ᐅ Typical energy consumption based on practical experience?
Created on: 18 Jun 2013 21:50
G
Gabi&Gerold
Hello everyone,
We are new here, and unfortunately, the reason is not a happy one. I would like to continue working on my outdoor area but, to my frustration, I have to deal with this online.
We have been living for a year now in a low-energy prefabricated house. The Vitocal 200 heating system has already had several failures, with customer service disappointing us repeatedly. (We expect more from our apprentices.) But that is a different topic.
From the beginning, I had the impression that the air-source heat pump consumes quite a lot of energy. This was repeatedly denied, and I was referred to the year-end statement from my energy provider. Now I have checked the meter myself and almost fainted: 5500 kWh of electricity consumption just for the heat pump in one year!
Before receiving the usual "relative explanations" from the manufacturer that I’m used to, here is some information about us:
We live in the Southwest Palatinate region (together with Mainau, the warmest area in Germany).
We are both working full-time, only occupying the house in the evenings, and only one person showers.
The set temperature is 20°C (68°F).
The blower door test was passed with very good results.
The house is ventilated by opening windows 3-4 times a day; otherwise, the windows remain closed.
The prefabricated home provider advertises this house with heating costs of €36 per month, which corresponds to approximately 2080 kWh annually based on the EON tariff.
Their calculation is based on 22°C (72°F) in the living room and bathroom, 20°C (68°F) in the kitchen and children’s room, and 18°C (64°F) in the bedroom and other rooms.
We maintain 20°C (68°F) in the living room and bathroom; the heating in the children’s, bedrooms, and adjacent rooms is turned off. Most of the doors on the upper floor remain closed.
We think that with these settings, we are on the energy-saving side, which is why I am so surprised by our energy consumption despite the harsh winter.
As a solution, a service technician suggested lowering the set temperature even further! He was serious about this.
Since the provider does not take our complaints seriously and either does not respond or only replies after weeks, we are now looking for support here.
Who else lives in a comparable prefabricated house? What is your energy consumption? Please post! I need comparative figures to assert myself against my provider.
If you have neighbors living in such a house, please ask them and share their consumption here.
Thank you in advance for your responses.
We are new here, and unfortunately, the reason is not a happy one. I would like to continue working on my outdoor area but, to my frustration, I have to deal with this online.
We have been living for a year now in a low-energy prefabricated house. The Vitocal 200 heating system has already had several failures, with customer service disappointing us repeatedly. (We expect more from our apprentices.) But that is a different topic.
From the beginning, I had the impression that the air-source heat pump consumes quite a lot of energy. This was repeatedly denied, and I was referred to the year-end statement from my energy provider. Now I have checked the meter myself and almost fainted: 5500 kWh of electricity consumption just for the heat pump in one year!
Before receiving the usual "relative explanations" from the manufacturer that I’m used to, here is some information about us:
We live in the Southwest Palatinate region (together with Mainau, the warmest area in Germany).
We are both working full-time, only occupying the house in the evenings, and only one person showers.
The set temperature is 20°C (68°F).
The blower door test was passed with very good results.
The house is ventilated by opening windows 3-4 times a day; otherwise, the windows remain closed.
The prefabricated home provider advertises this house with heating costs of €36 per month, which corresponds to approximately 2080 kWh annually based on the EON tariff.
Their calculation is based on 22°C (72°F) in the living room and bathroom, 20°C (68°F) in the kitchen and children’s room, and 18°C (64°F) in the bedroom and other rooms.
We maintain 20°C (68°F) in the living room and bathroom; the heating in the children’s, bedrooms, and adjacent rooms is turned off. Most of the doors on the upper floor remain closed.
We think that with these settings, we are on the energy-saving side, which is why I am so surprised by our energy consumption despite the harsh winter.
As a solution, a service technician suggested lowering the set temperature even further! He was serious about this.
Since the provider does not take our complaints seriously and either does not respond or only replies after weeks, we are now looking for support here.
Who else lives in a comparable prefabricated house? What is your energy consumption? Please post! I need comparative figures to assert myself against my provider.
If you have neighbors living in such a house, please ask them and share their consumption here.
Thank you in advance for your responses.
BeHaElJa schrieb:
When planning the heating system and pipe layout, make sure your heating specialist carries out a room-by-room heat load calculation—don’t settle for just “15 cm (6 inches) pipe spacing everywhere.” Verify the planned heating system – focus on the U-value and perform a heat load calculation for your entire building using a heating demand calculator (you can find the necessary values in the energy saving regulation documents).@BeHaElJa
I see this mentioned repeatedly. What exactly does it mean? That every room should have a different pipe spacing? Our heating installer planned 15 cm (6 inches) spacing everywhere, with 10 cm (4 inches) in the bathrooms and also 10 cm (4 inches) along the exterior walls in the living rooms.
@cartime
What you should know about underfloor heating—it should look like this:
And not like this:
The heating circuits should not exceed 100 meters (330 feet) in length and should be approximately the same length in each room. The spacing of the heating pipes in front of floor-to-ceiling windows should be about 5 cm (2 inches). There should be thermal insulation and impact sound insulation underneath the underfloor heating. In the areas around doors or expansion joints, the supply and return pipes of the heating circuits should have additional protection. The water used should be low in oxygen. The expansion vessels must be made of stainless steel. A hydraulic balancing should be carried out after the system is commissioned, and a fine adjustment should be done during the first winter.
