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planning:thermal_protection:integrated_thermal_protection [2016/08/22 17:29] – [The level of insulation in Passive Houses] kdreimaneplanning:thermal_protection:integrated_thermal_protection [2021/06/11 15:28] (current) – [See also] nsukhija
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 In warmer climates or during summer months, [[[[Planning:Thermal protection:Integrated thermal protection#Detailed information on Passive House insulation|good insulation]] also provides **protection against heat**. Effective sunshades for the windows and sufficient ventilation are also essential to ensure a maximum level of comfort during hot periods.   In warmer climates or during summer months, [[[[Planning:Thermal protection:Integrated thermal protection#Detailed information on Passive House insulation|good insulation]] also provides **protection against heat**. Effective sunshades for the windows and sufficient ventilation are also essential to ensure a maximum level of comfort during hot periods.  
  
-Good insulation and airtight construction have proved to be extremely effective in Passive Houses.  Another essential principle is "[[basics:building_physics_-_basics:thermal_bridges#What defines thermal bridge free design|thermal bridge free design]]": the insulation is applied **without any “weak spots”** around the whole building so as to eliminate cold corners as well as excessive heat losses. This method is another essential principle assuring a high level of quality and comfort in Passive Houses while preventing damages due to moisture build up.\\+Good insulation and airtight construction have proved to be extremely effective in Passive Houses.  Another essential principle is "[[basics:building_physics_-_basics:What defines thermal bridge free design?|thermal bridge free design]]": the insulation is applied **without any “weak spots”** around the whole building so as to eliminate cold corners as well as excessive heat losses. This method is another essential principle assuring a high level of quality and comfort in Passive Houses while preventing damages due to moisture build up.\\
 \\ \\
  
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 What does this imply for the insulating building envelope?  What does this imply for the insulating building envelope? 
 +
 +----
 +
  
 ==== Insulating materials ==== ==== Insulating materials ====
-Such low U-values can only be achieved with very well-insulating materials.  The following table shows how thick an external building element, consisting only of the material specified, should be in order to achieve a typical Passive House U-value of 0.13 W/(m²K).\\ +
-\\+
 ^   material     thermal conductivity\\ //W/mK//     thickness required for U=0.13 W/(m²K)\\ //m//   ^ ^   material     thermal conductivity\\ //W/mK//     thickness required for U=0.13 W/(m²K)\\ //m//   ^
 |   reinforced concrete     2.3     17.30   | |   reinforced concrete     2.3     17.30   |
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 |   **vacuum insulation material (silica)**     **0.008**     **0.06**   | |   **vacuum insulation material (silica)**     **0.008**     **0.06**   |
 |   **vacuum insulation material (high vacuum)**     **0.002**     **0.015**   |\\ |   **vacuum insulation material (high vacuum)**     **0.002**     **0.015**   |\\
 +Such low U-values can only be achieved with very well-insulating materials.  The following table shows how thick an external building element, consisting only of the material specified, should be in order to achieve a typical Passive House U-value of 0.13 W/(m²K).\\
 \\ \\
 +
 +[{{ :picopen:passive_house_external_wall.png|//**Examples of super-insulated external wall superstructures suitable for Passive Houses**//}}]
 The table graphically demonstrates that: The table graphically demonstrates that:
   * Building envelope areas with reasonable component thicknesses are only possible if the insulating effect is mostly achieved with good insulating material.    * Building envelope areas with reasonable component thicknesses are only possible if the insulating effect is mostly achieved with good insulating material. 
 +
   * All materials listed in the lower part of the table are ideal for this. Combined structures with other building materials are possible, and in some cases necessary: e.g. a concrete wall insulated on the outside, or a monolithic wall consisting of porous concrete and mineral foam insulation panels. The lower the thermal conductivity of the insulation material used is, the thinner the superstructures will be.         * All materials listed in the lower part of the table are ideal for this. Combined structures with other building materials are possible, and in some cases necessary: e.g. a concrete wall insulated on the outside, or a monolithic wall consisting of porous concrete and mineral foam insulation panels. The lower the thermal conductivity of the insulation material used is, the thinner the superstructures will be.      
  
