Deliverable 5.1 Report on Available Products and Passive Cooling Solutions. Final Version

Transcription

1 Deliverable 5.1 Report on Available Products and Passive Cooling Solutions Final Version

2 Report prepared under the project Transforming the market from cooling to sustainable summer comfort, supported by the European Commission by the Grant Agreement EIE/07/070/SI Keep Cool II. Project management: Barbara Droeschel Work package leader (WP5): Carlos Laia and Mathieu Richard Authors: PART A: and PART B: Martin Vukits, Dagmar Jähnig The sole responsibility for the content of this report lies with the authors. It does not represent the opinion of the European Communities. The European Commission is not responsible for any use that may be made of the information contained therein.

3 INDEX PART A Product Sheets for Sustainable Summer Confort SOLAR SHADING 1. Summary Overview 2. Light-Directing Blinds 3. External Venetian Blinds 4. Roller Shutters 5. Roller Blinds and Awnings 6. All Indoor Products (blinds, fabrics, curtains, foils) 7. Horizontal Solar Fins, Louvers and Balconies 8. Vertical Solar Fins and Louvers 9. Sun Protection Glass and Sun Protection Foils PART B Report on Passive Cooling Solutions 1. Night Ventilation 2. Burglary and Weather Protection for Free Ventilation 3. Plaster and Plasterboard Integrated with Phase-Change-Material 4. Air-Ground-Heat-Exchanger 5. Decentral Air Conditioning Appliance Integrated with PCM 6. Direct Cooling with Ground Energy Source 7. Water Basin, -wall and -fountain 8. Indoor Plants 9. Daylight Illumination 10. Fans

4 PART A Product sheets for sustainable summer comfort SOLAR SHADING

5 Summary overview Performance data of the various shading systems differ greatly. The table below provides a summary of the functions and features listed in the product factsheets by way of comparison. Each shading variant thus has its own characteristic prof le. Key 1 Maximum achievable energy transmission for use of solar energy / passive heating (based on the g value of the respective glazing) 2 Maximum achievable energy transmission for passive cooling purposes (based on the g value of the respective glazing) 3 Introduction of light through the shading (basic value is respectively the light transmission of the glazing TL) 4 Variability of a shading - Adaptation to changed energy fl ow during heating/cooling period (the higher the value, the more fl exible) 5 Selectivity number (light transmission TL to total energy transmission value gtotal, values above 5 are extremely good) 6 Heat loss through glazing can be reduced by certain shading systems 7 Effects on the cooling requirement of active cooling systems as a result of passive cooling / sun protection 8 Effects on the heating energy requirement during the day as a result of utilisation of solar energy (passive heating) 9 Effects on the heating requirement at night as a result of shading systems 10 Effects on the thermal comfort, e.g. overheating, transmission of cold 11 Effects on the visual comfort, e.g. protection against direct glaring, light density restriction, daylight regulation 12 Effects on psychological factors, in particular view to the outside, contact to the outside world when shading is activated 13 Effect on the electricity requirement for artifi cial lighting as a result of shading systems 14 Preferred installation position / orientation of the shading 15 Wind speed up to that a shading is functional 16 Average expected serviceable life of a product

6 Dynamic Solar Shading With Daylight Transport (in front of/in between/behind glazing) LIGHT-DIRECTING BLINDS PRODUCT DESCRIPTION Light-directing blinds are characterised by their highly ref ective slat curtain. In order to provide the best possible sun protection, the slats are adjusted depending on the position of the sun while diffuse (low-energy) light from the sky is simultaneously transported via the ref ectors (slats) into the room. The energy balance of such systems is optimal, they achieve the best sun protection values, reduce the requirement for artif cial illumination by up to 80 %, and also ensure solar gains for passive room heating. Light-directing blinds are highly eff cient passive cooling systems that, as they are adjustable and retractable, can be adapted very well to the outside conditions(direct and diffuse radiation). In the heating period, signif cant free, natural solar gains can be achieved as the shading system can be retracted to allow the solar energy into the building - passive heating. Light-directing blinds require motorised drives in combination with a user-oriented, automatic control. Motorised light-directing blinds, in connection with motorised drives, a well designed control system and openable windows ensure that no or only little cooling energy is required during the day, while ensuring eff cient cooling at night. PRODUCT WILL PROVIDE Sun protection /passive cooling - Protection against overheating and greenhouse effect. Signif cant reduction of the heat transmission from outside; the load on the active cooling system can be minimised and/or active cooling is not necessary at all. Use of free, renewable solar heat gains / passive heating - The curtain can be retracted and/or adjusted to let in welcome solar heat in winter time, which will reduce the load on the active heating system. Better utilisation of natural daylight and better daylighting strategy - The curtain can be adjusted to let daylight into the room, which reduces the energy requirement for artif cial lighting (internal heat load) by up to 80%. Glare protection - The slats can be adjusted to provide glare protection while, at the same time, directing the daylight - important for computer work. Increased comfort - Mirror slats are normally mounted behind glazing, resulting in relatively high glass surface temperatures despite a low transmission of energy (referred to the room). Heat loss through windows - Closed curtains can signif cantly reduce the heat loss through windows during winter. Contact to the outside world - Since the curtain is very f exible, contact to the outside world is ensured at all times.

7 FACTSHEET Light-directing Blinds IMPORTANT PARAMETERS and Typical Performance Energy transmittance value (g value), total energy transmittance value (g total value) and shading coeff cient (Fc) The energy transmittance value (g value) is the fraction of solar radiation that enters through the window and is converted to heat in the room. The energy transmission is composed of the direct transmission and the secondary heat transmission of the glazing. The total energy transmission value (g total or g t ) indicates the energy transmission for a system that comprises the glazing and the shading; this value is determined according to EN The quality of a shading system is def ned by the shading coeff cient (Fc value) - Fc = g t /g. The lower this value, the more eff cient is the sun protection. Fc = 1.0 no shading Fc = 0.1 very good shading Example - Light-directing blind Glass g = 0.65 (according to EN 410) Glass + solar shading g t = 0.10 (acc to EN 13363) Shading coeff cient Fc = g t /g = 0.15 As slats are tiltable, the shading coeff cient can be adjusted as required. Cooling period - solar shading activated g t = The load on the room climate is only 15% of the sun energy (corresponds to passive house standard). Heating period - solar shading deactivated g t = g = % of the solar energy can be utilised for heating. Effect on energy consumption Cooling period: energy saving of approx 30 kwh/m 2 a and more Heating period: energy saving of up to 10 kwh/m 2 a Heat transfer coeff cient (U value), reduction of heat loss through the window The U value (formerly k value) is the measured value of Depending on the user behaviour, the glazing, the glazing the heat transfer through a component; it is indicated in percentage and the installation position and tightness W/m 2 K. The smaller the U value the better, as less heat is of the curtain, an improvement of the U value by 5-10 % transferred through the component. can be achieved. Example - passive house U value wall 0.12 W/m 2 K U value window 0.80 W/m 2 K Effect on heating energy requirement Saving of up to 5 kwh/m 2 a Light transmission (T L or LT), reduction of power requirement for lighting The light transmittance TL indicates how much of the visible light spectrum (380 nm to 780 nm) is transmitted through a glazing, in percent. A high light transmission value of the glazing (T L > 80 %) is required to ensure good lighting of the room. Ref ector slats that follow the sun offer more eff cient daylight utilisation than shading systems mounted in front of or behind the glazing over the entire window. Effect on energy consumption Saving of artif cial light requirement during the day: up to 30 kwh/m 2 a Other Wind resistance during use Expected serviceable life Not relevant (light-directing systems are protected against outside inf uences by the window glass. Requirement approx 15 years (+/- 5) The values listed in the factsheets are average values from tests and simulations and refer to a building situated at the outskirts of a city; they should indicate the potential of solar shading products in terms of energy savings. The values are not applicable in the individual case, many parameters must be considered depending on the specifi c object, with different results. With regard to the cooling energy, the values refer to a conventional two-pane insulating glass without sun protection With regard to the heating energy, the values refer to a two-pane sun protection glass with low solar gains With regard to the lighting, the values refer to a simple, manually controllable glare protection. Energy values refer to the end energy.

