ᐅ Building Without a Ventilation System Using Porous Clay Blocks?

karliseppel schrieb:

Now you’ve really gone too far with the “breathing walls” idea...
Ask yourself what’s supposed to breathe when you place insulation on the interior side
and therefore inevitably need a vapor retarder for the living space.

-Calcium silicate brick

Interior insulation with hemp mats without plastic sheets still makes more sense
than covering exterior walls with 22mm (0.87 inch) thick polystyrene panels.
Because air can still pass through the hemp.

I couldn’t care less about a mandatory vapor retarder, just like I don’t care about KFW funding.
I renovate the way I want without any regulations or requirements.
I build 1.5 times cheaper than many energy consultants.

Note: Anyone who invests more than 200,000 euros in a high-tech system
a) wastes money and b) ends up with waste after 30 years.

The promised savings potential is always just a calculator exercise. Every reasonable heating technician just shakes their head nowadays when people still believe these claims.

Money will be wasted anyway, whether you buy a condominium or a low-energy house.

Personally, my electricity costs for the water heater are only 140 euros (about $150) per year (because only decadent people take a daily 1400-liter (370 gallon) full bath), plus around 500 euros (about $540) for 2.5 tons of hardwood briquettes. The gas condensing boiler runs at about 70 euros ($75) per month, and I have no wall or roof insulation. Windows: from 1978, double glazing.

And the energy consultant wants me to replace the windows too? I told him off and said: For 30,000 euros (about $32,500) I could buy over 146 tons of hardwood briquettes — that means I could heat for more than 140 years, since during winter we spend around 4 months in Thailand.

This is neither about throwing money out the window nor “getting mold because Styrofoam is stuck on the outside.”
On the contrary, the issue is different. Mold forms because moisture condenses where building components are colder, causing the moisture present in the indoor air to settle.
You haven’t even understood the basic principles yet.
You claim air comes through the walls… which is partly true, because that is exactly the problem with your hot tip for interior insulation without a vapor barrier.
I suggest you get familiar with the terms U-value, condensation, temperature profile, and dew point.

Your post is (once again) nonsense – and more importantly – not coherent.
You write about new windows costing 30,000€ – hmm. Even I only had costs of 27,000€, but I achieved the maximum insulation value with a Ug of 0.5 and over 50sqm (540 sqft) of window area if I remember correctly. That would mean you’d need a really large building since, in a building from 1978, the ratio of living area to window area was different than it is today.
Your 2.5t (2.5 tons) of hardwood charcoal briquettes have a heating value of around 12,500 kWh, while the 70€ monthly gas cost corresponds to about 14,000 kWh. That totals roughly 26,500 kWh – for a house that is likely only minimally heated during the coldest third of the year.
The total annual heating demand would probably be around 40,000 kWh. For a house built in ’78, I’d estimate approximately 250 kWh/year/m² (81 kWh/year/ft²) over 160 heated sqm (1,722 sqft).

So 30,000€ for windows (with what specifications?) in a 160 sqm (1,722 sqft) house... that’s quite a statement. Do you have no exterior walls and just glass?
Also impressive are 1,400€ heating costs for the 8 warmest months of the year.
You’re missing around 60% of heating costs if you don’t heat the house in winter (according to degree day distribution). Well – it’s minimally heated, so let’s say your costs correspond to about 50%.

That would actually be around 2,800€ heating costs.
If you could reduce these to well below 1,000€ by proper insulation and new windows for about 50,000€, you’d break even in about 25 years and at the same time do something for the environment.
(Considering that the exterior plaster would probably be due anyway and should actually only be partially included in the energy renovation costs.)

If, however, due to your personal lifestyle, you prefer to spend the heating season on the other side of the world, that has nothing to do with general recommendations in the field of energy-efficient building renovation but rather falls into the category of barroom slogans.

But with your construction tips, maybe you could start a caretaker service in Phuket...

