General: The model CAR-II Constant Airfl ow Regulator is a modulating orifi ce that automatically regulates airfl ows in duct systems to constant levels. The passive control element responds to duct pressure, and requires no electric or pneumatic sensors or controls.

The CAR-II compensates for changes in duct pressure caused by thermal stack effect, building pressure, dust clogging of fi lters, etc. The CAR-II also provides a low cost solution to balancing forced air systems for heating, air conditioning and ventilation, eliminating the need for on-site balancing. The CAR-II will regulate airfl ow in supply, return or exhaust duct systems.

The active control element of the CAR-II is a unique aerofoil. Using Bernoulli effect, the active control element of the CAR-II is a unique aero-wing damper that lifts in response to increasing static pressure. This operation regulates the free-area opening through the control, resulting in maintenance of velocity and specifi c airfl ow set points. Each CAR-II is designed and produced for control of air in temperatures ranging from -25° to 140° F (-32° to 60° C.)

Construction (Round): The round CAR-II is constructed of a UL94V-0 ABS plastic, and is UL 2043 safety listed and labeled for fl ame and smoke genera-tion. The assembly is sized to fi t inside standard rigid round ducting, as well as fi ttings such as takeoffs, tees, etc. A lip or fl ex-type ring seal gasket around the circumference ensures a tight, no-leak fi t.

Construction (Rectangular): The CAR-II regulating element is available in a rectangular duct mounting plate. The assembly is sized to fi t inside standard square or rectangular ducting, as well as register boots, return grille collars, etc. Each mounting plate is designed to specifi cally accommodate the con-trol element, and prevent unwanted air leakage.

Constant Airfl ow RegulatorModel CAR- II

PRODUCTSPECIFICATIONS

AND ENGINEERINGINFORMATION

----SUBMITTAL DATA

1312-5-6-08

Dimensional Data

Duct CAR-II A B C D* E FROUND

4” 4 3.8 4.1 2.3 – – –

5” 5 4.8 5.1 3.5 – – –

6” 6 5.8 6.1 3.5 – – –

8” 8 7.6 8.1 3.5 – – –

10” 10 9.7 10.1 3.7 – – –

RECTANGULAR*

6” x 6” 4 – – – 5.9 1.9 1.0

6” x 6” 5 – – – 5.9 3.0 1.0

8” x 8” 5 – – – 7.9 3.0 1.0

8” x 8” 6 – – – 7.9 3.0 1.0

10” x 10” 5 – – – 9.9 3.0 1.0

10” x 10” 6 – – – 9.9 3.0 1.0

10” x 10” 8 – – – 9.9 2.7 1.0

12” x 12” 8 – – – 11.9 2.7 1.0

12” x 12” 10 – – – 11.9 3.1 1.0

14” x 14” 10 – – – 13.9 3.1 1.0* Standard sizes shown. Mounting plates are also available to accommodate any

rectangular duct size.

All sizes shown are in inches.

ROUND RECTANGULAR

C

B

D

EF

DA

Performance: The CAR-II airflow regulators control airfl ow accurately to within 10% of rated fl ow (15% for units 50 cfm or less), throughout the target operating pressure range of 0.2 to 0.8 in. w.g. (50 to 200 Pa). Each CAR-II is factory tested and calibrated to the rated set point before shipping. On-site fi eld adjustment of airfl ow set points can be made for supply air applications (contact factory). Each diameter of CAR-II regulator is available in multiple factory calibrated set points (see per-formance curves).

Maintenance: The CAR-II needs no maintenance when used in normal con-ditions. There is no risk of dust deposit or obstruction because the CAR-II has no airways subject to clogging. If the intended application includes air heav-ily loaded with grease or dust, a fi tting with an access panel or door, such as that used for fl ame dampers, should be provided.

Warranty: Guaranteed for 5 years, from date of shipment, against all defects in material or workmanship, provided that the material has been installed and utilized under normal con-ditions. This warranty is limited to the repair or replacement of the material.