8 Dynamic external solar shading EXTERNAL VENETIAN BLINDS PRODUCT DESCRIPTION The typical characteristic of external Venetian blinds, often called outside Venetian blinds, is the curtain of horizontal slats that can be tilted, raised and lowered. The tilting allows adjustment of the position of the slats in relation to the position of the sun in order to ensure good view to the outside and optimum use of free, natural daylight. Of course, it is possible to raise all the slats, for instance when there is no direct solar radiation or, conversely, if free solar gains are to be utilised. External Venetian blinds are highly eff cient, versatile shading systems that can be adapted very well to the outside climatic conditions, being adjustable and retractable. When solar radiation is too strong, up to 90% of the incident solar energy can be blocked by external Venetian blinds, by ref ection and absorption of the energy, so that overheating of the interior of the building is avoided and load on active cooling systems is drastically reduced - passive cooling. In the heating period, signif cant free, natural solar gains can be achieved as the shading system can be retracted to allow the solar energy into the building - passive heating. External Venetian blinds, in connection with motorised drives, a well designed control system and openable windows ensure that no or only little cooling energy is required during the day, while ensuring eff cient cooling at night; besides, they provide the necessary protection of the private sphere. PRODUCT WILL PROVIDE Sun protection /passive cooling - Protection against overheating and greenhouse effect. Signif cant reduction of heat transmission from outside; the load on the active cooling system can be minimised and/or active cooling is not necessary at all. Use of free, renewable solar heat gains / passive heating - The curtain can be retracted to let in welcome solar heat in winter time, which will reduce the load on the active heating system. Better utilisation of natural daylight and better daylighting strategy - Adjusting the slats according to the position of the sun allows optimum use of natural daylight, while at the same time providing protection against the sun. When selected properly (slat colour and size), the blinds will allow reduction of the energy need for artif cial lighting, which indirectly helps reduce the load on any active cooling system. Glare protection - Reduces the luminance values (the brightness of the light) at the workspace whenever required by law or for better comfort (e.g. computer work). Increased comfort - The surface temperature of the glazing - and thus the room temperature - is considerably reduced when the sun is high and the blinds are down. During the heating period, a retracted blind will ensure relatively higher temperatures on the glass surface, which helps heat the building. Heat loss through windows - During winter, fully closed blinds (at night) can also help slightly reduce the heat loss through windows - depending on the U value of these. Contact to the outside world - As the slats are very f exible and can be adjusted as desired, contact to the outside world is ensured at all times.

9 FACTSHEET External Venetian Blinds IMPORTANT PARAMETERS and Typical Performance Energy transmittance value (g value), total energy transmittance value (g total value) and shading coeff cient (Fc) The energy transmittance value (g value) is the fraction of solar radiation that enters through the window and is converted to heat in the room. The energy transmission is composed of the direct transmission and the secondary heat transmission of the glazing. The total energy transmission value (g total or g t ) indicates the energy transmission for a system that comprises the glazing and the shading; this value is determined according to EN The quality of a shading system is def ned by the shading coeff cient (Fc value) - Fc = g t /g. The lower this value, the more eff cient is the sun protection. Fc = 1.0 no shading Fc = 0.1 very good shading Example - external Venetian blind Glass g = 0.65 (according to EN 410) Glass + solar shading g t = 0.11 (acc to EN 13363) Shading coeff cient Fc = g t /g = 0.15 As slats are tiltable, the shading coeff cient can be adjusted as required) Cooling period - solar shading activated g t = The load on the room climate is only 15% of the sun energy (corresponds to passive house standard). Heating period - solar shading deactivated g t = g = % of the solar energy can be utilised for heating. Effect on energy consumption Cooling period: energy saving of approx 30 kwh/m 2 a and more Heating period: energy saving of up to 10 kwh/m 2 a Heat transfer coeff cient (U value), reduction of heat loss through the window The U value (formerly k value) is the measured value of the heat transfer through a component; it is indicated in W/m 2 K. The smaller the U value the better, as less heat is transferred through the component. Example - passive house U value wall 0.12 W/m 2 K U value window 0.80 W/m 2 K Depending on the user behaviour, the glazing, the glazing percentage and the installation position and tightness of the curtain, an improvement of the U value by 5-10 % can be achieved. Effect on heating energy requirement Saving of up to 5 kwh/m 2 a Light transmission (T L or LT), reduction of power requirement for lighting The light transmittance TL indicates how much of the visible light spectrum (380 nm to 780 nm) is transmitted through a glazing, in percent. A high light transmission value of the glazing (T L > 80 %) is required to ensure good lighting of the room. Slats that can be adjusted in relation to the position of the sun ensure a more eff cient utilisation of daylight than continuous shading systems mounted in front of or behind the glazing. Effect on energy consumption Saving of artif cial light requirement during the day: up to -15 kwh/m 2 a Other Wind resistance during use Expected serviceable life approx m/s approx years The values listed in the factsheets are average values from tests and simulations and refer to a building situated at the outskirts of a city; they should indicate the potential of solar shading products in terms of energy savings. The values are not applicable in the individual case, many parameters must be considered depending on the specifi c object, with different results. With regard to the cooling energy, the values refer to a conventional two-pane insulating glass without sun protection With regard to the heating energy, the values refer to a two-pane sun protection glass with low solar gains With regard to the lighting, the values refer to a simple, manually controllable glare protection. Energy values refer to the end energy.

10 Dynamic external solar shading ROLLER SHUTTERS PRODUCT DESCRIPTION Roller shutters are characterised by a curtain made of many horizontal prof led bars (mostly made of aluminium, plastic or wood) hinged together. These can be raised to open and can be closed tightly for solar protection and darkening purposes; to some extent, roller shutters fulf l some of the security requirements of the user. The entire curtain can be raised, for instance when there is no direct solar radiation or if free solar gains should be used. Special designs may have adjustable slats (similar to blinds) or special prof les to ensure that more natural daylight is utilised better. Roller shutters are very eff cient passive shading systems that can be adapted well to the outside climatic conditions (height adjustable). If solar radiation is too strong, up to 85% of the incident sun energy can be blocked (ref ected and absorbed) from the interior of the building drastically reducing the use of active cooling systems. During the heating period, signif cant solar gains can be achieved as the shading can be deactivated (retracted). Roller shutters, in connection with motorised drives, a well designed control system and openable windows ensure that no or only little cooling energy is required during the day, while ensuring eff cient cooling at night; besides, they provide the necessary protection of the private sphere. PRODUCT WILL PROVIDE Sun protection /passive cooling - Protection against overheating and greenhouse effect. Signif cant reduction of heat transmission from outside; the load on the active cooling system can be minimised and/or active cooling is not necessary at all. Use of free, renewable solar heat gains / passive heating - The curtain can be retracted to let in welcome solar heat in winter time, which will reduce the load on the active heating system. Better utilisation of natural daylight and better daylighting strategy - Depending on the height of the curtain, the amount of daylight can be regulated from 0-100%. Roller shutters are consequently particularly suited for relaxation rooms or bedrooms. Glare protection - Only ensured to a minor extent if curtain is almost closed. Consequence: no contact to the outside world, artif cial light must be switched on. Increased comfort - The surface temperature of the glazing - and thus the room temperature - is considerably reduced when the sun is high and the curtain is down. During the heating period, a closed curtain will ensure relatively higher temperatures on the glass surface, which helps heat the building. Heat loss through windows - Roller shutters can signif cantly reduce the heat loss through windows during winter - depending on the U value of these (between 10 and 40 %). Contact to the outside world - Roller shutters with adjustable slats or specially shaped daylight prof les ensure contact to the outside world even when the curtain is closed.

