ᐅ Energy Saving Regulation 2016 / KFW55 Standard / Gas and Solar in 2016
Created on: 1 Dec 2015 20:37
G
GrymI have a question regarding the 2016 energy saving regulation. It is often stated that the transmission heat loss is reduced by 20 percent, but I cannot find this figure, unlike the change in primary energy demand, in the legal text. Instead, it says:
Does this actually mean that these reference values have not applied before and only became valid from January 2016? Is the 20-percent tightening only implicit or calculated?
Furthermore, the KFW55 standard is based on these reference values concerning transmission heat loss. KFW55 corresponds to 70 percent, so is KFW55 about 30 percent stricter than the 2016 energy saving regulation regarding this parameter?
This is also suggested by the simplified benchmark values for KFW55, e.g., thermal bridge allowance 0.05 x 0.7 = 0.035 or 0.28 x 0.7 = 0.2. “Simplified” is relative, as you still have to calculate all thermal bridges.
Then the equation that KFW70 is roughly equivalent to the 2016 energy saving regulation is definitely not correct. KFW70 is at 85 percent of the reference values, while the 2016 energy saving regulation refers to 100 percent of the reference values. Therefore, KFW70 is still 15 percent stricter regarding transmission heat loss than the new energy saving regulation. Only in comparison of primary energy are the values closer, where KFW70 demands 70 percent and the energy saving regulation a tightening by 25 percent, so 75 percent.
This brings us to gas plus solar in 2016. A KFW70 house exceeds both primary energy demand and transmission heat loss requirements of the 2016 energy saving regulation. If there were KFW70 houses with gas plus solar before, there will continue to be. The requirements of the Renewable Energies Heat Act are met by the system under point I. 1.) a) aa).
Any opinions? Corrections? Counterarguments? Theories? Other comments?
From January 1, 2016, the specific transmission heat loss related to the heat-transmitting building envelope of a new residential building must not exceed 1.0 times the corresponding value of the respective reference building.
Does this actually mean that these reference values have not applied before and only became valid from January 2016? Is the 20-percent tightening only implicit or calculated?
Furthermore, the KFW55 standard is based on these reference values concerning transmission heat loss. KFW55 corresponds to 70 percent, so is KFW55 about 30 percent stricter than the 2016 energy saving regulation regarding this parameter?
This is also suggested by the simplified benchmark values for KFW55, e.g., thermal bridge allowance 0.05 x 0.7 = 0.035 or 0.28 x 0.7 = 0.2. “Simplified” is relative, as you still have to calculate all thermal bridges.
Then the equation that KFW70 is roughly equivalent to the 2016 energy saving regulation is definitely not correct. KFW70 is at 85 percent of the reference values, while the 2016 energy saving regulation refers to 100 percent of the reference values. Therefore, KFW70 is still 15 percent stricter regarding transmission heat loss than the new energy saving regulation. Only in comparison of primary energy are the values closer, where KFW70 demands 70 percent and the energy saving regulation a tightening by 25 percent, so 75 percent.
This brings us to gas plus solar in 2016. A KFW70 house exceeds both primary energy demand and transmission heat loss requirements of the 2016 energy saving regulation. If there were KFW70 houses with gas plus solar before, there will continue to be. The requirements of the Renewable Energies Heat Act are met by the system under point I. 1.) a) aa).
Any opinions? Corrections? Counterarguments? Theories? Other comments?
The topic is quite challenging. Surely, house building experts can also add some insights.
Rest see below.....Context. T:.....
( : Now my comments are hidden in a box....okay. I’ll leave it like this this time....)
Rest see below.....Context. T:.....
( : Now my comments are hidden in a box....okay. I’ll leave it like this this time....)
Grym schrieb:
I have a question regarding the 2016 Energy Saving Ordinance. It often says that the transmission heat loss is reduced by 20 percent, but I can’t find this figure, unlike the change in primary energy demand, explicitly stated in the legal text. Instead, it says this:
T: I understand the 2016 Energy Saving Ordinance as requiring roughly 20% better insulation overall than before (walls, slab-on-grade, roof, etc.).
Does this actually mean that these reference values had not applied previously and only take effect from January 2016 onwards? The 20 percent tightening is only implicit or a calculated value, right?
T: No, I believe the tightening is indeed practical and can be realized. Of course, the new reference values only apply from 2016 onwards.
