Administers a comprehensive industry statistics program

AHRI Member Profile

� Our members manufacture:

– Central air conditioning and heating

equipment

– Water heating equipment

– Commercial and industrial air-conditioning,

heating, and ventilation equipmentheating, and ventilation equipment

– Commercial and industrial refrigeration

equipment

– Hydronic heating equipment

– Components for heating, air-conditioning,

and refrigeration systems

AHRI Technical Committee on Sound

� The AHRI Technical Committee on Sound (TCoS) oversees the development and maintenance of all AHRI sound testing, rating, and application standards.

� The TCoS establishes and administers all AHRI policies on acoustical activities.acoustical activities.

� Its members participate in pertinent sound standards writing activities of other organizations.

� The TCoS provides assistance and advice to AHRI’s product sections on all acoustical issues.

AHRI Technical Committee on Sound� AHRI test setup and calibration sound standards include:

– ANSI/AHRI Standard 220-2012, Reverberation Room Qualification and Testing

Procedures for Determining Sound Power of HVAC Equipment;

– AHRI Standard 230, Sound Intensity Testing Procedures for Determining Sound

Power of HVAC Equipment;

– ANSI/AHRI Standard 250-2008, Performance and Calibration of Reference Sound

Sources;

� AHRI product specific sound standards include (15):– ANSI/AHRI Standards 260 (I-P)-2012 and 261(SI)-2012, Sound Rating of Ducted Air – ANSI/AHRI Standards 260 (I-P)-2012 and 261(SI)-2012, Sound Rating of Ducted Air

Moving and Conditioning Equipment;

– AHRI Standard 350-2008, Sound Performance Rating of Non-Ducted Indoor Air-

Conditioning Equipment.

– ANSI/AHRI Standard 575-2008, Method of Measuring Machinery Sound Within an

Equipment Space Proposed;

– AHRI Standard 885-2008 with Addendum 1, Procedure for Estimating Occupied

Space Sound Levels in the Application of Air Terminals and Air Outlets;

– Proposed AHRI Standard 1280P, Sound Performance Rating of Water Cooled

Refrigerating and Air-Conditioning Equipment.

AHRI Standards

�All AHRI standards are available for free download at:

– www.AHRInet.org

Air Handler Acoustics

Stephen Lind – Acoustics Engineer

La Crosse, WI

12-11-13

Air handling equipment makes noise

• To ensure proper acoustics in the space, you need

o Sound power levels as starting point for ASHRAE

Applications Handbook calculations

o Data per:

� AHRI Standard 260 for ducted equipment

� AHRI Standard 350 for un-ducted equipment

Supply DuctReturn DuctDirectly through building structure

Why AHRI 260?Application related acoustical components

returnairborne

supplyairborne

supplyairborne

supplybreakout

return breakout

through ceiling

supplybreakout

Application related acoustical sources/pathsMultiple noise sources (e.g. supply fan & return fan, or exhaust fan, compressor …)

Multiple paths (discharge, inlet, casing). Different attenuation on each path

Ducted Inlet

Casing

Ducted Discharge

returnairborne

supplyairborne

supplyairborne

supplybreakout

duct breakout

casing radiated

Need sound power of unit with all sources and all options accounted for along all relevant paths.

Fan Map: Sound is a function of the operating poin tFans – The Primary Acoustical Source

9.0

8.6

8.1 105 105

7.7 104 105 105

7.2 103 104 104 105 105

6.8 102 103 103 104 105 106

1500 RPM

1200 RPM

900 RPM

600 RPM

300 RPM

Sta

tic P

ress

ure,

in H

2O 6.3 101 102 102 103 104 104 105 106

5.9 100 101 102 102 103 104 104 105

5.4 99 100 100 101 102 102 103 104 105 106

5.0 98 99 99 100 101 102 103 103 104 105 106

4.5 97 97 98 99 100 100 101 102 103 104 104 105 106

4.1 96 96 97 97 98 99 100 101 101 102 103 104 105 106 106

3.6 94 95 95 96 97 97 98 99 100 101 102 102 103 104 105 106

3.2 93 94 94 95 96 97 97 98 99 100 101 102 103 104 105 106 107

2.7 92 92 93 93 94 95 96 97 98 98 99 100 101 102 104 105 106 107

2.3 90 90 91 92 93 93 94 95 96 97 98 99 100 101 102 104 105 106 107 108

1.8 89 89 90 91 92 93 93 94 95 96 98 99 100 101 102 104 105 106 107 108 110

1.4 89 90 91 92 93 94 95 96 98 99 100 102 103 104 105

0.9

0.5

2 5 7 9 12 14 17 19 21 24 26 28 31 33 36 38 40 43 45 47 50 52 54 57 59 62 64 66 69 71

