What to replace gas heaters?

[pudding]

Hello,

We have been living for 6 years in a concrete block house from the 50s in the Paris region, of around 85 m².
We have a big heating problem, in terms of (un) comfort.

The pavilion is oriented North / South, adjoining the west side, bare wall with no opening on the east side.
The pavilion is on 3 levels: ground floor (living room, kitchen), 1st floor (3 bedrooms + small shower room + WC), fitted attic (bedroom + bathroom).

Heating side, there is only 1 gas radiator per level !! But when I speak of a gas radiator, I mean with the gas coming directly to it, we have no water circuit, no boiler.
The ventilation is "natural" (openings in the walls / windows). The windows are double glazed.
The radiators are these: http://www.auer-gianola.fr/pages/produits/radiateur/mv.php (or maybe those http://www.auer-gianola.fr/pages/produits/radiateur/mc.php ) 4,5kW version.
Suffice to say that 1 radiator per level, in winter we curdle.
In the coldest of winter: 16 ° in the living room and 15 ° in our bedroom (the radiator being on the landing).
In our son's room, we put a backup electric heater to keep it 18-19 °).
The top floor (attic) is not really a problem because the heat is rising, it is better there (summer is another problem ...)

We had done in 2009 I believe (I just realized that the document is not dated ..) a thermal study, which leaves us perplexed as to its exploitation.
Unsurprisingly, it classifies us F (404 kWh) and F (80 kg CO²). And not surprisingly, exterior insulation is said to be essential.

We therefore had 2 quotes made for external insulation: 25.000 euros for this type of insulation: http://www.sto.fr/51193_FR-Produits-D%C3%A9tail.htm?prodId=161&meta_title=StoTherm%20Classic%201&lev1=1&lev2=5&lev3=18.
Not only is it a big investment, but living in a polystyrene box has personally frankly slowed me down so far. I had had contact with a company that wanted to do it in cork (at a slightly higher price but not costed on the estimate) but without the ten-year guarantee ...
And then 25.000 euros, it takes how many years to make them profitable ?? !!

The GDF invoices tell us in terms of consumption in annual kWh:
2007-2008: 17121
2008-2009: 16365
2009-2010: 17844
2010-2011: 15868
I do not know what are the reasons for these differences from one year to the next, maybe more or less severe and / or long winters.
The last gas bill therefore amounts to 980 euros (including 150 for a subscription) + 350 euros for the annual revision of the gas radiators.

Baby 2 is coming. Our concern is comfort !!
It seems obvious to us that the heating system must be changed (in particular by improving the distribution of radiators, and safety):
option 1) installation of electric heating: creation of the dedicated electric network + acquisition of radiators
This solution has the advantage of being "easy" to implement. But fear of the cost in terms of repercussion on the EDF bill (knowing that if the additional heating cost came back to 1500 Euros / year, we would find that acceptable since it is equivalent to the current gas bill including the revision of the radiators)
option 2) install a gas central heating with water circuit: creation of the water network + purchase of boiler + purchase of radiator.
This solution seems heavy to us in its implementation !!!

We currently have no quotes for these options. We had 3 craftsmen come in to get quotes to bring our electrical network up to standard (and take advantage of this to plan radiator sockets). None provided us with a quote ... Just finding a craftsman who is willing to work is difficult !!! Long live the Paris region !!!

I would be ready to switch to all-electric and wait to see what it costs us to get started or not in external insulation.
You reactions, your opinions, your suggestions please, we don't know what to do.

[Did67]

1) On the principle: expensive insulation! Certainly. To have. And to negotiate.

but:

a) the starting base (1 euros per year) is undervalued because:

- you are not hot; the bill will increase proportionally (roughly, each degree = + 7% as a first approximation); the bill for the same house, just properly heated, could rise to 1 euros. The study should give a total consumption.