To what extent primary energy consumption (depending on energy carrier) and insulation interact in the limiting case is unclear. See below: No idea at the moment.
Furthermore, the KfW55 standard is based on these reference values regarding transmission heat loss. KfW55 is at 70 percent, so is KfW55 therefore 30 percent “stricter” than the 2016 Energy Saving Ordinance in terms of this indicator?
T: Now I’m a bit confused, building expert: help.
KfW70: Is being discontinued without replacement. KfW55 and better: Will essentially remain as they are today.
Therefore, on paper, KfW55 and better deteriorate in relation to the new 100% reference 2016. But structurally, they remain basically unchanged.
This is also suggested by the simplified values for KfW55, e.g. thermal bridge surcharge 0.05×0.7=0.035 or 0.28×0.7=0.2. Simplified? You still have to calculate all thermal bridges.
T: You have to calculate all thermal bridges anyway... although there are different methods, some flat-rate, right?!
Then the equation “KfW70 roughly equals Energy Saving Ordinance 2016” is both true and not true at all. KfW70 is at 85 percent of the reference values, whereas the 2016 Energy Saving Ordinance refers to 100 percent of the reference values. So KfW70 is still 15 percent stricter with respect to transmission heat loss than the new Energy Saving Ordinance. Only when comparing primary energy do values approach each other: here KfW70 requires 70 percent, the Energy Saving Ordinance a tightening to 75 percent.
T: What you write is complicated. I would say: You don’t have to completely write off or scrap a KfW 70 building because of the 2016 Energy Saving Ordinance. It roughly matches the standard of a new Energy Saving Ordinance 2016-100% house. There are differences. Tendentially, KfW70 might be better in individual cases. Somewhat charmingly: Most buildings were ultimately built to KfW70 standard. Personally, I only know one KfW55 building in my area... but no consumption data yet.
This leads us to gas + solar in 2016. A KfW70 house exceeds both the primary energy demand and transmission heat loss requirements of the 2016 Energy Saving Ordinance. If there have been KfW70 houses with gas + solar before, those will continue to exist. The requirements of the Renewable Energy Heat Act are met by the system under point I.1.) a) aa).
T: I don’t think the whole topic is 100% clear yet.
You generally have to insulate better. Definitely. But how insulation and primary energy consumption interact, and how to balance these at what cost, I don’t understand myself yet (and I usually grasp these things quickly). I’d be happy if someone who understands this could explain it here.
The primary energy factor for electricity drops from 2.4 to 1.8. The factor for gas remains the same.
Still, it seems that meeting the 2016 values is not straightforward with gas/solar alone. At least not without thermal solar plus heating support, which naturally makes vacuum tube collectors sensible: expensive. Plus possibly further insulation measures. With (air) heat pumps, the values can probably be met on paper more easily, even “foregoing” insulation.
I’m curious where this is going, and when it will become clear.
Opinions? Corrections? Counterarguments? Theories? Other comments?
It has long been clear that there is no separate Energy Saving Regulation 2016 as such; rather, all requirements were already included in the Energy Saving Regulation 2014, effective from January 1, 2016. I often read in press articles, forums, etc., about improving insulation by 20 percent, but this is not stated anywhere in the law. For clarification, KFW standards always require compliance with two criteria: primary energy demand as a percentage of the Energy Saving Regulation standard and transmission heat loss as a percentage of the Energy Saving Regulation standard. Here, I am mainly referring to the latter, even though the namesake of the KFW standards is primary energy demand (for example, KFW55 means 55 percent of the Energy Saving Regulation standard regarding primary energy demand and 70 percent regarding transmission heat loss).
As far as I can see, the reference values related to transmission heat loss have only applied since January 2016. However, the same reference values have already been valid for calculating primary energy demand.
I would even go a step further and say that in 2016, gas heating without solar but with controlled residential ventilation was still possible. More details on this may follow later.
Thermal bridges do not have to be calculated, but neglecting them has a significant impact. Then, a value of 0.1 per m² (per square meter) of heat-transferring envelope surface should be assumed. For equivalence verification, 0.05 should be assumed, and precise calculations can certainly achieve values of 0.03 or better.
As far as I can see, the reference values related to transmission heat loss have only applied since January 2016. However, the same reference values have already been valid for calculating primary energy demand.
I would even go a step further and say that in 2016, gas heating without solar but with controlled residential ventilation was still possible. More details on this may follow later.