11 FACTSHEET Roller Shutters IMPORTANT PARAMETERS and Typical Performance Energy transmittance value (g value), total energy transmittance value (g total value) and shading coeff cient (Fc) The energy transmittance value (g value) is the fraction of solar radiation that enters through the window and is converted to heat in the room. The energy transmission is composed of the direct transmission and the secondary heat transmission of the glazing. The total energy transmission value (g total or g t ) indicates the energy transmission for a system that comprises the glazing and the shading; this value is determined according to EN The quality of a shading system is def ned by the shading coeff cient (Fc value) - Fc = g t /g. The lower this value, the more eff cient is the sun protection. Fc = 1.0 no shading Fc = 0.1 very good shading Example - Roller shutter Glass g = 0.65 (according to EN 410) Glass + solar shading g t = 0.14 (acc to EN 13363) Shading coeff cient Fc = g t /g = 0.19 Cooling period - solar shading activated g t = The load on the room climate is only 19% of the sun energy (corresponds to passive house standard). Heating period - solar shading deactivated g t = g = % of the solar energy can be utilised for heating. Effect on energy consumption Cooling period: energy saving of approx 25 kwh/m 2 a and more Heating period: energy saving of up to 10 kwh/m 2 a Heat transfer coeff cient (U value), reduction of heat loss through the window The U value (formerly k value) is the measured value of the heat transfer through a component; it is indicated in W/m 2 K. The smaller the U value the better, as less heat is transferred through the component. Example - passive house U value wall 0.12 W/m 2 K U value window 0.80 W/m 2 K Improvement of the U value depending on the material of the curtain and the tightness of the system in percent according to EN ISO : 3-pane insulating glass (U G 0.8 W/m 2 K) 7-17% 2-pane insulating glass (U G 2.1 W/m 2 K) 16-35% Non insulating glass (U G > 3.0 W/m 2 K) 20-44% Effect on heating energy requirement Saving of 5 to 30 kwh/m 2 a Light transmission (T L or LT), reduction of power requirement for lighting The light transmittance TL indicates how much of the visible light spectrum (380 nm to 780 nm) is transmitted through a glazing, in percent. A high light transmission value of the glazing (T L > 80 %) is required to ensure good lighting of the room. Other Wind resistance during use Expected serviceable life Continuous shading systems reduce the incident light (shading principle). In order to reduce the artif cial light requirement, the height of the curtain must be adapted to the outside light conditions. Effect on energy consumption Conventional roller shutters: additional energy consumption of > 5 kwh/m 2 a Daylight roller shutters: saving of up to 10 kwh/m 2 a approx m/s approx years The values listed in the factsheets are average values from tests and simulations and refer to a building situated at the outskirts of a city; they should indicate the potential of solar shading products in terms of energy savings. The values are not applicable in the individual case, many parameters must be considered depending on the specifi c object, with different results. With regard to the cooling energy, the values refer to a conventional two-pane insulating glass without sun protection With regard to the heating energy, the values refer to a two-pane sun protection glass with low solar gains With regard to the lighting, the values refer to a simple, manually controllable glare protection. Energy values refer to the end energy.

12 Dynamic external solar shading ROLLER BLINDS and AWNINGS PRODUCT DESCRIPTION Roller blinds and awnings are characterised by a curtain made of textile that normally has a transmission value of 2-15% so that one can see through it; besides, the entire curtain can be retracted, for instance when there is no direct solar radiation or, conversely, if free solar gains are to be utilised. When solar radiation is too strong, up to 80% of the incident solar energy can be blocked by external roller blinds and awnings, by ref ection and absorption of the energy, so that overheating of the interior of the building is avoided and load on active cooling systems is drastically reduced - passive cooling. In the heating period, signif cant free, natural solar gains can be achieved as the shading system can be retracted to allow the solar energy into the building - passive heating. Roller blinds and awnings, in connection with motorised drives, a well designed control system and openable windows ensure that no or only little cooling energy is required during the day, while ensuring eff cient cooling at night. PRODUCT WILL PROVIDE Sun protection /passive cooling - Protection against overheating and greenhouse effect. Signif cant reduction of heat transmission from outside; the load on the active cooling system can be minimised and/or active cooling is not necessary at all. Use of free, renewable solar heat gains / passive heating - The curtain can be retracted to let in welcome solar heat in winter time, which will reduce the load on the active heating system. Better utilisation of natural daylight and better daylighting strategy - Transparent screens ensure utilisation of daylight while simultaneously providing protection against the sun. Glare protection - Reduces the luminance values (the brightness of the light) at the workspace whenever required by law or for better comfort (e.g. computer work). Increased comfort - The surface temperature of the glazing - and thus the room temperature - is considerably reduced when the sun is high and the blinds are down. During the heating period, a retracted blind will ensure relatively higher temperatures on the glass surface, which helps heat the building. Heat loss through windows - During winter, fully closed blinds (at night) can also help reduce the heat loss through windows - depending on the U value of these. Contact to the outside world - The view through a textile shading system is determined by its transparency, type of holes and colour of the fabric.

13 FACTSHEET External Roller Blinds and Awnings IMPORTANT PARAMETERS and Typical Performance Energy transmittance value (g value), total energy transmittance value (g total value) and shading coeff cient (Fc) The energy transmittance value (g value) is the fraction of solar radiation that enters through the window and is converted to heat in the room. The energy transmission is composed of the direct transmission and the secondary heat transmission of the glazing. The total energy transmission value (g total or g t ) indicates the energy transmission for a system that comprises the glazing and the shading; this value is determined according to EN The quality of a shading system is def ned by the shading coeff cient (Fc value) - Fc = g t /g. The lower this value, the more eff cient is the sun protection. Fc = 1.0 no shading Fc = 0.1 very good shading Example - Awning Glass g = 0.65 (according to EN 410) Glass + solar shading g t = 0.17 (acc to EN 13363) Shading coeff cient Fc = g t /g = 0.17 Cooling period - solar shading activated g t = The load on the room climate is only 17% of the sun energy (corresponds to passive house standard). Heating period - solar shading deactivated g t = g = % of the solar energy can be utilised for heating. Effect on energy consumption Cooling period: energy saving of approx 25 kwh/m 2 a and more Heating period: energy saving of up to 10 kwh/m 2 a Heat transfer coeff cient (U value), reduction of heat loss through the window The U value (formerly k value) is the measured value of the heat transfer through a component; it is indicated in W/m 2 K. The smaller the U value the better, as less heat is transferred through the component. Example - passive house U value wall 0.12 W/m 2 K U value window 0.80 W/m 2 K Depending on the user behaviour, the glazing, the glazing percentage and the installation position and tightness of the curtain, an improvement of the U value by 5-20 % can be achieved. Effect on heating energy requirement Saving up to 5 kwh/m 2 a Light transmission (T L or LT), reduction of power requirement for lighting The light transmittance TL indicates how much of the visible light spectrum (380 nm to 780 nm) is transmitted through a glazing, in percent. A high light transmission value of the glazing (T L > 80 %) is required to ensure good lighting of the room. Continuous shading systems reduce the incident light. In order to reduce the artif cial light requirement, the height of the curtain or the light transmission must be adapted to the outside light conditions. Effect on energy consumption Higher use of artif cial light during the day, > 5 possible Other Wind resistance during use Expected serviceable life approx 10 m/s (+/- 5) approx years The values listed in the factsheets are average values from tests and simulations and refer to a building situated at the outskirts of a city; they should indicate the potential of solar shading products in terms of energy savings. The values are not applicable in the individual case, many parameters must be considered depending on the specifi c object, with different results. With regard to the cooling energy, the values refer to a conventional two-pane insulating glass without sun protection With regard to the heating energy, the values refer to a two-pane sun protection glass with low solar gains With regard to the lighting, the values refer to a simple, manually controllable glare protection. Energy values refer to the end energy.