A ladle 404 kWh / m² / year gives 35 kWh per year in average year to have the 000 or 19 ° "normal", taking into account the climate. Or 20 l of fuel, or 3 euros. Luckily for you, natural gas is cheaper. This is called a "thermal sink".

- the gas has not stopped increasing

b) insulation increases the value of the house; heating costs go up in smoke! It's a difference to remember! With rising energy costs, well-rated homes will keep increasing in value where bad ones will lose value as they will gradually become "unheatable" for the common man - let's bet on a tripling of energy costs in 15 / 20 years. It's not sure but not completely crazy either!

So 4 or 5 euros, that makes you think differently!

2) polystyrene: apart from the eco-friendly ayatollahs, a polystyrene blanket for an entire house, it is the equivalent of a few tens (max 1 or 2 hundreds) of liters of fuel. That is to say the consumption of one or two months! We could calculate that with density.

So there is no photo! CO² balance question = 5% benefit!

Afterwards, if we can afford "natural" as the ultimate luxury, it is of course even better.

3) ITE (insulation from the outside): don't forget the comfort gain also in summer; the walls remain cool behind the insulation; insulation is always seen in connection with heating (due to costs); but its impact on comfort in summer cannot be overlooked; Finally, depending on your age, think about the old days, the sensitivity to heat waves ...

4) with a good ITE, the existing heating should suffice (even if the distribution is not ideal ...

In short, in my opinion, worrying about radiators and not insulation is a mistake! Big bullshit! (very respectfully).

[Did67]

option 1) installation of electric heating: creation of the dedicated electric network + acquisition of radiators
This solution has the advantage of being "easy" to implement. But fear of the cost in terms of repercussion on the EDF bill (knowing that if the additional heating cost came back to 1500 Euros / year, we would find that acceptable since it is equivalent to the current gas bill including the revision of the radiators)
option 2) install a gas central heating with water circuit: creation of the water network + purchase of boiler + purchase of radiator.
This solution seems heavy to us in its implementation !!!

.

Yep! I had zapped it.

Electric heating (without gas): again, to be hot, you need 35 kWh; the average price is 000 to 0,11; you end up with an invoice of more than 0,12 euros ...

Or you set to 17 to have, as currently, 15 to 17 kWH "only" or a bill of 000 euros ... (and cold, therefore).

2) Heating circuit: well be aware that the way you "inject" your calories into your "leaky shell" will not change anything in the equation. To be warm, 35 kWh, or the equivalent of 000 liters of fuel, will be needed. This is what the house would lose if it were at 3 °! So that's what you have to "pump" in the house to maintain the 500 °! Everything else is daydreaming!

You will end up with an installation at 25 euros + bills of 000 euros for natural gas with a good boiler.

You will be hot near the radiators and a little cold elsewhere: the temperature Like is the average between the temperature of the walls (cold, because they are not insulated) and the air temperature (let's assume that it is 20 °). It is not the one marked on the thermostat !!!

[pudding]

Thank you for this reasoned response. This is enough to feed my thinking.

[dedeleco]

For the most part, agree with Did67, but less pessimistic.
First reactions, how are your attic spaces insulated?
What thickness of insulation under the roof in what condition ???
If almost nothing, it is to insulate to the maximum well before the external insulation !! the heat rises and leaves by the roof.

The ventilation is "natural" (holes in the walls / windows)

What dimensions?
can also be with catastrophic losses and therefore to control as much as possible by closing them to the maximum possible, just at the limit of excessive humidity.
In your colander house double glazing saves almost nothing, and I hope you haven't spent too much on these double glazing? because this expense is only justified after having isolated everything, attics and walls, and often excessive natural ventilation (absurd standards for gas, buy a CO detector instead !!)

