I normally only have the one machine on constantly, my server boron. It’s a fairly old self-built P4 with an old Radeon 9600 AGP graphics card, which puts out more heat than most of my newer machines. When idling, there’s enough heat to keep the cabinet at a mild temperature on these cold nights, but the room is not so easily heated. In summer, there is the opposite problem of too much warmth which on really hot days can only be solved with air conditioning.

With a temperature sensor or two, I could set up boron to run a CPU-intensive task (such as a BOINC project like Folding@Home or Seti@Home) when it’s cold to produce heat while at the same time doing something useful. While it’s not an efficient way of heating a room, you gain both heat AND processed data, rather than just producing heat and nothing else like an electric heater would.

If I had more (quiet) computers in my room, I could keep them off most of the time, then turn them on automatically (using Wake-on-LAN, for example) when heat is needed to do some number crunching.

This idea could be applied to an entire house, like my future self-built house (still in the dream stage, and probably will be for at least 15 years). The heat produced by computation could be put to use heating a house in winter, directly using the warm air, or just helping to heat hot water in the summer by using a heat exchanger to pre-heat the water going into the boiler.

In fact the same could be, and probably is, applied on a commercial scale in newly designed efficient corporate buildings, where the heat from server rooms and networking closets is used to improve the efficiency of heating and hot water provision. Many new well-designed buildings take into account natural air flow, attempting to minimise the amount of energy required for environmental control. Such a use of the inefficiency of necessary electronic systems would add to this eco-design.

Back in the present, in my current location, using the machines I have, this could be accomplished quite easily by setting up a computer-connected thermistor measuring the ambient room temperature and some simple software to monitor the temperature and start/stop intensive tasks as necessary. Not difficult or expensive at all. It could also be applied to the MythTV box, sodium, downstairs in one of the coldest rooms of the house.

If you know of anyone or any buildings that use something like this, I’d be interested to hear about them. Please add a comment below if you are aware of any instances of this idea in use.