Re: Software for Central Heating Control

[John Rumm <see.my.signature@xxxxxxxxxxxx>]

rowan@xxxxxxxxxxxxxxxxxxxxx wrote:

Oh another one!

There is another thread running on this here:

http://groups.google.com/group/uk.d-i-y/browse_frm/thread/b5ac5d41956ffc24/684c4ea70c6c5acb?lnk=st&q=group%3Auk.d-i-y+boiler+control+questions&rnum=1&hl=en#684c4ea70c6c5acb
http://tinyurl.com/9tvhd

> I'm having a loft conversion done at present, and I'd like to take the

Does that mean you will be losing storage tanks etc?

> opportunity to upgrade my central heating control system, which is
> currently pretty dumb (3-on 3-off per day controller for hot water and
> heating, with thermostatic radiator valves). I'm looking for some
> software that will let me run much more sophisticated control


> algorithms. Some of the things I'd like to be able to do are:

>  - control three heating zones plus hot water
>  - allow different control temperatures for each zone at different
> times of day and days of the week
>  - correct for outside temperature, wind speed and direction etc.
 >  - learn house warm-up time under various conditions and come on "just
 > in time" to achieve the required temperature
 >  - easy to use and flexible manual override facilities via wall-mounted
 > control panels, a web based interface or by phone (e.g. hotter, cooler,
 > on, off, come on for 1 hour etc.)

All this can be done with standard off the shelf control kit withotu
needing to get too cleaver (unless you want to!)

S Plan+ system with some programmable (optimising) thermostats would do
that. Add a external weather compensator etc.

>  - don't heat rooms when they are unoccupied
>  - don't heat rooms when the windows are open
>  - heat only as much water as is expected to be required for the time
> of day (i.e. don't heat a full tank unless people are expected to be
> bathing or the washing is being done)

>  - use oil, off-peak electricity and full-price electricity in the most
> cost effective manner

Ignore electric while the oil tank is not empty then ;-)

>  - automatically adjust boiler operating temperature for optimum
> efficiency (i.e. lower the boiler temperature when the heat demand is
> lower)

This may depend on how the temperature is adjusted on your boiler - on
many it is a hard wired knob which is not that well suited to automated
control.

> My vision is to run the control software on a small solid state single
> board computer with the necessary I/O (interface to temperature and
> other sensors, mains relays for zone valves and pumps, wall mounted
> control panels, web server for network based contol etc.), with the
> control program developed on a PC and downloaded to the SBC when the
> algorithms need to change.

Small embedded PCs with flash file systems are ideal for this sort of
application and can be bought off the shelf. You could in reality do it
with just about anything (old micro computer of some description) since
you have very low computational requirements.

You can mix in some X10 automation stuff as required for some of the
applications, and a smart security system like:

http://www.tlc-direct.co.uk/Main_Index/Alarm_Index/Wireless_index/ESP_Infinite_Main/index.html

will handle the GSM and Telephone interfaces to the home automation kit
to give you the non web based remote access.

> What software exists which can help implement this sort of control?
> What languages are best for implementing the algoithms?

Whatever you can: a) get a development system for that suits your chosen
target and b) that you feel comfortable developing in.

> Who else is working in this field?

Have a look at some of the many X10 and home automation sites.

> What is the best hardware?

Define best?

--
Cheers,

John.

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