Written for HVAC Professionals by HVAC Professionals

Hot-Wire Anemometer Helped Change My Diagnostics

When it comes to commercial service, especially on the airside of the HVAC system, I found the Fieldpiece STA2 in-duct hot wire anemometer not only helped me with diagnosing issues, it also allowed me to measure airflow instead of guessing.

Whether I measure in a return duct or supply duct, the open area of an economizer screen, or the intake of an exhaust fan, I get accurate results in minutes.

I started using this tool in 2015, mostly on residential and light commercial systems and mostly for returns where balancing hoods didn’t fit. Then, in 2020 I started using the STA2 on economizers to set them up and verify performance.

This instrument is easy to set up and goes beyond displaying average velocity. If you input the dimensions of the opening, the STA2 calculates and displays airflow in CFM (cubic feet/minute) with the touch of a button. It has a range of 40-3960 feet per minute (FPM), resolution of 1 fpm, and a temperature range from -4°F to 140°F.

The STA2 has another great feature which is the 38-in. telescoping probe with etched ruler and flat edges to help you always know the position of the thermistor.

This instrument minimizes turbulence effect, offers hands-free testing with its magnetic hanger, and has a fast response time.
It comes in a rigid plastic case, and the anemometer itself is very durable due to the rubber casing around it.

The only downside that I’ve found with the STA2 is it’s not rechargeable. Despite that, if you are looking for a great tool check it out at ncilink.com/STA2.

— Andrew Smith, Instructor, National Comfort Institute, Inc.