First of all, I want to clarify that my goal is not to save the world (sorry, my bad), but solely to reduce heating costs! I have been calculating back and forth for some time now but unfortunately can’t come to an optimal conclusion.
So here’s my attempt to use collective intelligence. Perhaps someone has already considered the same issues.
My house (old, 25cm (10 inches) Ytong blocks) could be improved in terms of U-value by adding a brick-style polystyrene cladding, or I could install a heat pump. Currently, I am heating with oil but could switch to gas. Oil heating still has a certain grandfathering protection for a while, but it’s likely that I will face problems with oil in the future.
Switching to gas would cost me about $8,000, the heat pump around $15,000. The polystyrene (or similar) cladding would indeed lower heating costs, but when I asked for information, no one could really tell me by what percentage my costs would drop if I improved the U-value (currently 0.35 for 25cm (10 inches) Ytong) by a factor X through additional insulation.
Are there tables or simple rough calculations that could help me decide without having to take another university-level math course first?
Thanks in advance for any information from someone who, like me, does not want to wait for the climate transition that will supposedly bring us winter temperatures of +15°C (59°F). 😉
So here’s my attempt to use collective intelligence. Perhaps someone has already considered the same issues.
My house (old, 25cm (10 inches) Ytong blocks) could be improved in terms of U-value by adding a brick-style polystyrene cladding, or I could install a heat pump. Currently, I am heating with oil but could switch to gas. Oil heating still has a certain grandfathering protection for a while, but it’s likely that I will face problems with oil in the future.
Switching to gas would cost me about $8,000, the heat pump around $15,000. The polystyrene (or similar) cladding would indeed lower heating costs, but when I asked for information, no one could really tell me by what percentage my costs would drop if I improved the U-value (currently 0.35 for 25cm (10 inches) Ytong) by a factor X through additional insulation.
Are there tables or simple rough calculations that could help me decide without having to take another university-level math course first?
Thanks in advance for any information from someone who, like me, does not want to wait for the climate transition that will supposedly bring us winter temperatures of +15°C (59°F). 😉
Höhlenmensch7 Dec 2021 11:39@apokolok
You’re absolutely right, the total cost of external insulation (materials plus labor) often greatly exceeds the energy savings. Unless you need to renovate the facade for other reasons, then the situation obviously changes.
That’s the problem: due to the ongoing environmental discussions, which nobody wants to ignore, there’s constant subtle pressure to take action—even if, for example, you’re completely satisfied with your facade. Those who are building new or have to invest for repair reasons really have no choice. But there are many, like me, who are quite happy and don’t have any issues.
However, these people are constantly encouraged—citing environmental problems, savings through new technology, saving the planet, etc.—to get involved and make changes. Thermal insulation and airtightness are pushed to levels that, in many cases, have been proven to be pointless. In the rush to promote new technologies, the issue of payback periods often gets pushed into the background—sometimes for reasons that benefit the providers. This is what I refer to with my skepticism.
We shouldn’t always put financial savings at the forefront, but it’s often overlooked that after the typical assumed 15 years, the initial investment is only just paid off, and the promised profit phase has usually ended by then because the equipment is already outdated or needs replacement.
Maybe my skepticism comes from experiencing these downsides disproportionately, which naturally shapes my view. The best example was a few years ago when the chimney sweep recommended replacing my oil boiler because the exhaust emissions no longer met the required standards. All the specialist companies said the same. By chance, I learned there’s a way to improve combustion in old boilers with an easy-to-install combustion aid, which brought my exhaust loss down to 8.5%, solving the problem! Everyone I told afterwards said they had never heard of it and thought it wasn’t possible. Only the chimney sweep—who actually measures—remarked it was “surprising” what’s possible.
If anyone else has a similar issue, feel free to send me a private message, and I’ll gladly share this tip.
As I said, I am willing to do my part to help the planet, but in the end, I have to pay for it myself, so I always keep the cost in mind. The necessary retrofits end up eating into the payback period, which I have to pay upfront!
Regardless of my pricing info on the heat pumps (made in China), I recently bought a very reasonably priced small heat pump (used, because the seller had to upgrade since that one wasn’t sufficient—so much for expert planning!) that I’ll try out with hot water first. I will measure and compare to see if, what, and how much it benefits me, and then decide whether to switch fully to heat pumps. As the saying goes: trial makes wise. If I get results, I’ll share them here.
