Carnes AXA User Manual

Non Fan Powered Units

ACCESSORIES - Discharge Sound Attenuator | Model AXA

www.carnes.com B-79

Design

Model Numbering Series Size OPTION

12 345 67

A X A B 0 2

A - Air

Terminal

X - Shipped

Separately

SIZE

01
02
04
06
07
08
09
10

H - Hanger Brackets

A - Attenuator

FEATURES

•

Sturdy 24 gauge galvanized steel
construction.

•

Convenient Slip and Drive connection on
the inlet and outlet.

•

Insulation is 1” thick, 1.5 lb./cu. ft.dual
density fiberglass material (others available).

•

Optional hanger brackets.

AIR

FLOW

B

A

C

S & Drive Connections

Optional

Hanger Brackets

DIMENSIONS (Listed in Inches)

DISCHARGE SOUND ATTENUATOR

UNIT SIZE

SIZE AV AD AB A B C

01 05/06 --- --- 12 (305) 8 (203) 34-1/2 (876)
02 07/08 0505/0606/0707/0808 06/07/08 12 (305) 10 (254) 34-1/2 (876)
04 10 1010 10 14 (356) 12-1/2 (318) 34-1/2 (876)
06 12 1212 12 16 (405) 15 (381) 34-1/2 (876)
07 14 1414 14 20 (508) 17-1/2 (445) 22-1/2 (571)
08 --- 1616 16 24 (610) 17-1/2 (445) 22-1/2 (571)
09 18/24 --- 18/24 32 (813) 17-1/2 (445) 22-1/2 (571)
10 16 --- --- 24 (610) 18 (457) 22-1/2 (571)

Metal Brackets

MODEL NUMBERING SYSTEM - Model AXA

CARNES CLEAN AIR SILENCER | Model AXPA

Non Fan Powered Units

B-80 www.carnes.com

The Carnes Model AXPA Clean Air Silencer has
been designed and engineered to reduce discharge
sound levels of Clean Air Terminal Units. The Model
AXPA is a “reactive type” silencer which attenuates
discharge noise levels from air terminals and other
devices without the use of sound absorptive
materials such as fiberglass, mineral wool, etc. This
eliminates indoor air quality concerns when using the
Model AXPA Silencer.

Most other manufactured sound attenuators require
a considerable amount of straight duct upstream to
achieve any reduction in sound levels. The straight
duct is necessary to allow the air flow to become
uniform after being discharged from a VAV terminal
unit. Most HVAC systems today have limited space
available and additional upstream duct is not permit­ted or cost effective. The Model AXPA Silencer does
not require additional straight duct upstream
because it is designed and tuned specifically to
straighten the air pattern and attenuate sound
directly after the VAV damper.

The Model AXPA Silencer has an integral air flow
straightening section upstream of the sound
attenuating section. The air flow straightening

section consists of a short piece of straight duct
upstream of a long radius elliptical flow nozzle to
minimize turbulence (self noise) and to reduce
pressure drop of the silencer. This unique feature
allows for direct coupling of the Model AXPA Silencer
to the Clean Air Terminal Unit without the use of any
transitions or flow straightening ducts.

Through extensive acoustic tuning and laboratory
testing conducted in accordance with ARI Standard
880, the Model AXPA Silencer has proven to
effectively reduce discharge sound levels of air
terminals. The testing and rating (per ARI 880) was
conducted with the Model AXPA Silencer connected
directly to the Clean Air Terminal Unit. This unique
testing configuration provides the designer with real
world test results, eliminating questions regarding
the VAV damper effect on the silencer performance.

All Model AXPA Silencers include a removable
access door. This access door allows for periodic
cleaning of the sound attenuating cavity. Model
AXPA Clean Air Silencers combined with the Clean
Air Terminals are an excellent choice for hospital,
clean room and laboratory applications.

• No insulation or sound absorptive material in

the airstream makes this unit an excellent
choice for clean-room, hospital and laboratory
applications.

• Low pressure drop design.

• Convenient slip and drive connection on inlet

and outlet. Sized to match Clean Air Terminal
Units.

• Sturdy 22 gauge galvanized steel construction.

• Gasketed access panel to allow for cleaning.

• Tuned for direct connection to air terminals. No

need for additional air straightening duct
upstream.

• Air flow capacities to 4200 CFM.

• Optional hanger brackets (Unattached).

• Optional 1” external thermally insulated casings

must meet UL Test 181 for erosion resistance
and NFPA 90A requirements for 250°F
continuous temperature.

