Plug tops / Plug caps?

[ericmark]

Yes, lamp is the whole fitting, bulb, wick, mantel, tube, etc. is a part inside the lamp.

 

[JohnW2]

Yes, lamp is the whole fitting, bulb, wick, mantel, tube, etc. is a part inside the lamp.

Exactly - which, as I always say, is why I find it bizarre that I am today expected to ask for "a lamp to put into my (table/standard/inspection/whatever) lamp"

 

[JohnW2]

Radiator store heat ...

Yes, but not much, nor for very long.

, but more likely picture windows either side of the living room, single glazed.

Heat losses from room will surely be the same (for given room and outside temps) regardless of whether the air in it has been heated 'directly' or via radiator, won't it?

I will assume there was a leak under the floor, but I simply don't know.

You were seemingly implying that your ducted hot air system 'cost a fortune to run' because it was a ducted hot air system - which, as I said, I couldn't really understand. However, if it cost a fortune to run because it was faulty (leaking) that surely has nothing to do with the tyoe of heating (a 'wet system' which was constantly 'leaking under the floor' might also cost a lot to run ).

 

[ericmark]

Heat losses from room will surely be the same (for given room and outside temps) regardless of whether the air in it has been heated 'directly' or via radiator, won't it?

Oh, what a can of worms you have opened. I have debated this a lot with my son, as to the Myson fan assisted radiator, and if moving air around is good or bad.

If I put sensors around the room, I see some massive differential in the recorded temperature, but this is not the case all the time, so at the moment on the table 20.3°C behind me TRV shows 18°C, near the door, 20.5°C, and TRV 90° to one behind me, 20.5°C. All in the same room. Run a fan and air near windows is same temperature to centre of the room, as to if this is good or bad, not sure. But with the house in question, single glazed windows, so wanted to leave the air next to windows undisturbed, behind long curtains, also the vents, closing them was like the song about the dampers, the heat went into the rooms just the same, and also we really needed a humidifier, I would put trays of water in the air intake. The air was so dry.

The ground floor had ducts underneath it, so air could blow under the house with the air bricks, and I do think a lot of heat lost through the floor.

It was 1978 our winter of discontent, so the electric was turned off I am sure you remember, and the central heating can't run without the fans, so the house got very cold. And no other form of heating. Since then, we have been careful to ensure we don't rely on electric from DNO for heating, last house had a 4.5 kW gas fire in living room, this house an open fire in living room, plus CH is battery backed.

So heat pumps are a non-starter for heating. The labour government actions have ensured that, not that the Conservative government actions in the way they treated the miners was any better.

 

[SUNRAY]

The ones melting metal (or glass) are called furnaces too, the ones generating steam for heating homes seem to be called boilers. At least that’s what I‘ve gathered from decades of reading US books and DIY forum posts.

Since 2002 my work has been mostly controls and the majority of that has been commercial heating/cooling /ventilation etc. Having worked for/with a number of west pond engineers/consultants I think I'm safe to say the term furnace has been used by all of them where we would say boiler, also I think possibly the same for cooler Vs chiller.

Yes but were they actually producing steam or merely water vapour I`m sure most folk would want to know?

I'm sure it would quickly convert to water vapour not far round the system.

 

[JohnW2]

Oh, what a can of worms you have opened. I have debated this a lot with my son, as to the Myson fan assisted radiator, and if moving air around is good or bad. .... If I put sensors around the room, I see some massive differential in the recorded temperature ...

Yes, potentially true. I was thinking/talking about situations in which all of the air in a room was heated to a uniform temp, in which case I can't see why it would matter whether it had been heated 'directly' or via radiators. However, if one takes steps to (as far as possible) keep heated air away from the places of greatest potential heat loss (usually windows), one can obviously change that situation. With ducted heated air one is presumably essentially stuck with all of the air being similarly heated, and the same with radiators if combined with effective fans. As you go on to say ...

.....Run a fan and air near windows is same temperature to centre of the room, as to if this is good or bad, not sure.

It's not so much a case of 'good or bad' as of 'what one wants' (in terms of uniform heating of room, or otherwise).

Having said that, I'm not sure that, in practice, radiators (without fans) are actually going to be allthat much different from blown air since, although the radiators could theoretically be positioned as far as possible from windows etc, in practice by far the most common location is actually 'under the window'!

It was 1978 our winter of discontent, so the electric was turned off I am sure you remember, and the central heating can't run without the fans, so the house got very cold. And no other form of heating.

Yes, I remember such times well, but it didn't impact significantly on me in terms of heating (or cooking - and we also had torches and candles!), since at that time I didn't have 'central heating' of any sort!

