Active Mechanical Air Balancing Valve

autoflow air balancing valve


The AutoFlow Valve is a self balancing air flow regulator that provides set airflows at each port on duct systems over a variable pressure range.

The operation of the unit is via increased air resistance at higher air flow using a dynamic weighted valve flap and fixed air port. The higher the pressure, the further the valve closes over, and by restricting the free area, the airflow is controlled. By using this method, and the principles of air movement, with AutoFlow Valve on each port balances the whole system.

Due to the pendulum effect to restrict the airflow, when pressure drops for any reason, the AutoFlow valve automatically compensates enabling the lower pressure to deliver airflow within the required control range. The AutoFlow valve comes set at 9l/s, however is easily adjustable to cover a mutliple reuiqred airflow rates, upto 19l/s, by snapping out the relevant tabs above the valve, which are marked.

The AutoFlow Valve avoids time consuming works on projects with balancing communal ducting. It is also an effective energy saving tool, as the AutoFlow Valve restricts the airflow and pressure through the port, causing the air to naturally look for the next efficient route. Therefore, when each port has the AutoFlow Valve in place, the pressure is spread equally to all the ports and ensures each port is extracting at the same, constant rate.

The environmental impact of these devices can be expressed as:

  • Energy Loses are reduced as high, uncontrolled and unnessary air flow rates are eliminated
  • Optomised air flow rates at all times and dwellings, reducing condensation issues and improving air quality
  • Consiquential maintenance and energy saving on main ventilation motors


  1. Automatic self balancing
  2. Simple adjustment before installation to allow the airflow requirements to be set between 9l/s and 19l/s
  3. Ease of Installation
  4. Standard extract rates set by Building Regulations Part F
  5. No Electrical power required
  6. Easy commissioning
  7. Automatic so no multiple adjustments to balance whole system
  8. Fit and forget: no secondary access to properties required
  9. Stainless Steel construction for extended life
  10. Enables low profile inlet grille
  11. Balances not just initially but for the lifetime of the unit
  12. Compensates for variable air pressures in a ventilation systems



Download AUTOFLOW AIR VALVE specifications (Adobe PDF format):



If you have any questions about AUTOFLOW AIR VALVE or another Vapour Flow product, or need more information, just request a free call back and we’ll talk you through it all.

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