basics:internal_heat_capacity
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basics:internal_heat_capacity [2014/09/18 18:19] – external edit 127.0.0.1 | basics:internal_heat_capacity [2022/01/18 15:34] (current) – [Literature] yaling.hsiao@passiv.de | ||
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In order to obtain the results given below, many simulations based on the entire year were carried out for various residential buildings with respectively controlled varying characteristics. | In order to obtain the results given below, many simulations based on the entire year were carried out for various residential buildings with respectively controlled varying characteristics. | ||
* In the first part, the internal heat capacity was varied, | * In the first part, the internal heat capacity was varied, | ||
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* in the second part, the externally applied thermal protection was varied. | * in the second part, the externally applied thermal protection was varied. | ||
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* **Why is the influence so small? | * **Why is the influence so small? | ||
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* **Why is the influence so high all the same?** In fact, for this building there is a certain seasonal storage effect. | * **Why is the influence so high all the same?** In fact, for this building there is a certain seasonal storage effect. | ||
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* The frequency of overheating events (left axis, red curve) as a percentage of the hours in a year in which the operative temperature exceeds 25 °C. This is a measure of the “discomfort” or more correctly, the length of the periods in which comfort does not prevail. | * The frequency of overheating events (left axis, red curve) as a percentage of the hours in a year in which the operative temperature exceeds 25 °C. This is a measure of the “discomfort” or more correctly, the length of the periods in which comfort does not prevail. | ||
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* The annual heating demand (right axis, green curve). This hardly varies and is nothing new; it confirms the result already obtained above.\\ | * The annual heating demand (right axis, green curve). This hardly varies and is nothing new; it confirms the result already obtained above.\\ | ||
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* **Why is the influence still so great?** It is a widely held view that insulation that is “even thicker” than the good insulation already present initially serves no purpose, (because the insulation does not have any effect on other heat losses which predominate). This view is incorrect, as proven by the analysis shown. The reason for this is that in the energy balance of a Passive House, it is actually the transmission heat losses that are still dominant or recurrently predominant – ventilation heat losses are very small due to the heat recovery; and the losses through windows are over compensated by their solar gains. | * **Why is the influence still so great?** It is a widely held view that insulation that is “even thicker” than the good insulation already present initially serves no purpose, (because the insulation does not have any effect on other heat losses which predominate). This view is incorrect, as proven by the analysis shown. The reason for this is that in the energy balance of a Passive House, it is actually the transmission heat losses that are still dominant or recurrently predominant – ventilation heat losses are very small due to the heat recovery; and the losses through windows are over compensated by their solar gains. | ||
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* **Why don’t we recommend even better insulation in spite of this?** It is not worthwhile to increase the level of insulation above that which is necessary for achieving the Passive House Standard. Although thicker insulation continues to save additional heating energy (even down to zero, if insulated thickly enough), saving from 2007 kWh/a to 791 kWh/a only " | * **Why don’t we recommend even better insulation in spite of this?** It is not worthwhile to increase the level of insulation above that which is necessary for achieving the Passive House Standard. Although thicker insulation continues to save additional heating energy (even down to zero, if insulated thickly enough), saving from 2007 kWh/a to 791 kWh/a only " | ||
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* The frequency of overheating events (left axis, red curve) as a percentage of the hours in a year on which the operative temperature exceeds 25 °C. This is a measure of the “discomfort” or more correctly, the length of the periods in which comfort does not prevail. | * The frequency of overheating events (left axis, red curve) as a percentage of the hours in a year on which the operative temperature exceeds 25 °C. This is a measure of the “discomfort” or more correctly, the length of the periods in which comfort does not prevail. | ||
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* The annual heating demand (right axis, green curve). | * The annual heating demand (right axis, green curve). | ||
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However, the internal heat capacity is not the most important influencing parameter for summer comfort. | However, the internal heat capacity is not the most important influencing parameter for summer comfort. | ||
* Possibilities for increased ventilation, | * Possibilities for increased ventilation, | ||
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* shading from high solar gains | * shading from high solar gains | ||
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* and restriction of internal heat loads | * and restriction of internal heat loads | ||
are the more important parameters. | are the more important parameters. | ||
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===== Literature ===== | ===== Literature ===== | ||
- | **[AkkP-05]** Energiebilanz und Temperaturverhalten; | + | **[AkkP-05]** Energiebilanz und Temperaturverhalten; |
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- | **[AkkP-33]** Passivhaus-Schulen; | + | **[AkkP-33]** Passivhaus-Schulen; |
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**[Feist 1993]** Feist, Wolfgang: Passivhäuser in Mitteleuropa; | **[Feist 1993]** Feist, Wolfgang: Passivhäuser in Mitteleuropa; | ||
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- | **[Feist 1998a]** Feist, Wolfgang: Passivhaus Sommerklima-Studie; | + | **[Feist 1998a]** Feist, Wolfgang: Passivhaus Sommerklima-Studie; |
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- | **[Schnieders 2009]** Schnieders, Jürgen: **Passive Houses in South West Europe** — A quantitative investigation of some passive and active space conditioning techniques for highly energy efficient dwellings in the South West European region. 2< | + | **[Schnieders 2009]** Schnieders, Jürgen: **Passive Houses in South West Europe** — A quantitative investigation of some passive and active space conditioning techniques for highly energy efficient dwellings in the South West European region. 2< |
basics/internal_heat_capacity.1411057157.txt.gz · Last modified: 2014/09/18 18:19 by 127.0.0.1