Temperature monitoring

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Example temperature graph of 3 different sensors.
Example temperature graph of 3 different sensors.

I have set up a computerized temperature monitoring system to let me track the current weather and temperature inside and outside of my house.

Contents

[edit] Reasons

Computers are highly sensitive to being adequately cooled. If their CPU or power supply fans fail or the ambient room temperature becomes too hot, then your machines can quickly fail and damage themselves. High-end datacenters and server rooms usually have special raised floors and dedicated air conditioning systems just to ensure that cooling will always be adequate.

However, in a residential computer room with only a small number of computers, like my Cowhouse datacenter, it can be necessary to make some compromises and try to be more proactive about monitoring temperatures. In order to do this, I wanted to install some digital temperature monitoring so that I could ensure that heat buildup did not become a problem.

Another of my reasons for this project was to try to verify the benefits of installing an forced-air ventilation fan in the attic. To do this, I able to track the temperature within my attic relative to the ambient outdoor temperature, and compare the relative differences when I had the attic fan on or off.

[edit] Instrumentation

Temperature meter connected by serial port.
Temperature meter connected by serial port.

Currently I have 3 temperature probes located around my house:

  • upstairs in the attic
  • outside the window of the downstairs office
  • inside the downstairs office

Eventually I'd like to expand to include a pool water temperature sensor and the upstairs loft area.

The temperature probes are Dallas DS18S20 connected to a QKits small circuit board plugged into the RS-232 serial port of my Linux server.

Temperature sensor outside of downstairs office, including its thermal shielding to deflect direct sunlight.
Temperature sensor outside of downstairs office, including its thermal shielding to deflect direct sunlight.

[edit] Software

For the software, I wrote some quick-and-dirty Perl scripts to perform the data collection and graph creation, which run on my Linux server. I used the Perl modules Device::SerialPort and RRDs (included with RRDtool).

[edit] External links