14 Dynamic Indoor Solar Shading ALL INDOOR PRODUCTS (blinds, fabrics, curtains, foils) PRODUCT DESCRIPTION The characteristic of indoor shading systems is that they are installed inside the room; due to the physical conditions (conversion of sun energy into thermal radiation) this results in a relatively low sun protection effect. Only highly ref ecting and pure white surface achieve more favourable values thanks to their high degree of ref ection. The type and the materials used for indoor shading devices are relatively insignif cant in terms of the sun protection effect; aluminium slats, foil roller blinds and textile curtains differ primarily by their glare protection effect and by the degree of utilisation of daylight. As far as energy balance is concerned, a combination of indoor shading devices and insulation glazing offers better results than a combination of indoor shading devices and sun protection glazing; even though overall energy transmission is slightly better if sun protection glazing is used, due to the low daylight transmission, the energy requirement for illumination and thus also the cooling required due to the electrically generated internal thermal loads will increase; also, the usable solar gains decrease during the heating period. In connection with a well-thought out control and openable windows, indoor shading devices contribute to lowering the cooling energy requirement during the day while ensuring eff cient cooling at night; in addition, some systems provide the necessary protection of the private sphere. PRODUCT WILL PROVIDE Sun protection /passive cooling - Moderate reduction of heat transmission from outside; the requirement for active cooling may be minimised. Use of free, renewable solar heat gains / passive heating - The curtain can be retracted to let in welcome solar heat in winter time, which will reduce the load on the active heating system. Better utilisation of natural daylight and better daylighting strategy - Adjustable slats and height-adjustable curtains allow optimum use of natural daylight, while at the same time providing protection against the sun. When selected properly (slat colour and size), the blinds will allow reduction of the energy need for artif cial lighting, which indirectly helps reduce the load on any active cooling system. Glare protection - Reduces the luminance values (the brightness of the light) at the workspace whenever required by law or for better comfort (e.g. computer work). Increased comfort - The surface temperatures of indoor shading systems are generally higher than those of comparable outdoor shading devices; this may result in discomfort during summer, whereas in winter, this is usually experienced as comfort. Heat loss through windows - Closed curtains can signif cantly reduce the heat loss through windows - depending on the U value of these. (In comparison, the heat loss is less than for outside shading systems). Contact to the outside world - As the curtains are very f exible and can be adjusted as desired, contact to the outside world is ensured at all times.

15 FACTSHEET all indoor solar shadings (blinds, fabrics, curtains, foils) IMPORTANT PARAMETERS and Typical Performance Energy transmittance value (g value), total energy transmittance value (g total value) and shading coeff cient (Fc) The energy transmittance value (g value) is the fraction Example - Textile inside shading of solar radiation that enters through the window and is Glass g = 0.65 (according to EN 410) converted to heat in the room. The energy transmission is Glass + solar shading g t = 0.40 (acc to EN 13363) composed of the direct transmission and the secondary Shading coeff cient Fc = g t /g = 0.56 heat transmission of the glazing. The total energy transmission value (g total or g t ) indicates the energy transmission for a system that comprises the glazing and the shading; this value is determined according to EN The quality of a shading system is def ned by the shading coeff cient (Fc value) - Fc = g t /g. The lower this value, the more eff cient is the sun protection. Fc = 1.0 no shading Fc = 0.1 very good shading Cooling period - solar shading activated g t = The load on the room climate is only 40% of the sun energy. Values above 0.25 normally do not suff ce to cover peak loads. Heating period - solar shading deactivated g t = g = % of the solar energy can be utilised for heating. Effect on energy consumption Cooling period: energy saving of approx 10 kwh/m 2 a and more Heating period: energy saving of up to 10 kwh/m 2 a Heat transfer coeff cient (U value), reduction of heat loss through the window The U value (formerly k value) is the measured value of Two-dimensional shading systems reduce the incident the heat transfer through a component; it is indicated in light (shading principle). In order to reduce the artif - W/m 2 K. The smaller the U value the better, as less heat is cial light requirement, the height of the curtain must be transferred through the component. adapted to the outside light conditions. Example - passive house U value wall 0.12 W/m 2 K U value window 0.80 W/m 2 K Effect on heating energy requirement Continuous glare protection: additional energy consumption of > 5 kwh/m 2 a Glare protection slats: saving of < 5 kwh/m 2 a Light transmission (T L or LT), reduction of power requirement for lighting The light transmittance TL indicates how much of the Depending on the adjustability of the curtains, light visible light spectrum (380 nm to 780 nm) is transmitted control between 5 and 100 % is possible (tightly closing through a glazing, in percent. systems may also darken a room). A high light transmission value of the glazing (T L > 80 %) is required to ensure good lighting of the room. Effect on energy consumption For light, tiltable slats up to 10 kwh/m 2 a Higher artif cial light requirement for textile shading systems Other Wind resistance during use Expected serviceable life Not relevant approx 10 years (+/- 5 years) The values listed in the factsheets are average values from tests and simulations and refer to a building situated at the outskirts of a city; they should indicate the potential of solar shading products in terms of energy savings. The values are not applicable in the individual case, many parameters must be considered depending on the specifi c object, with different results. With regard to the cooling energy, the values refer to a conventional two-pane insulating glass without sun protection With regard to the heating energy, the values refer to a two-pane sun protection glass with low solar gains With regard to the lighting, the values refer to a simple, manually controllable glare protection. Energy values refer to the end energy.

16 Static external solar shading (swivelling or rigid) Horizontal SOLAR FINS, LOUVERS and BALCONIES PRODUCT DESCRIPTION Horizontally mounted rigid or swivelling shading devices (protruding or mounted to the front) normally fulf l architectural requirements, while simultaneously offering protection against the sun and a largely unobstructed view. Horizontally protruding systems are suited as sun protection for facades facing South; swivelling louvers mounted to the front are suited for low sun altitudes at Eastern and Western facades. Normally, the f ns are made of aluminium, while some are made of glass, stainless steel or fabric. Compared to outside dynamic solar shading systems, horizontally mounted louvers (rigid or swivelling) feature good sun protection values. As these shading systems are permanently present, they can be adapted to different outside conditions only to a certain extent, resulting in a reduced utilisation of diffuse daylight (natural light) and solar gains (passive heating). The low f exibility of the systems consequently also affects the energy balance (cooling, heating, light). Accurate planning of the system is required to ensure optimal sun protection. Front-mounted swivelling shading devices, in connection with motorised drives, a well designed control system and openable windows ensure that no or only little cooling energy is required during the day, while ensuring eff cient cooling at night. The performance data for non-swivelling systems are accordingly lower, with a negative effect on the energy balance. PRODUCT WILL PROVIDE Sun protection /passive cooling - Moderate reduction of heat transmission from outside; however, the load on active cooling systems can be minimised. In the case of horizontally protruding systems on a lightweight construction, thermal problems might still be experienced in the building when sun is low. Use of free, renewable solar heat gains / passive heating - Normally, the system does not provide shading when the sun is low; solar heating is thus ensured. Better utilisation of natural daylight and better daylighting strategy - Rigid horizontal shading systems hardly allow for any utilisation of the zenith light; swivelling louvers, on the other hand, may transmit daylight. Glare protection - When the sun is low, additional glare protection (mounted on the inside) is required. Increased comfort - Protruding louvers only shade the glass surface when the sun is high, however, the introduced heat is highest when the sun is low. Frontmounted swivelling louvers may reduce the surface temperature of the glazing and thus the room temperature. Heat loss through windows - Due to the design of the system, the heat loss through windows during winter cannot be reduced. Contact to the outside world - Contact to the outside world is ensured at all times.

