Interesting place for a room stat

[Doomed]

In a cupboard in the corner of a bedroom I find this

 

[davesparks]

Surely that has got to be a frost stat, nobody would be so stupid as to fit a room stat there would they?

 

[snowhead]

nobody would be so stupid as to fit a room stat there would they?

You under estimate (or should that be over estimate) peoples intelligence.
If it can be done, whether it should be or not, then people will do it.

 

[telectrix]

it's got a technical name... the science of stupid.

 

[Doomed]

Surely that has got to be a frost stat, nobody would be so stupid as to fit a room stat there would they?

Definately a room stat, my only thought is that it makes it compliant by having one fitted.

 

[Paul L]

It says it all about the cutting corners because i cant be bothered world that some people live in these days. Absolutely crazy and it got me thinking as to what the best position actually is for room stats as there seems to be a few trains of thought.
My mum lives in a housing association bungalow and a few years ago when the heating was upgraded they put the room stat literally by the front door where it opens because there happened to be a handy piece of trunking there. Every time the door is opened, particularly in winter surely there will be a big effect on that stat? but the maintenance company the housing association use say its exactly the right place for it.
Doesn't seem right to me at all but maybe there is some theory or thinking behind it that makes sense or not?

 

[davesparks]

The room stat should be in the room which has the control radiator in it, the one which does not have a TRV. The temperature of this room is controlled by the room stat.

All other rooms are then balanced relative to this room using the TRV's

 

[Paul L]

Thanks davesparks, that's just how i have always done it. The Engineer was insistent that by the front door was the right place for it but it just seems wrong to me when that area is subject to quite big fluctuations in temperature.
Probably another example of someone just doing what is easiest rather than what is right, my mum being a pensioner it seems its ok to fob her off.

 

[EricMark]

There are a number of reasons to have a wall mounted thermostat.
1) To stop system freezing.
2) To auto switch off boiler in summer months.
3) To allow remote control.
4) To comply with silly laws.
5) To control temperature of the room.
I can't see from picture type of boiler, but I can see the thermostat is rather basic, so could be froststat, but not a modulating thermostat just simple off/on, and today most gas boilers modulate, (turn up/down) so the control needs to be a modulating control, most common is a thermostatic radiator valve (TRV) however the TRV has a problem, it can't tell a boiler when to run, in theory you could design the boiler so once it hits lowest output and the return water is over temperature it switches off, but what you can't do is once switches off, know when to switch on again.

So you want a thermostat which will turn off the boiler in summer, and turn it back on in winter, the difference between off and on can be large, so missing out the neutral works well.

So the scenario, the TRV controls bedroom heat say 18 degs C, the thermostat is set to 20 degs C off, 17 degs C on, so all winter it does nothing, when we get a warm day in spring it turns off heating and when we get a cool day in autumn it turns back on again.

I have a similar system, OK because the thermostat is so high it may need to be a little higher temperature, but once set what every room it will never need touching again.

OK a Nest Gen 3 thermostat is clearly designed to connect to the boiler ebus using OpenTherm protocol and regulate the boiler output from some central room, but that thermostat is a very simple cheap one. Of course you can take it a little further, a programmable wall thermostat and programmable TRV head can be set to work together and allow for it getting cooler over night, but today Nest Gen 3 is rather the odd one out, most of the higher range thermostats talk to the TRV head.

We need to remember it is the TRV which controls room temperature in most cases, not the wall thermostat, there may be the odd open plan house where a single thermostat on the wall will work, but in most cases today we need multi thermostats one or two for each room, even if only the cheap eQ-3 with bluetooth so a pair can talk to each other when controlling the same room, or without bluetooth if only one radiator in the room, it is the TRV head that does the controlling in most cases today.

Wall thermostat only turns off system in summer.

 

[Zerax]

Well... Ideally... in every room, you want a thermostat and some sort of on/off control with a centralised 'intelligent' programmer. This allows each room to individually 'call for heat' as and when required. If no heating is being 'called' then the boiler shuts down.

The 'conventional' arrangements that we mostly see of TRVs and a room stat is merely a very primitive early version.

One of my bug-bears is how backwards this country is in proper control and regulation of our heating... how out-of-date and lowly the building regulations are. Even with the high controllability of electric heating, the existing regulations make it very difficult to do properly.

 

[EricMark]

I agree with @Zerax we do seem backwards, however most of that is due to government intervention. With a zoned heating system I have only found one make of thermostat that will allow OpenTherm and zones, EPH make thermostats that can be set as slave and master so can work with zone valves.

However they don't connect with TRV heads. Same as Nest.

So with have Drayton who make a predictive TRV head, but that connects to a single wall thermostat, so not suitable for zoned systems using an on/off zone valve.

So there is no control system that can be guaranteed to work with all systems, they are all a compromise.

Even without zone valves there are problems.

Let me look at the nearest we can get to perfect system, Myson iVector radiators as we want a fast warm up time to use geofencing, but the fan assisted radiator does not control water flow, it controls by varying fan speed, so all radiators in series not parallel. So the faster and the more the fan runs the cooler the return water and the higher the boiler output will be. Can also use same units for cooling, so yes bees knees, but just look at the price.

Every other system has radiators in parallel, so may fit the odd Myson kick space, but in the main it either needs completely re-piping, or can't be fitted, so we do look for high output but low water content radiators, but control is the TRV, lock shield and by-pass valve. I will admit we can get eQ-3 heads for £10 which are programmable and you set in degrees C, but most have *123456 which is about as much good as a chocolate fire guard.