First with your invoices giving 16 ° C in winter, to have 20 ° C you need 4 ° C more or with the 7% per ° C of Did67, you need 4x7 = 28% more expense !!
However, your invoices of 16000 17000KWh per year correspond for your 85m2 to 210KWh / m2an and 28% more amount to 269KWh / m2an real and not to 404KWh / m2an !!
So the situation is less worse than the thermal diagnosis !!
So if your radiators were more powerful you could be hot enough by paying around 28% more !!
Your 3 radiators of 4,5KW or a total of 13,5KWh are not powerful enough for your current thermal losses of 270 to 300KWh / m2an max (not 404 !!), you would need more with 30% more either 18KWh or a more or more powerful radiator.
You can replace them with log or pellet stoves which will heat more and less.
Your gas radiators are on suction cup or chimney ????
On suction cups only certain pellet stoves are possible.
How efficient are your gas heaters ???
If unknown, it is small (exchanger surface too small) and their power must be reduced to improve, lower gas pressure)

Instead of electricity, you can put a wood or pellet stove or insert on an additional fireplace or pellet suction cup, which increases power without paying more, if necessary.
For me, we throw wood everywhere around my home and I can have free wood by recovering it !! For you it may be possible?
Wood requires more care than gas, not too much for pellets.

For what thickness of insulation is your exterior insulation quote?
Better thick, 15 to 20cm !!
For what area how much per m2.
And above all for what guaranteed savings in heating?

In your place, as I have in my houses, I would have closed the "natural" ventilation, open only rarely, I would have insulated the roof and attic well and I would have at least a powerful insert or wood stove downstairs. allowing strong heating (with distribution of hot air through ducts upwards, an inexpensive solution) so as not to be cold and to spend little in money, instead of the gas that you can conserve.
Personally I carry out myself the maintenance of radiators and insert, cleaning, sweeping and verification of safety, better than some pros more inclined to multiply breakdowns and expenses (350 € saved and much less breakdowns) !!!

I would not switch to electric heating, even with heat pump (nonsense which pushes nuclear with inevitable nuclear disaster in France sooner or later, as in Fukushima-Chernobyl, since the French are not more infallible than the Japanese), but to the wood as in one of my houses with a fireplace and insert that replaces the absurd all electric, while I have not managed to exhaust at home and my neighbors all the wood fell to the ground in the storm of late 1999 !!

[Did67]

However, your invoices of 16000 17000KWh per year correspond for your 85m2 to 210KWh / m2an and 28% more amount to 269KWh / m2an real and not to 404KWh / m2an !!!!

Normal: the 404 is calculated; it is a standardized "theoretical" data, for a nominal heating, I do not remember any more memory: 19 or 20 ° + including the DHW it seems to me ...

But you're right, it may indeed be probably less worse than calculated if we take the readings and add the 28%. It remains a lot. Too much to heat with electricity!

[pudding]

For the most part, agree with Did67, but less pessimistic.
First reactions, how are your attic spaces insulated?
What thickness of insulation under the roof in what condition ???
If almost nothing, it is to insulate to the maximum well before the external insulation !! the heat rises and leaves by the roof.

The ventilation is "natural" (holes in the walls / windows)

What dimensions?
can also be with catastrophic losses and therefore to control as much as possible by closing them to the maximum possible, just at the limit of excessive humidity.

I also think that these orifices have significant consequences, but that has not been quantified.
What do you think of installing a humidity-controlled CMV?

In your colander house double glazing saves almost nothing, and I hope you haven't spent too much on these double glazing?

they had been set up by the previous owners.

because this expense is only justified after having isolated everything, attics and walls, and often excessive natural ventilation (absurd standards for gas, buy a CO detector !!)

