Electronic – How to detect when the air flow in a room stops and report it


I have a server room with an air conditioning unit. The unit is supposed to run 24×7, but ND tends to get 100 °F in the summer and -40 °F in the winter. This is a little harsh on the equipment and we have had failures. I have a temperature sensor, but I want a little more warning.

I am trying to cook up some solution that monitors the air flow and sends an e-mail when the air stops. I have looked at various anemometer (wind speed indicators), but they all seem to log data and not provide updates, plus they all seem to be rather large and not a good thing to have spinning in a server room. I want to hang the sensor from the ceiling in front of the air conditioner.

Best Answer

For a very simple sensor you could hang two parallel strips of thin (very flexible) foil in front of the air vent. When air is flowing they'd end up pushed together, giving you (essentially) a switch closure you could read.

You'd still need something to notice and give a yell, like the Arduino + ethernet shield mentioned elsewhere, but this is about as simple a sensor as you could get.