Interesting - that makes sense now that I think about it. To make sure I'm understanding - I took "duct pressure" to mean the pressure exerted on the duct by the HVAC system. But that reading is actually a pressure reading of the overall air pressure in the duct? Now that I think about it, that makes sense because you would need more than one data point/measuring point to get the pressure exerted on the duct by the HVAC system.
I was planning on using the Ecobee sensors for everything so I only have one Puck. I'll move that puck into the same room as one of the vents so I can work out a more accurate reading.
That being said - right now the Puck is one room away is reading 100.17 and the nearest Flair vent is reading 100.21. Checking my Ecobee it looks like the AC is not running, but the low-speed mode of the system fan is running. This is with the Flair vent closed. If I'm following correctly, that means that assuming the pressure where the Puck is doesn't differ much from the room the vent is in, the HVAC fan is exerting 0.04 kPA of pressure in the duct? These units of measure are new to me, so someone that knows more about measuring HVAC pressure - does that sound like I'm in the right ballpark to be calculating this number correctly?