17 FACTSHEET Horizontal Solarfins, Louvers and Balconies IMPORTANT PARAMETERS and Typical Performance Energy transmittance value (g value), total energy transmittance value (g total value) and shading coeff cient (Fc) The energy transmittance value (g value) is the fraction of solar radiation that enters through the window and is converted to heat in the room. The energy transmission is composed of the direct transmission and the secondary heat transmission of the glazing. The total energy transmission value (g total or g t ) indicates the energy transmission for a system that comprises the glazing and the shading. The effectiveness of a permanent horizontal shading is def ned by the shading coeff cient (F 0 value) in DIN V ; it depends on the position of the sun, the orientation of the façade and the form of the shading, and is in the range between 0.6 and 1 (1 no shading effect). Heat transfer coeff cient (U value), reduction of heat loss through the window Example - Large horizontal louvers Glass g = 0.65 (according to EN 410) Glass + solar shading g t = 0.39 (acc to DIN V ) Best shading coeff cient F 0 = 0.6 (South-facing facades) Cooling period (sun protection depends on position of the sun) g t = In the best case scenario, the load on the room climate is only 39% of the sun energy. Values above 0.25 normally do not suff ce to cover peak loads. Heating period (utilisation of solar energy depends on position of the sun) Provided the systems do not produce an own shade, up to 65% of the solar energy can be used for heating when the sun is low. Effect on energy consumption Cooling period: energy saving of up to 10 kwh/m 2 a Heating period: energy saving of up to 10 kwh/m 2 a (effect is lower for unfavourable arrangement) The U value (formerly k value) is the measured value of the heat transfer through a component; it is indicated in W/m 2 K. The smaller the U value the better, as less heat is transferred through the component. No improvement is possible. Effect on heating energy requirement Saving of 0 kwh/m 2 a Example - passive house U value wall 0.12 W/m 2 K U value window 0.80 W/m 2 K Light transmission (T L or LT), reduction of power requirement for lighting The light transmittance TL indicates how much of the visible light spectrum (380 nm to 780 nm) is transmitted through a glazing, in percent. A high light transmission value of the glazing (T L > 80 %) is required to ensure good lighting of the room. A permanently mounted shading system will result in a loss of valuable daylight (diffuse radiation) particularly during times of the day and year with little light. Effect on energy consumption Increased requirement for artif cial light during the day, > 5 kwh/m 2 a Other Wind resistance during use Expected serviceable life Requirement > 30 m/s (as non retractable) approx years The values listed in the factsheets are average values from tests and simulations and refer to a building situated at the outskirts of a city; they should indicate the potential of solar shading products in terms of energy savings. The values are not applicable in the individual case, many parameters must be considered depending on the specifi c object, with different results. With regard to the cooling energy, the values refer to a conventional two-pane insulating glass without sun protection With regard to the heating energy, the values refer to a two-pane sun protection glass with low solar gains With regard to the lighting, the values refer to a simple, manually controllable glare protection. Energy values refer to the end energy.

18 Static external solar shading (swivelling or rigid) Vertical SOLAR FINS and LOUVERS PRODUCT DESCRIPTION Vertically mounted, swivelling louvers and solar f ns must fulf l architectural requirements, while simultaneously offering protection against the sun and an unobstructed view. Vertical louvers and solar f ns are suited as sun protection in particular for Eastern and Western facades, however, they may also be used for facades facing South. Normally, the f ns are made of aluminium, while some are made of glass, stainless steel, metal or fabric. To ensure visual contact to the outside world also when closed (when sun is low), metal systems are often perforated. Most systems provide only a moderate shading effect and daylight utilisation; however, they do ensure good contact to the outside world. If the distance to the glazing is large, daylight utilisation, in particular of the zenith light part, can be reduced signif cantly owing to the produced own shade. The performance data for swivelling systems are signif cantly better. Accurate planning of the system is required to ensure optimal sun protection. Swivelling vertical louvers, in connection with motorised drives, a control system that automatically follows the sun, and openable windows ensure that only little heat is introduced during the day, while ensuring eff cient cooling at night. The performance data for non swivelling systems are accordingly lower, which normally affects the energy balance negatively. PRODUCT WILL PROVIDE Sun protection /passive cooling - Depending on the type of product, good to moderate reduction of the introduced heat; the load on the active cooling system can be reduced and/or active cooling is not necessary at all. Use of free, renewable solar heat gains / passive heating - The f ns can optionally be opened towards the sun to reduce the load on the active heating system during the heating period. Better utilisation of natural daylight and better daylighting strategy - Adjusting the f ns according to the position of the sun allows optimum use of natural daylight, while at the same time providing protection against the sun. Rigid louvers, on the other hand, increase the artif cial light requirement. Glare protection - Only swivelling systems combined with separate glare protection can reduce luminance values (the brightness of the light) at the workspace whenever required by law or for better comfort (e.g. computer work). Increased comfort - Only swivelling f ns reduce surface temperatures of the glazing - and thus the room temperature - when the sun is high. Heat loss through windows - Normally, the heat loss through windows cannot be reduced due to the design of the system. Contact to the outside world - As the f ns are f exible and can be adjusted as desired, contact to the outside world is ensured at all times.

19 FACTSHEET Vertical Solarfins and Louvers IMPORTANT PARAMETERS and Typical Performance Energy transmittance value (g value), total energy transmittance value (g total value) and shading coeff cient (Fc) The energy transmittance value (g value) is the fraction of solar radiation that enters through the window and is converted to heat in the room. The energy transmission is composed of the direct transmission and the secondary heat transmission of the glazing. The total energy transmission value (g total or g t ) indicates the energy transmission for a system that comprises the glazing and the shading. The effectiveness of a permanent vertical shading is def ned by the shading coeff cient (F 1 value) in DIN V ; it depends on the position of the sun, the orientation of the façade and the form of the shading, and is in the range between 0.6 and 1 (1 no shading effect). Example - Large vertical louvers Glass g = 0.65 (according to EN 410) Glass + solar shading g t = 0.42 (acc to DIN V ) Best shading coeff cient F 1 = 0.65 (East- and Westhfacing facades) Cooling period (sun protection depends on position of the sun) g t = In the best case scenario, the load on the room climate is only 42% of the sun energy. Values above 0.25 normally do not suff ce to cover peak loads. Heating period (utilisation of solar energy depends on position of the sun) Provided the systems do not produce an own shade, up to 65% of the solar energy can be used for heating when the sun is low. Effect on energy consumption Cooling period: energy saving of up to 10 kwh/m 2 a Heating period: energy saving of up to 10 kwh/m 2 a (effect is lower for unfavourable arrangement) Heat transfer coeff cient (U value), reduction of heat loss through the window The U value (formerly k value) is the measured value of No improvement is possible. the heat transfer through a component; it is indicated in W/m 2 K. The smaller the U value the better, as less heat is Effect on heating energy requirement transferred through the component. Saving of 0 kwh/m 2 a Example - passive house U value wall 0.12 W/m 2 K U value window 0.80 W/m 2 K Light transmission (T L or LT), reduction of power requirement for lighting The light transmittance TL indicates how much of the visible light spectrum (380 nm to 780 nm) is transmitted through a glazing, in percent. A high light transmission value of the glazing (T L > 80 %) is required to ensure good lighting of the room. A permanently mounted shading system will result in a loss of valuable daylight (diffuse radiation) particularly during times of the day and year with little light. Effect on energy consumption Increased requirement for artif cial light during the day, > 5 kwh/m 2 a Other Wind resistance during use Expected serviceable life Requirement > 30 m/s (as non retractable) approx years The values listed in the factsheets are average values from tests and simulations and refer to a building situated at the outskirts of a city; they should indicate the potential of solar shading products in terms of energy savings. The values are not applicable in the individual case, many parameters must be considered depending on the specifi c object, with different results. With regard to the cooling energy, the values refer to a conventional two-pane insulating glass without sun protection With regard to the heating energy, the values refer to a two-pane sun protection glass with low solar gains With regard to the lighting, the values refer to a simple, manually controllable glare protection. Energy values refer to the end energy.

