Review on Digital Indoor Thermometer Hygrometer: Room Humidity Gauge with MAX/MIN Display, Big Screen, Stand, Wall Hanging, and Magnet (3-Pack) by Emmanuel Chouinard

We've just upgraded our air conditioners and are now checking that the duct system is properly distributing airflow to the rooms. I received this set of 3 matching thermometers to check the temperature versus what the AC system generally reports (also to argue with a family who insist their rooms are too hot or too cold). I wasn't expecting scientific accuracy from cheap devices, but this is a bit disappointing. They consistently read between 3 and 5 degrees higher than other thermometers I own (which match the AC setting). In addition, when changing to a known different climate (e.g. from the terrace into the house), they react very DELAYED to the new setting: The change from 90 -> 75 took about 15 minutes. bad because I like min/max readings and big temperature and humidity readings. But I just don't trust the information. In my attached photo they don't even match - and I promise you I'm not sitting in a 77 degree office!