Unvented or vented ?

[SteamyTea]

1 hour ago, scottishjohn said:

graphene heatings panels

What are these?

https://spectrum.ieee.org/nanoclast/green-tech/conservation/graphene-heating-system-dramatically-reduces-home-energy-costs

See the disclosure statement.

 

[scottishjohn]

2 minutes ago, SteamyTea said:

What are these?

https://spectrum.ieee.org/nanoclast/green-tech/conservation/graphene-heating-system-dramatically-reduces-home-energy-costs

See the disclosure statement.

 

various types coming on the market ,but basically a film type of heating panel that can be underfloor or in the wall of ceiling ,and are promising more heat for same input --less loss in transmission and can run direct from  dc -or with transformer from mains .

so maybe good for off grid applications with pv+batteries only+passiv type house ?

http://nexgenheating.com/home/

 

 

[SteamyTea]

5 minutes ago, scottishjohn said:

but basically a film type of heating panel that can be underfloor or in the wall of ceiling

It is selling the infra red dream again.

Work well until you put some clothes on.

I really thought this nonsense had been banished, but seems that people think there is a real advantage to it still.

[Jeremy Harris]

9 minutes ago, scottishjohn said:

various types coming on the market ,but basically a film type of heating panel that can be underfloor or in the wall of ceiling ,and are promising more heat for same input --less loss in transmission and can run direct from  dc -or with transformer from mains .

so maybe good for off grid applications with pv+batteries only+passiv type house ?

http://nexgenheating.com/home/

 

 

 

 

All electric heaters, bar none, are 100% efficient.  The heat output from any electric resistance heater is exactly the same as the electrical power input, so 1 kW in = 1 kW out.  Nexgen are just hype merchants who skate around the advertising rules using carefully chosen words to suggest that their heaters "might" be more efficient than others, as a way of fooling those who just have no grasp of the basic laws of physics.

 

The hard truth is that a 1 kW electric radiant heater from the 1950's will be exactly the same, in terms of efficiency, as a 1 kW super-duper graphite (or whatever other resistance material someone wants to promote as sales hype) electric radiant heater.

 

A friend of mine who lives in Penryn had a house, built in the 1970's, that had built in electric radiant ceiling heating.  That was 100% efficient, but cost an arm and a leg to run, as the house wasn't insulated and was pretty draughty.  Back then I think these electric heating solutions were initially dreamt up from the time a decade earlier when we all were led to believe that future electricity would be so cheap that it wouldn't be worth metering it. 

[scottishjohn]

4 minutes ago, JSHarris said:

he heat output from any electric resistance heater is exactly the same as the electrical power input, so 1 kW in = 1 kW out

I agree --but even a willis heater is the same ,just its transferring it to water ,which is then pumped around .

 

I was postulating on @TerryE using his willis to good effect ,but it seems he also has a ASHP 

cost of UFHsystem --and then to run with electric -what are  the total  costs-verus all electric of some sort  

and on the assumption his figures are correct £10 extra for winter weeks only by using willis --,then cut out cost of complicated UFH system --could  be geting closer than you think in running costs to go full elctric element  in a near passiv house.

big difference is you are not using a "thermal mass " to store it over night , and the shoulder months when you all complain about overheating --that would not be the same problem  and floor would not absorb and store heat from passiv solar input ,so maybe cut down on need for air con ?

and being quick reacting you only heat when you want it -no hysteresis problems  or much less of a problem 

[Jeremy Harris]

Heat storage in the slab is essential, though, it's both more cost-effective and also works to regulate the house temperature very well indeed.  Very gently warming the slab (we're talking about 1°C or 2°C above room temperature at the most) can be achieved with a Willis heater or ASHP running on E7, so reducing the cost.  If the floor wasn't a slab, but had some form of direct electric heating, then the electricity usage would shift to the daytime as well as the night, so cost more to run.  In addition, the control system would need to be pretty intelligent, in order to cope with the more rapid response to external conditions that would result from losing heat capacity in the internal structure.  Doing away with wet UFH would also remove the ability to cool the slab in warm weather, something that's extremely useful we've found.

[ProDave]

There is no hysteresis in our house.  We don't have any overshoot issues with the UFH  It heats up gently and slowly and when the thermostats switch off it does not get hotter.  I think the secret here is the UFH runs at a low temperature and only heats the house gently.  Any "control system" that overshoots has too much "gain", and that could be in the form of a heating surface too hot or too much heating power for the size of the building.

 

As we have said before if you choose to use panel heaters on the wall, they would be more efficient than electric under floor heating, not because the heaters are more efficient, but because UFH will result in a bit more heat loss through the floor.

 

Re the ASHP Vs Willis. Our heating bill for last winter was £234.  If we assume the ASHP was running at a COP of 3, then that would about £700 for resistance heating instead, so the ASHP is saving us about £400 of electricity or more each year. Considering it cost a lot less than £1000 I think it is very well worth it.

