Storage Heaters to use or not to use??

Richie-from-the-Boro

john1 wrote: »

Richie-from-the-Boro


grahamc2003 - #15 - 18" thick : I've never seen an 18" thick domestic storage heater in my long life, has anyone else reading this seen one ?



For information although I cannot be sure as storage heaters being 18" thick ,but some of the early ones came very close.


I recall extremely deep and wide storage heaters in our village school hall the mid 1970's.

My recollection was that when students arrived in the morning the hall was warm but by early evening the heat output was exhausted. For evening meetings we relied on infra-red suspended ceiling heaters to supplement the heaters (as well as body heat :rotfl: )

Apparently in the US they call them Electric Thermal Storage heaters (ETS) see http://www.steffes.com/off-peak-heating/room-unit-clearances.html and you will get an idea what the old style UK heaters looked like

HiYa john1, oh yes I remember them well in schools / village & church halls / libraries even retail shops etc, they would be what I'd describe as institutions, my point was I've never seen them that big in a domestic setting. The thing is a unit that size would totally overwhelm any standard dwelling / rooms cubic area both then and nowadays.

The perennial issue of 'its cold by teatime' is an ongoing one and one that's very easily solved and should have been designed out 30 or more years ago:

- find a better insulator
- build a better cabinet
- make the ubiquitous damper a dual not single flap

Heat is lost to the room in only two ways, it radiates out and it leaks out of the top or bottom in the form of hot air.

A really simple solution would be to have a bottom damper linked to the top damper. Hot air is only created when it flows in from the bottom, over and through the bricks and out through the top, that's convection. If however a linkage from the top damper to a bottom acting damper was created then the air flow would be reduced or stopped and only the radiative element of leakage would remain. The bottom line truth on 'no heat left' is you did not store enough in the first place.

grahamc2003

Richie-from-the-Boro wrote: »

Have you and I got our usually working well wires crossed M8 ? The heavier higher density bricks capacity to absorb more heat generated from converted electricity I [on the Carlsberg priciple] accept.

My question was how does this new claimed [alchemy] insulation stop heat leaking into the room from the enclosure when the heater is not [damper closed etc] in use, preserving more heat to be released only when needed ? It as a product that is never mentioned, no papers, no claims, no trumpet encore, just a suspect silence, no proof !

I'm sorry Richie, but I have great difficulty understanding most of what you say about storage heaters. (And especially when you say you have never in your long life seen an 18inch thick one, then the next day say you remember them well).

Modern slimline SH preserve heat better than the old thick ones - if you don't accept that as a fact then don't read on. The fact in the previous sentence means the material is a better heat insulator.

I have no idea what you are talking about with a top and bottom damper. I have seen several makes of modern storage heater, and they all only have a top damper. You have said before that the damper should always remain closed constantly for best operation - again, that is simply nonsense when the damper in slimlines is one of the two major enhancements in the technology (the other is the much better insulation and capacity performance of the 'bricks'). The damper allows the release of heat from the centre of the heater later in the day. Most complaints about running out of heat are due to thick old style storage heaters without those two benefits - correctly sized modern slimline storage heaters correctly operated maintain acceptable temperatures in well insulated houses until the ambient temperature goes a few degrees below zero, when supplementary heating is required.

While you are welcome to your views surrounding storage heaters, I find them quite wacky I wonder on what basis you formed them. I don't think I can help further, so I'll leave the last word to you.

Richie-from-the-Boro

grahamc2003 wrote: »

I'm sorry Richie, but I have great difficulty understanding most of what you say about storage heaters. (And especially when you say you have never in your long life seen an 18inch thick one, then the next day say you remember them well).

Modern slimline SH preserve heat better than the old thick ones - if you don't accept that as a fact then don't read on. The fact in the previous sentence means the material is a better heat insulator.