 

[ebee]

Yes, I remember such times well, but it didn't impact significantly on me in terms of heating (or cooking - and we also had torches and candles!), since at that time I didn't have 'central heating' of any so

Almost the same - we did have solid fuel central heating and a back boiler in the fire feeding the immersion heater , so the fire was coal like in the main room and the cylinder in the bathroom aove got hot so the bathroom warmed up a bit and there was a little heating in the radiators but with no pump running it relied on gravity only so quite small and a very long time to get warmer from cold but slightly better than nothing I think.

Overall it could have been worse but it was never good at that turbulent time and our normal 40 hour working week was affected

 

[ericmark]

although the radiators could theoretically be positioned as far as possible from windows etc, in practice by far the most common location is actually 'under the window'!

That is also now questionable. We were shown as how the radiators worked, but this was before double glazing. Under the window is often good for furniture placement, often a problem with curtains wrong side of radiator, but it also means the thermostat is against a cold wall, which is OK once the thermals have established themselves, but until that point the thermostat is at a lower temperature to the room in general.

There are options with some TRV heads,

where we can link wall thermostats to the TRV head, some makes you can designate rooms, Wiser does this, so if you fit a wall thermostat in the same room as the TRV the wall thermostat will control it.

It seems the old idea of a wall thermostat in the hall is no longer valid, and we have been told for years not to have a TRV in the room with the thermostat, that is also not required any more, the whole control method has changed, maybe because how we use central heating has also changed. My parents would have the CH come on in the morning so getting up to a warm house, but then they would light fires, I have never lit a fire in the grate, I have the option, but never used it.

The old system had the input to the radiator at the top and output at the bottom, this assists thermal flow, but places the TRV where it is directly heated by the radiator, to one side at the bottom is likely the best place to sample the whole rooms' temperature.

However, if this thermal circulation was valid, then this room with two TRV heads a wall thermostat and a weather station, would show the same temperature on all once the central heating is running. But 21°C, 19°C, 21°C, 20.6°C shown at moment radiators cool, but on an earlier post when radiator was hot, the difference was much larger, pointing to these diagrams being wrong, and just a figment of someone's imagination, as to what they think will happen.

Same with the comparison with vented, and condensing heat pump tumble driers, my vented was set to 1 kW and would dry clothes in around 90–120 minutes, the heat pump around 650 watt and around 2–2.5 hours. Yes the heat pump uses less, but also takes longer, had I had the option of turning the vented down to 650 watts, I wonder how long it would have taken? At least the vented did have 1 kW or 2 kW option, the non heat pump condensing drier often has no option to reduce power use.

Also to looking at energy use as a whole, rather than in isolation, i.e. how much heat released to the room, be if a tumble drier or simple light bulb, no good testing in a huge warehouse, need to consider how they interact with other things in the home, in winter maybe we could fit energy saving bulbs which give off inferred heat, so we can turn down background heating. So air changes waste less heat? Or we could make cars able to use the petrol like fuel we can get from sewage farms rather than dig up lithium?

One of the public schools had a motto anything in moderation, nothing in excess. It's time to stop knee-jerk reactions to things, start off slowly, so errors like thalidomide are found early.

 

[JohnW2]

That is also now questionable. We were shown <images> as how the radiators worked, but this was before double glazing. Under the window is often good for furniture placement, often a problem with curtains wrong side of radiator, ....

It may be 'questionable' but 'under the window' remains by far the most common location for radiators. Indeed, given that the only sensible location for radiators is around the periphery of a room, even with double (or triple) glazing, I imagine that the window is likely to still be colder than any of the other walls, isn't it?

but it also means the thermostat is against a cold wall, which is OK once the thermals have established themselves, but until that point the thermostat is at a lower temperature to the room in general.

True, but that is likely to result in more rapid heating up' of the room, isn't it?

The old system had the input to the radiator at the top and output at the bottom, this assists thermal flow, but places the TRV where it is directly heated by the radiator, to one side at the bottom is likely the best place to sample the whole rooms' temperature.

The TRV does not have to be at the 'input' side of the radiator. One can have the input to the top of the radiator and the TRV at the bottom.

 

[ericmark]

The whole input, output, top, bottom is an unanswered question, I found harder to trim the lock shield valve when the TRV is on the output, tended to over shoot more. But have found what really happens, is not the same as what we think will happen.

Same with radiator under window or on internal wall. It may affect when the heating cuts in, but once running, should not in theory at least make any difference.

My heating in living room is turned down at 23:00 there was yesterday a slight over shoot, but the graphs don't quite match however, the point is, still at 17°C when it turned back on again at 9 am, so unlikely to have any problem due to hysteresis, but with my first house, having the heating off for 3 hours caused a massive temperature drop.