I’ll stop here… and think “Don’t feed the troll” – but it’s already too late.

karliseppel schrieb:

I stop here... and think to myself DFTT – but already too late

Yep

Best regards

karliseppel schrieb:
This is neither about throwing money out the window nor "getting mold because there is Styrofoam stuck outside."
On the contrary, mold occurs because moisture condenses where building components are colder, causing the moisture in the indoor air to settle.
You haven't even understood the basic principles yet.
You say air passes through the walls... which you are somewhat right about,
because that is exactly the problem with your hot tip of internal insulation without a vapor barrier.
I recommend you get familiar with the terms U-value, condensation, temperature gradient, and dew point.

But this is about ventilation systems and 36cm (14 inches) hollow brick walls, isn't it?
I already understand the basics, including that salespeople try to push ventilation systems on me.
I would argue that a brick house does not require a ventilation system. Last summer,
just as a reference, with 38°C (100°F) outside temperature, we didn't even need the Honeywell fan indoors,
because bricks manage the heat outside and do not absorb it like prefabricated houses with ultra insulation.
The same applies in winter: if you constantly suppress indoor humidity with vapor barriers and no ventilation,
you only have two options:
a) humidify the air mechanically (technology that lasts 20–25 years = waste; money burns)
b) occasionally open windows
c) buy an air humidifier for about 200 euros net plus a few bottles of distilled water for pennies

karliseppel schrieb:
Your post is nonsense (again) — and more importantly, inconsistent.
You mention new windows costing €30,000 — hmm. Even I spent "only" €27,000,
but I achieved maximum insulation with a Ug of 0.5 and over 50m² (540 sq ft) of window area if I remember correctly.
You'd have to have a really large house, as the ratio of living area to window area was different in 1978 compared to today.
Your 2.5t (2.5 metric tons) of hardwood briquettes have a heating value of approx. 12,500 kWh, and the monthly €70 gas bill is around 14,000 kWh.
That adds up to about 26,500 kWh for a house that is probably only minimally heated during the coldest third of the year.
The total annual heating demand is likely around 40,000 kWh. For a house from 1978, I would estimate roughly 250 kWh/a/m² for 160 heated m² (1720 sq ft).

Your post is just rough theory as well.
Reason: €30,000 can go quickly if you choose aluminum/wood-combination windows. I'm not concerned about the insulation value either,
because during the day we set thermostats to frost protection, and the Bullerjan/Chief heater warms up insanely fast.
Fire basket with two handfuls of pellets + fire paste + 5 hardwood briquettes. After 30 minutes, about 20°C (68°F) even at -10°C (14°F) outside.
Window quotes under €16,000 are on my desk; those would be plastic with triple glazing and proper fittings due to weight.
The house is already large; the basement alone has > 400 m² (4300 sq ft) and fits about 12 cars plus 20 motorcycles.
There is so much steel in the basement, you could probably build four single-family homes there.

I have all offers on the table, from fixed solid fuel boilers to Fröhling wood chip systems, pellet stoves, etc.,
combined with a solar thermal system (which contributes almost nothing).

My conclusion: a floor-level condensing boiler plus Chief/Bullerjan/Swedish stoves are the most efficient systems, excluding the AEG eco shower boiler (no instantaneous heating).
I've done all the calculations.

Bottom line: the more technology, the more money is wasted over the next 30 years.

The core problem in Germany: buildings are constructed too expensively. So I gave it some thought.
The heating savings from a theoretical 240 kWh/a/m² to 160 kWh/a/m² on 160 m² (1720 sq ft) is just theoretical. Including all renovation costs,
the added value is minimal, similar to solar thermal system calculations, which effectively bring nothing except reducing the builder’s budget.

karliseppel schrieb:
So €30,000 for windows (with which values exactly) for 160 m² (1720 sq ft) living space...
That's a statement. Do you have no exterior walls and everything is glass?
Also, heating costs of €1,400 for the 8 warmest months per year seem low.
You're missing about 60% of the heating costs if you don't heat the house in winter
(based on degree day distribution). Well, it's minimally heated... so let's say your costs represent about 50%.