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 -> State of the art vacuum insulation materials allow for very slender, yet highly insulated, building elements.\\ -> State of the art vacuum insulation materials allow for very slender, yet highly insulated, building elements.\\
 -> “Semi-translucent envelopes" are another, somewhat different approach which has also proven to provide efficient insulation for buildings.\\ It directs a certain share of the global radiation inside the insulated construction thereby\\ reducing the temperature differences and achieving a lower equivalent U-value.\\  -> “Semi-translucent envelopes" are another, somewhat different approach which has also proven to provide efficient insulation for buildings.\\ It directs a certain share of the global radiation inside the insulated construction thereby\\ reducing the temperature differences and achieving a lower equivalent U-value.\\ 
-\\ + 
-|{{:picopen:passive_house_external_wall.png|}}| +---- 
-|//**Examples of super-insulated external wall\\  + 
- superstructures suitable for Passive Houses**//|\\ + 
-\\+
  
 ==== What about affordability? ==== ==== What about affordability? ====
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 The values for a typical wall of an old building, which is not even poorly insulated, are given in the first row. The occupants will spend about € 644 each year just to compensate for the heat losses through 100 m² of this wall.  Applying insulation according to the Passive House standard, heat losses will decrease by a factor of 10; the annual costs for the energy loss through the external wall are reduced to less than 64 €/year. This means: The values for a typical wall of an old building, which is not even poorly insulated, are given in the first row. The occupants will spend about € 644 each year just to compensate for the heat losses through 100 m² of this wall.  Applying insulation according to the Passive House standard, heat losses will decrease by a factor of 10; the annual costs for the energy loss through the external wall are reduced to less than 64 €/year. This means:
  
-|€ 580 savings in heating costs every year!|+**€ 580 savings in heating costs every year!**
  
