Digi-VAV®

The Digi-VAV® measures the true fan airflow using our embedded patented technologies.  It also measures the CO2 concentration level in the outside and supply air streams. The Digi-VAV® resets the minimum airflow at each terminal box, optimizes both the AHU outside air intake and the supply air static pressure, and implements volumetric tracking return air fan control.  This results in improved comfort, reduced energy consumption, and proper building pressure control.

Typical System Problems:

  • Excess airflow results in the excessive consumption of heating /cooling energy
  • Fixed outdoor air intake ratio at AHU level
  • Fixed minimum air flow rates at the terminal box level
  • Cannot guarantee fresh air requirement levels are achieved
  • Poor building pressure control
  • Compressor hunting for DX units
  • High installation and ongoing maintenance costs due to the need for individual CO2 sensors

Digi-VAV® Solutions:

  • The indoor air quality requirements are satisfied by resetting the  minimum airflow for each zone based on the zone occupancy schedules and supply air quality
  • The outdoor air intake ratio is reset based upon the building occupancy conditions
  • The static pressure is reset based upon the fan airflow
  • The floating compressor staging is used to prevent compressor hunting
  • The building pressure is maintained properly using volumetric tracking return fan control

Click on the links below for more information about the Digi-VAV® 

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Features

Digi-VAV® Resets: 

  • Minimum airflow of each terminal box
  • Minimum outside air intake based upon the building occupancy schedule
  • Static pressure based upon the true airflow as measured by the speed and power of the VFD

Benefits

  • Decreases heat/reheat energy consumption by about 30 – 80%
  • Lowers cooling energy consumption by about 10 – 25%
  • Reduces fan power consumption by about 30 – 50%
  • Ensures  adequate indoor air quality, zone thermal control, and building pressures
  • Complies with ASHRAE Standard 62.1 & CA Tile 24 air quality requirements
  • Eliminates the need for individual CO2 room sensors

FAQs

How does the Digi-VAV® save energy?

  • The Digi-VAV® dynamically resets the minimum airflow of each terminal box based on the supply air quality and the occupancy status. This allows for a lower and more accurate minimum airflow set-point, thus reducing unnecessary heating and cooling at the terminal box
  • The Digi-VAV® dynamically resets the supply static pressure based on the measured building load.  It also lowers the set-point to allow the fan to run at lower speeds

Does the Digi-VAV® control the staging of the compressors?

  • Yes

Does the Digi-VAV® controller replace the existing AHU controller or terminal box controller?

  • No, the controllers remain

Does the Digi-VAV® communicate with the AHU controller or terminal box controller?

  • No, the Digi-VAV® communicates with the BAS controller thus providing the revised set-point for the supply static pressure, minimum OA damper, and terminal box minimum airflow

Do the existing supply fan VFDs need to be replaced?

  • No, they do not need to be replaced

Where is the Digi-VAV® mounted?

  • The Digi-VAV® is mounted inside the mechanical room next to the AHU

How long does it typically take to install a Digi-VAV® unit?

  • It takes approximately 3 hours to mount a Digi-VAV® and 30 minutes to program each terminal box