Thermometer Trick for Vents

https://fernandokncz158.rivetgarden.com/posts/comfort-experts-on-ac-repair-in-north-fort-worth-when-your-system-runs-but-does-not-cool-2

Thermometer Trick for Vents Quick tip from our house: put a cheap kitchen thermometer in a supply vent after the AC runs 15 minutes, then check the air at the return. We see about an 18 degree drop when things are healthy