Hello everyone,
I already have several energy performance certificates showing that for KfW55, a final energy demand of about 17 kWh/m²a (5.2 kBtu/ft² per year) has been calculated. This corresponds to an annual final energy demand of 2550 kWh/a (8700 kBtu/year) for a heated area of 150 m² (1615 ft²). The insulation, air-to-water heat pump, etc., also match my planned new build in timber frame construction. Here are my questions, as I feel a bit stuck:
1.) Has anyone had experience with similar figures and can confirm that these calculated values are realistic in practice?
2.) Can these numbers really be accurate, that only 2550 kWh/a (8700 kBtu/year) are needed? With electricity costs of €0.22, that would be only €560, and heat pumps produce more kilowatts of heat per kilowatt of electricity consumed.
3.) How exactly are the seasonal performance factors (seasonal COPs) calculated based on this final energy demand?
I have different seasonal performance factors for various heat pumps. I want to calculate the annual electricity demand in order to estimate running costs and assess from when a ground-source heat pump becomes worthwhile.
Split heat pump: 3.34
Monobloc heat pump: 3.67
Ground-source heat pump with horizontal loop: 4.67
Thank you very much
I already have several energy performance certificates showing that for KfW55, a final energy demand of about 17 kWh/m²a (5.2 kBtu/ft² per year) has been calculated. This corresponds to an annual final energy demand of 2550 kWh/a (8700 kBtu/year) for a heated area of 150 m² (1615 ft²). The insulation, air-to-water heat pump, etc., also match my planned new build in timber frame construction. Here are my questions, as I feel a bit stuck:
1.) Has anyone had experience with similar figures and can confirm that these calculated values are realistic in practice?
2.) Can these numbers really be accurate, that only 2550 kWh/a (8700 kBtu/year) are needed? With electricity costs of €0.22, that would be only €560, and heat pumps produce more kilowatts of heat per kilowatt of electricity consumed.
3.) How exactly are the seasonal performance factors (seasonal COPs) calculated based on this final energy demand?
I have different seasonal performance factors for various heat pumps. I want to calculate the annual electricity demand in order to estimate running costs and assess from when a ground-source heat pump becomes worthwhile.
Split heat pump: 3.34
Monobloc heat pump: 3.67
Ground-source heat pump with horizontal loop: 4.67
Thank you very much
S
Sebastian792 Dec 2015 20:05Yes, some want to avoid the heating load calculation with this – but the general consensus is that the figures do not reflect the actual consumption.
Of course, you have a comparison value, but that does not help with the question at hand. And here, an attempt was made to estimate electricity consumption using these parameters – right?
Of course, you have a comparison value, but that does not help with the question at hand. And here, an attempt was made to estimate electricity consumption using these parameters – right?
Sebastian79 schrieb:
Yes, some people want to avoid doing the heating load calculation this way – but the general consensus is that these numbers don’t reflect the actual consumption.
Of course, you have a point of comparison, but that doesn’t help with the actual question. And here, the parameters were used to try to estimate electricity consumption – right?Okay, to clarify the connection to the question, I specifically responded to part of the original inquiry (so no one has to scroll back):
World-e schrieb:
1.) Has anyone had experience with similar data and can confirm the calculated values in real life?
2.) Are these figures even realistic, that only 2550 kWh/year are needed? With electricity costs of €0.22, that would be only €560, and a heat pump extracts more kW of heat from one kW of electricity.
3.) How exactly are the annual performance factors calculated based on this final energy demand?1. Reality varies every year: weather, user behavior, actual heating system, how well the heating is tuned, etc. The values can only serve as very rough guidelines.
2. See my previous post: the figures may be consistent purely in terms of quantities.
3. Basically, the energy consumption is divided by the annual performance factor to determine the costs.
In the energy saving regulation, the final energy refers to the electricity consumed by the heat pump, right? And within that, the annual performance factor is expressed in the form of the system performance factor. How can I calculate what effect a better annual performance factor has, or how much less electricity the heat pump consumes?