Note: this is a non-expert opinion:
Should the grounding not be done by the MEP engineer (mechanical, electrical, plumbing) rather than the architect?
@WildThing
Yes, each room must be considered individually...within one room, we sometimes have three different pipe spacings depending on the routing.
What you should know about underfloor heating—it should look like this:
And not like this:
The heating circuits should not exceed 100 meters (330 feet) in length and should be approximately the same length in each room. The spacing of the heating pipes in front of floor-to-ceiling windows should be about 5 cm (2 inches). There should be thermal insulation and impact sound insulation underneath the underfloor heating. In the areas around doors or expansion joints, the supply and return pipes of the heating circuits should have additional protection. The water used should be low in oxygen. The expansion vessels must be made of stainless steel. A hydraulic balancing should be carried out after the system is commissioned, and a fine adjustment should be done during the first winter.
Note: this is a non-expert opinion:
Should the grounding not be done by the MEP engineer (mechanical, electrical, plumbing) rather than the architect?
@WildThing
Yes, each room must be considered individually...within one room, we sometimes have three different pipe spacings depending on the routing.
Preliminary: I am just an amateur.
It is difficult (impossible) to say from a distance whether this fits. Rough approximation: many windows or large exterior wall surfaces → shorter spacing for the floor heating pipes. Also, the basic rule seems to be that the heating system heats the critical room, and all others follow. In other words, if your heating requires a supply temperature of 40°C (104°F) for a poorly designed room, the system must provide that. However, heat pumps become less efficient the higher the supply temperatures. Other oversized rooms might actually only need around 28°C (82°F) and regulate themselves “down.” So the heat cannot be absorbed, and the heating system struggles 😀 That’s why it’s worth the effort, especially with heat pumps, to look at each room individually.
Additionally, it is important because you also need to size the heating system. If it is too large, it costs too much; if it is too small, you will have to heat in winter with an electric backup heater (seasonal performance factor of 1).
It is difficult (impossible) to say from a distance whether this fits. Rough approximation: many windows or large exterior wall surfaces → shorter spacing for the floor heating pipes. Also, the basic rule seems to be that the heating system heats the critical room, and all others follow. In other words, if your heating requires a supply temperature of 40°C (104°F) for a poorly designed room, the system must provide that. However, heat pumps become less efficient the higher the supply temperatures. Other oversized rooms might actually only need around 28°C (82°F) and regulate themselves “down.” So the heat cannot be absorbed, and the heating system struggles 😀 That’s why it’s worth the effort, especially with heat pumps, to look at each room individually.
Additionally, it is important because you also need to size the heating system. If it is too large, it costs too much; if it is too small, you will have to heat in winter with an electric backup heater (seasonal performance factor of 1).
boa,
I’m copying the information and pictures to print them out.
Only question is, who do I give them to? :-)
Seriously, after each important step in the construction, we will have an expert come to inspect, but they can only assess the current condition and then file complaints or demand improvements.
Given how things are going on our construction site, I don’t have much hope that the next phases like heating installation will go smoothly.
Why did we get into this mess?
Because we were simply... foolish. Tired and drained from months of comparing options while choosing a builder. And too naive and trusting.
We were blinded by the label “Test winner at Focus Money prefab home providers.”
And unfortunately, we didn’t have the foresight to hire an independent external building expert from the start, especially for a project that was supposed to take only 4.5 months until move-in (everyone laugh).
Maybe it would have gone differently if the construction and everything before it hadn’t been handled only by my sister and me, but if men had taken care of the meetings, contracts, and so on.
Looking back, I almost think someone thought, great, two naive women under time pressure to move out of their apartments.
Easy prey :-)
I’m copying the information and pictures to print them out.
Only question is, who do I give them to? :-)
Seriously, after each important step in the construction, we will have an expert come to inspect, but they can only assess the current condition and then file complaints or demand improvements.
Given how things are going on our construction site, I don’t have much hope that the next phases like heating installation will go smoothly.
Why did we get into this mess?
Because we were simply... foolish. Tired and drained from months of comparing options while choosing a builder. And too naive and trusting.
We were blinded by the label “Test winner at Focus Money prefab home providers.”
And unfortunately, we didn’t have the foresight to hire an independent external building expert from the start, especially for a project that was supposed to take only 4.5 months until move-in (everyone laugh).
Maybe it would have gone differently if the construction and everything before it hadn’t been handled only by my sister and me, but if men had taken care of the meetings, contracts, and so on.
Looking back, I almost think someone thought, great, two naive women under time pressure to move out of their apartments.
Easy prey :-)
B
Bauexperte1 Apr 2015 23:45Good evening,
Regards, Bauexperte
cartime schrieb:That is still better than having no knowledge of the true status; it’s not like building a house doesn’t cost money.
Seriously, we will have an expert come to check after each important work step, but they can only determine the current condition and then report any issues and insist on improvements.
cartime schrieb:I just looked into it for the first time; I come from the other side. Which of the five “test winners” did you end up choosing?
Why did we get into this mess?
[...] And we were too naive and trusting. We were blinded by the logo “Test winner at Focus Money prefab house provider.”
cartime schrieb:You shouldn’t look back at all, only forward; you already know what you and your team did wrong. The best condition now is to do better—with the help of your expert moving forward 😉
In hindsight, I almost think someone thought, great, two naive women who are also under time pressure to move out of their apartments. Easy prey 🙂
Regards, Bauexperte
Similar topics