 What should be done in order to achieve these savings?  What should be done in order to achieve these savings? 
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 //Our suggestion//:  //Our suggestion//: 
   * Wait until it's time to repaint the external wall or repair the plaster – it won't be too long unless you’ve already just done it. The scaffolding and for painting the facade will end up costing you around € 2,500, an investment you will have to make anyways.    * Wait until it's time to repaint the external wall or repair the plaster – it won't be too long unless you’ve already just done it. The scaffolding and for painting the facade will end up costing you around € 2,500, an investment you will have to make anyways. 
 +
   * Next, you should ask your bank for a mortgage loan which you can pay off in instalments of 580€/yr including interest and repayment, over a period of 20 years.  The size of the loan will be around € 8,300 at the current interest rate of approx. 3.5 % . (Please note again that this calculation is based on figures typical for Germany; interest rates may vary in other countries). Add to this the 2500 € spent on the scaffolding and repainting and you will end up with a total investment of around € 10,800 - a rather small investment considering the vast savings in heating costs in the future. For new constructions, top quality insulation is even more affordable.\\   * Next, you should ask your bank for a mortgage loan which you can pay off in instalments of 580€/yr including interest and repayment, over a period of 20 years.  The size of the loan will be around € 8,300 at the current interest rate of approx. 3.5 % . (Please note again that this calculation is based on figures typical for Germany; interest rates may vary in other countries). Add to this the 2500 € spent on the scaffolding and repainting and you will end up with a total investment of around € 10,800 - a rather small investment considering the vast savings in heating costs in the future. For new constructions, top quality insulation is even more affordable.\\
 \\ \\
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 Existing Passive Houses illustrate that thicker layers of insulation required for conventional insulation materials can easily be realised: Existing Passive Houses illustrate that thicker layers of insulation required for conventional insulation materials can easily be realised:
   * Most constructions provide **plenty of space for insulation**.  If there is no space or adding space would involve additional cost, one can resort to better quality insulation materials.   * Most constructions provide **plenty of space for insulation**.  If there is no space or adding space would involve additional cost, one can resort to better quality insulation materials.
 +
   * Thicker layers of insulation are easy to handle; applying them required hardly more effort than that needed for thinner layers, provided that it is applied properly.  Of course, increased levels of insulation will cost more -  however, insulation materials are **relatively inexpensive**.     * Thicker layers of insulation are easy to handle; applying them required hardly more effort than that needed for thinner layers, provided that it is applied properly.  Of course, increased levels of insulation will cost more -  however, insulation materials are **relatively inexpensive**.  
 +
   * Passive-House-suitable components for building envelopes are available for **all types of constructions**.  This has already been demonstrated in all kinds of Passive Houses:  brickwork constructions (cavity-wall, wall with a compound insulation system or curtain-wall  facade), pre-fabricated building elements consisting of lightweight concrete, prefabricated concrete building elements, timber constructions (classical or lightweight construction beams), formwork element techniques, metal structure building elements and semi-translucent wall superstructures.   * Passive-House-suitable components for building envelopes are available for **all types of constructions**.  This has already been demonstrated in all kinds of Passive Houses:  brickwork constructions (cavity-wall, wall with a compound insulation system or curtain-wall  facade), pre-fabricated building elements consisting of lightweight concrete, prefabricated concrete building elements, timber constructions (classical or lightweight construction beams), formwork element techniques, metal structure building elements and semi-translucent wall superstructures.
 +
   * Measurements in completed Passive Houses have shown that the insulation effect of "thick insulation layers" exactly meets the expectations.  The actual heat losses were just as small as calculated and the houses stayed warm with the minimum heat input stated.  This is proven by thermal images (see below) which reveal clearly elevated temperatures at the interior surfaces of the building.  Highly insulating components, as used in Passive Houses, have significant advantages over standard building envelopes which are usually poorly or moderately insulated.\\   * Measurements in completed Passive Houses have shown that the insulation effect of "thick insulation layers" exactly meets the expectations.  The actual heat losses were just as small as calculated and the houses stayed warm with the minimum heat input stated.  This is proven by thermal images (see below) which reveal clearly elevated temperatures at the interior surfaces of the building.  Highly insulating components, as used in Passive Houses, have significant advantages over standard building envelopes which are usually poorly or moderately insulated.\\
 \\ \\
-Due to the low heat losses, **interior surface stay at the same pleasant temperature year round** – even without heating surfaces in the components.  As a result, the difference between the radiation temperatures from various directions in the room is small, which is a prerequisite for excellent [[basics:building_physics_-_basics:thermal_comfort|comfort]].  The high interior surface temperatures also help **prevent condensation on the surface of the components**.  With normal usage, damage due to moisture build up in external building components can be practically excluded in the Passive House.  This has also been proven in practice. \\ +Due to the low heat losses, **interior surface stay at the same pleasant temperature year round** – even without heating surfaces in the components.  As a result, the difference between the radiation temperatures from various directions in the room is small, which is a prerequisite for excellent [[basics:building_physics_-_basics:thermal_comfort|comfort]].  The high interior surface temperatures also help **prevent condensation on the surface of the components**.  With normal usage, damage due to moisture build up in external building components can be practically excluded in the Passive House.  This has also been proven in practice. \\ 
-\\ + 
-|   {{ :picopen:thermo_ext_wall_passive_house_en.png }}   | +[{{ :picopen:thermo_ext_wall_passive_house_en.png| **Thermography (infrared image) of the base point of a Passive House taken at the inside of an external wallAverage surface temperature approx. 20°C Minimum temperature at the edge 19°C**}}] 
-|//**Thermography (infrared image) of the base point of a\\  + 
-Passive House taken at the inside of an external wall\\ + 
-Average surface temperature approx. 20°C\\  +In warmer climates or during summer months the interior surface temperature is also close to the indoor air temperature which means that it is lower than that of poorly insulated components which allow heat to be transported from the outside towards the inside. Highly insulated constructions have a **high temperature amplitude attenuation** reducing the temperature fluctuation of external building components, even with very small masses (e.g. double plaster board).  This effect is so great that it provides for **optimal “summer behaviour” of the component**.  What is even more important though is the long time constant of the building due to the good insulation, which allows for the full utilisation of the thermally connected inner building mass.  As a result, a Passive House in Central Europe can be cooled by night-ventilation and will stay pleasantly cool throughout the day, provided that solar radiation is limited to a reasonable extent.  The "summer case" should be just as well-planned as the winter situation: the [[planning:calculating_energy_efficiency:phpp_-_the_passive_house_planning_package|Passive House Planning Package (PHPP)]] is an excellent tool for this purpose.\\ 
-Minimum temperature at the edge 19°C** + 
-//|\\ +To a certain extent, highly insulated components mitigate any **remaining thermal bridges** compared with moderately insulated components – this is particularly important in [[planning:refurbishment_with_passive_house_components:thermal_envelope:minimising_thermal_bridges|refurbishments]].  Although people tend to believe it must be the other way round, this has been proven to be true in numerous cases and can be explained quite simply:  In highly insulated buildings the supporting structures and the inner component layer are protected by thick layers of insulation and stay evenly warm in continuous areas.  As a result, they aren’t even affected by minor thermal bridges. In poorly insulated constructions on the other hand, great parts of the structure are already cold. Additional thermal bridges quickly cause temperatures to fall below the dew point. Nevertheless, thermal bridges do cause additional heat losses in Passive Houses too. That is why, in spite of the large error margin, we recommend that thermal bridges be reduced to a minimum when designing a Passive House. 
-\\ + 
-In warmer climates or during summer months the interior surface temperature is also close to the indoor air temperature which means that it is lower than that of poorly insulated components which allow heat to be transported from the outside towards the inside. Highly insulated constructions have a **high temperature amplitude attenuation** reducing the temperature fluctuation of external building components, even with very small masses (e.g. double plaster board).  This effect is so great that it provides for **optimal “summer behaviour” of the component**.  What is even more important though is the long time constant of the building due to the good insulation, which allows for the full utilisation of the thermally connected inner building mass.  As a result, a Passive House in Central Europe can be cooled by night-ventilation and will stay pleasantly cool throughout the day, provided that solar radiation is limited to a reasonable extent.  The "summer case" should be just as well-planned as the winter situation: the [[planning:calculating_energy_efficiency:phpp_-_the_passive_house_planning_package|Passive House Planning Package (PHPP)]] is an excellent tool for this purpose.\\ + 
-\\ +----
-To a certain extent, highly insulated components mitigate any **remaining thermal bridges** compared with moderately insulated components – this is particularly important in [[planning:refurbishment_with_passive_house_components:thermal_envelope:minimising_thermal_bridges|refurbishments]].  Although people tend to believe it must be the other way round, this has been proven to be true in numerous cases and can be explained quite simply:  In highly insulated buildings the supporting structures and the inner component layer are protected by thick layers of insulation and stay evenly warm in continuous areas.  As a result, they aren’t even affected by minor thermal bridges. In poorly insulated constructions on the other hand, great parts of the structure are already cold. Additional thermal bridges quickly cause temperatures to fall below the dew point. Nevertheless, thermal bridges do cause additional heat losses in Passive Houses too. That is why, in spite of the large error margin, we recommend that thermal bridges be reduced to a minimum when designing a Passive House.+
  