 

[scottishjohn]

day time --thats when PV is at its best and thats where the battery storage comes in for the PV-sell nothing back to grid  probably

house cooling at night --not really a problem if well insulated

I have been living with a UFH system that has no slab  for years and idon,t see it as big problem as you infer -especially with mega insulated house

 

[scottishjohn]

2 minutes ago, ProDave said:

Re the ASHP Vs Willis. Our heating bill for last winter was £234.  If we assume the ASHP was running at a COP of 3, then that would about £700 for resistance heating instead, so the ASHP is saving us about £400 of electricity or more each year. Considering it cost a lot less than £1000 I think it is very well worth it.

 

I take everything people say as being correct -so there is a definite mis match between what you are saying and @TerryE

the question is why the mismatch ?

 do not take offence if it questioned--there may there is a reason ,no one is being accused of varnishing the truth 

I am not a ludite in these things and continue to question  and try to find improvements over what has been done in past and look to future 

If we believe what governments are saying then electric power of some sort is the way we are heading --quite quickly 

[Jeremy Harris]

12 minutes ago, scottishjohn said:

day time --thats when PV is at its best and thats where the battery storage comes in for the PV-sell nothing back to grid  probably

house cooling at night --not really a problem if well insulated

I have been living with a UFH system that has no slab  for years and idon,t see it as big problem as you infer -especially with mega insulated house

 

 

The snag is that PV doesn't generate much when the outside temperature is low and heating is needed.  In general, solar gain will heat the house up during bright winter days, so the time when heating would be needed would be cold and overcast days or cold nights, both times when PV wouldn't be delivering any useful power.

[ProDave]

10 minutes ago, scottishjohn said:

I take everything people say as being correct -so there is a definite mis match between what you are saying and @TerryE

the question is why the mismatch ?

 do not take offence if it questioned--there may there is a reason ,no one is being accused of varnishing the truth 

I am not a ludite in these things and continue to question  and try to find improvements over what has been done in past and look to future 

If we believe what governments are saying then electric power of some sort is the way we are heading --quite quickly 

Terry's house is better insulated than mine, and he lives in a less harsh climate, so his heating requirement is lower.

[Ed Davies]

48 minutes ago, scottishjohn said:

I was postulating on @TerryE using his willis to good effect ,but it seems he also has a ASHP 

 

No, he doesn't have an ASHP. Some of this discussion is about his calculations of what the costs and benefits of adding one would be.

[Ed Davies]

1 hour ago, SteamyTea said:

It is selling the infra red dream again.

Work well until you put some clothes on.

I really thought this nonsense had been banished, but seems that people think there is a real advantage to it still.

 

Sorry Steamy, but your previous arguments, elsewhere, against thermal IR radiation being significant have totally failed to convince me of much (other than that you don't understand the inverse square law when it's applied to spread-out sources). There are benefits to heaters which produce a larger proportion of their output via thermal IR vs ones which mostly just heat the air. E.g., UFH (about 50% thermal IR) vs traditional radiators (a lot less than 50% via radiation). OTOH, in a reasonably airtight house with MHRV this advantage is tiny.

[scottishjohn]

just for a laugh iasked for ringback from nexgen 

 

tied him in knots inabout 5 mins +said thank you and goodbye 

simple questions like how much to supply complete system for a house of 130sqm +2000kw heat load 

 

 cost of equipment-- waffled on about choice of themostat and control system 

I said you quote for what you would fit -- then he waffled some more and i said  BYe bye 

the only price i got from him was 600w for a room   would require 2 sqm of foil @£35 sq m +control system -thats when he started to waffle when i asked for costs of control system 

and idid ask to speak to a technical person 

he also maintains that thier type of IR is 20% better than wire type heating panels and best place to fit it was in the walls as you get better IR to rather than heating under of furniture and carpet +it don,t really like cermaic tiles.

and as i will be using cermaic tiles that was the final thing for me

Edited July 9, 2019 by scottishjohn

[SteamyTea]

2 hours ago, Ed Davies said:

Sorry Steamy, but your previous arguments

My argument was not to do with the emitter area or temperature, it was to do with the albedo, temperature, area, line of sight and distance of the object receiving the IR.

[Clive Osborne]

On 09/07/2019 at 11:21, scottishjohn said:

just for a laugh iasked for ringback from nexgen 

 

tied him in knots inabout 5 mins +said thank you and goodbye 

simple questions like how much to supply complete system for a house of 130sqm +2000kw heat load 

 

 cost of equipment-- waffled on about choice of themostat and control system 

I said you quote for what you would fit -- then he waffled some more and i said  BYe bye 

the only price i got from him was 600w for a room   would require 2 sqm of foil @£35 sq m +control system -thats when he started to waffle when i asked for costs of control system 

and idid ask to speak to a technical person 

he also maintains that thier type of IR is 20% better than wire type heating panels and best place to fit it was in the walls as you get better IR to rather than heating under of furniture and carpet +it don,t really like cermaic tiles.

and as i will be using cermaic tiles that was the final thing for me

I am from Nexgen technical happy to discuss anything on a open forum here. I have no idea who you spoke to but it wasn't me. 