20 Permanent, selective sun protection SUN PROTECTION GLASS and SUN PROTECTION FOILS PRODUCT DESCRIPTION Sun protection glass and foil-laminated (laminated) glass primarily fulf l architectural requirements, ensuring strut free or respectively unobstructed contact to the outside world. The sun protection function results from the selection of specif c wave lengths, i.e. specif c sun spectra, primarily short-wave infrared, are f ltered out. Systems with a low g value (g < 0.4) also f lter out part of the visible light; this results in a low light yield and a colour shift of the daylight. Due to the technology used, sun protection glass and laminated glazing have an unfavourable energy balance; they cannot reduce the energy input to the same extent as outside shading systems (ratio approx. 3:1). As they are permanently active, the solar gains for heating are reduced to a minimum. Besides, with an increasing sun protection effect, utilisation of daylight decreases or respectively the requirement for artif cial illumination increases (percentage of electrically produced internal thermal loads increases). Trying to compensate for a reduced light yield by increasing the glazing part will result in increased heat losses. Sun protection glass and laminated glazing are also effective when there is no functional necessity for it! PRODUCT WILL PROVIDE Sun protection /passive cooling - Suff cient to cover the basic load to prevent over-heating during summer. Additional passive or active measures are required for peak loads. Use of free, renewable solar heat gains / passive heating - Not ensured to a suff cient degree (not approved for passive house standard). Better utilisation of natural daylight and better daylighting strategy - Utilisation of daylight decreases the higher the sun protection! Glare protection - A dynamic glare protection mounted on the inside is required when sun is low. Increased comfort - As the glass surfaces are not positioned behind louvers or fabric, the surface temperatures are relatively high when the sun shines on them. Heat loss through windows - Sun protection lamination does not improve the U value of glazing. Increasing the part of the non-laminated glass surface to compensate for the daylight loss will result in increased losses of heating energy (deterioration of the U value of the façade). Contact to the outside world - Contact to the outside world is ensured at all times.

21 FACTSHEET Sun Protection Glass and Foils IMPORTANT PARAMETERS and Typical Performance Energy transmittance value (g value), total energy transmittance value (g total value) and shading coeff cient (Fc) The energy transmittance value (g value) is the fraction of solar radiation that enters through the window and is converted to heat in the room. The energy transmission is composed of the direct transmission and the secondary heat transmission of the glazing. For sun protection glass, a shading coeff cient is already included in the system (lamination); for additional shading systems, gt must be calculated according to EN The total energy transmission value (g total or g t ) indicates the energy transmission for a system that comprises the glazing and the shading. Example - Sun protection glass without additional shading Glass g = 0.35 (according to EN 410) Cooling period - solar shading activated g t = The load on the room climate is only 35% of the sun energy. Values above 0.25 normally do not suff ce to cover peak loads Heating period - solar shading deactivated 30 to 65 % solar energy gains less result in accordingly higher heating requirement. Effect on energy consumption Cooling period: energy saving of up to 10 kwh/m 2 a Heating period: additional energy requirement of up to 10 kwh/m 2 a The result of the energy balance (saving for cooling relative to increased heating requirement and power requirement for lighting) may also be negative. Sun protection glazing may therefore not be installed in passive houses. Heat transfer coeff cient (U value), reduction of heat loss through the window The U value (formerly k value) is the measured value of No improvement is possible. the heat transfer through a component; it is indicated in W/m 2 K. The smaller the U value the better, as less heat is Effect on heating energy requirement transferred through the component. Saving of 0 kwh/m 2 a Example - passive house U value wall 0.12 W/m 2 K U value window 0.80 W/m 2 K Light transmission (T L or LT), reduction of power requirement for lighting The light transmittance TL indicates how much of the visible light spectrum (380 nm to 780 nm) is transmitted through a glazing, in percent. A high light transmission value of the glazing (T L > 80 %) is required to ensure good lighting of the room. For g values < 0.45, the visible light is selectively blocked (20-50 %), resulting in an increased requirement for artif cial light. Increasing the percentage of the glass surfaces cannot compensate the light loss, but causes a higher cooling load and heating energy requirement. Effect on energy consumption Increased requirement for artif cial light of 5 to 15 kwh/m 2 a Other Wind resistance during use Expected serviceable life Requirements according to national standards Requirement: 20 years (+/- 5) The values listed in the factsheets are average values from tests and simulations and refer to a building situated at the outskirts of a city; they should indicate the potential of solar shading products in terms of energy savings. The values are not applicable in the individual case, many parameters must be considered depending on the specifi c object, with different results. With regard to the cooling energy, the values refer to a conventional two-pane insulating glass without sun protection With regard to the heating energy, the values refer to a two-pane sun protection glass with low solar gains With regard to the lighting, the values refer to a simple, manually controllable glare protection. Energy values refer to the end energy.

22 FACTSHEET IMPORTANT PARAMETERS and Typical Performance Energy transmittance value (g value), total energy transmittance value (g total value) and shading coeff cient (Fc) Heat transfer coeff cient (U value), reduction of heat loss through the window Light transmission (T L or LT), reduction of power requirement for lighting Imprint Keep Cool II is an projekt of IEE Intelligent Energy Europe Project management: Barbara Dröschel, IZES GmbH, Published and produced by: ES-SO Europeas Solar Shading Organization ES-SO vzw, Naessenslaan 9, B-1860 Meise, Belgium, Tel: , info@es-so.eu, HP Other Author: J. Gesrtmann, SLS Praun & Gesrtmann GmbH, Graz, Reviewing: Author: J. Gerstmann, SLS Praun & Gesrtmann GmbH, Graz, Layout: Author: SLS Praun & Gerstmann GmbH, Graz, Images: SLS Praun & Gerstmann, ES-SO, Somfy The sole responsibility for the content of this report lies with the author. The It does values not represent listed in the the factsheets opinion of are the average European values Communities. from tests and simulations and refer to a building situated at the outskirts of a The city; European they should Commission indicate the is not potential responsible of solar for shading any use products that may in be terms made of of energy the information savings. The contained values are therein. not applicable in the individual case, many parameters must be considered depending on the specifi c object, with different results. Reprint With regard allowed to in the parts cooling and energy, with detailed the values reference only. to a conventional two-pane insulating glass without sun protection Printed With regard on non-chlorine to the heating bleached energy, paper. the values refer to a two-pane sun protection glass with low solar gains With regard to the lighting, the values refer to a simple, manually controllable glare protection. Energy values refer to the end energy.

23 PART B Report on Passive Cooling Solutions

24 Products for Passive Cooling Night Ventilation The thermal storage capacity of materials can be used to reduce the peaks of temperature in buildings. During summer, thermal mass can be used to lower the upper daytime temperature, thereby reducing the need for cooling. The over a day warmed-up thermal mass is cooled by night time ventilation, when outdoor temperatures are low, and allow heat dissipation at the following day when indoor temperatures are high. If a night-ventilation-system is performed well, the building has got adequate thermal mass and solar gains are reduced to a minimum, the installation of an active cooling system can be dispensable. Free night ventilation is operating due to the density difference of internal and external air; density is a function of the temperature. Because night temperatures are - at least in central Europe - mostly under 21 C and room temperatures are higher, a dens ity difference is most of the time effective. Wind also generates pressure differences between air-inlet- and -outlet-openings. To do efficient night ventilation it is indispensable that the building can be good flown through by air. Free night ventilation via opened windows can achieve air flow rates from 10 h -1 and more. Free ventilation can also be realized with overflow-elements in the façade. The thermal mass of a building is the stabilisation-element of the room temperature. The bigger thermal mass, the more evenly the room temperature. Big thermal masses (density x specific heat capacity) are making temperature-vacillations smoother. For the temperature-vacillation within a day the surfaces in the room are crucial. The heat-penetration-coefficient is a mass of the short-termheat-impact. The higher the heat-penetration-coefficient, the faster heat can be absorbed or emitted. So, heat peaks can be absorbed at day and given off from the building component at night. If there is too less thermal mass existing, overheating will take place. With heat loaded thermal mass has to be cooled with fresh external air during night and early in the morning. Short time ventilation and ventilation at morning is not sufficient, the penetration time is too short. The recooling period should take at least 5 hours. Ideally night ventilation should take place from 10pm to 10am. Night Ventilation 1/2