There are definitely enough exterior walls;
I don’t care about the €1,400 heating cost because every year I get a refund from the gas company. Also, I can deduct about €50 per month in pump and burner electricity during winter from the total bill,
which I used to pay.
The advantage of the AEG eco boilers is that the gas boilers can be completely switched off; i.e., from April to October, the gas boilers mostly don’t run except for occasional snow and 0°C (32°F) in September.
Minimal heating runs just to prevent pipes from freezing and bursting. The stainless steel water pipes have triple insulation.
They can withstand around -15°C (5°F) for two weeks. It doesn’t get colder anyway.

karliseppel schrieb:
That would actually be around €2,800 heating cost.
If you could reduce this to well under €1,000 through proper insulation and new windows for about €50,000, you would amortize in roughly 25 years and do something for the environment.
(Although the exterior plaster would probably be due anyway and should only be partially calculated as part of energy retrofitting.)

Insulation and new windows would cost me around €70,000; the 22 cm (9 inches) Styrofoam insulation was quoted at €100 per m² (11 sq ft) — apparently local prices?
But: after recently seeing an expert report on building damage, damp walls, and fungus, I’m done with the Styrofoam stuff. I don’t want it.
KfW funding and subsidies don’t interest me either because I pay cash against invoice and don’t take out loans. I can build as I please.
The roof only gets 400 mm (16 inches) of internal insulation and that’s it.

If I were to install a new heating system, insulate the façade very thickly, and get new windows,
I’d be around €105,000 plus 15% for incidentals including a new roof.
The roof is currently tight, heating consumption is average (not perfect) but with little technology
that can fail and burn my money.
With that money, I’d rather renovate a third or fourth house and sell it for profit.

karliseppel schrieb:
If, however, during the heating season you prefer to be on the other side of the world due to your individual lifestyle, that has nothing to do with general recommendations regarding energy-efficient building retrofits but rather falls under pub talk.

But with your construction tips, maybe you could start a caretaker service in Phuket...

What do you mean individual? I don’t care about the environment whether I burn €1,000 or €2,000 worth of gas and briquettes per year.
I also drive an 8-valve without a turbo. Why? Because those engines are reliable and don’t need a full overhaul every few thousand kilometers like DPFs, turbos, etc.
2 liters displacement, 9 liters super gasoline, 10 liters LPG — end of story.

Anyone who wants to build an energy-efficient house for €450,000 is welcome to do so. For me, it’s pure marketing,
funded by building societies providing advance financing, hoping some will fail financially; then forced auctions, etc.

Building costs in Germany are simply too high. No idea why citizens willingly accept such high development fees?
I’d start there. It’s unacceptable that burying an electric cable from the house through the garden to the street distribution box/ground splice costs more than €14,000. Same for sewer and water lines, etc.
The entire house-building craze is the same! In some countries, building houses is noticeably cheaper.
More technology means more money wasted and more future waste.

P.S. No wonder many people leave completely within a few years?

Phuket doesn’t interest me in Thailand. There are more beautiful places. And caretaker? I am fortunate enough to be able to hire help.

Bauexperte schrieb:
Yep

Best regards

Recently, an energy consultant visited my construction site and tried to push something on me that I didn’t want.
Then he became rude.
In the end, I called his supervisor briefly and had the foreman removed from the site. He’s not needed here anymore. That’s how it is.

Hello,

kamnik schrieb:
Recently, an energy consultant came to my construction site and tried to push something on me that I didn’t want. Then he became rude. The end result: I called his supervisor briefly and had the foreman removed from the site. He doesn’t need to come back. That’s how it is.

At the moment, I don’t see what this information is supposed to tell me? I don’t push anything on anyone – and I don’t have a supervisor either. And while we’re on the subject...

kamnik schrieb:

... I could post a few expert review videos here, but according to the moderator, I’m not allowed to (because he apparently works for some companies) and doesn’t like the argumentation...

I once learned that a person can only think badly of others as much as he is himself. For someone who is supposedly self-employed, I expect them to stay grounded in reality and not get lost in assumptions; the latter is just barroom talk.

If you took the time to read the forum rules, you would find that it’s completely irrelevant who and how many partners I work with. I am a mod, nothing more and nothing less.

Kind regards