Thermometer Trick for Vents

https://spencerjwog025.almoheet-travel.com/how-ac-repair-estimates-work-at-comfort-experts-in-north-fort-worth

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