I have no idea what you are talking about with a top and bottom damper. I have seen several makes of modern storage heater, and they all only have a top damper. You have said before that the damper should always remain closed constantly for best operation - again, that is simply nonsense when the damper in slimlines is one of the two major enhancements in the technology (the other is the much better insulation and capacity performance of the 'bricks'). The damper allows the release of heat from the centre of the heater later in the day. Most complaints about running out of heat are due to thick old style storage heaters without those two benefits - correctly sized modern slimline storage heaters correctly operated maintain acceptable temperatures in well insulated houses until the ambient temperature goes a few degrees below zero, when supplementary heating is required.

While you are welcome to your views surrounding storage heaters, I find them quite wacky I wonder on what basis you formed them. I don't think I can help further, so I'll leave the last word to you.

Again I did not say what you claim I said, we were and are talking about a domestic setting not a commercial setting.

Never heard of a 'slime line' can you explain please which heater / insulation uses slime ?

Again please tell me which .........'material is a better heat insulator'

Richie-from-the-Boro

grahamc2003, don't turn this into a fight M8. Modern slimline storage heater preserve heat better than the old thick ones is your claim, I find no evidence from you or any of the manufacturers to support that assertion.

- which damper material is the better insulator, and what is it ?, that's what I want to know
- the bricks or their capacity is nothing to do with the question of leakage
- agreed I've never seen one with a bottom damper, but its a good idea, that would stop / slow convection
- the capacity [quantity of electricity turned into heat energy] performance of the bricks is nothing to do with leakage

How is the damper in the slimline improved ?, this the insulation, is the only way the thing can stay hot longer. Better insulation properties applied on all sides of the box, particularly putting a damper on the base, would dramatically improve leakage and the 'its empty by teatime' complaint would disappear.

Again grahamc2003, assuming the radiator or radiators are correctly sized [% (y) = 1 –0.06√SD] I'm trying to discover how a storage heater can reduce leakage [working on radiant] such that when the damper is opened [working on both radiant & convection] there is sufficient energy left in the bricks to convect into the room.

Naf

It's been pointed out to you already, so please direct us to which words you find difficult and maybe we can help make them mono-syllabic.

Old SHs, like I have, are extremely poor at retaining heat. Having warmed overnight they are cool to the touch by early evening, even in warm-ish weather and even with the damper closed. Lots of heat is lost both through the body of the heater and past the damper.
Newer heaters show a number of marked improvements:
They utilise a more effective insulating material that despite being thinner, still contains the heat inside the SH better.
They contain improved bricks which are capable of storing the same amount of heat in a smaller volume.
- Both of these allow storage heaters to be made much thinner and still perform at least as well as their older counterparts. It is unnecessary to know exactly what these materials are, it is a matter of fact that the newer materials are performing better than the old. Although I am sure a google search could provide the answers.
In addition to the above, newer heaters also employ an additional damper, so that even if the main body's heat is used up during the daytime, the second damper only opens from about 5 to give an extra burst.
They also function better when charging overnight - where old SHs will charge all night at the chosen setting, newer models take account of how hot they already are, and only top themselves up; thereby conserving energy.

Richie-from-the-Boro

Naf wrote: »

It's been pointed out to you already, so please direct us to which words you find difficult and maybe we can help make them mono-syllabic.

Old SHs, like I have, are extremely poor at retaining heat. Having warmed overnight they are cool to the touch by early evening, even in warm-ish weather and even with the damper closed. Lots of heat is lost both through the body of the heater and past the damper.

- agreed, I and others have said that 1000's of times

Newer heaters show a number of marked improvements:
They utilise a more effective insulating material that despite being thinner, still contains the heat inside the SH better.

- yes that's what Graham keeps saying - what I want to know is what is this 'more effective insulating material'

They contain improved bricks which are capable of storing the same amount of heat in a smaller volume.

- agreed, I and others have said that 1000's of times

- Both of these allow storage heaters to be made much thinner and still perform at least as well as their older counterparts. It is unnecessary to know exactly what these materials are, it is a matter of fact that the newer materials are performing better than the old.

- yes that's what Graham keeps saying - what I want to know is what is this 'more effective insulating material'

Although I am sure a google search could provide the answers.

