Wifi TRVs

[Jon Connell]

So reading into these wifi thermostat things, I learned that some of them can also control wireless TRVs to more precisely regulate the temperature of individual rooms according to a schedule.

Our house has two heating zones as a result of the house basically being in two halves and having an oil boiler heating each half. But that still leaves plenty of scope for having rooms having their own schedules. Our oil bills are high enough that I think something as costly as a load of wireless TRVs could be worth the effort.

Does anyone have this working and if you do, what devices did you choose?

[Chris J Dixon]

I have a couple of these

(The "Radio Exhaust" is actually a radiator bleeding device, and this combination is £10 cheaper than one without the freebie)

They seem to work as anticipated.

Chris

[Andy Burns]

So these things replace the TRV head and depress/release the plunger automatically several times a day, all from coin cells? How long do the batteries last?

[Chris J Dixon]

2 x AA actually - they last months.

The mechanism is driven by a small motor, which makes incremental adjustments as required.

Chris

[Andy Burns]

Ahh, I took the "other people also bought 20 pack of coin cells" suggestion too seriously ...

[chris French]

Ah, I was going to try that out in our living room. good to know they work ok.

There is some sort of open source project using the Conrad valves.

[Tim Watts]

On Monday 18 November 2013 17:25 Jon Connell wrote in uk.d-i-y:

"Z-Wave" seems to be some sort of emerging standard for radio home automation:

I have not figured out all of the comboinations yet - but it's looks like it's worth a read...

[Tim Watts]

On Monday 18 November 2013 18:25 Andy Burns wrote in uk.d-i-y:

AA's usually and 1-2 years claimed.

[Andy Burns]

Yes, I'm considering using a Fibaro FGD211 dimmer module, not for the z-wave interface but simply as small dimmer module that will work 2-way from momentary pull ceiling switches.

The central radio hub seemed to be around 500 notes ... sod that for now.

[Andy Burns]

At £41 a Z-stick is still a bit steep for a USB dongle, but more tempting and linux friendly ...

[Tim Watts]

On Monday 18 November 2013 20:06 Andy Burns wrote in uk.d-i-y:

I'm looking for a room timer/stat that can be paired with either the Danfoss or Stella-Z valve.

I'd prefer to have most of the system independant (OK, the boiler relay is a point of failure). So far most of the room stats seem to be stats only...

[harryagain]

So what's the point of such an expensive device? Is there a heat sensor in each room?

Money could probably be spent elsewhere to greater benefit.

[Tim Watts]

On Tuesday 19 November 2013 06:34 harryagain wrote in uk.d-i-y:

Maybe he wants the comfort and convenience...

[Jon Connell]

I hope these things work better together than DECT phones. I've yet to see two DECT phones work together.

Nice to see some standardisation though. I was interested in this:

(I have Apple stuff, so I am a sucker who is easily sold on pretty interfaces)

No mention of Z-Wave though :S

[Tim Watts]

On Tuesday 19 November 2013 08:27 Jon Connell wrote in uk.d-i-y:

It is not ZWave - but there will (claimed) be an API for remote something.

It does look highly polished - as Honeywell products are.

I hope they make it easy to buy - previously they had been selling in the UK via a single distrubutor so it was actually cheaper/easier to buy direct from Germany!

One other comment - the radio protocol used buy the HR80 family was pretty simple and robust against missed messages, despite being simplex.

One of the faults with the Conrad FHT system is it is also simplex, throuws out the message 3 times and has no inherent stability against missed messages - a problem apparantly when you get much beyond 8-10 zones as the probability of packet collision is now very high.

Whilst Honeywell will never open the radio protocol, it is likely to be fairly well designed.

[Jon Connell]

Not heating rooms unnecessarily ought to pay back the investment cost. Same argument as LED lighting, which is also freakin' expensive.

Yes.

The only other thing that would have significant impact on my heating bills would be better insulation. We have brick walls with no cavities and a roof with unknown levels of insulation (no loft). My current estimates on retrofitting insulation suggest that it would actually be cheaper to carry on burning oil!

[harryagain]

Well you should be fitting internal or external insulation. No calculation can be made as the future price of oil is unknown so that is a foolish remark. It also depends on how long you intend to stay. It will add value to the house as the energy efficiency rating will be raised. My own house had solid walls. It now has no heating bill after extensive insulation.

[dennis]

What you want is a room stat that will switch the radiator valve on and switch the boiler "demand" on at the same time. Just like a zone valve.

If you can't switch demand on when needed the radiator won't get hot. The alternative of running the boiler all the time heat might be needed isn't such a good idea but better than plain TRVs.

[dennis]

You need to look at the green deal. You can now get external insulation. It probably won't save a fortune but it should reduce heat loss, make you more comfortable and not increase your bills.

You may benefit from a heat pump and remove the oil at the same time.

[Jonathan]

I hope you now regret it.

Jonathan