zWave Radiator Valves

[mpooley]

Hi all
I have a had my homebrew Heating control working steadily for over a year now
with 1 wire sensors and Control relays working the boiler and zone valves.

But I would like to go further and control individual Radiator valves.
I would need to buy these but would want to make the controller myself so that I could add it into my VB.net Control program .

Has anyone ever managed to do anything like this?

I see that danfoss do a zwave rad valve, are there any other manufacturers?

all advice appreciated.

Mike

[BruceB]

I was thinking of something similar a couple of years back but have not had time to pursue it.

Do not know whether you are committed to Zwave but if you google zigbee radiator valve, a good number of promising hits appear.

Regards
Bruce

[Baz]

Someone on here has shown it is possible to turn off a normal TRV by heating it with a 1W resistor. Fancy electronics next to hot radiator  lifetime 10 years max (in your dreams). Phone cable run round is a bit more hassle but min life 40 years.

[mpooley]

not exactly sure what you mean.
a small heating element controlled by wire?

[A.L.]

not exactly sure what you mean.
a small heating element controlled by wire?

- more details here - www.navitron.org.uk/forum/index.php/topic,4638.msg45718.html#msg45718

[mpooley]

Thanks 
it looks like no definitive answer was found back then though.

I have a couple of those digital rad valves and they seem to work ok but with three drawbacks
they are about £30 each ouch i would need about 21 !
they are much too fiddly to set up for every rad in the house
they are not nerdy enough!  i want complete computer control so I can look at nice graphs 

Maybe they could be adapted but at £30 each I would have to cut back on the rads I could control - maybe 13 ! still £390 !! though

Mike

[wookey]

mpooley. Have you checked out the HR20 firmware update site? http://sourceforge.net/projects/openhr20/

It has a serial port so you can control it over serial. Quite a lot of people are using this code/schematics. The awkward bit is that the docs are at least 50% in german, but this english thread is a good start: http://embdev.net/topic/118781

I think there is a windows app/dev kit you can drive it all from.

Yes they are not super-cheap. But realistically how cheap do you think you can make a low-power motorised digital radiator control head with lcd and serial? There is some room for improvement to £20 rather than £30, but that requires adoption and higher numbers.

Keep an eye on ebay. I got 5 for £50 via this forum, which is a nice price. I have failed to do the necessary hacking best part of 2 years. Maybe I'll have a go tomorrow :-)

[TimSmall]

You can get ~£10 each 24 volt thermo-electric valve heads which are normally used in under floor heating setups, and PWM control these if you need to modulate them.  I believe you can put them onto normal TRV valve heads.

I believe you can radio-remote control the Honeywell HR20 valves tho, which would be a big plus to my mind.

BTW, have you looked at "DZ" (DIY-zoning)?

Tim.

[mpooley]

Thanks!
Just had a quick Google of DZ and will have a read thanks
is there any info on controlling these underfloor valves anywhere
please tell me more 

Mike

[TimSmall]

Well, I don't have a massive amount to say on the topic I'm afraid, other than the fact that it's definitely possible without too much trouble, and that I'm planning to use them in my new house (eco-renovation finishing this summer), but I probably won't get onto it for a few months (next winter at the latest for obvious reasons!).

If you just want on/off control, then a bank of relays will do it.  If you want proportional control, then a set of suitable MOSFETs with a pulse-width modulated input would do it (off the shelf Arduino motor controller boards maybe?).

This is the sort of thing which I had in mind:

http://www.ebay.co.uk/itm/150627414039

I'll be using DZ as the control software (there are things like an Android app for remote control, plus it's all open source software - which is my thing).

Tim.

[mpooley]

Ahhh! thanks that is just what i'm looking for Except they are not wireless 
But definitely the best thing i have seen yet.
And they definitely fit in place of a TRV  do they ?

The control would not be hard as I already have a VB prog running 24/7 controlling my boiler and zones
I would just need to add more zones -
Its the wiring that would be difficult as wifey is very fussy! and I had a hard time fitting all the sensors because of that.

The relay control would just be an extension of what I have now - using one wire. which has been very reliable.
although tricky to wire as the chip pins are so small.
No the only thing stopping me going straight ahead with these valves is the wiring!

thanks again
I will be looking at it closely.


Just had a thought I wonder if its possible to send PCM down a copper pipe ?

I think i will ask lol

Mike

[wookey]

What's the power-consumption of those actuators? The other solenoid or thermal-wax on-off valves I've seen use 3-5W all the time they are on, which is a problem if you got several of them that are on for long periods. That's the joy of the HR20s - no power consumption except when changing settings.

And I'm not sure how they'll take to PWM modulation if they are designed for on-off switching a few times/day. Might work - might die in a few weeks. I guess the thermal ones will be fine - solenoid ones perhaps less so?

I did ask the power-consumption quesiton of a UFH company just before xmas but they didn't know and just told me where they come from. I've not got round to asking them yet. Emmeti don't say but Watts Industries have a datasheet: www.totaline.com.tr/pdf/DigerHVACKatalog/Watts_Fancoil_Vana_Motorlar%C4%B1_22C.pdf which is a relatively good 2.5W.

Still if you've got 10 of these on 8 hours a day for 5 months, that's 30kWh/yr, which is currently £4.20/yr. Not terrible, but not great either.

[Baz]

I think they work by heating up a thermal expansion element like in a TMV so could be pulse controlled but the effect might be variable dependingon local temperature. It alos looks like thy are designed to be easy fit to a multiway manifold of the type used for underfloor not for a normal TMV.
For minimal power you need some kind of serrvo. Radio control ones are only a fiver but you need to start extolling the virtues of wires. A hollow skirting board would be a good idea.

[mpooley]

Has anyone tried fitting these to a rad?

and Baz I would much prefer to use wires but it's a hell of a lot more difficult.

If I could run enough cable around the house just on the skirting It would be good.
I suppose It might be possible  with a bit of ingenuity.

I like my idea of using the pipe as a carrier for digital on/off switching if it was feasible.
I wish I still had my old oscilloscope. 
I think a local battery behind each rad could then power the rad especially if using a servo type rad valve. The two I have got run on batteries and have lasted over a year so far.
I wish I could bring myself to break one open and have a look inside 

Mike

[ericw]

It alos looks like thy are designed to be easy fit to a multiway manifold of the type used for underfloor not for a normal TMV.

The datasheet gives the fitting as M30 x 1.5, which according to the installation instructions for the Pegler i30 unit is used by most (but not all) TRV's.