- not true, I can't find any .. .. teach me

In addition to the above, newer heaters also employ an additional damper, so that even if the main body's heat is used up during the daytime, the second damper only opens from about 5 to give an extra burst.

Now then Naf this is interesting new information I've opened many of these and have as clear understanding of what's in them, where is this second damper that only opens from 5pm ?. If you have a reference I'd appreciate a link my friend.

Can I assume there exists a second damper say 8 bricks down horizontal on a 16 bricker, allowing the top 8 bricks to exhaust heat before 5pm and preserving the bottom 8 bricks for after 5pm ? An alternate design would be a single top damper 'split' into two halves with only one ever opening before 5pm and both after 5pm.

They also function better when charging overnight - where old SHs will charge all night at the chosen setting, newer models take account of how hot they already are, and only top themselves up; thereby conserving energy.

- they've been able to do this for 30 decades, I had a weather watcher system [outside thermocouple linked to the case stat] in 1981

- Naf the only thing you bring to the debate is the existence of a second damper, but it is a critically important bit of new information. Thanks for that, its helpful.

Naf

Richie-from-the-Boro wrote: »

- yes that's what Graham keeps saying - what I want to know is what is this 'more effective insulating material'
...
- yes that's what Graham keeps saying - what I want to know is what is this 'more effective insulating material'
...
- not true, I can't find any .. .. teach me

I can't find the what either; perhaps different companies use different materials, but don't like to disclose it as some kind of trade secret?

Richie-from-the-Boro wrote: »

Now then Naf this is interesting new information I've opened many of these and have as clear understanding of what's in them, where is this second damper that only opens from 5pm ?. If you have a reference I'd appreciate a link my friend.

Can I assume there exists a second damper say 8 bricks down horizontal on a 16 bricker, allowing the top 8 bricks to exhaust heat before 5pm and preserving the bottom 8 bricks for after 5pm ? An alternate design would be a single top damper 'split' into two halves with only one ever opening before 5pm and both after 5pm.
...
- Naf the only thing you bring to the debate is the existence of a second damper, but it is a critically important bit of new information. Thanks for that, its helpful.

I can't find where I originally found this either unfortunately. It was when I was researching storage heaters before moving into this place, having always had gas CH before...

john1

Older storage heaters used mainly mineralwool (plus asbestos) for the insulation whilst modern heaters ( e.g. Dimplex, et al) use a combination of mineral wool and microporous silica.

Microporous silica has a working temperature of up to +1000°C with low thermal conductivity.


The modern heater bricks have also move on a lot from the original type. Being made from high density bonded magnetite which has better heat retention properties than the original clay based bricks.

Having only experience of UK domestic installations re a second damper; I have never come across a second damper. All the heaters I have worked on simply have a mechanical louvre at the top of the heater controlling the hot air output from the heater core.
Some storage heaters have an internal fan which is normally thermostatically controlled but could be also be controlled by a external time switch. The Dimplex CLXS range has this facility I understand.

Richie-from-the-Boro

Thanks for that Naf, I can't find any either, basic science suggests that if you don't create an airflow then you are radiative only and what we used to call 'lagging' now called insulation can 'hold in' more of that heat by suppressing transfer through the walls of the heater panel.

My 25 year old theory that if you damper the bottom as well as the top then you are radiative only, assuming the insulation material is within or exceeding spec its only moving air that transfers the bulk of the heat. This leaves the greater amount of stored heat available to anyone at any point opening a damper and and allowing convection as a vehicle for heat transport.

I seem to be annoying people and don't mean to do so, the question I pose is the one asked by hundreds if not many many thousands"""it's too hot in the morning and why is all the heat gone by teatime""" If we assume :

- individuals know how to use them - and they don't
- and sufficient storage quantity of heat per Sq area is built in - and it isn't
- and the damper is down all day but """all the heat gone by teatime"""
- if the insulation works and sufficient stored heat was there in the first place how has the heat .. .. as it were 'gone' ?