First with your invoices giving 16 ° C in winter, to have 20 ° C you need 4 ° C more or with the 7% per ° C of Did67, you need 4x7 = 28% more expense !!
However, your invoices of 16000 17000KWh per year correspond for your 85m2 to 210KWh / m2an and 28% more amount to 269KWh / m2an real and not to 404KWh / m2an !!
So the situation is less worse than the thermal diagnosis !!
So if your radiators were more powerful you could be hot enough by paying around 28% more !!
Your 3 radiators of 4,5KW or a total of 13,5KWh are not powerful enough for your current thermal losses of 270 to 300KWh / m2an max (not 404 !!), you would need more with 30% more either 18KWh or a more or more powerful radiator.
You can replace them with log or pellet stoves which will heat more and less.
Your gas radiators are on suction cup or chimney ????
On suction cups only certain pellet stoves are possible.
How efficient are your gas heaters ???
If unknown, it is small (exchanger surface too small) and their power must be reduced to improve, lower gas pressure)
Instead of electricity, you can put a wood or pellet stove or insert on an additional fireplace or pellet suction cup, which increases power without paying more, if necessary.
For me, we throw wood everywhere around my home and I can have free wood by recovering it !! For you it may be possible?
Wood requires more care than gas, not too much for pellets.

For what thickness of insulation is your exterior insulation quote?

I have 1 of the 2 quotes under my eyes: "10 cm of RT + gray polystyrene (RT = 3.19)" for 105m² of facade.

Better thick, 15 to 20cm !!
For what area how much per m2.
And above all for what guaranteed savings in heating?

That, unfortunately I don't know. The thermal balance suggested that we insulate the facade with R> 2.8 and the attic with R> 5, this bringing us to a theoretical consumption of 295 kWh. That is a gain of 110 compared to the current situation. We expected something more "spectacular" ... (especially considering the cost of the site !!)

In your place, as I have in my houses, I would have closed the "natural" ventilation, open only rarely, I would have insulated the roof and attic well and I would have at least a powerful insert or wood stove downstairs. allowing strong heating (with distribution of hot air through ducts upwards, an inexpensive solution) so as not to be cold and to spend little in money, instead of the gas that you can conserve.
Personally I carry out myself the maintenance of radiators and insert, cleaning, sweeping and verification of safety, better than some pros more inclined to multiply breakdowns and expenses (350 € saved and much less breakdowns) !!!

This is the advantage of good DIY enthusiasts!
That said, we have never had a failure yet ... crossing our fingers.

I would not switch to electric heating, even with heat pump (nonsense which pushes nuclear with inevitable nuclear disaster in France sooner or later, as in Fukushima-Chernobyl, since the French are not more infallible than the Japanese), but to the wood as in one of my houses with a fireplace and insert that replaces the absurd all electric, while I have not managed to exhaust at home and my neighbors all the wood fell to the ground in the storm of late 1999 !!

As for wood heating, isn't it restrictive when you have a city life, absent from 8 am to 19 pm. When you go on vacation, how do you maintain a "frost-free" temperature in the house. It imposes storage capacity that we don't have. We are not in the countryside so no woods nearby.

As for the stove / insert that we had envisaged (in a total gas removal project + installation of electric heaters + stove), we gave up because from what I read our house is too small, and it is overheating who watches us.

The problem with the attic is that they are low ceiling (2m05) and inhabited. So if we add more thicknesses, the livability will become "difficult" I do not know what the current insulation is made of, but it is certain that we still have to add / change.

Thank you for your ideas / suggestions / experience.

[pudding]

However, your invoices of 16000 17000KWh per year correspond for your 85m2 to 210KWh / m2an and 28% more amount to 269KWh / m2an real and not to 404KWh / m2an !!!!

Normal: the 404 is calculated; it is a standardized "theoretical" data, for a nominal heating, I do not remember any more memory: 19 or 20 ° + including the DHW it seems to me ...

But you're right, it may indeed be probably less worse than calculated if we take the readings and add the 28%. It remains a lot. Too much to heat with electricity!

On the thermal balance it says:
"Why are there differences between a conventional method and invoices? 1-Different interior temperature and occupancy scenario: the conventional calculation is made for a constant interior temperature of 18-19 ° C in all rooms with a night reduction for 8 hours and one week of vacancy in the winter period. .."