Typical Specifi cationModel CAR-II Constant Airfl ow Regu-lators by American ALDES Ventila-tion Corporation, Sarasota, Florida, shall solely operate on duct pressure and require no external power supply. Each regulator shall be preset and fac-tory calibrated requiring no fi eld adjust-ment to the airfl ows as indicated on the schedule, and shall be rated for use in air temperatures ranging from -25° to 140° F (-32° to 60° C.)Constant airflow regulators shall be capable of maintaining constant airfl ow within +/- 10% of scheduled fl ow rates (15% for units 50 cfm or less), within the operating range of 0.2 to 0.8 in. w.g. dif-ferential pressure, or 0.6 to 2.4 in. w.g. on high-pressure models. Regulators shall be provided as an assembly con-sisting of a 94V-0 UL ABS plastic body housed within a round sleeve or fl anged plate for mounting in either round or rectangular duct. Each round sleeve must be fi tted with a lip gasket to assure perimeter air tightness with the interior surface of the duct. All regulators must be listed per UL2043 and carry the UL mark indicating compliance. All Con-stant Airfl ow Regulators will require no maintenance and must be warranted for a period of no less than fi ve years. Constant Airfl ow Regulators shall be installed in tight ducting systems in ac-cordance with all applicable codes and manufacturer’s instructions.

Constant airfl ow is achieved by control-ling the free area through the device. At minimum static pressure, the aero-wing is parallel to the air stream. As the static pres-sure increases, the aero-wing lifts, thereby reducing the amount of free area through the regulator. At the same time, the higher static pressure increases the air velocity resulting in CONSTANT AIRFLOW. This occurs regardless of pressure differences in the range of 0.2 to 0.8 in. w.g. (50 to 200 Pa). The air velocity in the duct is in the range of 60 to 700 ft/min. (0.3 to 3.5 m/s).

Typical Applications

• Supply and exhaust air of of-fi ces.

• Balancing exhaust and supply airfl ows in high-rise building duct risers.

• Bathroom exhaust in nursing homes, hotels, motels, dormito-ries, apartment buildings, offi ces, etc.

• Clean room air supply balancing for ceiling fi lter modules. Main-tains constant airflow even as fi lter resistance increases.

• Regulation of makeup air.

• Balancing supply airflow from packaged roof top A/C units.

• Balancing supply and exhaust of heat recovery ventilation sys-tems

• Regulating outdoor air injection from central supply fan into indi-vidual room fan coil units, or heat pumps.

• Balancing airfl ows on series fan powered terminal unit systems.

• Supply air to sleeping quarters in military facilities, submarines, etc.

How the CAR-II Works

(6” EXAMPLE SHOWN)

Performance charts refl ect airfl ow measurements taken at 68°

(20° C) at 1 atmosphere pressure. CAR-II’s designed for sys-

tem pressures above 0.8 in. w.g. are also available. Consult

the factory for information.

5” DIA. (125mm)

4” DIA. (100mm)

0

AIR

FLO

W(L

/S)

25

PRESSURE DIFFERENCE (IN. W.G.)

PRESSURE DIFFERENCE (PASCALS)

20012550 10075 150

160

200

50

60

40

30

20

10

00

120

80

40

175

AIR

FLO

W(M

3H

)

0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

100

120

AIR

FLO

W(C

FM

)

80

60

40

20

0

105(180)

90(150)

75(125)

60(100)

50(90)

35(60)

CAR-II Airfl ow Performance Data

4537 NORTHGATE COURTSARASOTA, FL 34234-2124, USATel: 941-351-3441 Fax: 941-351-3442www.americanaldes.com E-mail: info@aldes-us.com

50 100750

160

AIR

FLO

W(C

FM

)

AIR

FLO

W(L

/S)

AIR

FLO

W(M

3H

)

25

PRESSURE DIFFERENCE (PASCALS)

200125 150

250

30080

90

70

60

50

40

30

0

200

150

100

0

175

140

120

100

60

80

0

PRESSURE DIFFERENCE (IN. W.G.)

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

180

200

75(125)

90(150)

105(180)

125(210)

140(240)

160(270)

175(300)

10” DIA. (250mm)

8” DIA. (200mm)

6” DIA. (150mm)

AIR

FLO

W(L

/S)

AIR

FLO

W(M

3H

)

PRESSURE DIFFERENCE (IN. W.G.)

450

500

120

140

100

80

60

0

400

300

350

250

200

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

0 25 50

PRESSURE DIFFERENCE (PASCALS)

200125100 150 17575

160

120

200

240

280

320

0

AIR

FLO

W(C

FM

)

0

295(500)

265(450)

235(400)

205(350)

175(300)

160(270)

140(240)

125(210)

0450

AIR

FLO

W(C

FM

)

AIR

FLO

W(L

/S)

AIR

FLO

W(M

3H

)

25

PRESSURE DIFFERENCE (IN. W.G.)

PRESSURE DIFFERENCE (PASCALS)

200125 150

700200

150

100

50

600

100

0 0

175

00 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8

400

350

300

250

200

150

100

50

200

300

400

500

50 10075410(700)380(650)

355(600)

325(550)

295(500)

265(450)

235(400)

205(350)