This information is for sure valuable and I would definitely include readings from stable infrastructure devices in any environmental monitoring. On the other

This information is for sure valuable and I would definitely include readings from stable infrastructure devices in any environmental monitoring. On the other hand, sometimes you want to measure cabinets where either no easily accessible monitoring device is located (servers operated by contractors, telecommunications equipment that does not connect to ethernet or standard protocols,...) or you want to have readings directly at cold-air-outlets/hot-air-inlets, or in the middle of corridors. In that situation some independent sensor network might be a reasonable solution, I had good experience with onewire temperature sensors, not the most precise thermometers, but rather cheap, and very easy to connect in parallel to a 3-wire cable (GND, +5V, Data). All devices have a worldwide unique ID and can be read out by a simple... cat /mnt/onewire/01-ABCDEFGHIJKL/temperature - DS18S20 temperature sensor http://www.maxim-ic.com/datasheet/index.mvp/id/2815 - DS9490 USB to 1Wire interface (like a USB stick with a RJ11 connector on the back) http://www.maxim-ic.com/datasheet/index.mvp/id/3834 - Onewire Filesystem http://owfs.org/