Hello,

Interesting query: I've been looking at various of the above and found
some interesting units such as the Honeywell CM67 and also units made by
Danfoss and Sunvic.

What I'm considering doing with a CH upgrade is rather than setting up a 2
(or 3 or 4) zoned system, I'd rather have electric valves on each radiator
(thermo-hydraulic actuators) and a local room timer-thermostat. Maximum
flexibility.

Then I find the above RF capable units and think "hmmm - less wiring..."
Fused spur off the ring near each rad and one receiver and actuator
and I'm done...

But, I have a problem... how to turn the CH pump on or off. So I'm
thinking, I wondering if any of those units can drive multiple receivers,
so the second set of receivers can be wired in parallel to generate a
"demand" signal which I used to control the pump.

The Honeywell unit looks the best on paper as it's using the newer 868MHz
RF band and uses a short pulsed signal. So in theory one should be able to
set two receivers to the same code as one thermostat unit and have it work.??

Anyone ever tried this or have an alternative idea for doing something
similar?

Ta muchly

Timbo

--
Tim Southerwood
Website: http://www.dionic.net/

On Tue, 23 Nov 2004 15:32:24 +0000, Tim S wrote:

Hello,

Interesting query: I've been looking at various of the above and found
some interesting units such as the Honeywell CM67 and also units made by
Danfoss and Sunvic.

What I'm considering doing with a CH upgrade is rather than setting up a 2
(or 3 or 4) zoned system, I'd rather have electric valves on each radiator
(thermo-hydraulic actuators) and a local room timer-thermostat. Maximum
flexibility.

Then I find the above RF capable units and think "hmmm - less wiring..."
Fused spur off the ring near each rad and one receiver and actuator
and I'm done...

But, I have a problem... how to turn the CH pump on or off. So I'm
thinking, I wondering if any of those units can drive multiple receivers,
so the second set of receivers can be wired in parallel to generate a
"demand" signal which I used to control the pump.

The Honeywell unit looks the best on paper as it's using the newer 868MHz
RF band and uses a short pulsed signal. So in theory one should be able to
set two receivers to the same code as one thermostat unit and have it work.??

Anyone ever tried this or have an alternative idea for doing something
similar?

Ta muchly

Timbo

I haven't done this, but I am fairly certain that it would work
because part of the installation is to pair up the receiver with the
transmitter. You would simply do that on multiple receivers.

There is no return path to the transmitter so it would have no way of
knowing.




--

..andy

To email, substitute .nospam with .gl

On Tue, 23 Nov 2004 16:33:13 +0000, Andy Hall
strung together this:

I haven't done this, but I am fairly certain that it would work
because part of the installation is to pair up the receiver with the
transmitter. You would simply do that on multiple receivers.

I haven't actually used these or read the instructions but some
pairing\learning processes effectively default the transmitter and
receiver first.
Bit of trial and error I think.
--

SJW
A.C.S. Ltd
Please reply to group or use 'usenet' in email subject

On Tue, 23 Nov 2004 20:41:25 +0000, Lurch wrote:

On Tue, 23 Nov 2004 16:33:13 +0000, Andy Hall strung
together this:

I haven't done this, but I am fairly certain that it would work because
part of the installation is to pair up the receiver with the transmitter.
You would simply do that on multiple receivers.

I haven't actually used these or read the instructions but some
pairing\learning processes effectively default the transmitter and
receiver first.
Bit of trial and error I think.

[Reply to Andy and Lurch]

Yes - my feeling too - that the RF is one way only so in theory multiple
receivers would work.

It would be bloody expensive to set up 10 areas this way (I found some
prices) so I might compromise and control a few main areas and just have
common areas (hall, kitchen, bathroom etc) "on" whenever *any* controlled
area demands heat (and leave the TRVs in place). Seems like a variation on
the standard system where a central clock and hall thermostat control
evrything.

I think it would work quite well. Sort of S plan plus, but with more
flexibility. I don't like the idea of defining zones in hard plumbing as
the house in question does not lend itself to the notion that "room x =
bedroom". The way it's laid out, today's bedroom could be tomorrow's
secondary living room or study etc. Such is life with bungalows ;-

I emailed Honeywell and Sunvic and they are supposed to be getting a
technical bloke to come back to me so I'll post their answers here if I
get them.

I should contact Danfoss too - as they have an RX3B reciever that can
listen on 3 channels and provide a common demand signal. Though either
way, I'll be wiring their relays in parallel as I'm looking at 5 zones
minimum even with my compromise solution.

If anyone has any alternative suggestions, such as a 5-10 zone central
controller with extra-low voltage signal cable going between various
modules, rather than RF, I'd be interested.

Sure this problem must have been solved before...