• Shipped separately (consult factory for shipping

attached).

Features Include:

t Model AXPA

[Patent 5,663,535]

Non Fan Powered Units

www.carnes.com B-81

APPLICATION/PERFORMANCE DATA | Model AXPA

Models AVC, AVW and AVE with and without AXPA Clean Air Silencer

Sound Data (Discharge Noise Criteria)

Discharge Sound Power

NOTES: 1.ΔPsstatic pressure difference from inlet to discharge.

2.

Δ

P

s is the minimum pressure required to deliver CFM shown with the primary damper in wide open position.

3.

Dash (--) indicates NC level less than 10.

NC levels are derived from tests conducted in accordance with ARI Standard 880-2008 and are calculated in accordance with ARI Standard 885-2008 as
application data. NC is not part of the ARI certification program.

Discharge NC levels are based on —

a) 5 foot rectangular duct.
b) 5 foot lined flex duct (8” diameter).
c) Space effect factor (2400 ft

3

) at 5 feet from outlet.
d) End reflection.
e) Environmental adjustment factor.

Inlet
Size

(In.) CFM

Minimum ΔΔP

s

(Damper Full Open)

AVC
AVE

w/AXPA

AVW

1-Row

w/AXPA

AVW

2-Row

w/AXPA

5

75 .01 .02 .02
100 .02 .04 .04
200 .08 .14 .16
300 .20 .33 .36
350 .29 .45 .49

6

110 .01 .02 .04
200 .03 .07 .10
300 .07 .15 .18
400 .15 .27 .31
500 .25 .42 .46

7

140 .00 .01 .01
200 .01 .02 .04
400 .05 .11 .14
600 .13 .25 .35
700 .19 .35 .48

8

185 .01 .03 .05
400 .04 .14 .20
600 .10 .29 .41
800 .20 .50 .68

1000 .33 .75 1.01

10

300 .00 .02 .05
500 .00 .05 .10
800 .00 .11 .22

1200 .00 .22 .42
1500 .00 .33 .60

12

430 .01 .03 .05
800 .02 .09 .13

1200 .05 .20 .29
1800 .13 .41 .61
2300 .22 .65 .94

14

600 .00 .01 .03

1000 .01 .04 .11
1600 .01 .12 .21
2400 .03 .29 .41
3100 .06 .51 .63

16

780 .01 .03 .06

1600 .04 .12 .18
2400 .09 .26 .38
3600 .21 .56 .77
4200 .29 .74 1.01

Min. ΔΔPs 1.0” ΔΔPs 1.5” ΔΔPs 3.0” ΔΔPs

AVC
AVE

w/

AXPA

AVW

w/

AXPA

AVC
AVE

w/

AXPA

AVW

w/

AXPA

AVC
AVE

w/

AXPA

AVW

w/

AXPA

AVC
AVE

w/

AXPA

AVW

w/

AXPA

-- -- 10 11 10 12 11 14

-- -- 11 13 12 13 13 15

-- 10 15 16 16 18 18 22
11 12 19 20 21 22 23 27
11 13 19 20 21 22 23 27

-- -- 11 12 12 13 14 16

-- -- 13 14 14 15 17 22
10 11 16 16 18 19 21 27
10 12 16 16 18 20 21 27
11 13 18 19 20 21 25 28

-- -- 13 13 13 15 15 22

-- -- 14 14 14 16 18 23

-- -- 15 16 16 16 19 24
10 11 18 19 19 20 21 27
10 11 18 19 19 21 21 27

-- -- 13 14 14 15 20 20

-- -- 14 15 15 16 21 21
10 10 16 16 18 19 23 23
10 11 16 16 18 19 23 23
11 12 16 16 18 19 23 24

-- -- 14 14 15 18 22 25

-- -- 14 14 15 18 22 25

-- -- 15 15 16 18 22 25

-- 10 17 17 19 19 23 26

-- 10 17 18 19 19 23 26

-- -- 13 17 14 19 18 23

-- -- 13 17 15 19 19 24

-- 10 14 17 17 20 22 27

-- 11 15 18 17 20 23 27
10 13 15 18 19 20 25 28

-- -- 14 15 15 18 22 24

-- -- 14 15 15 18 22 24

-- -- 14 16 16 19 22 25
10 12 15 16 19 20 27 27
10 13 15 16 19 20 27 27

-- -- 13 13 14 14 19 20

-- -- 14 13 15 15 20 22
10 11 15 15 18 18 23 25
12 13 15 15 18 18 23 25
13 16 15 16 18 19 25 26