[scottishjohn]

 Ok make your case for using nexgen instead of wet UFH heating  in a NEAR  to passiv house 

130sqm heating load calculates out at 2400kw per year .

I would like not to have spend loads of money on an a ASHP and UFh heating system and possibly run it from solar PV and switch to mains when not enough PV  inthe darkest part of the winter and at night 

[Clive Osborne]

On 09/07/2019 at 09:57, JSHarris said:

 

 

All electric heaters, bar none, are 100% efficient.  The heat output from any electric resistance heater is exactly the same as the electrical power input, so 1 kW in = 1 kW out.  Nexgen are just hype merchants who skate around the advertising rules using carefully chosen words to suggest that their heaters "might" be more efficient than others, as a way of fooling those who just have no grasp of the basic laws of physics.

 

The hard truth is that a 1 kW electric radiant heater from the 1950's will be exactly the same, in terms of efficiency, as a 1 kW super-duper graphite (or whatever other resistance material someone wants to promote as sales hype) electric radiant heater.

 

A friend of mine who lives in Penryn had a house, built in the 1970's, that had built in electric radiant ceiling heating.  That was 100% efficient, but cost an arm and a leg to run, as the house wasn't insulated and was pretty draughty.  Back then I think these electric heating solutions were initially dreamt up from the time a decade earlier when we all were led to believe that future electricity would be so cheap that it wouldn't be worth metering it. 

I'm from Nexgen Heating happy to be taken to task on the hype merchant skirting around advertising laws. You comment regarding an electrical heating system from 1950s being the same running cost as Nexgen . I'm happy to be taken to task as well.

[Jeremy Harris]

4 minutes ago, Clive Osborne said:

I'm from Nexgen Heating happy to be taken to task on the hype merchant skirting around advertising laws. You comment regarding an electrical heating system from 1950s being the same running cost as Nexgen . I'm happy to be taken to task as well.

 

 

Not what I wrote.  Try reading it again, perhaps?

 

Are you suggesting that your heaters are greater than 100% efficient?  If so, perhaps you might care to explain exactly how you achieve this.  Alternatively, perhaps you might wish to try and explain why any other electric resistance heater can be less than 100% efficient, and how that manages to comply with the laws of physics.

 

 

 

[Clive Osborne]

18 minutes ago, scottishjohn said:

 Ok make your case for using nexgen instead of wet UFH heating  in a NEAR  to passiv house 

130sqm heating load calculates out at 2400kw per year .

I would like not to have spend loads of money on an a ASHP and UFh heating system and possibly run it from solar PV and switch to mains when not enough PV  inthe darkest part of the winter and at night 

Let's work on heat loss per square meter and go from there. Then I am happy to go through it with you.

[ProDave]

1 minute ago, Clive Osborne said:

Let's work on heat loss per square meter and go from there. Then I am happy to go through it with you.

Heat loss is discussing for instance the insulation of a building. The question was about efficiency of a particular make of resistance heater Vs a different make.

[Clive Osborne]

On 09/07/2019 at 09:56, SteamyTea said:

It is selling the infra red dream again.

Work well until you put some clothes on.

I really thought this nonsense had been banished, but seems that people think there is a real advantage to it still.

This is nonsense far infrared penetrates clothes. Some energy is absorbed by the material but not all.

[Jeremy Harris]

@Clive Osborne, could you please answer the efficiency question?

 

Are your electric resistance heaters any more efficient than any other form of electric resistance heating, and if so, could you please explain why that is? (in terms that this humble scientist can understand).

[Clive Osborne]

32 minutes ago, JSHarris said:

 

 

Not what I wrote.  Try reading it again, perhaps?

 

Are you suggesting that your heaters are greater than 100% efficient?  If so, perhaps you might care to explain exactly how you achieve this.  Alternatively, perhaps you might wish to try and explain why any other electric resistance heater can be less than 100% efficient, and how that manages to comply with the laws of physics.

 

 

 

Nobody has said that it's over 100% efficient. Other forms can be due to heating air via convection. Nexgen also harnesses the full benefits of FIR . Both in temperature in wavelength. As I have said in other posts we will reduce independent tests soon I will post them 

[Jeremy Harris]

7 minutes ago, Clive Osborne said:

Nobody has said that it's over 100% efficient. Other forms can be due to heating air via convection. Nexgen also harnesses the full benefits of FIR . Both in temperature in wavelength. As I have said in other posts we will reduce independent tests soon I will post them 

 

Sorry, but what exactly did you mean, then, when you quoted my post about efficiency, and added this comment? :

 

52 minutes ago, Clive Osborne said:

I'm from Nexgen Heating happy to be taken to task on the hype merchant skirting around advertising laws. You comment regarding an electrical heating system from 1950s being the same running cost as Nexgen . I'm happy to be taken to task as well.

 

I made no mention of running cost at all, you raised that when writing that comment above, and that begs the question about efficiency, as running cost is directly proportional to efficiency (unless someone has re-written the laws of physics recently).