Straw house: which heater to replace the gas?

[Woodcutter]

Yes but you agree that the insulation could be great if the plaster is not there (which is the case) it would be a null result !!!

Not necessarily. If one of the layers of the wall already provides an airtight seal, then the wind on one side cannot move the air trapped in the entire thickness of the straw, it can just quickly renew the layers of air close to the outside, which reduces the "real" thickness of insulation.

Walls = 38 cm approximately and for the already coated face 42/43 cm
Roof = insulation of wood wool panels 20 cm
Slab was carried out in a conventional way (ie not especially ecologically) and the floor of the floor is lined with hemp panels.
The interior partitions are insulated in cork.

The windows are double glazed 4/16/4 low emissivity and of course wooden.

With 38 cm of straw, you must have boots placed on edge, I suppose?
If so, that gives you a fairly interesting thermal resistance, around 8 m².K / W.

For the low level, I don't know with the info you give me and for the roof, it is apparently the "weak point" since it will have a resistance of barely 5 m².K / W. Is it airtight?

Are your windows with an Ar blade?

I actually think that if the production is of good quality, you can switch to BBC, ie less than 50 kWh / m² / year.

[fowleil]

The boots are effectively placed on edge and we have coated them inside with a layer of earth but afterwards we have doubled everything in plasterboard.

The plastered face on the outside is the one that is most exposed to the wind so it is indeed a good point but on the other hand the garage attached to the house by the north is not finished either plastered level and the insulation roof was clearly tucked in due to lack of time so for once when you enter the garage and there is wind outside you can feel it ... And that's probably where the whole of the house is cooled when there is wind. Unfortunately for us, we are in a fairly windy region so we have very often.

Today for example there is no wind at all and I cut the boiler because I am already too hot it is 21 ° C in the living rooms and it is only in the morning. If there was wind I may have the same temperature but I will be colder.

The roof is actually less well insulated compared to the walls, but hey, we had taken good care of the installation of the panels and everything was covered with a wooden frieze, which adds a little bit of insulation.

My glazing is fine with a rear blade.

I can't wait to be next winter because even when all the weak points have been improved we should save a lot of money for better comfort.

[fowleil]

Good then for the news, we brought the guy to check if the boiler had no particular concerns etc but nothing all is well on that side and even all tell us that our current boiler is efficient.

We only had confirmation that we were paying double compared to city gas, so suddenly, as Primagaz recently increased its prices, we really decided to change the heating system.

- wood-fired boiler replacing our current boiler = impossible in relation to the location of the fireplace (not existing) it would be too "dangerous" because the house is too deep according to the heating engineer and secondly it is still not too suitable for a heating floor.

They therefore offer us:
- Air / water heat pump in addition to our current boiler and in theory once the house is finished it should be enough without the gas.
Quote: 6000 € would remain at our expense 3600 €

- a wood stove in the living room which would be centered in the house and would heat the whole.
But with this solution can we hope to get rid of primagaz? Will the stove suffice one day as the only means of heating?
4000 € would remain 2400 €

What do you think ? What solution would allow us to make real savings?

Goods.

[Christophe]

deuxio it is still not too much for a heated floor.

Is that so? This is the news of the day!

We have been heating for 2 years with a wooden boiler (logs) and heated floors: on the contrary, the high inertia of PCs is recommended with a wood boiler. PCs thus buffer wood energy!

It always disturbs me to hear such comments from professionals ... Is your heating engineer a fool?

Let him come here for a ride ... it will educate him!

[Philippe Schutt]

We only had confirmation that we were paying double compared to city gas, so suddenly, as Primagaz recently increased its prices, we really decided to change the heating system.

Good idea, wood costs roughly half: 0.04 € / kwh

- wood-fired boiler replacing our current boiler = impossible in relation to the location of the fireplace (not existing) it would be too "dangerous" because the house is too deep according to the heating engineer.

Misery, have you built in a well?

and secondly it is still not too suitable for a heated floor.

Straw is not suitable for construction.

They therefore offer us:
- Air / water heat pump in addition to our current boiler and in theory once the house is finished it should be enough without the gas.
Quote: 6000 € would remain at our expense 3600 €

it's economical in mid-season, say up to + 2 ° outside, after that it spoils. So you have to see the weather at home.

- a wood stove in the living room which would be centered in the house and would heat the whole.
But with this solution can we hope to get rid of primagaz? Will the stove suffice one day as the only means of heating?
4000 € would remain 2400 €

So you would no longer use the slab? What about automation, domestic hot water, autonomy when you leave for a few days?