Summary:
I have an energy performance certificate with a heat pump, where the following values were calculated for KfW55. The insulation, size, etc. also correspond to my planned new build using timber frame construction.
Usable floor area: 154.4m² (1,663 ft²)
Heating demand: 45 kWh/m²a
Primary energy demand: 37.2 kWh/m²a
Final energy demand: 14.3 kWh/m²a
System performance factor eP: 0.766
Annual renewable electricity production / photovoltaic system: 3,000 kWh/a
Coverage ratio of the photovoltaic system: 38.3%
A heating engineer provided figures for various heat pumps and their seasonal performance factors (SPF):
Split heat pump: 3.34
Monobloc heat pump: 3.67
Ground source heat pump with horizontal collector: 4.67
Now to my questions:
1.) At an electricity price of 0.22 € per kWh, the annual costs would be 14.3 kWh/m²a * 154.4m² * 0.22 € = 485 €. Am I calculating this correctly?
2.) How can I use the available data to compare the types of heat pumps? Since the different types vary in price and seasonal performance factor, I would like to know when the more expensive options pay off. It would be great if someone could explain this to me or provide a sample calculation.
Thank you very much in advance.
I have an energy performance certificate with a heat pump, where the following values were calculated for KfW55. The insulation, size, etc. also correspond to my planned new build using timber frame construction.
Usable floor area: 154.4m² (1,663 ft²)
Heating demand: 45 kWh/m²a
Primary energy demand: 37.2 kWh/m²a
Final energy demand: 14.3 kWh/m²a
System performance factor eP: 0.766
Annual renewable electricity production / photovoltaic system: 3,000 kWh/a
Coverage ratio of the photovoltaic system: 38.3%
A heating engineer provided figures for various heat pumps and their seasonal performance factors (SPF):
Split heat pump: 3.34
Monobloc heat pump: 3.67
Ground source heat pump with horizontal collector: 4.67
Now to my questions:
1.) At an electricity price of 0.22 € per kWh, the annual costs would be 14.3 kWh/m²a * 154.4m² * 0.22 € = 485 €. Am I calculating this correctly?
2.) How can I use the available data to compare the types of heat pumps? Since the different types vary in price and seasonal performance factor, I would like to know when the more expensive options pay off. It would be great if someone could explain this to me or provide a sample calculation.
Thank you very much in advance.
N
nordanney3 Dec 2015 13:17Just to ask it the other way around: What additional costs do you have for each heat pump?
Then you can start thinking about it yourself, because the difference in the annual consumption will roughly be between 50-100€ (about 55-110 USD), depending, of course, on the winter conditions, your heating habits, hot water usage, etc. When you start calculating, please also consider that a coverage rate of 38.3% from the photovoltaic system for heating is highly unrealistic, unless you have a storage battery. If you operate the photovoltaic system as a business, you MUST also account for the self-consumption including VAT and record it in your profit and loss statement (and then declare it accordingly in your income tax return). So, you don’t get the electricity for free...
Then you can start thinking about it yourself, because the difference in the annual consumption will roughly be between 50-100€ (about 55-110 USD), depending, of course, on the winter conditions, your heating habits, hot water usage, etc. When you start calculating, please also consider that a coverage rate of 38.3% from the photovoltaic system for heating is highly unrealistic, unless you have a storage battery. If you operate the photovoltaic system as a business, you MUST also account for the self-consumption including VAT and record it in your profit and loss statement (and then declare it accordingly in your income tax return). So, you don’t get the electricity for free...
So the additional cost between a split and a monoblock heat pump is supposed to be around 4000€ (about 4400 USD), but I don’t have a concrete offer yet because my house planning isn’t that advanced. I just want to understand it beforehand.
Between a split heat pump and a ground source heat pump with a horizontal collector, the additional cost in a current construction project is only 3000€ (about 3300 USD), but the homeowner is also doing a lot of the work on the horizontal collector themselves.
Between a split heat pump and a ground source heat pump with a horizontal collector, the additional cost in a current construction project is only 3000€ (about 3300 USD), but the homeowner is also doing a lot of the work on the horizontal collector themselves.
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