Hello everyone,
During the planning phase of building a house, you inevitably come across forums about home construction and topics related to energy standards. I have already read several books and browsed various websites on the subject. I should mention that I am not a professional in this field. What I have noticed is that the entire topic of "economic / ecological home construction" is heavily influenced by commercial interests. The so-called "smart" consumer is often misled by marketing terms and a government-led campaign for "CO2-efficient building." Books or websites dealing with this subject often do not provide clear, comprehensive assessments.
In the "better" literature, insulation materials are compared in terms of insulation value and whether they are expensive or affordable. However, I still cannot determine what makes the most sense for my individual case. I simply do not want to spend excessive amounts of money, especially on things that do not add value, such as polystyrene insulation. If additional costs for a particular heating system are reasonable over a feasible period, then yes.
Our current goal is to build a simple single-family home with about 130 - 140 sqm (1400 - 1500 sq ft). The house should cost around €200,000 (without outdoor landscaping, floor coverings, land, or additional construction-related costs; our expectations are modest).
I am interested in knowing, based on the current state of technology, what is the most energy-efficient and cost-effective building option?
Energy-saving regulation / building standards according to KfW, yes or no, and if yes, which level?
Solid construction or prefabricated house?
Condensing boiler technology or heat pump?
Thank you very much for your answers!
Best regards
During the planning phase of building a house, you inevitably come across forums about home construction and topics related to energy standards. I have already read several books and browsed various websites on the subject. I should mention that I am not a professional in this field. What I have noticed is that the entire topic of "economic / ecological home construction" is heavily influenced by commercial interests. The so-called "smart" consumer is often misled by marketing terms and a government-led campaign for "CO2-efficient building." Books or websites dealing with this subject often do not provide clear, comprehensive assessments.
In the "better" literature, insulation materials are compared in terms of insulation value and whether they are expensive or affordable. However, I still cannot determine what makes the most sense for my individual case. I simply do not want to spend excessive amounts of money, especially on things that do not add value, such as polystyrene insulation. If additional costs for a particular heating system are reasonable over a feasible period, then yes.
Our current goal is to build a simple single-family home with about 130 - 140 sqm (1400 - 1500 sq ft). The house should cost around €200,000 (without outdoor landscaping, floor coverings, land, or additional construction-related costs; our expectations are modest).
I am interested in knowing, based on the current state of technology, what is the most energy-efficient and cost-effective building option?
Energy-saving regulation / building standards according to KfW, yes or no, and if yes, which level?
Solid construction or prefabricated house?
Condensing boiler technology or heat pump?
Thank you very much for your answers!
Best regards
C
chand19868 Aug 2017 14:42Marvinius II schrieb:
To the engineers here: Ever heard of energy density?Sarcasm? If so, be careful—I really know my way around thermodynamics and efficiency chains. By the way, I’m originally a physicist, even if I don’t work in that field.
Marvinius II schrieb:
With 50 kg (110 lbs) of gasoline/diesel I can drive 500 to 1000 km (310 to 620 miles), [...] Plus the tank. Plus the engine. Plus the transmission. Or how exactly do those 50 kg (110 lbs) of gasoline turn the wheels? An electric car doesn’t have any of these components.
Marvinius II schrieb:
With 500 kg (1100 lbs)! Battery, maximum 400 km (250 miles), [...]The battery does not contain any measurable fuel mass but rather an energy potential gradient with zero weight. So you are comparing incomparable things.
Now to energy density: it is irrelevant for comparison. The only thing that matters is the efficiencies, because only(!) these show how effective the conversion is from chemical energy (fuel’s heating value) or electrical potential (battery) into kinetic energy (driving).
And as I stated above, these efficiencies explain why my comment about oil power plants plus electric cars is logically consistent.
Please note that an internal combustion engine has a performance map, and you rarely operate in the optimal range. Real-world efficiencies are measured through test drives and are around 16% for combustion engines. The 45% efficiency cited by various sources is just the optimal area of the performance map, not a practically achievable figure. So it’s misleading. And in that 16% real efficiency, neither refining nor transportation to gas stations is even included.
Marvinius II schrieb:
The electric car spends at least 30 minutes charging...No. Those who already own (still expensive) electric cars charge during downtime at home. If you are not a long-distance driver but belong to the group that drives about 40 km (25 miles) per day on average, you almost never charge elsewhere or simply haven’t realized that you should change your habits. The best place to “refuel” electricity is at home.
C
chand19868 Aug 2017 14:57kaho674 schrieb:
The goal must be to charge the car while driving on the road.Why? That makes sense for a minority of passenger cars, and it would also be useful for freight transport. But the average passenger car is parked over 90% of the time and not driving. In that case, it makes more sense to refuel then.
Marvinius II8 Aug 2017 15:17Electric cars already existed at the beginning of the 20th century. They lost out to internal combustion engines, for example due to battery capacity and charging infrastructure. These problems are still unresolved. And a Tesla S, despite lacking a transmission, weighs about 500 kg (1100 lbs) more than a comparable internal combustion vehicle. Without batteries with an energy density similar to gasoline and fast charging that takes minutes instead of hours, this won’t work...
C
chand19868 Aug 2017 15:41Marvinius II schrieb:
They lost to combustion engines, for example due to battery capacity and charging infrastructure. These problems are still unresolved.Really? You can drive electrically from the northernmost to the southernmost parts of Europe without running out of battery charge. And this is already possible during the early expansion phase of the charging network. East-west routes are still somewhat limited in comparison.
Marvinius II schrieb:
And a Tesla Model S weighs about 500 kg (1100 lbs) more than a comparable combustion engine car, despite lacking a gearbox, etc.Which combustion car are you comparing it to? A similarly sized BMW 5 Series with comparable performance weighs about 200 kg (440 lbs) less. (And "comparable performance" is generous when referring to the combustion engine.)
Marvinius II schrieb:
Without batteries with an energy density like gasoline and fast charging that takes minutes instead of hours, it won’t work...You list “natural sciences” as your profession. So just disregard the at most marginally relevant factor of energy density and focus on what really matters. Range does not automatically come from energy density.
Just look at the range. How many drivers actually need over 1000 km (620 miles) in one go? Very few. If charging comes to the car instead of the other way around, you’ve won. Then smaller ranges are sufficient. The fact that this has been understood much better in the sparsely populated Scandinavia than in comparatively densely populated Germany says everything about the typical German attitude of “we’ve always done it this way.”
That the electric cars available for sale today don’t come from Germany (even though we’re supposedly the car nation), and that American and Chinese manufacturers consider the German market fairly irrelevant, should be food for thought.