Of course, it might sound exaggerated when I say most of the “advisors” seem to focus more on their own interests than on providing optimal advice, but when you check offers online—for example, those claiming free information—you quickly realize (if you can research yourself) that it’s just about collecting data. Many of these providers aren’t even capable of properly answering questions on the topic. And I have never found the “advisors” who follow to be objective.
So thumbs up to all skeptics—keep it up; and good luck to everyone else. Don’t forget to recalculate after 15 years, but don’t forget anything! I know my opinion is unlikely to be the majority view, but the critical side also needs to be heard.
That’s all—sorry again for the long post...
You’re absolutely right, the total cost of external insulation (materials plus labor) often greatly exceeds the energy savings. Unless you need to renovate the facade for other reasons, then the situation obviously changes.
That’s the problem: due to the ongoing environmental discussions, which nobody wants to ignore, there’s constant subtle pressure to take action—even if, for example, you’re completely satisfied with your facade. Those who are building new or have to invest for repair reasons really have no choice. But there are many, like me, who are quite happy and don’t have any issues.
However, these people are constantly encouraged—citing environmental problems, savings through new technology, saving the planet, etc.—to get involved and make changes. Thermal insulation and airtightness are pushed to levels that, in many cases, have been proven to be pointless. In the rush to promote new technologies, the issue of payback periods often gets pushed into the background—sometimes for reasons that benefit the providers. This is what I refer to with my skepticism.
We shouldn’t always put financial savings at the forefront, but it’s often overlooked that after the typical assumed 15 years, the initial investment is only just paid off, and the promised profit phase has usually ended by then because the equipment is already outdated or needs replacement.
Maybe my skepticism comes from experiencing these downsides disproportionately, which naturally shapes my view. The best example was a few years ago when the chimney sweep recommended replacing my oil boiler because the exhaust emissions no longer met the required standards. All the specialist companies said the same. By chance, I learned there’s a way to improve combustion in old boilers with an easy-to-install combustion aid, which brought my exhaust loss down to 8.5%, solving the problem! Everyone I told afterwards said they had never heard of it and thought it wasn’t possible. Only the chimney sweep—who actually measures—remarked it was “surprising” what’s possible.
If anyone else has a similar issue, feel free to send me a private message, and I’ll gladly share this tip.
As I said, I am willing to do my part to help the planet, but in the end, I have to pay for it myself, so I always keep the cost in mind. The necessary retrofits end up eating into the payback period, which I have to pay upfront!
Regardless of my pricing info on the heat pumps (made in China), I recently bought a very reasonably priced small heat pump (used, because the seller had to upgrade since that one wasn’t sufficient—so much for expert planning!) that I’ll try out with hot water first. I will measure and compare to see if, what, and how much it benefits me, and then decide whether to switch fully to heat pumps. As the saying goes: trial makes wise. If I get results, I’ll share them here.
Of course, it might sound exaggerated when I say most of the “advisors” seem to focus more on their own interests than on providing optimal advice, but when you check offers online—for example, those claiming free information—you quickly realize (if you can research yourself) that it’s just about collecting data. Many of these providers aren’t even capable of properly answering questions on the topic. And I have never found the “advisors” who follow to be objective.
So thumbs up to all skeptics—keep it up; and good luck to everyone else. Don’t forget to recalculate after 15 years, but don’t forget anything! I know my opinion is unlikely to be the majority view, but the critical side also needs to be heard.
That’s all—sorry again for the long post...
Höhlenmensch schrieb:
But there are many people who, like me, are quite satisfied and don’t have any problems.
However, they are constantly encouraged to take action, with references to… environmental issues / saving through the use of new technology / saving the world, etc. Ah, so now we have the culprits: do-gooders and world saviors have forced you against your will to start this thread. It really feels like everyone is against you. It’s alarming how far the eco-dictatorship has already spread 😳
H
hampshire7 Dec 2021 13:18Hangman schrieb:
Ah, so now we have the culprits: do-gooders and world saviors forced you to start this thread against your will. Truly, everyone is against you. It’s concerning how far the eco-dictatorship has already progressed 😳 I read it without any reproach.
Höhlenmensch schrieb:
I don’t want to go into this further because there are, of course, accurate consultants as well. However, many (especially the more affordable ones) are basically “sales pushers” who like to create problems, want to make plans, measure the heating room, etc., just to justify the consulting effort and then offer corresponding proposals that are usually company-specific due to commission reasons.Wow, I would seriously confront that guy if he serves interests other than those of his client. Were you a) properly informed that a third party partially pays the fee and b) given the option to pay fully yourself?My clients – although I don’t provide energy consulting – almost all choose the subsidized fee arrangement, where the subsidy portion is fixed and transparently communicated to the client. However, this usually involves measures with concrete procurement, while in my opinion, an energy consultant should propose manufacturer-neutral solutions.
https://www.instagram.com/11antgmxde/
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S
Stefan0018 Dec 2021 08:39Höhlenmensch schrieb:
I don’t see insulation for the ground floor/basement as a loss, since for the reasons mentioned, I don’t want a cold basement.