Ta

Timbo

--
Tim Southerwood
Website: http://www.dionic.net/

On Wed, 24 Nov 2004 12:22:37 +0000, Tim S wrote:


I think it would work quite well. Sort of S plan plus, but with more
flexibility. I don't like the idea of defining zones in hard plumbing as
the house in question does not lend itself to the notion that "room x =
bedroom". The way it's laid out, today's bedroom could be tomorrow's
secondary living room or study etc. Such is life with bungalows ;-

[replying to myself - first sign of madness :/ ]

There is another solution I though of... Using a manifold with lots of
electric valves. Got the idea from some underfloor heating company on the
web. If I don't want [afford] a timer/thermostat in every area, I could
lock certain circuits on.

I could get away with one RF module per circuit, and make up my own box
full of DIN mounted relays to provide the common demand signal.

As it happens the manifold would be centrally located in the house so
not much difficulty with plumbing, and it would be adjacent to the boiler
and pump anyway.

Hmm...

Tim

--
Tim Southerwood
Website: http://www.dionic.net/

On Wed, 24 Nov 2004 12:22:37 +0000, Tim S strung
together this:

If anyone has any alternative suggestions, such as a 5-10 zone central
controller with extra-low voltage signal cable going between various
modules, rather than RF, I'd be interested.

No doubt there will be but I think we'd be getting into industrial
control solutions. I've worked on a few commercial systems and the
controls aren't cheap.
I think a homebrew solution is what you're after.
If you're keen on the low voltage idea then you just need a low
voltage link from the actuator to the a'c where that would control a
relay controlling the pump. AFAIK most, (all?), RF thermostat
receivers have volt free CO contacts.
Obviously could be a problem if the actuators are mains voltage, as
this would require more relays by the valves to switch the LV demand
pair, but depending how much you're prepared to spend it might not be
such a major hassle.
--

SJW
A.C.S. Ltd
Please reply to group or use 'usenet' in email subject

On Wed, 24 Nov 2004 12:49:43 +0000, Tim S wrote:

On Wed, 24 Nov 2004 12:22:37 +0000, Tim S wrote:


I think it would work quite well. Sort of S plan plus, but with more
flexibility. I don't like the idea of defining zones in hard plumbing as
the house in question does not lend itself to the notion that "room x =
bedroom". The way it's laid out, today's bedroom could be tomorrow's
secondary living room or study etc. Such is life with bungalows ;-

[replying to myself - first sign of madness :/ ]

There is another solution I though of... Using a manifold with lots of
electric valves. Got the idea from some underfloor heating company on the
web. If I don't want [afford] a timer/thermostat in every area, I could
lock certain circuits on.

I could get away with one RF module per circuit, and make up my own box
full of DIN mounted relays to provide the common demand signal.

As it happens the manifold would be centrally located in the house so
not much difficulty with plumbing, and it would be adjacent to the boiler
and pump anyway.

Hi,

Another way would be to have some resistance wire in the TRV. When
current flows through it the heat from the wire lowers the temperature
the TRV closes at.

This could work quite well as in mild weather it's OK to turn off the
rads in rooms that aren't being used, but in colder weather some
background heat is still a good idea.

Or the current can be switched at different duty cycles to vary the
effect, an old laptop with a parallel port interface circuit would be
ideal for this.

cheers,
Pete.

On Tue, 23 Nov 2004 15:32:24 +0000, Tim S wrote:

Hello,

Interesting query: I've been looking at various of the above and found
some interesting units such as the Honeywell CM67 and also units made by
Danfoss and Sunvic.

What I'm considering doing with a CH upgrade is rather than setting up a 2
(or 3 or 4) zoned system, I'd rather have electric valves on each radiator
(thermo-hydraulic actuators) and a local room timer-thermostat. Maximum
flexibility.

OK - I've figured it out...

1) Sunvic did come back and say that multiple recievers *could* be keyed
to one transmitter. But this has become less relevant...

What I've more or less decided to do is to:

Have the plumber install lots of spring-return-close 2 port valves with
microswitches in the central location (adjacent to thermal store unit).
Probably one per room. Effectively a DIY manifold with valves, but using
serviceable standard parts. Run 10-15mm pipework to existing rads.

OK, that's lots, probably 10. But two port valves aren't too expensive and
the fitting isn't much extra work as I need the central section of
pipework for rads and hot water replaced anyway as it's rubbish.

Bearing in mind, altering plumbing later is a pain, but altering localised
electrics is easy.

So I have *potentially* a 10 zone system. But the RF thermostats are
expensive, so me and the missus just worked out we have 4 areas which
could be grouped into zones at present.

