Automatically regulate airflow in duct systems to constant levels, no electric or pneumatic sensors or controls required

Here's why thousands of multi-family buildings across the nation use Aldes Constant Airflow Regulators  

Your low-cost solution to balancing forced-air systems for heating, air conditioning and ventilation, eliminating the need for on-site balancing.

Regulates airflow in supply, return, or exhaust duct systems. Sized to fit standard rigid round ducting, as well as fittings such as take-offfs, tees. etc. A lip or flex-type ring seal gasket around the circumference ensures a tight, no-leak fit.


Needs no maintenance when used in normal conditions. No risk of dust deposit or obstruction; there are no airways subject to clogging.

No cleaning required

In central systems, the supply and return/exhaust airflow for each area is automatically balanced by installing the CAR-II in the branch ducts or terminal device locations.

Automatic airflow balancing

When outside air temperatures are cold, warm air indoor expands and rises like a chimney. This results in pressure variation to vertically ducted central ventilation systems, causing over-ventilation at some levels that wastes energy, and under-ventilation at other levels which prevents proper contaminant removal.

These pressure imbalances can also cause cross-contamination or force unwanted air from one compartment to the next. Cross-contamination is often the cause of many poor indoor air quality problems. 

Installing a CAR-II at each grille or diffuser location eliminates stack effect on the ventilation system.

Corrects stack effect

Building codes and standards for energy efficient building practices have specific requirements for outside airflow control and exhaust ventilation. The CAR-II is the easiest way to ensure precise airflow controls and code compliance without expensive and time-consuming field adjustments and measurements.

Code compliance

Controls airflow accurately to within 10% of rated flow. Each CAR-II is factory tested and calibrated to the rated set point before shipping. On-site filed adjustment of airflow set points can be made for supply air applications.

Precise airflow

If unforeseen installation challenges result in field modifications to the ventilation system, CAR-II's will automatically adjust to compensate for changes in duct length, duct leakage, proper filter selection, filter loading, and damper settings. It will always deliver the proper airflow rate. 

Automatic corrections

CAR-IIs are available in 4, 5, 6, 8, and 10-inch diameters. Each diameter of CAR-II regulator is available in multiple factory-calibrated set points. 

Multiple sizes

The active control element of the CAR-II is a unique

aerowing. The active control element of the CAR-II lifts in response to increasing static pressure in the same way the 

wing of an airplane provides lift as faster air moves over it. This operation regulates the free-area opening through the 

control, resulting in maintenance of the factory calibrated airflow set points. 

How does the CAR-II work?

Project References? Yes, we have plenty!

American Aldes CAR-II's have been installed in thousands of apartment, condo, senior living , hotel and other multi-family buildings. Don't just take our word for it. Below you'll see just a sampling of the many recent installations across the country.

  • Grand Central Station, New York
  • Washington Dulles International Airport, Virginia
  • Maxfield Building, California
  • Plaza Hotel New York, New York
  • Courtyard, Columbia
  • Holiday Inn Greensboro Coliseum, Nort Carolina
  • Residence Inn Nashville, Tennessee
  • The Enclave at Cathedral, New York
  • 10 Light Street, Maryland
  • Aster Assisted Living, Wisconsin
  • CityVue Apartments, Minnesota
  • Gallagher Plaza, Oregon
  • Junction Shop Mill, Massachusetts
  • Barry's Corner, Massachusetts
  • Liberty Towers, New Jersey
  • SkyHouse River Oaks, Texas
  • 30 Park Place, New York
  • Houston Marriott Medical Center, Texas
  • Sheraton Seattle, Washington
  • Pentagon Apartments, Minnesota
  • Munger Graduate Residences, Michigan
  • Ronald McDonald House, Ohio
  • Bridges at Warwick, Pennsylvania
  • Hotel Breakers, Ohio

4 ways to take the next step

American Aldes is the premier manufacturer of ventilation products for homes, multi-family dwellings, hotels, schools and numerous other residential and commercial applications. Products are designed for superior airflow control, energy-efficient performance, and healthy indoor environment.

American Aldes is based in Florida and is a subsidiary of the ALDES Group, an international, family-owned group of more than 1,300 employees and 17 subsidiaries in 13 countries.