How to control heating?

[clivejo]

I now have a heat store which seems to be working well.  One charge every evening seems to provide my heating and DHW needs.  I just would like it to be more intelligent, based on time of day, temperature out side, and my habits.  This means some kind of automation.  The computing end of it I'm ok with but I cant find an electric valve Id be happy to use.  There must be something out there that could do the job.  I would like something that only needs power when operating and ideally a stepping motor with about 5-10 positions between fully open and closed.  I need something small enough to attach to existing pipe work (mostly upstairs under floor boards) on 15mm copper.

Something like this http://www.ebay.co.uk/itm/Electric-Solenoid-Valve-Water-Air-Pipeline-1-2-12V-/350470321633 but as above.

[biff]

sounds like you might be searching for a honeywell zone valve,  3 port or 2 port. very reliable and trusty.can be activated by stat same time as pump.
                                                                                  biff

[clivejo]

I cant afford 6 or 7 of them things!!  Plus I want something that only uses power to operate!

[wookey]

I failed to find anything that did this for less than £150 when I looked a couple of years back. A quick look now finds more options but all still very expensive. e.g emmeti UK will sell you a mo-mo 3-way valve+motor for £94 (valve)+£214(motor). http://www.emmeti.co.uk/wp-content/uploads/Emmeti-UK-Pricelist-2011-Heating-Manifolds-Type-3-T3-UFH-Control-Set-Accessories.pdf

You can get mo-mo drivers for the normal 2 or 3-way heating valves but they are ~£60 and no intermediate positions. If you want a cheap multiposition valve then you're going to have buy a stepper motor and contrive to fit it to a shaft. The heating industry seems to have no interest in providing basic control blocks for anything less than 'effing expensive', and they mostly want to provide you with closed-loop control systems which is all designed specifically to avoid any external control by those of us with a clue.

[Baz]

TMV and radio control servo.

[TimSmall]

We seem to be discussing this on the thread next door too...

http://www.navitron.org.uk/forum/index.php/topic,16021.0.html

A TRV body plus either a thermo-electric head, or a hacked Honeywell HR20 (or even just the TRV head + a resistor) would all do it at more like ten to thirty quid per valve I think...

I'm planning on using the opensource "DIY Zoning" software, but you may prefer to roll your own (it already has "wet" central heating users in the UK I believe).

Tim.

[clivejo]

I am hoping to get a Raspberry PI and put together an IO board.  Video will be overkill but apparently that can be scaled down to conserve power. 

There must be something somewhere cheap and cheerful.  I was looking at the solenoids for water intake on a washing machine but these would require power while in operation , which is against one of my design briefs/requirements.

[TimSmall]

I am hoping to get a Raspberry PI and put together an IO board.  Video will be overkill but apparently that can be scaled down to conserve power. 

I probably won't use one of those, but probably something similar (Linux/ARM).

There must be something somewhere cheap and cheerful.  I was looking at the solenoids for water intake on a washing machine but these would require power while in operation , which is against one of my design briefs/requirements.

Probably one of battery TRV replacements is likely to be the best bet I'd have thought - it's the most mass-market product and hence is likely to have the lowest price I'd have thought....  No doubt it'd be possible to do better cheaper, but probably only when you're talking about making 10000 plus of whatever sort of design you come up with!

Tim.