From years of experience, I can say that 70% of the heat goes into the ground floor and the remaining 30% downward is effectively a "heated basement ceiling."
In my opinion, that is not a loss. I believe you are mistaken about the scale.
You are now heating the entire area/volume in the basement 24/7. Just to maybe find 15 instead of 10 degrees comfortable for around 8 hours per week.
Usually, it is much more economical to simply run a fan heater for those 8 hours, no matter how inefficient it may be. It might cost as much during those 8 hours as your underfloor heating would consume over 16 or 32 hours, but that is still better than running it for 168 hours continuously! This is not about a 20-30% efficiency difference, but several times more!
Höhlenmensch schrieb:
@apokolok
Independently from my price information regarding heat pumps (China), I recently bought a small heat pump very cheaply (used, because the seller had to upgrade since this unit wasn’t powerful enough – so much for planning by professional companies!). I will initially try it for domestic hot water.
I will see, measure, and compare what it brings me, if anything, and how much, to decide whether to fully switch to a heat pump. – As the saying goes: Trial makes wise ;-)
Once I have data, I will post it. This is a good example: with domestic hot water, you’ve chosen the area where a heat pump operates most inefficiently! Every degree of temperature lift the heat pump has to achieve significantly reduces its efficiency.
You don’t need to worry about smoothing the curve with your insulation material if you use this as your baseline for forming an opinion about heat pumps.
Regarding insulation: also calculate the U-value per euro, not just related to thickness. What matters is your U-value per euro. A smoothing efficiency curve doesn’t take into account that most of the costs are not the material, but the installation.
Overall, many of your thoughts are not wrong, but I think you sometimes lack an overview of the bigger picture and especially the scale (what impacts where and by how much) seems mixed up for you.
PS: Make a detailed note of all the costs involved in your heat pump trial and then calculate how much more insulation with guaranteed results you could have gotten for that amount.
I’m also a fan of small experiments, but they usually escalate a lot and are fun gimmicks for learning, but economically hard to justify.
Höhlenmensch9 Dec 2021 00:06@Stefan001
Thanks for the warnings; the issue with the basement certainly applies to most people.
However, I spend many hours (office/workshop) in the basement and use it like the ground floor. Also, I have an open basement staircase without doors, etc.
Surely I could insulate some rooms better, but the "luxury" of moving around downstairs as freely as on the ground floor is worth it to me, so I’m satisfied with this solution. Apparently, the basement is quite well insulated from the outside with the 36 Ytong blocks, even though it protrudes 1.3 meters (4 feet 3 inches) from the ground because of the windows.
As mentioned above, I have temporarily abandoned the idea of external insulation for the ground floor because the material and labor costs are significantly higher than the extra heating oil costs.
That was the reason I started this thread (U-value total for Ytong plus insulation). If the day comes when oil heating is no longer permitted, the situation might look different.
Even though I may seem to focus on prices, I’m not an extreme penny-pincher, so I don’t see an extra liter of oil as a problem. I am not an expert on wall insulation, so I didn’t factor in any DIY work and was overwhelmed by the total price.
The installation technology is not a problem for me, which is why I tried the small heat pump (still unused at the moment due to lack of time).
Your comment about the inefficiency of heat pumps for hot water is interesting. I had already done some research, but the more I learned, the more problematic it seemed.
Question why? – If I heat 10 liters (2.6 gallons) of water from 20°C (68°F) to 40°C (104°F), the heat pump needs X watts // All three values I can measure – temperature, electrical power (kW), time.
I thought it wouldn’t matter if I use that water for showering or for the heating system – 40°C (104°F) is 40°C (104°F), right?
Maybe I am missing something. I usually like quick experiments – (the heat pump cost me very little).
As a small note on skepticism: a long time ago, I was recommended by Viessmann to use a new control system that supposedly saves energy!
