Monitoring server room temperature

Question

I have a small server room with its own AC unit. Recently, the AC died, and the temperature increased from 70 F to > 90 F. We rarely go in this room, so I was lucky that someone happened to notice that the fans were running a lot louder than normal as they walked past the door. It looks like I need a way to be notified when the temperature in that room gets too hot.

What tools are you using to monitor the temperature in your server room? How does this tool notify you of a problem (email, SNMP, etc).

Note: I've read this question on server temperature, but I'm interested in the whole room, not just the inside of a server case.

Edit:

Thanks for all the great responses so far! Many of these products measure much more than just temperature. What else should I be looking at and why?

Answer 1

For monitoring server / data room I am using GSM control panel. It can monitor temperatures and can send information by SMS to several numbers. Furthermore, it can be used as alarm system for security, power failure, fire protection or even control electrical devices through SMS (ex. power on conditioner). System can be configured by SMS or configuration tool via USB. More information about this device can be founded http://www.eldes.lt/en/gsm-remote-control-alarm-systems/esim262.html

Answer 2

Someone in a mailing-list, that I'm member of, recommends ENVIROMUX-MINI.

Answer 3

Do you need to check only temperature inside the room?

I use Sky Control system to check our server room. We've put temperature sensor, leakage, humidity and smoke sensors and it has already saved us twice. Can be easily set up even without technical knowledge.