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basics:summer [2019/04/17 09:34]
cblagojevic [The influence of the window size and quality of glazing]
basics:summer [2020/08/05 16:18] (current)
wfeist [Base case of a Passive House with tilted windows when required]
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 ===== Summer climate in the Passive House – an important issue ===== ===== Summer climate in the Passive House – an important issue =====
  
-The question of low-energy buildings overheating in summer "due to their high level of insulation"​ is still one that is frequently raised in the public debate.((First of all, some general remarks concerning the laws of physics: **insulation does not "​create"​ any additional heat**; it only reduces the heat exchange between systems with different temperatures. ​ Therefore, it also protects a cool system from gaining heat from the surroundings. ​ For this reason, cooling devices are thermally protected – a popular example is that of keeping chilled water cool in a (well-insulating) thermos flask.)) Practical experience with Passive Houses has clearly shown that these houses have a pleasant (cool) indoor climate even during excessively hot periods. However, this requires **professional planning**, made possible by reliable tools like the [[planning:​calculating_energy_efficiency:​phpp_-_the_passive_house_planning_package|PHPP]]. This article deals with the summer characteristics of Passive Houses in climates such as that in Central Europe – where residential buildings typically ​do not require active cooling.\\+The question of low-energy buildings overheating in summer "due to their high level of insulation"​ is still one that is frequently raised in the public debate.((First of all, some general remarks concerning the laws of physics: **insulation does not "​create"​ any additional heat**; it only reduces the heat exchange between systems with different temperatures. ​ Therefore, it also protects a cool system from gaining heat from the surroundings. ​ For this reason, cooling devices are thermally protected – a popular example is that of keeping chilled water cool in a (well-insulating) thermos flask.)) ​In this study we document research on a residential passive houses in climates, where a passive temperature control in summer is possible (as was up to the year 2003 the case in most parts of Central Europe). ​Practical experience with such passive summer performance of Passive Houses has clearly shown that these houses have a pleasant (cool) indoor climate even during excessively hot Central European ​periods. However, this requires **professional planning**, made possible by reliable tools like the [[planning:​calculating_energy_efficiency:​phpp_-_the_passive_house_planning_package|PHPP]]. The PHPP implemented a [[:​a_simplified_method_for_determining_thermal_comfort_in_summer_for_buildings_without_active_cooling|passive cooling sheet]]. This article deals with the summer characteristics of Passive Houses in climates such as that in Central Europe – where residential buildings typically ​did not require active cooling ​so far. This may change with climate change, if the frequency of tropical nights will further increase.\\
 \\ \\
 |{{ :​picopen:​gemessene_sommertemperaturen.png?​400 }}| |{{ :​picopen:​gemessene_sommertemperaturen.png?​400 }}|
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 **Thermal building simulations** are used to determine the summer characteristics of Passive Houses built according to **different construction methods** and having a **different orientation** – taking account of the type and level of shading and ventilation. The first systematic investigation was carried out in the "​Passive House Summer Climate Study" which was completed in 1998 ([[basics:​Summer#​Literature|[Feist 1998a] ]]). The study was the result of the joint research project carried out on behalf of G&H Ladenburg, ISORAST GmbH Taunusstein,​ Nordhessische Kalksandsteinwerke GmbH&​Co;​ Rasch&​Partner GmbH Darmstadt; Schwenk Dämmtechnik GmbH Landsberg and VEGLA GmbH Aachen. ​ We should explicitly like to thank the initiators at this point. Since then, the findings have also been confirmed in practice in **numerous realised Passive Houses**. ​ A metrological concomitant study, in which the focal point was on the summer situation, was published in [[basics:​Summer#​Literature|[Peper/​Feist 2002] ]]. **Thermal building simulations** are used to determine the summer characteristics of Passive Houses built according to **different construction methods** and having a **different orientation** – taking account of the type and level of shading and ventilation. The first systematic investigation was carried out in the "​Passive House Summer Climate Study" which was completed in 1998 ([[basics:​Summer#​Literature|[Feist 1998a] ]]). The study was the result of the joint research project carried out on behalf of G&H Ladenburg, ISORAST GmbH Taunusstein,​ Nordhessische Kalksandsteinwerke GmbH&​Co;​ Rasch&​Partner GmbH Darmstadt; Schwenk Dämmtechnik GmbH Landsberg and VEGLA GmbH Aachen. ​ We should explicitly like to thank the initiators at this point. Since then, the findings have also been confirmed in practice in **numerous realised Passive Houses**. ​ A metrological concomitant study, in which the focal point was on the summer situation, was published in [[basics:​Summer#​Literature|[Peper/​Feist 2002] ]].
  
-In this paper some parts of the study are summarised and substantiated based on existing measurement results. ​ An earlier version of this article was published in 1999 in the Protocol Volume of the Working Group for Cost-efficient Passive Houses ​ Volume 15 ([[basics:​Summer#​Literature|[Feist 1999] ]]). A procedure was developed in this working group with which the results for the summer case could be determined more easily. ​  This PHI Summer Case procedure has been documented in the Protocol Volume. ​ Since 2000 the procedure has been  included ​ in the form of spreadsheet formulae** in the PHPP** (Passive House Planning Package) [[basics:​Summer#​Literature|[PHPP 2007] ]]. Each planner of a Passive House can determine the influences, as dealt with below, for his/her own building project by using this and thus achieve a comfortable summer climate by designing the building professionally.\\+In this paper some parts of the study are summarised and substantiated based on existing measurement results. ​ An earlier version of this article was published in 1999 in the Protocol Volume of the Working Group for Cost-efficient Passive Houses ​ Volume 15 ([[basics:​Summer#​Literature|[Feist 1999] ]]). A procedure was developed in this working group with which the results for the summer case could be determined more easily. ​  This PHI Summer Case procedure has been documented in the Protocol Volume. ​ Since 2000 the procedure has been  included ​ in the form of [[:​a_simplified_method_for_determining_thermal_comfort_in_summer_for_buildings_without_active_cooling|spreadsheet]] formulae** in the PHPP** (Passive House Planning Package) [[basics:​Summer#​Literature|[PHPP 2007] ]]. Each planner of a Passive House can determine the influences, as dealt with below, for his/her own building project by using this and thus achieve a comfortable summer climate by designing the building professionally.\\
 \\ \\
  
