Re: Gas boiler control

["Patrick Lidstone" <patrick@xxxxxxxxxxxx>]

> If there are no products commecially available, has anyone
experimented with microcontroller heating control?
>

Although I make do with one boiler, Pete :-), I do run a homebrew
predictive controller, based on weather data collected locally and
medium range weather forecasts. My overall personal approach is aimed
primarily at keeping the house at a comfortable temperature for the
prevailing conditions, rather then saving energy per-se (although
hopefully it does that too). I don't have any means of comparing the
relative efficiency of my controller with conventional controls,
because I haven't run the boiler using an ordinary
controller/thermostat arrangement for any length of time, but the
overall energy input has to be lower if only because the target
temperatures are more tightly controlled than they would be
otherwise. It sounds like you already have a reasonably efficient
multi-zoned system, which has to work in your favour. If you live in
a modern building, the thermal coefficients are likely to be such
that you are unlikely to benefit from the heat-storage effects of the
building fabric, although, conversely, if it is south facing, you may
see significant transient temperature rises from solar radiation (aka
the sun), which strategically positioned sensors can compensate for,
reducing the heat input cycle. If you live in a thick-walled
building, there may well be savings to be had from the medium range
predicative element because of the building fabric's "storage
heater"
factor. I think I also probably make decent savings from combining
boiler control with occupancy detection/alarm status - the room
temperature is set back when the house is unoccupied for short
periods, and set back yet again for medium and long periods
unoccupancy. The inconvenience of coming home to a cool house is
dealt with by sending a text message or using a wap browser to set
the system back to normal operation in anticipation of inpending
return. A zoned heating system also lends itself nicely to
automation. If my heating system was multizoned, I would extend the
occupancy concept to aim for a specific target temperature in the
last known occupied zones (which allows for people sitting still
whilst watching tv etc quite nicely), whilst setting back unoccupied
zones.

HTH a bit

Patrick