Smart thermostatic radiator valves - z-wave

sirkuk

And as for battery life on the Drayton Wiser system, I had around a year before I had to start replacing batteries in the TRVs (had the system for almost two years now). For the rooms with fewer temperature changes (like spare bedrooms), the batteries lasted longer from not having to drive the TRV motors so often and less so for the rooms with more temperature changes (and the rooms the kids mostly occupied by boosting the temperature manually on each TRV once they worked out you can twist the tops to call for heat - you can however lock this feature out on individual TRVs).

Will I Aint

My neighbour has all his rad controlled by TRVs, he's usinging Z-wave and Homeseer 3.  The problem with temp sensors on the TRVs is that they are next to a heat source so can skew the readings.  He's got zwave temp sensors in every room, most of the TRVs he's rigged to a power supply rather than the battery wth a dowel across the contacts because of the frequent changing kills the batteries and the polling of zwave can be inconsistant.

The TRVs are controlled via Homeseer events depending on if the house is empty (using Geofences).  He has integrated the Nest thermostat but a word of warning on that one.  If you are looking for full automation the API is being locked down and a lot of the people using complex home automation are moving away from the nest thermostat.  I'll have a look as i'm sure he's sent me a link to the thermostat preferred over the nest one and the TRVs.

Will I Aint

I believe the one they are moving towards is Honeywell Lyric.

neilball

The issue of a built-in air sensor on the radiator actuator can sometimes be a problem, but in many cases it works well enough. The strong convection currents created by the radiator help this providing it’s not covered.  That said, most decent control systems that have radiator actuators with built-in sensors also slow you to add a separate room sensor that is used in place of the built in sensor. This means you could try without a dedicated room sensor and add it later if needed rather, than having to buy room sensors throughout from the start.

Will I Aint

agreed, the cost is not insignificant.  TRVs for zwave are around £60 new, multi sensors in the £40-60 range, it soon adds up.  Not to mention alot of them are downright fugly.  I've got black rads downstairs and i don't want some white monstrosity bolted on the side.

xxGBHxx

It's odd.

You're agreeing to disagree and then agreeing with exactly what I said?

What we've both said amounts to.

If you have no controls then any controls (smart or otherwise) make a huge difference/saving.It will take a long time to recoup the costs of a smart system (you quote 5-10 years even in your best installs)Smart systems offer big convenience benefitsSome installs never recoup the install costsI've never claimed you don't get cheaper heating. I've never claimed you don't get convenience. I've never claimed you'll never ever get back your money (though you agree it's a possibility) and indeed your 5-10 year quote is almost exactly in line with what I put in my reply.

All I was trying to do was to make the OP aware of what the reality of smart systems is. He's looking more at convenience and fine grain control than cost savings and for that any smart system should be great. He's looking for integration into OpenHAB so I would suggest he go look at the OpenHAB forums and see what integrates the best.

I will say it again.

If you want smart heating because you want to save money then you need to understand that it's a long time (5-10 years by your own estimate) before you see the benefit of those savings and that  time might even be never.

If you want smart heating because it offers fine grain control and convenience then you'll see immediate benefits accepting it's going to cost you a LOT in the short to medium term for that convenience.

That pretty much sums up my posts.

G

neilball

No worries, seems like we’re both trying to make the same points after all

arachnoid

Thanks all for your inputs. There is a lot of talk about cost saving but this is not my primary objective.

Thinking to start with some z-wave thermostats in the rooms that are less occupied. This should at least reduce energy wasted in heating those spaces unnecessarily whilst leaving key spaces heated (by room thermostat adjustment)?