Look I've got no problem, my home is and always has been perfect day & night even in the worst of weather, I've had this stuff for more than 3 decades in more than 3 dwellings, I've never opened a damper in all that time, I just don't believe that brand 'x' is 2.5 times more efficient [whatever that means] than brand 'y'.

If I was to pose my question a different way, Id pose a scenario :

MSE Mary has her shower and hot chocolate drink, closes the damper makes an excellent prediction on the next days weather and goes to bed. The next morning she gets up, grabs a slice of toast with her coffee while watching News24 and goes out to her waiting taxi, picks up her boss MSE Martin Lewis on the way and arrives at the office on time.

At the end of the business day she arrives home, the flats not cold and the damper has never been opened since last night, but after her shower and expecting company she opens the damper to allow a little more heat into the room, within an hour all the heat has gone .. .. why ? sufficient storage quantity of heat per Sq area per 18 hour cycle was put in, the damper was closed why is it cold after only one hour? and how can design improve that shortfall ?.

Richie-from-the-Boro

john1 wrote: »

Older storage heaters used mainly mineralwool (plus asbestos) for the insulation whilst modern heaters ( e.g. Dimplex, et al) use a combination of mineral wool and microporous silica.

Microporous silica has a working temperature of up to +1000°C with low thermal conductivity.


The modern heater bricks have also move on a lot from the original type. Being made from high density bonded magnetite which has better heat retention properties than the original clay based bricks.

Having only experience of UK domestic installations re a second damper; I have never come across a second damper. All the heaters I have worked on simply have a mechanical louvre at the top of the heater controlling the hot air output from the heater core.
Some storage heaters have an internal fan which is normally thermostatically controlled but could be also be controlled by a external time switch. The Dimplex CLXS range has this facility I understand.

Thanks for that john1, yeh Dimplex et al do, they can even run central control over the copper [wire] 13a / 20a core. I too have never seen a dual damper. The 'fan' based are the leakiest of all because they suck down out of the core meaning there can be no insulation at the bottom. My problem is I'm not convinced that the reduced conductivity of silica and additional storage capacity of magnetite combined give a 250% [in heat retention] improvement, because 100% of the retention would have to be earned by the reduction in conductivity not the capacity of the bricks to store it. But I'm open to persuasion, its the radiation [infra-red] bit and to a lesser extent the insulation [conductive] bit that's bugging me, not remotely interested in the capacity of the improved bricks, which I have agreed many times.

More info and a light bulb is lit for me - 7th Nov

Microporous Silica has the lowest thermal conductivity of any rigid board material for service up to 1000°C, however in the application for debate above its not board and its not rigid, and its a 'mixed with' flexible product but I accept the argument and the nana-tech behind the product science.

- microporous insulation is by definition around 90% air
- the air is contained in minute cells, smaller than the mean free path of an air molecule
- in heat transfer, gaseous conduction occurs when gas molecules collide and transfer their kinetic energy
- the mean free path is the average distance they need to travel before they hit another molecule
- if the collisions are prevented, as in a microporous insulation, heat transfer through the gas is dramatically reduced
- the main constituent of a microporous insulation is usually pyrogenic silica
- it has a low intrinsic thermal conductivity of around 1.4 W/m.K, meaning it’s a good insulation anyway
- by size comparison, the diameter of a human hair can be anything from 1000 to more than 7000 times bigger
- the other ingredient in the mix is the opacifier which is a fine mineral oxide powder
- this opacifier gives the insulation the ability to block the movement of infrared radiation almost completely

NOTE01 Opacifier :

Physics, URL="http://en.wikipedia.org/wiki/Stefan–Boltzmann_law"]Stephan-Boltzmann[/URL fourth power law - radiative heat losses from a surface are directly proportional to the fourth power of the temperature difference. At temperatures above 100 °C (around 212 °F) radiation becomes the dominant mode of heat transfer and increases rapidly as things get hotter

NOTE02 : Heat Load calculator here