56%WO

91%WO

Sta

tic P

ress

ure,

in H

2O

Fan Flow, kCFM

9.0

8.6

8.1 105 105

7.7 104 105 105

7.2 103 104 104 105 105

6.8 102 103 103 104 105 106

1500 RPM

1200 RPM

900 RPM

600 RPM

300 RPM

Sta

tic P

ress

ure,

in H

2O

Empirical data requiredIn the unit per AHRI 260

6.8 102 103 103 104 105 106

6.3 101 102 102 103 104 104 105 106

5.9 100 101 102 102 103 104 104 105

5.4 99 100 100 101 102 102 103 104 105 106

5.0 98 99 99 100 101 102 103 103 104 105 106

4.5 97 97 98 99 100 100 101 102 103 104 104 105 106

4.1 96 96 97 97 98 99 100 101 101 102 103 104 105 106 106

3.6 94 95 95 96 97 97 98 99 100 101 102 102 103 104 105 106

3.2 93 94 94 95 96 97 97 98 99 100 101 102 103 104 105 106 107

2.7 92 92 93 93 94 95 96 97 98 98 99 100 101 102 104 105 106 107

2.3 90 90 91 92 93 93 94 95 96 97 98 99 100 101 102 104 105 106 107 108

1.8 89 89 90 91 92 93 93 94 95 96 98 99 100 101 102 104 105 106 107 108 110

1.4 89 90 91 92 93 94 95 96 98 99 100 102 103 104 105

0.9

0.5

2 5 7 9 12 14 17 19 21 24 26 28 31 33 36 38 40 43 45 47 50 52 54 57 59 62 64 66 69 71

56%WO

91%WO

Sta

tic P

ress

ure,

in H

2O

Fan Flow, kCFM

AHRI 260 Components

Throttle on both sides

Ducted discharge or Ducted inlet

Casing

Free inlet plus Casing

Throttle on non tested side

both sides

Throttle on non tested side

Measurement: Reverberation Room

Microphone path

Ideally the sound is “the same” everywhere in the room...

... in real life there are variations. Follow AHRI Standard 220 to make sure variations are “small” enough.

We move the microphone and average to get a statist ically correct representative sample.

Sound Power from a Reverberation Room

Microphone path

Measure sound pressure due to RSS (Known power per AHRI 250)

Measure sound pressure due to unit

Determine power to pressure transfer function

Determine power for unit

Each has a different acoustical signature

Housed (FC or AF)

Direct drive plenum fan

Belt drive plenum fan

Fan arrays

Appurtenances change unit acoustics

PlenumLined Longer Lined

Rest of AHUC

oil

Filt

er

Opening PlenumLined plenum

Longer Lined plenum

Opening Location & Size

Bringing it All Together

Unit sound power (discharge, DD)

Lined plenum

30

40

50

60

70

80

90

63

12

5

25

0

50

0

10

00

20

00

40

00

80

00

So

un

d P

ow

er

Lev

el (

dB

re

1 p

W)

Octave Band Center Frequency (Hz)

DD unit

Unit sound power (inlet, DI)

Coi

l

Car

t. F

ilter

Ple

num

30

40

50

60

70

80

90

63

12

5

25

0

50

0

10

00

20

00

40

00

80

00

So

un

d P

ow

er

Lev

el (

dB

re

1 p

W)

Octave Band Center Frequency (Hz)

DI unit

AHRI 260Base Unit

(discharge, DD) (inlet, DI)

Room Lp

Oct

ave

Ban

d S

ound

Pre

ssur

e Le

vel d

B r

e 20

µP

a

Octave Band Center Frequency (Hz)

ASHRAE Applications Handbook

Criteria based on space type

AHRI Sound AHRI Sound

Standards – Chillers

Air Cooled Chiller Sound Rating

� North America:• AHRI 370 (Sound Power)• Reverberation Room Method

• Free field Over a Reflecting Plane• Units are usually installed outside.

