Need to know How to Measure Air Velocity in a Duct? We have the answers here and a variety of solutions to choose from.

How to Measure Air Velocity in a Duct

We had HVAC professionals in mind when we designed these Air Velocity Sensors for Ducts that measure air velocity, temperature, and humidity. Just 4 easy steps make installation a breeze! It only requires a single hole and there’s no need for screws or getting your hands inside the duct. READ BLOG: on Multi-point Measurement in a Duct based on ASHRAE and Tchebycheff Rule.
So what makes these air velocity sensors “intelligent”? These “next-generation” air flow switches for ducts can connect to a data acquisition instrument by an intuitive USB interface. The data from a single point or multiple points can be viewed in real-time, aggregated, logged, and analyzed using a robust software that allows for graphing, data logging, and printing.
- Conformal-Coated Electronics – robust, UV-tolerant, splash-proof enclosure for use in corrosive or alkaline environments
- Innovative “Outside the Duct” Installation – single hole for mounting sensor assembly, without the need for screws or hands inside the duct
- Remote Sensor Head Options – multiple designs are available to support a wide range of application scenarios
- Configured-to-order – choice of air velocity range, supply voltage, mechanical length, and output communication style
- Analog & Digital Communication – supports 0-5V, 0-10V, 4-20mA, and digital UART or I²C communication outputs
- Universal Supply Voltage – suitable for applications where AC or DC supply voltages are encountered
- Single or Multi-Channel Data Acquisition up to 180 sensors measuring air velocity, air temperature, surface temperature, humidity, & barometric pressure data in real-time
- Real-Time Data Logging – of air velocity, temperature, humidity, and pressure with compensation for changing humidity and barometric pressure (altitude)
- Graphing Features – Line Graph and Gradient Graph features allow users to simply drag-and-drop the desired sensors into an easy-to-view graphing section, and export in jpeg format



How to Measure Air Velocity in a Duct based on Tchebycheff Rule
The °C SPAR Sensor Pole Array from Degree Controls is optimal for in-duct HVAC airflow analysis. It is a linear array of airflow sensors assembled into a single tube element with USB outputs. The °C SPAR is designed for multi-point experimentation where there are predefined measurement locations, just as shown in the Log-Tchebycheff Rule for calculating volumetric flow within ducts. With the °C SPAR, air velocity, temperature, and humidity can be measured and recorded at multiple points in real-time for building duct performance testing.