25 Products for Passive Cooling Boundary conditions for free night cooling: o The (daily total) cooling load of the building should not be higher than 150 Wh/m²d (external shading!) o The building should own an adequate thermal mass o An operative air change during day should be done o Night ventilation of at least 5 hours per night when the external air temperature is under 21 C. o Air change rate should be (much) more than 2 h -1 o Free night ventilation only implementing, when the building can be streamed through well by air; burglary and weatherprotections are existing. o Mechanical night ventilation only, if free ventilation is not feasible With the help of thermal building simulation programmes, room temperatures of buildings in dependence of the construction and the weather can be determined. Zimmermann, M.; Rationelle Energienutzung in Gebäuden; Handbuch der passiven Kühlung; EMPA ZEN; 1999 Blümel, E., Fink, C., Kouba R.; Passive Kühlkonzepte für Büro- und Verwaltungsgebäude; Leitfaden zur Planung von passiven Kühlkonzepten mittels Nachtlüftung und luft- bzw. wasserdurchströmten Erdreichwärmetauschern; Programmlinie Haus der Zukunft des bm:vit; 2002 N.N.; Specialist Natural And Energy Efficient Ventilation Applications; Pfafferott, J.; internet-x.pdf, BINE Informationsdienst, Night Ventilation 2/2

26 Products for Passive Cooling Burglary and weather protection for free ventilation To guarantee undisturbed free- and night-ventilation, it is important that weather occurrences don t influence its operation and the walland window-openings are burglar-proofed. Free night ventilation can be done via opened or tilted windows and via overflow elements integrated in the façade, roofs or windows. There are loads of possibilities to configurate overflow-elements and protect opened windows. Overflow elements situated in walls and windows have to be equipped with weather- and insect-protection and with an automatic controlled ventilation flap. Such elements can be integrated in the building during construction or they can be adapted in an existing building. Burglary and weather protection for free ventilation 1/2

27 Products for Passive Cooling Windows can be opened manually or automatically to generate an air flow. In both cases weather- and burglarprotection can be guaranteed. Burglar protection can be done with: o window grills o automatic window-chain-drives and spindle drives are protecting tilted windows o lockable window brackets by tilted windows o construction preventatives o roller shutter o blinds o sun protection devices in front of windows (lamellae) o etc. Weather protection can be managed with: o automatically window closing with the assistance of rain- and wind-sensors o reeled out roller shutters or blinds o construction preventatives o sun protection o bottom-up tilted windows o forward situated façade o etc. Insurance coverage must be warranted in both cases. Protection-measures must be approved by insurances explicitly. Sources: Burglary and weather protection for free ventilation 2/2

28 Products for Passive Cooling Plaster and plasterboard integrated with Phase-Change-Material Systems that use Phase Change Materials (PCM) can be used to store energy and they increase the thermal mass of a building. All substances store energy when their temperature changes, but when a phase change occurs in a substance, the energy stored is higher. Furthermore, heat storage and recovery occur isothermally, which makes them ideal for space heating /cooling applications. Microscopically plastic-capsules with a core made of wax get insert into the plaster or plaster-boards during fabrication. The melting temperature of the wax can be defined during manufacturing. If the room temperature is rising above this melting point (around 21 to 26 C), wax gets liquid and it absorbs the surplus of room-heat. If room-temperature is falling, the wax is getting hard and is giving heat to the room-air. For the periodical melting and solidification, air-temperature differences during day and night are used, for example via night ventilation. The PCM-primary-product (Micronal PCM from basf) is delivered as liquid dispersion or as powder. During manufacturing it is added to plaster, plasterboards, spackle or chipboards. BASF started to merchandise the PCM-primary-product Micronal- PCM in maxit Germany GmbH has taken a plaster containing Micronal PCM into their product assortment, called maxit clima. All constructions integrated PCM have to be regenerated during night to have a sufficient heat storage capacity next day. This regeneration can occur via night ventilation, with integrated capillary tubes or if existing via static cooling systems or air conditioning. Plaster and plasterboard integrated with Phase-Change-Material 1/2

29 Products for Passive Cooling In the following table plaster-boards integrated with PCM are faced to a conventional one [1]: Parameter Switch-temperature Latent heat capacity at the switch point Specific heat capacity Heat conduction Micronal PCM Smartboard 23 Micronal PCM Smartboard C 26 C - Standard plaster board 330 kj/m² 330 kj/m² 0 kj/m² 1.2 kj/kgk 1.2 kj/kgk 0.85 kj/kgk 0.18 W/mK 0.18 W/mK 0.19 W/mK There is available the simulation software PCMexpress, whereby it is possible to generate a building and simulate a trend of room temperatures over a year. The result shows the impact of PCM-components to the room temperatures compared to conventional materials. Available products: Plaster: Maxit clima 21, 26 Plasterboards: micronal pcm smartboard 21, 23, 26 Primary product: Micronal PCM N.N.; plasterboards; Plaster and plasterboard integrated with Phase-Change-Material 2/2

30 Products for Passive Cooling Air-ground-heat-exchanger Air-ground-heat-exchangers are air-flown plastic-, concrete- or fibrecement-tubes which are horizontally placed in the ground. The nearly constant temperature of the ground in a certain depth is utilized. External air gets pre-cooled in summer or pre-heated in winter before it reaches the ventilation system of the building. In the following figure there is shown the temperature-trend through an air-ground-heatexchanger in summer. They are placed either in the foundation of a building or in a free surface in a frost free depth. The ground serves as thermal mass which balances heat seasonal and day wise. Those ground register should be applied in such climate where large temperature differences between summer and winter as well as between day and night occur. Example of a temperature profile through an air-ground-heat-exchanger Air-ground-heat-exchanger 1/2

31 Products for Passive Cooling The functional principle of air-ground-heat-exchangers is quite simple. Although there exist a number of parameters, which influences the performance of the exchanger. Beside factors which have a direct impact on the power of the exchanger (flow-rate, tube diameter, laying depth, length, material and ground consistence) there are some indirect factors (drop in pressure through the exchanger, impact of air-hygienic, investment costs and so on) which have to be considered by planning and construction. The biggest sensitivity of the cooling capacity shows the flowrate-parameter. Although the drop in pressure through the tubes is from a decisive impact. Further parameters with a decisive impact are the length of the air-ground-heatexchanger, the laying depth and the ground consistence. A low impact of the cooling capacity shows the tube-diameter and the tube-material. The air ground heat exchanger must not be overloaded during a season. The operating time of the air flow rate through the exchanger should be tuned to the capacity of the ground. Basically the flow rate through the heat exchanger should not be very much higher than the hygienic one. Cooling power is a function of: Dimensioning (rool-of-thumb): Air velocity through the register: Drop in pressure per tube: Distance betweet single tubes: Tube length: Laying depth: Air flow rate Tube-diameter Laying depth Length of heat exchanger Ground consistence 1 5 m/s Pa/m per tube Around 1 m > 30 m m Ideal dimensioned air-ground-heat-exchangers reach a specific cooling energy gain of 300 Wh/m²d. Based on the laying area, a specific cooling power of 40 to 60 W/m² can be determined. Blümel, E., Fink, C., Kouba R.; Passive Kühlkonzepte für Büro- und Verwaltungsgebäude; Leitfaden zur Planung von passiven Kühlkonzepten mittels Nachtlüftung und luft- bzw. wasserdurchströmten Erdreichwärmetauschern; Programmlinie Haus der Zukunft des bm:vit; 2002 Zimmermann, M.; Rationelle Energienutzung in Gebäuden; Handbuch der passiven Kühlung; EMPA ZEN; 1999 Air-ground-heat-exchanger 2/2

32 Products for Passive Cooling Decentral air conditioning appliance integrated with PCM Systems that use Phase Change Materials (PCM) can be used to store energy. All substances store energy when their temperature changes, but when a phase change occurs in a substance, the energy stored is higher. Furthermore, heat storage and recovery occur isothermally, which makes them ideal for space heating /cooling applications. With decentral air conditioning appliances integrated with PCM it is possible to cool a building without active cooling system. These devices are using the temperature difference of the external air between night and day. At day external air gets cooled by the PCM-storage module before it reaches the room. The heat of the external air gets stored in the PCMpackage. At night the package gets regenerated with cool external air. Decentral air conditioning appliance integrated with PCM 1/2