 

[JohnW2]

The whole input, output, top, bottom is an unanswered question, I found harder to trim the lock shield valve when the TRV is on the output, tended to over shoot more. But have found what really happens, is not the same as what we think will happen.

Maybe, but I made the point because a lot of people seem to think (wrongly) that TRV has to be on input, or wven that both input and output have to be at the bottom (since that seems to have become the norm, domestically).

 

[ebee]

Maybe, but I made the point because a lot of people seem to think (wrongly) that TRV has to be on input, or wven that both input and output have to be at the bottom (since that seems to have become the norm, domestically).

Yes I discovered something unexpected initially - as a humble Electrician working with plumbing/heating bods one job where once again I was asked to wire in the controls , this particular one was for our local Clown Hall, a rather big building so had some features that were not as simple as you find in a simple domestic system.
The central part of the system was in the cellar with one room pretty much taken over by it.
Sensors on the pipework to direct the hot water for heating to run thru certain pipes but not others , about 5 distinct zones, it initially surprised me that the sensors were all placed on the returning leg from each zone rather than the outgoing leg as I had had initially guessed, I did have to have a little think as to why before it all clicked in my mind.

 

[JohnW2]

Yes I discovered something unexpected initially .... Sensors on the pipework to direct the hot water for heating to run thru certain pipes but not others , about 5 distinct zones, it initially surprised me that the sensors were all placed on the returning leg from each zone rather than the outgoing leg as I had had initially guessed, I did have to have a little think as to why before it all clicked in my mind.

Sensors on pipes are obviously a different kettle of fish from TRVs. The latter are just sensing the surrounding ambient temp, so it doesn't matter whether they are installed on the input or output side of a radiator. Those sensing pipe temp will obviously only achieve something if sensing the temp on the return pipes - indeed, were they on the 'outgoing' pipes, they would presumably prevent the system ever working, since they would always be seeing a very high temp?

However, as I said, there are seemingly two widely-believed myths about radiators. I mentioned two - (a) that TRV must be on the flow ('input' to radiator) and (b) that both flow and return have to be connected at the bottom of the radiator. Together, they mean that it is perfectly OK, if one so wishes, to have flow connected to the top of radiator and return to the bottom, with the TRV at the bottom if one so wishes. The third one is a belief that TRVs have to be installed with their sensor heads 'vertical'. The design of TRVs used to tend to 'force' one to do that, but now that virtually all TRVs have 15mm compression joints for both 'in' and 'out', it's just as easy to have the sensor head horizontal - and, if there is space for that, it's probably preferable, since it moves the sensor a bit further from the hot radiator.

 

[ericmark]

@JohnW2 you make some good points, but we also need to realise not all TRVs are equal, some have the lock shield built into the TRV, some sense water and air, to compensate for how hot the radiator is. What seemed odd, was there were no user settings for this feature.

The TRV is designed for modulating boilers, so they will allow a constant supply of water but increase or reduce this supply to suit the room, so the return water is as cool as possible, so the boiler can extract the latent heat from the flue gases, with the whole system working in an analogue manner.

But they can still work with on/off boiler control, however, not quite as well as they work with a modulating boiler.

My mothers' house with a modulating boiler, the radiators were always warm, there was an on/off wall thermostat, but set correctly, it would only turn off on warm days, the TRV was set so on cold days it did not let the hall get hot enough to turn off the boiler. Better quality boilers, today, allow the thermostat to turn boiler up/down not on/off.

Also, the thermostats themselves come in many different flavours, with my Drayton Wiser there is no need for any wall thermostat, I actually do have one, but the TRV heads can directly connect to the hub and control if boiler is on or off.

The problem is manufacturers instructions often give basic information, which is not always correct. From the Energenie instructions

This is an electronic valve which can link to some wall thermostats, it did at one time link to Nest, until Google took over Nest. If one tries to write instructions, one has so many exceptions they become confusing. The Kasa TRV I have, can be linked to a wall mounted sensor, either with or without local HMI, (Human Machine Interface) so would not matter where on the radiator the TRV is mounted, as it is monitoring the room temperature elsewhere.

I am told if I assign a Wiser TRV and Wall thermostat to the same room, they will work the same way, but trying to read the instructions to find out exactly how they work is not easy, with features which can be turned on and off, not just Wiser, but most of the electronic TRV heads, even the cheapest like the Eqiva eQ-3 which I got for £15 each, will detect windows being opened and can be programmed to delay heating when detected, so my kitchen radiator auto turns off for 20 minutes when I open back door to unload the car of shopping.

With all these features, geo-fencing, working out how long a room takes to heat, and turning on, so the room is warm by a set time, not just switching on at a set time, means it is very hard to talk about TRV control in general terms.