 ===== See also ===== ===== See also =====
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 [[planning:thermal_protection:don_t_save_on_the_insulation|]] [[planning:thermal_protection:don_t_save_on_the_insulation|]]
  
-[[planning:thermal_protection:windows:requirements_for_windows:required_u-values_for_passive_house_windows|Required U-values for Passive House windows]]+[[planning:thermal_protection:windows:requirements_for_windows:required_u-values_for_passive_house_windows|Required U-values for Passive House windows]]  {{:picopen:members_only.png?25|}}
  
 [[planning:calculating_energy_efficiency:phpp_-_the_passive_house_planning_package:u-values|PHPP - The overall heat transfer coefficient or U-value]] [[planning:calculating_energy_efficiency:phpp_-_the_passive_house_planning_package:u-values|PHPP - The overall heat transfer coefficient or U-value]]
  
-[[planning:refurbishment with Passive House components:thermal envelope:Insulation measures for the external envelope]]+[[planning:refurbishment with Passive House components:thermal envelope:Insulation measures for the external envelope]]  {{:picopen:members_only.png?25}}
  
 [[basics:passive_houses_in_different_climates:passive_houses_in_cold_climates:frost-free_foundations|]] [[basics:passive_houses_in_different_climates:passive_houses_in_cold_climates:frost-free_foundations|]]
  
 [[basics:passive_houses_in_different_climates:passive_house_in_tropical_climates:interior_insulation_in_tropical_climates|]] [[basics:passive_houses_in_different_climates:passive_house_in_tropical_climates:interior_insulation_in_tropical_climates|]]
 +
 +[[phi_publications:Nr.48 Heat losses towards the ground|Heat losses towards the ground]]  {{:picopen:members_only.png?25}}
 +
 +[[certification:addendum_concerning_the_use_of_vacuum_insulation]]
  
 ===== Multimedia ===== ===== Multimedia =====
  
 [[http://www.passivehouse-international.org/index.php?page_id=181#insulationandairtightness|Video on insulation and airtightness]] [[http://www.passivehouse-international.org/index.php?page_id=181#insulationandairtightness|Video on insulation and airtightness]]
planning/thermal_protection/integrated_thermal_protection.1471879769.txt.gz · Last modified: 2016/08/22 17:29 by kdreimane