eFlow-MAX+ High Capacity Constant Airflow Regulator


In stock

Operating Pressure Range 0.2 to 4.0 in w.g. (50-1000Pa)

eFlow-MAX+ is the next-generation of the eFlow-MAX Constant Airflow Regulator. This enhanced version showcases an advanced, durable, easy to adjust lock-in nub for CFM control, meticulously designed for optimal performance and efficiency.

eFlow-MAX+ is a field adjustable High-Capacity Constant Airflow Regulator. It is designed to automatically and precisely balance airflow into or out of a space without the need for electricity. Its design saves significant amounts of energy, money and provides High Indoor Air Quality. This round damper is designed to provide pressure-independent maximum constant airflow in round duct systems without use of electricity, sensors or controls. As pressure increases, the blade moves to keep airflow stable over a wide pressure range. This new eFlow-MAX+ features an updated external mechanism that can be used to adjust airflow manually, and with ease, without any tools.  eFlow-MAX+ can be easily installed inside standard ductwork. Mounting may be horizontal or vertical.

eFlow-MAX+ features laser-welded, heavy galvanized steel body, aluminum control plate, solid plastic airflow control and airtight seal to ensure no-leak fit. It is also available in stainless steel.

eFlow-MAX+ is maintenance free and corrosion-proof under normal constitutions.


eFlow-MAX+ 10” Airflow Range 295-940 CFM, eFlow-MAX+ 3” Airflow Range 24-75 CFM, eFlow-MAX+ 4” Airflow Range 40-130 CFM, eFlow-MAX+ 5” Airflow Range 60-165 CFM, eFlow-MAX+ 6” Airflow Range 100-265 CFM, eFlow-MAX+ 8” Airflow Range 150-530 CFM

Key Features

Updated Features:

  • Enhanced, easy-to-adjust, durable CFM control
  • Lock-in nub for easy and secure CFM adjustment
  • No tools required to adjust CFM setpoint
  • Clearly readable scale with CFM and CMH volume flow indicators
  • Ideal for visible installation


● Diameters offered: 3”, 4″, 5”, 6”, 8″, 10″
● Operating Pressure Range: 0.2 to 4.0 in w.c. (50-1000Pa)
● Airflow settings: 24-940 CFM
● Temperature Limits: -22° to 212°F (-30° to 100°C)
● Suitable for both supply and exhaust applications
● No external power supply needed
● Factory calibrated
● Field Adjustable CFM setpoint
● Capable of maintaining constant airflow within + 10% for nominal airflow > 60 CFM (100 m3/h) and + 5 CFM (10 m3/h) for nominal airflow < 60 CFM. (100 m3/h) throughout the target operating pressure range of 0.2 to 4.0 in. w.g. (50 to 1000 Pa).
● Optimum air velocity: 885 FPM (4.5 m/s) and it should not drop below 530 FPM (2.7 m/s)
● Sound power levels shall not exceed those for each size and CFM rating as scheduled.
● Laser-welded, heavy galvanized steel body, plastic airflow control and air tightness seal to ensure no-leak fit
● Available in stainless steel
● Available with Dual Flow setting motorized option
● Available with 25mm or 50mm insulation shell
● Energy efficient
● Ideal solution for meeting rooms, classrooms, concert halls, etc.
● Maintenance free and corrosion-proof under normal conditions
● Warranty guaranteed for Five (5) years



● Energy Efficiency Programs
● Subsidized Housing Projects
● Government Facilities
● Military facilities
● Healthcare
● High Rises
● Commercial Buildings
● Residential Buildings
● Assisted Living Facilities
● Hospitality/Hotels
● Dormitories and Schools Buildings
● Office buildings
● Balancing airflow supply from roof-top A/C units
● Balancing supply and exhaust of heat recovery ventilation systems
● Regulating outdoor air-supply into individual room fan coil units or heat pumps
● Balancing airflow on series-fan-powered terminal unit system


Warranty is guaranteed for five (5) years, from the date of shipment, against all defects in material, given that the material has been installed and used under normal conditions. The warranty is limited to the repair or replacement of the material upon its return freight paid to our factory. This warranty is not transferable and is limited to the original end user.

Technical Data Download

eFlow-MAX+High Capacity Constant Airflow Regulator Submittal Data Sheet

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