33 Products for Passive Cooling In the device integrated is one heat exchanger for heating or cooling function. If the cooling power of the PCM-package doesn t suffice, the heat exchanger can deliver additional cooling power. The mode of operation is either circulation-aircooling or fresh-air-cooling. Basically, cooling power is resulting out of the temperature difference between melting-point of the PCM-package and the room-air-temperature as well as the air flow rate through the package. Melting point and heat capacity of a PCM-package: 20 C and 30 Wh/kg Rated air flow per device: 160 m 3 /h Dimensioning parameters for cooling loads up to 50 W/m²: m PCM 5,5 kg/m² Sources: N.N., PCM air conditioning device, 20.html, N.N., PCM-package: locale=en Decentral air conditioning appliance integrated with PCM 2/2

34 Products for Passive Cooling Direct cooling with ground energy source Ground shows a relative constant temperature of around ten degrees in a certain depth. Thermodynamically viewed it can be used directly as cold source for room cooling applications where temperatures of around twenty-five degrees are aspired in summer. The cooling energy gets transported out of the building via water or brine. The heat exchanger in the ground can be a deep-ground-sond or a pile-foundation-tube. It is possible to do free cooling; the only energy demand shows the pump, which transfers cooling energy to the ground-heat exchanger. energy-sond: The cold contribution in the building can occur by space cooling systems which need a higher cold water temperature like ceiling cooling elements or concrete core activation. The heat transfer medium can be water in frost free depth otherwise brine. The energy delivery runs between cold contribution and ground heat exchanger. The cold source is the deep ground energy. As mentioned above, ground has got a temperature of around ten degrees in a certain depth. This cold source is made available via pilefoundation-tubes, so called pile-sond or deep-ground-sonds, so called energy-sonds. pile-sond: Energy sonds are plastic double-tubes which are brought in ground-boreholes. These boreholes are separately drilled and they can reach a depth of one hundred meters or deeper with a diameter of around ten decimetres. The number of boreholes is according to the cooling energy demand of the building. Direct cooling with ground energy source 1/2

35 Products for Passive Cooling The position of energy-piles is different. Local build pilefoundation sond-tubes are fixed in the concrete-reinforcementcage. The sonds can be situated relative free in the impalement. The bigger the number of sonds in a pile, the bigger the peak of power; but thereby the average power rises insignificant. Energy-sonds and -piles are a relative inexpensive system to generate heat or cold out of the ground. Where no flowing ground water is present, a carefully planning and an equated energy balance between heat-removal and heat-input is very important. This shows not only simulation-results, also the experience by realised applications. The power of energy-sonds and energy-piles is lying between 15 and 80 W/m borehole- or pile-depth. It is a function of the ground-conditions (wet or dry ground, ground water, material). A soil analysis has to be done in every case to know the exactly power of a ground source. The energy yield of ground energy usage has to be considered, the boreholes and piles must not be overloaded. That means cooling power and times should be adapted smart. The energy output can be between 10 and 80 kwh/ma. As mentioned before, each case has to be specially considered. Sources: Zimmermann, M.; Rationelle Energienutzung in Gebäuden; Handbuch der passiven Kühlung; EMPA ZEN; 1999 Rehau; Raugeo Systemtechnik zur Erdwärmenutzung, 2007 Rehau; Geothermie, 2007 Direct cooling with ground energy source 2/2

36 Products for Passive Cooling Water basin, -wall and -fountain By a selective positioning of water surfaces in buildings, respectively building parts, a not insignificant contribution to the space-cooling can be realised due to the exploitation of the evaporating heat of water. Concerning to the evaporation of water, ambient air will be detract evaporating heat and so, airtemperature decreases. For this kind of cooling water basins (indoor ponds, artificial creek courses and water landscapes), water walls and indoor fountains are available and can be integrated aesthetically in the building. Volatilizing is a slow evaporating of water, where the evaporating heat of the environment is detracted. The amount of evaporated water and required heat from the ambience is proportional to the difference of the partial pressure of the unsaturated humid air and the partial pressure of the water vapour in the interface. Provided that the partial pressure of the water vapour is bigger than the partial pressure of the unsaturated humid air. Water basin, -wall and -fountain 1/2

37 Products for Passive Cooling The generated cooling power per m² water-surface due to volatilizing is depending on: Air humidity [kg/kg] Interface humidity [kg/kg] Evaporating heat of water [kj/kg] Evaporating amount [kg/m²h] and Wet-bulb-temperature/ water-surface-temperature [ C ] Air temperature [ C] Convective heat transfer between sheet surface and air [W/m²K] (depending on air velocity) Values out of literature: W/m² (silent water surface fountain) [1,2] [1] Recknagel, H., Sprenger, E., Schramek, E.R.; Taschenbuch für Heizung- und Klimatechnik, einschließlich Warmwasser- und Kältetechnik, Oldenbourg, München, 1999, 69. Auflage, page 1606 [2] Lichtmeß, M.; Analyse der theoretischen Kühlleistung eines Wasserbeckens in Gebäudenähe, Water basin, -wall and -fountain 2/2

38 Products for Passive Cooling Indoor plants Indoor plants improve the room indoor environment quality by temperature decrease and natural air-humidification; out of it a resulting cooling-function, which is very efficient in summer. Plants are improving air quality, binding house dust and eliminating pollutants. Due to this psychologically features they contribute to human well being in buildings. Due to evaporating of water on the surface of the plant s sheets a certain cooling power is generated. This cooling power is depending on the volume of evaporating water, air temperature, velocity and humidity. The evaporating-amount of plants is directly proportional to the current illumination-power, so that there are significant day/night fluctuations. The light demand of plants should be considered where they get placed (sunny or shady position). Interesting for office-rooms is the acoustic-absorption function of indoor plants; sheet surfaces are absorbing, reflecting and spreading acoustic waves. Indoor plants 1/2

39 Products for Passive Cooling The evaporating amount [kg/m²h] of plants is depending upon: Cooling power per transpiration active sheet surface is depending upon: Type of plant Season Difference of air- and sheet-interface-humidity x [g/kg] Illumination power [lux] Evaporating amount of the plant [kg/m²h] Evaporating heat of water r [kj/kg] and Convective heat transfer between sheet surface and air [W/m²K] (is depending on air velocity) Difference of air- to sheet-surface-temperature [K] Value from literature: By close planting a cooling power of 16 W/m² due to evaporating power can result [1] Every individual case should be considered especially. [1] Preisack, E.B., Holzer, P., Rodleitner H.; Neubau Biohof Achleitner, Gebäude aus Stroh & Lehm, Raumklimatisierung mit Hilfe von Pflanzen, Programmlinie Haus der Zukunft des bm:vit; 2002, page 42 Indoor plants 2/2

40 Products for Passive Cooling Daylight illumination Electrical lighting generates a certain amount of cooling load. In some buildings it is necessary to active lighting during day, even when the sun is shining. With so called SolaTubes it is possible to use daylight instead of electrically generated illumination. With that device, it is possible to decrease the consumption of currant for lighting and also the demand of cooling energy. Daylight respectively sunlight is collected via a lense at the top of the roof or at the exterior side of a wall. This lense avoids over-illumination at midday in summer. A reflected tube conducts the collected light to a second lense, which is smoothly spreading the light inside a room. 99.7% of the light comes through this lens-pipe-lense-system. A further feature is the UV-blocking function and the lighting power is dimmable. The light contribution lens integrated can be a conventional lighting system, so no additional lighting is necessary. The tube could also be used for ventilation activities. In the two following pictures an unlighted bathroom is faced to a (day)lighted one. Daylight illumination 1/2

41 Products for Passive Cooling An extract of features of Solatubes is shown here: pipe diameter lighted area maximum length 250 mm 14 m² mm 25 m² 9 Source: Daylight illumination 2/2