So, 4 receivers into a wiring box driving a set of valves each. Common up
all the valve microswitches and I have the demand circuit. Easy!

Plus I can trivially reconfigure the zones (I did say that zoning in
Dad's house is not a given and is likely to change over time). Also I can
very easily add extra programmer-thermostats + RF receivers in the future
(any make, they don't need to be compatible) and create extra zones if it
seems necessary.

I like this idea. Not novel, (S-Plan-Plus taken to extreme I suppose??)
but it's quite practical.

Pretty bomb proof too. As long as I make sure the 2 port valves have the
little manual override lever and I leave the existing TRVs in place (but
normally set to max) I have a manual backup when all the complex
technology blows up at the least convenient time possible, as is wont to
happen.

Yep - think that's sorted - unless a learned friend here spots a fatal
flaw...

Thanks for your various suggestions folks :-)

Timbo

On Wed, 24 Nov 2004 22:31:28 +0000, Pete C
wrote:



Hi,

Another way would be to have some resistance wire in the TRV. When
current flows through it the heat from the wire lowers the temperature
the TRV closes at.

This could work quite well as in mild weather it's OK to turn off the
rads in rooms that aren't being used, but in colder weather some
background heat is still a good idea.

Or the current can be switched at different duty cycles to vary the
effect, an old laptop with a parallel port interface circuit would be
ideal for this.

cheers,
Pete.

You can buy valve heads that do this made by Sauter, called thermal
drives. RS have them as part 328-8562 or less from ControlsCenter.

I've been using Sauter's motorised variety (AXM 117S) which work from
24v ac or dc with a 0-10v control signal. THese fit on in place of
the TRV head and can be set to any open or closed position from a DAC.
They work quite effectively.




--

..andy

To email, substitute .nospam with .gl

On Wed, 24 Nov 2004 22:31:28 +0000, Pete C wrote:

Hi,

Another way would be to have some resistance wire in the TRV. When current
flows through it the heat from the wire lowers the temperature the TRV
closes at.

This could work quite well as in mild weather it's OK to turn off the rads
in rooms that aren't being used, but in colder weather some background
heat is still a good idea.

Or the current can be switched at different duty cycles to vary the
effect, an old laptop with a parallel port interface circuit would be
ideal for this.

cheers,
Pete.

Bit like a set-back thermostat? Good idea. I'm not quite into the old
laptop idea though, as I want this to work ;- I'm a programmer, so I
know when not to depend on computers, which is most of the time if at all
possible, especially if involves me getting cold :/

Always, always have a *big* manual override switch.

Cheers - I do like the first idea though!

Timbo

On Wed, 24 Nov 2004 23:01:02 +0000, Andy Hall wrote:

You can buy valve heads that do this made by Sauter, called thermal
drives. RS have them as part 328-8562 or less from ControlsCenter.

I've been using Sauter's motorised variety (AXM 117S) which work from 24v
ac or dc with a 0-10v control signal. THese fit on in place of the TRV
head and can be set to any open or closed position from a DAC. They work
quite effectively.

Something similar is called a thermo-hydraulic actuator? (Heater heats
liquid, moves rod to operate valve head). I was going along these lines
(Danfoss ones are about 15+VAT, but driven at 240VAC) until I
hit upon the idea of just centralising everything except the actual
thermostat transmitters.

Timbo

On Wed, 24 Nov 2004 23:20:56 +0000, Tim S wrote:

On Wed, 24 Nov 2004 23:01:02 +0000, Andy Hall wrote:

You can buy valve heads that do this made by Sauter, called thermal
drives. RS have them as part 328-8562 or less from ControlsCenter.

I've been using Sauter's motorised variety (AXM 117S) which work from 24v
ac or dc with a 0-10v control signal. THese fit on in place of the TRV
head and can be set to any open or closed position from a DAC. They work
quite effectively.

Something similar is called a thermo-hydraulic actuator? (Heater heats
liquid, moves rod to operate valve head). I was going along these lines
(Danfoss ones are about 15+VAT, but driven at 240VAC) until I
hit upon the idea of just centralising everything except the actual
thermostat transmitters.

Timbo


The thermal drives are effectively as you describe.

They can be controlled in a pseudo-analogue way by varying the power
duty cycle but it's not very accurate.

The motorised ones have a built in servo which periodically
recalibrates itself against the end stop. Thus the 10v dc voltage
gives quite accurate and repeatable results.

http://www.sauter-controls.com/pds/pds/indexe.html


I wanted to have genuine proportional control so went for this
approach.

If you wanted similar for your solution, Sauter do make similar valves
that are equivalents or similar function to heating zone valves but
again with analogue control. I believe they cost around £70 though
:-(



--

..andy

To email, substitute .nospam with .gl