[dedeleco]

The thermal balance suggested that we insulate the facade with R> 2.8 and the attic with R> 5, this bringing us to a theoretical consumption of 295 kWh. That is a gain of 110 compared to the current situation. We expected something more "spectacular" ... (especially considering the cost of the site !!)

This heat balance derails, because in my opinion you are there at 295kWh / m2an, if you close the vents completely, which are delusional with gas or wood standards (large holes of 300cm2 per radiator to avoid asphyxiation while a CO detector makes it possible to avoid this low risk with really bad luck and a lot of errors) !!!!!
The humidity-controlled CMV if it works well is a solution, but the manual shutter also works (which works for me).

You have what surface of concrete block walls towards outside and roof space (very little insulated if they overheat in summer at the moment)
By climbing on the roof and lifting tiles you can know the level of insulation.
With the facade with R> 2.8 and the attic with R> 5, (8cm and 16cm of insulation) in my opinion you must be very below 295KWh / m2an because you are currently below it !!!!!

If your 3-storey house of 85m2 total to 85/3 = 28m2 per level or 5x6m of rectangle? gives on the 3 exterior sides 5 + 6 + 6 = 17 linear m on 3x3 = 9m high, a wall surface of 17x9 = 153m2 of exterior wall (to be specified) which with an R = 2,8 gives 1/2,8, 0,36 = 2Watts / m20 ° C and therefore if T int -Text = 20 ° C gives a loss of 0,36x153x1102 = 1,1Watts = 1KW of losses or about 10/4,5 of your current heating power of 3x13,5 = 10KW and therefore if the rest is well insulated, roof spaces, ventilation, etc ..., your consumption must be divided by XNUMX !!!!!
Your concrete blocks have a thermal conductivity around 1watt / m ° K or 30 times approximately that of still air insulators, and therefore 20cm of concrete block does not reach 1cm of air insulator (PSE) (R = 0,3 approximately) and therefore put 10 cm, and more of this insulation is equivalent to dividing by 10 the thermal losses and the consumption in KWh, roughly to a factor of 2 near given the possibilities of errors in the installation !!
If this result is not guaranteed (at least 5 times less losses in the quote, ie 300KWh / m2y going to 60KWh / m2an, there is a problem that is hidden from you, big difficulty in your house, with irreducible losses (large windows, thermal bridges, etc.), or major errors in the installation !!!

Otherwise you can keep the gas and reduce the bill by heating yourself with wood, logs or pellets much cheaper, when you are at home (nights and weekends).

As for the stove / insert that we had envisaged (in a total gas removal project + installation of electric heaters + stove), we gave up because from what I read our house is too small, and it is overheating who watches us.

is extremely false, your house will not be overheated (with its current losses which prevent it from heating sufficiently) with a stove or insert between 4 and 12KW, and distribution of hot air via ducts to the upper floors, retaining gas radiators for your absences, but with a greatly reduced heating bill for not too much investment.
In one of my much better insulated houses I use a wood insert without overheating for 65m2 !!
Nice, quickly hot air in 30min when you arrive, and it's nice, while the walls are much slower to heat !!

[Philippe Schutt]

some ideas
1. if the gas radiators are real suction cups, there is no need for high / low ventilation and the gain is already serious. Save 10%
2. you have to review the insulation quote, which seems overestimated by around € 10000 compared to the rates in eastern France.
3. replace the lowest radiator, in principle the coldest point, with a pellet stove of about 10-12kw. Save 30% in €, 0% in kwh (check prices)
4. roof space: consider an over-roof if the 15cm extension is possible. Save 15%
my estimate is for equal comfort, and watch out for 7% for each degree because for the 1st degree 7% is 0.07 but for the 2nd 0.075 and 0.08 for the 3rd, since the base increases each time.
Finally, concerning the external insulation, I had it done at home, but given the simplicity of the work I would do it myself if it had to be done again. especially with such a quote.