CFM400 Large Vane Thermo-Anemometer

The product works effectively and accurately for me personally. I use this product to measure airflow from my HVAC vents because certain areas of the house were warmer than others. With this device, I was able to gather information on the flow of each duct from each vent to determine which were underperforming. I found that one of my ducts needed some adjustment and that one of my vents was obstructed. The product is also simple to use. The only steps necessary to operate it are to turn it on, select the mode, and hold it in front of the vent. The display is straightforward to understand, with an easily readable odometer, and transitioning from airflow to temperature measurement is simple. It consistently produces the same measurements when measuring a vent multiple times in succession. So it seems fairly accurate? It has a small form factor, so it doesn’t take up much space. Everything stores neatly in the case when done!

Got this tool to balance the HVAC in my home and get proper airflow throughout. This is very easy to use and has a clear, easy to read screen. Unfortunately can't speak to accuracy as I don't have another meter to compare, but it worked perfectly for my needs.

The specs call for the ability to measure very high CFM rates. It appears that this might have been at the expense of low CFM accuracy. I test against two blowers from highly reputable manufacturers. The specs for the blowers matched test results from other test devices. Unless the manufacturer posts a CFM vs accuracy graph, this value is of little practical use to me.