The first electronic TRV heads I fitted were Energenie, and not as simple as one first thinks, any TRV head takes time to open and close, so the lock shield valve needs setting so the radiator takes time to heat up, say 10 minutes, this means things work gradual. More of a problem if the TRV is on return, as we want to stop the radiator over heating, so two temperatures current and target, so if target moves from say 16°C to 20°C it will likely after two hours have over shot, so if so we close the lock shield and if not reached after 3 hours we open lock shield until the thermostat is spot on, and after some time trimming it was spot on +/- 1°C. All four rooms with Energenie heads were spot on, but there was another problem, the anti hysteresis software was too good, so set 16°C to 20°C and at 18.5°C within 1/2 hour, but nearly 3 hours to reach 20°C, so it was programmed 16°C to 22°C for 1/2 hour then 22°C to 20°C and it hit 20°C within 1/2 hour, told the drayton has special software to stop this.

However for a schedule temperature change this is OK, but for a geofencing using IFTTT this will not work, very few live far enough away from work for the geofencing to work on time.

When I was about to move house new owners did not want electronic valves, so replaced with the old wax heads, set to around 3.5 they gave 20°C, however now the lock shield had been set for the electronic heads, I found the old heads also seemed to work far better, but unless you know head set at 20°C how do you know if lock shield wants trimming or TRV needs trimming? As said *123456 is as good as a chocolate fire guard, what is wrong with actually marking in °C?

Same heads fitted in new house, no where near as good, oil fired boiler, that switches on/off it does not modulate, so near impossible to set up, is dip in temperature due to TRV, lock shield or boiler turning off, it does work, but really the cheap eQ-3 bluetooth heads do nearly as good as job to the Energenie, so £15 or £37?

Other makes are more expensive, so you buy a Hive wall thermostat really cheap, then pay £54 for the TRV head to go with it, my house 14 radiators with TRV's not including toilet, That's £756 for the TRV heads if using Hive, so Hive works out rather expensive.

So full control looking £500 to £1000, how much gas needs saving to get that back? At 5% interest on money, add £90 to annual bill to pay back in 25 years, so must save £90 to break even. Yes the idea seems great, only heat a room just before needed, but that needs insulated internal walls and floors, I turned off the heating to office, outside 5°C, office 15°C from the heat from other rooms running at 20°C.

So there is a good reason why UK houses don't have a state of art system, it does not pay for its self. Brother-in-law did have state of art house, LPG, Solar, and wood burning all feed to central water store and while away his house stayed at 12°C with just solar power, so geofencing turned it up as he got home, it was installed when house built, but as an after fit, looking at £24,000 for heating. Yes good, should be at that price, he would light log burner for one burn in evening and that kept house warm. But how much fuel oil can you get for £24,000, at 69 year old no way will it pay for its self.

 

[Zerax]

I agree with the cost/return problem... but we should be building all new houses as intelligently as possible. There's a new development near me which has been built in full compliance with the building regs, however:

Roofs not oriented to maximise solar (if fitted in future)
All have gas boilers to wall hung radiators
No underfloor heating
No ground source heat pumps
No provision for all properties to be near electric car charging
No 3P supplies
No shared bins/recycling

And in my town, there are several thousand more of these houses all with permission to be built !!

Astonishing incompetence...

 

[EricMark]

Why would you want under floor heating? For an old peoples home, yes it can work, but for most homes we only want to heat the room when used. Under floor heating is too slow, there is a reason why we stopped using the Roman hypocaust. It used too much fuel.

Having a heat store is only any good if you can control the output, so a massive water tank heated by solar will work, but we all know the storage heater was a total failure.

One problem is we auto expect other houses to work similar to our own, my house did get some sun, but not excessive, but mothers house had a bay window, lovely when house was built but with double glazing it was a sun trap specially in winter when the sun is low, it would rapid heat room when sun was out, but no effect when over cast, so the central heating had to cope with the change, so a high output radiator but as light as possible so it did not store heat, so when sun came out it could react fast and stop the room overheating, it was the use of an electronic TRV head which transformed that room, stopping it over heating.

As to solar panels, and orientation of the roof, if the slop faces south then the time the panels produce is shorter than if they face east and west, and in real terms you are better with a 4 section roof with a ridge facing south so to extend the time they produce power for, and of course we have to consider again the way the government has regulated their use where if you exceed a generation limit you get paid less.

With my new house for the first time I have started using air conditioning, again direction windows face, I love looking out on the valley the rolling fields and woodland beyond, to have angled the house so I did not get that view would have resulted in my not buying it.

There is no reason why I need so many rooms in the house, two bathrooms, two kitchens, three toilets there are only two of us living in a 5 bedroom house, so I select which rooms to heat and cool, it would have been impossible to penetrate the rock the house sits on to have ground source heat pumps.

But at least the builder did fit a chimney, I am sure it was designed to have fires in the grate, however I have the pipe from the AC going up it, saves leaving a window open. Only real change is I have a plate so I can block it off.

 

[Cbuk2k2]

A lot of smart controls can use intelligent radiator valves that feed back the room temp and can change set point based on the programmer.

 

[telectrix]

I agree with the cost/return problem... but we should be building all new houses as intelligently as possible. There's a new development near me which has been built in full compliance with the building regs, however:

Roofs not oriented to maximise solar (if fitted in future)
All have gas boilers to wall hung radiators
No underfloor heating
No ground source heat pumps
No provision for all properties to be near electric car charging
No 3P supplies
No shared bins/recycling

And in my town, there are several thousand more of these houses all with permission to be built !!

Astonishing incompetence...

who cares. theyonly designed for a lifespan of 20 years anyway. new builds suck.