� Europe/Asia:• Eurovent

• Reverberation Room Method

• Free field over a reflecting plane

• Sound Intensity• Units are usually installed outside.

• Units are too big for many reverberation rooms.

• Sound Intensity

• ISO 3744

38

Water Cooled Chiller Sound Measurement and Rating

AHRI 575 – Method of Measuring Machinery Sound

Within an Equipment Space

� Spatially-averaged Sound Pressure around rectangular grid

� Measurements 1.5 meters (5-ft) above grade

� Measurement points 1-meter (3.3-ft) away from unit, 1-meter apart.

39

MeasurementRectangle

Water Cooled Chiller Sound Measurement and Rating

AHRI 575 – Method of Measuring Machinery Sound

Within an Equipment Space

� Provides Octave Band and A-weighted Sound Pressure Levels, spatially averaged around the machine.

� This is a method of measuring sound pressure level of machinery installed in a mechanical equipment space. It is was not intended to be used for sound rating of equipment.

� Results depend on the environment, such as the room reverberation, proximity to walls and other noise sources.

40

Water Cooled Chiller Sound Measurement and Rating –

Why Sound Pressure?

� History:� Late 1960’s and early 1970’s

� Occupational Hearing Exposure (OSHA)

� Time weighted average over an eight hour shift (TWA)

115 dBA Max Allowed for 15 minutes� 115 dBA Max Allowed for 15 minutes

� 90 dBA TWA – Max allowed average

� 85 dBA TWA action level

� Need sound pressure for hearing exposure calculations.

� Directivity Information.

� Sound level at the control panel.

41

Water Cooled Chiller Sound Measurement and Rating –

How to get Sound Power

� How do we get sound POWER from sound pressure?

� Sound Pressure Level (Pa) in a free field is numerically equal to Sound Intensity Level (W/m2).

� Integrate the Sound Intensity Level over the Measurement Area to obtain the Sound Power.

SLL pw log10+=

42

AHRI Chiller Sound

Standards – The Standards – The

Future

AHRI 1280 – Water Cooled Chiller Sound Power

� AHRI 575

• Sound Pressure

• Test Method

• Mechanical Equipment

� AHRI 1280

• Sound Power

• Rating Standard

• Multiple Methods:• Mechanical Equipment Room

• Multiple Methods:• Free-Field

• Reverberation Room

• Sound Intensity

44

AHRI 1280 – Water Cooled Chiller Sound Power

�Why?

�EU – Some manufacturers publishing sound power

data

�Eliminates installation specific sound level

45

�Eliminates installation specific sound level

increases.

�When?

�Standard is still in development

�Estimate 2014 release

AHRI 1280 – Water Cooled Chiller Sound Power

� How will it work?

� Reverberation Room – as per AHRI 370

� Free-Field – Under Development

� One or Two heights of measurements

� Integrated to obtain sound power

46

� Integrated to obtain sound power

� Sound Intensity – Under Development

� Enveloping surface

� Includes scanning and point to point

� Requires top measurements

� Tolerances will be built into the standard

AHRI 1280 – Water Cooled Chiller Sound Power

• 400 ton centrifugal chiller, operating at AHRI 550/590 operating conditions, • Fully loaded – AHRI 575 sound pressure level = 85 dBA• 16 point AHRI 575 grid:

3 2 1 16 154 14

5 13

47

5 13

6 127 8 9 10 11

• AHRI 1280 sound power rating = 101 dBA.

AHRI 1280 – Water Cooled Chiller Sound Power

• 2000 ton centrifugal chiller, operating at AHRI 550/590 operating conditions, • Fully loaded – AHRI 575 sound pressure level = 86 dBA• 24 point AHRI 575 grid:

4 3 2 1 24 23 225 216 207 19

48

• AHRI 1280 sound power rating = 105 dBA.

7 198 189 17

10 11 12 13 14 15 16

Questions?