planning:calculating_energy_efficiency:phpp_-_the_passive_house_planning_package:phpp_-_validated_and_proven_in_practice

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planning:calculating_energy_efficiency:phpp_-_the_passive_house_planning_package:phpp_-_validated_and_proven_in_practice [2014/09/18 18:19]
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planning:calculating_energy_efficiency:phpp_-_the_passive_house_planning_package:phpp_-_validated_and_proven_in_practice [2019/02/28 09:18] (current)
cblagojevic
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   * In residential buildings with efficient household appliances, values of about 2.1 W/m² (±0.3) for **internal heat sources** are realistic during the heating period (rather than 5 W/m², as frequently assumed). The PHPP includes a calculation sheet which allows for more accurate determination of the internal heat sources of a specific building project. Assuming unrealistically high internal heat gains would result in unrealistically low values for energy use, suggesting that very low or even zero-energy houses are possible with moderate building standards. Practice has shown that this not true. \\   * In residential buildings with efficient household appliances, values of about 2.1 W/m² (±0.3) for **internal heat sources** are realistic during the heating period (rather than 5 W/m², as frequently assumed). The PHPP includes a calculation sheet which allows for more accurate determination of the internal heat sources of a specific building project. Assuming unrealistically high internal heat gains would result in unrealistically low values for energy use, suggesting that very low or even zero-energy houses are possible with moderate building standards. Practice has shown that this not true. \\
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   * Realistic shading factors and dirt which is always present on surfaces should be taken into account for the calculation of **solar gains**. \\   * Realistic shading factors and dirt which is always present on surfaces should be taken into account for the calculation of **solar gains**. \\
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   * Overall **temperature correction factors** are often set too low for well-insulated buildings: e.g. for top floor ceilings, realistic values for top floor ceilings are in the range of 1.0 rather than 0.8. \\   * Overall **temperature correction factors** are often set too low for well-insulated buildings: e.g. for top floor ceilings, realistic values for top floor ceilings are in the range of 1.0 rather than 0.8. \\
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   * The airtightness value that is actually achieved, i.e. the measured n<​sub>​50</​sub>​ value must be assumed for the "​additional air exchange rate due to **leaks** and window opening"​ - as is done in the PHPP and in DIN EN ISO 832. \\   * The airtightness value that is actually achieved, i.e. the measured n<​sub>​50</​sub>​ value must be assumed for the "​additional air exchange rate due to **leaks** and window opening"​ - as is done in the PHPP and in DIN EN ISO 832. \\
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planning/calculating_energy_efficiency/phpp_-_the_passive_house_planning_package/phpp_-_validated_and_proven_in_practice.txt · Last modified: 2019/02/28 09:18 by cblagojevic