I got one of these devices (modulated burner technology) and later sold it again after I repaired the old controller myself. They always say to run fully automated and avoid manual interventions. I measured everything precisely and logged the data – it didn’t make any difference. During transitional seasons, I just turn it off during the day with a timer. By “no difference,” I mean, of course, more than just a few liters of oil. (Just as additional info: I don’t have a condensing boiler but an old conventional burner, hence all these considerations.)
In summer, I also run hot water partly with electricity (and solar collector) and keep the boiler off as advised by professionals. I have a separate hot water tank with a 3 kW heating element that heats up in the morning and then switches off. I admit the water isn’t quite as warm in the evening, but I shower in the morning. I measured and found that the extra oil consumption was higher than the electricity use. Probably the standby losses of the boiler were higher than expected.
I had planned, as an experiment, to install a motorized boiler damper like I had seen in industrial large boilers, but the chimney sweep forbade it as it is not allowed.
Let’s see what the cost of hot water operation will be once I have the heat pump running. With the heating element, I can measure and compare exactly.
Since the outside temperature is already on the lower side and the heat pump’s electric heating elements switch on for this reason, I asked a neighbor nearby (in a newly built home without a chimney – so with a heat pump) to record the electricity meter readings because I wanted to know precisely.
He looked at me puzzled, so I dropped the topic not to be too persistent. When I suggested he note the electricity for the heat pump and electricity for the rest separately, he said he didn’t care because he had to pay for it anyway. 🤨
Thanks for the warnings; the issue with the basement certainly applies to most people.
However, I spend many hours (office/workshop) in the basement and use it like the ground floor. Also, I have an open basement staircase without doors, etc.
Surely I could insulate some rooms better, but the "luxury" of moving around downstairs as freely as on the ground floor is worth it to me, so I’m satisfied with this solution. Apparently, the basement is quite well insulated from the outside with the 36 Ytong blocks, even though it protrudes 1.3 meters (4 feet 3 inches) from the ground because of the windows.
As mentioned above, I have temporarily abandoned the idea of external insulation for the ground floor because the material and labor costs are significantly higher than the extra heating oil costs.
That was the reason I started this thread (U-value total for Ytong plus insulation). If the day comes when oil heating is no longer permitted, the situation might look different.
Even though I may seem to focus on prices, I’m not an extreme penny-pincher, so I don’t see an extra liter of oil as a problem. I am not an expert on wall insulation, so I didn’t factor in any DIY work and was overwhelmed by the total price.
The installation technology is not a problem for me, which is why I tried the small heat pump (still unused at the moment due to lack of time).
Your comment about the inefficiency of heat pumps for hot water is interesting. I had already done some research, but the more I learned, the more problematic it seemed.
Question why? – If I heat 10 liters (2.6 gallons) of water from 20°C (68°F) to 40°C (104°F), the heat pump needs X watts // All three values I can measure – temperature, electrical power (kW), time.
I thought it wouldn’t matter if I use that water for showering or for the heating system – 40°C (104°F) is 40°C (104°F), right?
Maybe I am missing something. I usually like quick experiments – (the heat pump cost me very little).
As a small note on skepticism: a long time ago, I was recommended by Viessmann to use a new control system that supposedly saves energy!
I got one of these devices (modulated burner technology) and later sold it again after I repaired the old controller myself. They always say to run fully automated and avoid manual interventions. I measured everything precisely and logged the data – it didn’t make any difference. During transitional seasons, I just turn it off during the day with a timer. By “no difference,” I mean, of course, more than just a few liters of oil. (Just as additional info: I don’t have a condensing boiler but an old conventional burner, hence all these considerations.)
In summer, I also run hot water partly with electricity (and solar collector) and keep the boiler off as advised by professionals. I have a separate hot water tank with a 3 kW heating element that heats up in the morning and then switches off. I admit the water isn’t quite as warm in the evening, but I shower in the morning. I measured and found that the extra oil consumption was higher than the electricity use. Probably the standby losses of the boiler were higher than expected.
I had planned, as an experiment, to install a motorized boiler damper like I had seen in industrial large boilers, but the chimney sweep forbade it as it is not allowed.
Let’s see what the cost of hot water operation will be once I have the heat pump running. With the heating element, I can measure and compare exactly.
Since the outside temperature is already on the lower side and the heat pump’s electric heating elements switch on for this reason, I asked a neighbor nearby (in a newly built home without a chimney – so with a heat pump) to record the electricity meter readings because I wanted to know precisely.
He looked at me puzzled, so I dropped the topic not to be too persistent. When I suggested he note the electricity for the heat pump and electricity for the rest separately, he said he didn’t care because he had to pay for it anyway. 🤨
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