Thermal bridges do not have to be calculated, but neglecting them has a significant impact. Then, a value of 0.1 per m² (per square meter) of heat-transferring envelope surface should be assumed. For equivalence verification, 0.05 should be assumed, and precise calculations can certainly achieve values of 0.03 or better.
I’m treading on thin ice here. I hope to learn more about this topic (because it interests me a lot). I enjoy learning about it.
It will probably be "somehow" possible. But will controlled residential ventilation with heat recovery be enough?
We will see. There are claims about it. I’m not convinced yet. I think it only works with heating support from thermal solar systems. And that’s also a bit of optimistic calculation.
My 1970s building is already basically equipped with all these systems, and its thermal transmission losses are quite good, but the primary energy factor is thrown off by the gas plus auxiliary energy consumption...
When I have more facts, I can do some more detailed calculations on a case-by-case basis...
From what I know so far: buildings slightly better than KfW 70 would probably just meet the KfW 2016 standard.
I need more facts... but at the moment I don’t have them.
Since I’m considering having a new energy certificate issued in 2016 anyway because of the photovoltaic system, and it would fit, I would have the building re-certified to that standard (a fictive resale value for peace of mind, just for fun).
I believe they were calculated for my building. I’ll have to look through the 50+ pages of documents tomorrow.
Grym schrieb:
I would even go one step further and say that the 2016 standard might be achievable with gas heating without solar but with controlled residential ventilation. More details on that possibly later.
It will probably be "somehow" possible. But will controlled residential ventilation with heat recovery be enough?
We will see. There are claims about it. I’m not convinced yet. I think it only works with heating support from thermal solar systems. And that’s also a bit of optimistic calculation.
My 1970s building is already basically equipped with all these systems, and its thermal transmission losses are quite good, but the primary energy factor is thrown off by the gas plus auxiliary energy consumption...
When I have more facts, I can do some more detailed calculations on a case-by-case basis...
From what I know so far: buildings slightly better than KfW 70 would probably just meet the KfW 2016 standard.
I need more facts... but at the moment I don’t have them.
Since I’m considering having a new energy certificate issued in 2016 anyway because of the photovoltaic system, and it would fit, I would have the building re-certified to that standard (a fictive resale value for peace of mind, just for fun).
Grym schrieb:
Thermal bridges do not need to be calculated, but they have quite a strong impact if not considered. Then 0.1 per m² of heat-transmitting building envelope surface should be assumed. For equivalence proof, 0.05 is assumed; precisely calculated values of 0.03 and lower are certainly possible.
I believe they were calculated for my building. I’ll have to look through the 50+ pages of documents tomorrow.
Just a quick note on the mechanical ventilation with heat recovery solution without solar:
In a building with a basement within the thermal envelope, the volume becomes relatively large. For a house measuring 11 x 9 meters (36 x 30 feet) with two full floors and a basement, I have calculated a volume of about 850 m³ (30,000 ft³). Ventilation heat losses are calculated (as far as I know) using 0.34 x 0.55 x 850 = 159 W/K. For mechanical ventilation with heat recovery at 90 percent efficiency, the calculation is, to my knowledge, as follows: 0.34 x (0.55 x (1.00 - 0.90) + 0.2) x 850 = 0.34 x 0.255 x 850 = 74 W/K.
For a house of this size with a basement, ventilation losses (calculated!) account for almost half of the heat losses. The slab and basement walls are nicely accounted for by various factors, but I have not read anything suggesting that ventilation losses from the basement volume are given less attention.
If I save half of half, then I have already achieved my 25 percent primary energy savings. If I also meet the reference values, I have complied with the 2016 Energy Saving Ordinance. The 2016 Energy Saving Ordinance reference building uses gas without solar – that should not be forgotten!
The Renewable Energies Heat Act becomes slightly more complicated. It allows alternative measures and their combination. Mechanical ventilation with heat recovery is a fully valid alternative measure if it covers 50 percent of the energy demand. It doesn’t quite reach that, more like 25 percent. So, I have met about half of the requirement and must also fulfill another alternative measure about halfway. By improving insulation and reducing primary energy demand by 15 percent compared to the Energy Saving Ordinance standard, I have met another alternative measure. However, this only needs to be met halfway, so only about 7.5 percent compared to the reference values, which should be achievable. Just for your information, the U-value of the exterior wall is 0.28 W/(m²K) according to the 2016 Energy Saving Ordinance.