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 The analyses are based on plans of the inhabited Passive House in Darmstadt-Kranichstein. ​ The plans of a mid-terrace house were reduced to a simpler basic model for the optimisation. The basic model is clear enough while reflecting the zoning of the house and allowing for the simple modification of the essential characteristics of the model. The model with seven zones has been described in detail ([[Basics:​Summer#​Literature|in [Feist 1993] ]]):\\ The analyses are based on plans of the inhabited Passive House in Darmstadt-Kranichstein. ​ The plans of a mid-terrace house were reduced to a simpler basic model for the optimisation. The basic model is clear enough while reflecting the zoning of the house and allowing for the simple modification of the essential characteristics of the model. The model with seven zones has been described in detail ([[Basics:​Summer#​Literature|in [Feist 1993] ]]):\\
 \\ \\
-|{{:​picopen:​passive_house_da_section.png?400}}|**//zone -I\\ \\ zone 0\\ \\ zone I\\ \\ zone II\\ \\ zone III\\ \\ zone IV\\ \\ zone V\\ \\ zone VI\\ \\ zone VII//​**|//​ground temperature ​ 1 metre below the floor slab\\ \\ outdoor air temperature\\ \\ basement\\ \\ ground floor (front): living area\\ \\ ground floor (rear): kitchen ​and entrance area\\ \\ upper floor (front): children’s bedroom\\ \\ upper floor (rear): bedroom\\ \\ attic: guest room/​study\\ \\ centre: bathrooms ​and staircase//​|+|{{:​picopen:​section_with_zones.png?/480}}|**//zone -I\\ \\ zone 0\\ \\ zone I\\ \\ zone II\\ \\ zone III\\ \\ zone IV\\ \\ zone V\\ \\ zone VI\\ \\ zone VII//​**|//​ground temperature ​1m below floor slab\\ \\ outdoor air temperature\\ \\ basement\\ \\ ground floor (front):​living area\\ \\ ground floor (rear):​kitchen ​&entrance area\\ \\ upper floor(front):​ children’s bedroom\\ \\ upper floor(rear):​ bedroom\\ \\ attic: guest room/​study\\ \\ centre: bathrooms ​staircase//​|
 |//**__Fig. 2__:  cross-section of the Darmstadt Kranichstein Passive House including the individual zones.**//​|||\\ |//**__Fig. 2__:  cross-section of the Darmstadt Kranichstein Passive House including the individual zones.**//​|||\\
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 The model parameters have been documented in detail in the study [[basics:​Summer#​Literature|[Feist 1998a] ]]; __//**Tab. 1**//__ gives an overview of some of the essential parameters for this base case. The model parameters have been documented in detail in the study [[basics:​Summer#​Literature|[Feist 1998a] ]]; __//**Tab. 1**//__ gives an overview of some of the essential parameters for this base case.
  
-|{{ :picopen:phpp_daten_004.gif }}| +|{{:picprivate:pb15_02_table_2a.png?/​640 ​}}| 
-|//​**__Table 1:__ Parameters for the Darmstadt-Kranichstein Passive House (as built, simplified model)\\ during summer (mid-terrace house): U-values, ventilation,​ inernal sources**//​|\\+|//​**__Table 1:__ Parameters for the Darmstadt-Kranichstein Passive House (as built, ​using data from the simplified model, but all zones summed up) during summer ​period ​(mid-terrace house): U-values, ventilation,​ inernal sources**//​|\\
 \\ \\
 ==== Evaluation based on operative temperatures ==== ==== Evaluation based on operative temperatures ====
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 > If temperatures in the house exceed 21 °C __and__ the external temperature is lower than the indoor temperature,​\\ **in each room a window is placed in the "​tilted"​ position**. ​ This is possible in the Darmstadt Kranichstein Passive House, where there is at least one window with a turn-and-tilt fitting in each habitable room. > If temperatures in the house exceed 21 °C __and__ the external temperature is lower than the indoor temperature,​\\ **in each room a window is placed in the "​tilted"​ position**. ​ This is possible in the Darmstadt Kranichstein Passive House, where there is at least one window with a turn-and-tilt fitting in each habitable room.
  
-The tilted position of the window leads to considerably higher average air changes. //__**Fig. 7**__// shows that due to this, the temperatures in the house sink perceptibly to constantly comfortable levels during the summer.\\+The tilted position of the window leads to considerably higher average air changes. //__**Fig. 7**__// shows that due to this, the temperatures in the house sink perceptibly to constantly comfortable levels during the summer. This is one of several reasons, why we always recommend to have at least one window in each room openable and also have a tool to keep it fixed at a specific level [[operation:​operation_and_experience:​user_behaviour|(e.g.,​ a "​tilted window"​)]]. \\
 \\ \\
 |{{ :​picopen:​kippfenster_jahr_016.gif?​600 }}| |{{ :​picopen:​kippfenster_jahr_016.gif?​600 }}|
basics/summer.1555486483.txt.gz · Last modified: 2019/04/17 09:34 by cblagojevic