Digital Pro Anemometer Handheld AP-856A USB Anemometer HVAC Wind Speed Meter with Backlight Max/Min/Avg Functions for Measuring Wind Speed Air Velocity Temperature Air Flow Meter

Only backlit button should be given seperate and long term on .

I bought this to balance the airflow from the HVAC vents in my home, because we have some hotspots. This works great, it's sensitive enough to pick up very low air volumes, which is essential for balancing. You can't do volume testing with this, you'd need a different piece of equipment, but for air speed, this works great.

Reading other reviews makes it seem that some don't understand how to use these things. I have had great results using it for air volume for residential room-by-room air balancing. A simple 4x10 dust collection hood & a 4" to 2 1/2" reducer was all I needed to attach the wand to making an air capture hood to easily and accurately obtain airflow readings while quickly and easily changing my free area value on the device to match the pipe size being tested. 1. The wand for airflow IS directional, there's a direction of airflow indicator arrow located on the interior where the rotating vanes are on the perimeter 2. To enable PC connection you may have to enable COM3 legacy port if on windows 10/11 3. To properly get CFM or L/s reading, anyone actually trained for HVAC should already know this....but you need to set your free area in sq.ft on the unit when in AIRFLOW setting of either your square/rectangle duct or the cross-sectional free area of the round supply pipe if taking measurements at the register. For duct it's simple, HxW for free area, and for round pipe just google it. 4. Alternatively just leave it on velocity and capture the air speed and manually calculate your CFM or L/s if #3 proves too difficult to do on the fly.

The unit seems to be reliable, I have tested it against a airflow hood and came within about 4 percent of the hood readings. The unit is easy to use and navigate. I purchased this as a replacement vane anemometer and so far satisified.

This is a decent meter for the money, however it doesn't have the ability to measure humidity. That's the only reason why I returned it.

Air blows threw and does an accurate reading. Great product