In a building with a basement within the thermal envelope, the volume becomes relatively large. For a house measuring 11 x 9 meters (36 x 30 feet) with two full floors and a basement, I have calculated a volume of about 850 m³ (30,000 ft³). Ventilation heat losses are calculated (as far as I know) using 0.34 x 0.55 x 850 = 159 W/K. For mechanical ventilation with heat recovery at 90 percent efficiency, the calculation is, to my knowledge, as follows: 0.34 x (0.55 x (1.00 - 0.90) + 0.2) x 850 = 0.34 x 0.255 x 850 = 74 W/K.
For a house of this size with a basement, ventilation losses (calculated!) account for almost half of the heat losses. The slab and basement walls are nicely accounted for by various factors, but I have not read anything suggesting that ventilation losses from the basement volume are given less attention.
If I save half of half, then I have already achieved my 25 percent primary energy savings. If I also meet the reference values, I have complied with the 2016 Energy Saving Ordinance. The 2016 Energy Saving Ordinance reference building uses gas without solar – that should not be forgotten!
The Renewable Energies Heat Act becomes slightly more complicated. It allows alternative measures and their combination. Mechanical ventilation with heat recovery is a fully valid alternative measure if it covers 50 percent of the energy demand. It doesn’t quite reach that, more like 25 percent. So, I have met about half of the requirement and must also fulfill another alternative measure about halfway. By improving insulation and reducing primary energy demand by 15 percent compared to the Energy Saving Ordinance standard, I have met another alternative measure. However, this only needs to be met halfway, so only about 7.5 percent compared to the reference values, which should be achievable. Just for your information, the U-value of the exterior wall is 0.28 W/(m²K) according to the 2016 Energy Saving Ordinance.
[QUOTE="Grym, post: 109376, member: 20704"]
The Renewable Energy Heat Act becomes only slightly more complicated. It allows for substitute measures and their combinations. Controlled residential ventilation is a fully accepted substitute measure if it covers 50 percent of the energy demand. It doesn’t quite reach that, more like 25 percent. So I have met the requirement about halfway and must fulfill another substitute measure for roughly the other half. By improving insulation and reducing primary energy demand by 15 percent compared to the Energy Saving Ordinance standard, I have met another substitute measure. But this now only needs to be fulfilled halfway, so about 7.5 percent compared to the reference values, which should be doable. For your information, exterior wall U-value is 0.28 according to the 2016 Energy Saving Ordinance.
Hats off! Are you a business graduate? I believe so. Yes. I didn’t check your calculations at this late hour, but they seem plausible. I’ve seen something similar in my documents.
Now: You are a top-level business professional, one who can do everything. I know few like that and have the utmost respect for you (said exactly as written!!!!).
I think: The Renewable Energy Heat Act is the controversial point. Are the substitute measures and combinations allowed and accepted?
Best regards & for today I am off to @Sleep.
Thorsten
PS: An exterior wall U-value of 0.28 is peanuts, that can be easily achieved. My wooden house has 0.137. And that’s just so-so. Getting down to 0.10 is easily possible without much effort!!!!!
The Renewable Energy Heat Act becomes only slightly more complicated. It allows for substitute measures and their combinations. Controlled residential ventilation is a fully accepted substitute measure if it covers 50 percent of the energy demand. It doesn’t quite reach that, more like 25 percent. So I have met the requirement about halfway and must fulfill another substitute measure for roughly the other half. By improving insulation and reducing primary energy demand by 15 percent compared to the Energy Saving Ordinance standard, I have met another substitute measure. But this now only needs to be fulfilled halfway, so about 7.5 percent compared to the reference values, which should be doable. For your information, exterior wall U-value is 0.28 according to the 2016 Energy Saving Ordinance.
Hats off! Are you a business graduate? I believe so. Yes. I didn’t check your calculations at this late hour, but they seem plausible. I’ve seen something similar in my documents.
Now: You are a top-level business professional, one who can do everything. I know few like that and have the utmost respect for you (said exactly as written!!!!).
I think: The Renewable Energy Heat Act is the controversial point. Are the substitute measures and combinations allowed and accepted?
Best regards & for today I am off to @Sleep.
Thorsten
PS: An exterior wall U-value of 0.28 is peanuts, that can be easily achieved. My wooden house has 0.137. And that’s just so-so. Getting down to 0.10 is easily possible without much effort!!!!!
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