What do you think ? What solution would allow us to make real savings?
Goods.

ben primo take care of the insulation. While waiting to plaster, maybe you can staple plastic in front of the straw? Then, you have to see what you get from the gas boiler.
After that, depending on the climate,
the heat pump if the T ° are suitable, electric or / and solar DHW
or it may be possible to put a pellet boiler, because there are assemblies without chimney. DHW on boiler + other (electric or solar)
or a wood-burning stove-boiler if it is possible to mount a fireplace in the living room or pellet with or without a fireplace. DHW on stove + other
or a simple pellet stove, and lastly the wood stove because no autonomy. DHW electric or / and solar
it makes huge price differences ...
Should have some info on the configuration of the surroundings, house plans showing the position of the nourice of the PC and unfortunately budget.

[fowleil]

So let's say that he strongly advised against the wood boiler because:
- underfloor heating which requires a low temperature while a boiler produces very hot water ...
He told us that it was possible but we had to provide a buffer tank
- the chimney is really a problem. It would be too dangerous to put it on the roof of the garage and if we put it on the roof of the house it will be boring to do

It would not necessarily fit into our budget ...


For the question of the budget of our pocket if we have to go out 3500 € maximum it would be good, it will be really hard to go out more. (therefore excluding tax credit)

I feel a little lost in front of all these heating modes and we would like to make the right choice (this time) especially in relation to the cost of heating.

Here are the house plans:




Our current boiler would be worth only € 500 (new value € 4000 sic) according to the heating engineer because nobody buys this type of boiler because there are tax credits on new. That is his reasoning and for the moment our only reference ...

For the care of the insulation it goes without saying that it will be our priority for the next few months. We will catch up on the crepis next week and it will be finished at the end of summer at the start of autumn.

Our limited budget is undoubtedly a brake but hey we want to do something at all costs this year because there I can not get fat anymore Primagaz

Vis-à-vis the CAP it was rather bad a priori because the opinions seem still mixed about it and in addition it seems to consume candy in electricity right?

After the temperature level we are located in the region Rhone Alpes nord Drome. I did not really find on the weather net ...

Thank you for your enlightened help.

[Christophe]

So let's say that he strongly advised against the wood boiler because:
- underfloor heating which requires a low temperature while a boiler produces very hot water ...
He told us that it was possible but we had to provide a buffer tank

a) Yes the buffer is more or less compulsory in the case of a wood boiler but it can very well be constituted by the BALLOON of Hot Sanitary water.

b) All the PCs are supplied by a 3 or 4-way mixing valve: this lowers the T ° of the floors and increases that of the (or) boilers!

c) There is what is called homogenization flasks: it allows to have on the same circuit of low T ° (radiator, PCs ...) AND of high T ° (primary boiler circuit, DHW. ..)

If you count the laying of the floor for 3500 € I think you will never get there ...

Attention with tax credits: it is ONLY on the Duty Free of the material and not on the complete estimate therefore without the labor of installation nor the VAT!

See here: https://www.econologie.com/forums/credit-d-i ... t7272.html

[fowleil]

But the underfloor heating we already have!
It is a facility that dates back a year, we have a propane gas boiler with a heated floor on the ground floor and radiators upstairs.

It only counts the boiler to be changed and possibly the resulting mods (chimney etc)

So basically we would have a budget of 6000 € but with tax credit, it would ultimately cost us that 3500 € max (qqun will lend us the money to advance for the tax credit).

[Christophe]

Ah forgiveness zavé forgot!

In this case it is "playable":

If in the end you only want to pay € 3500, the site will cost you:

a) Let's say 1000 € TTC for the installation

b) There remains a buget (40% tax credit) to leave 2500 / 0.6 = 4200 HT of material, i.e. 4400 TTC (5.5 VAT).

But my opinion is that it is better not to reason with tax credit but with what we want and what we really need!

I have the impression that the tax credit is a very important thing for you, but it is likely to be the cause of overcharging, in the end you earn nothing.

So my advice: keep your old boiler and take care of your insulation!

[fowleil]

We absolutely do not try to buy "a tax credit" we will not choose our means of heating according to that in any case but above all because it will correspond to our needs.

Even taking care of the insulation we want to finally get rid of primagaz because even if consumption drops significantly knowing that I am paying a high price for heating myself will make my hair stand on end!

So I come back to my starting question:

What do you think of an air / water cap to replace our boiler?
We thought to keep it for the moment and couple the 2. Then sell it when it has more value. And then take only the cap to heat up and have a "solar" hot water tank. But hey it will only be in a few years because it is not in our current budget.

The brake we have is at the level of electrical consumption. I am afraid that it consumes a lot and when we search on the net we sometimes have 2 sounds of bells opposite pac ...

Knowing that our house has the potential to be completely finished once well insulated. There with the good weather we cut the heating for 1 week we turn it back on just a little in the evening more for fear of being cold in the morning than by real necessity.
I have 23/24 in the living room downstairs and a nice 20 in the bedrooms. Without turning on the heating in the morning we have 19 downstairs and 18 in the rooms. And it goes down to 4/5 ° C at night outside.

What bothers me with a pellet stove or even a simple wood stove is that our heated floor will no longer be useful ... I would have liked to keep it not so much for comfort but above all history of not having invested in it for nothing.