Torben Lundberg Architect m.a.a

Transcription

1 Torben Lundberg Architect m.a.a

2 The global climate agenda is all about the use of energy even in buildings Saving energy has become essential because of the rising coal and oil prices, uncertain energy resources in the future and the international commitments regarding CO2 reduction. Buildings use approximately 41% of Denmark's total energy consumption! Building heating and cooling represents more than 1 / 4 of Denmark's energy consumption. It is obvious that greater efforts is needed in that specific area. 41% buildings Buildings can be constructed with a positive energy balance. 33% transport >> In the future we need to target on the passive heating of our houses<< 26% industry

3 The meaning of passive heating is that the better you can keep the heat, the less energy is used to produce new heat. Today it is now possible to construct a house, which hardly use energy for heating and where the indoor environment is in a very high quality. A low energy house only need a very small amounts of heating. By building the house as a passive house, you can completely avoid the use of external heat input. These savings compensate for the cost of the extra insulation and better windows.

4 An energy frame is a manifestation of a building's total energy needs! The energy needs is in relation to the legislation divided into 5 points: 1. Heating 2. Ventilation 3. Cooling 4. Hot water 5. Possibly electricity for operation The energy frame takes into account the sun, the warm from persons and the building's heat accumulating properties. Energy savings has been fully crucial because of rising oil prices, uncertain energy supply resources in the future and the international commitments regarding CO2 reduction

5 Standard Class BR % 70 kwh/m2 per. y /A* kwh per. y (Current requirements!) Low Energy Class 2 75% 50 kwh/m2 per. y /A* kwh per. y (Estimated requirements in 2010!) Low Energy Class 1 50% 35 kwh/m2 per. y /A* kwh per. y (Estimated requirements in 2015!) (* A indicates the heated gross building area!) Low Energy Class 0 25% 0,25 x ( /A kwh per. y) (Estimated requirements in 2020!) (Passive house, 0 energyhouse, etc.) Low Energy Class plus (Plus house, Bolig+, etc.) Several municipalities have started to make demands for Low energy Class 1 or 2 as a minimum requirement. Other municipalities make the requirements in the local plans, by their own buildings and land sales.

6 To ensure that the building shell as a whole is designed with a reasonable insulation there is in BR 08 requirements for a maximum heat loss per m2 building shell without windows and doors. The requirements are: Building in 1 storey: Building in 2 storeys : Building in 3 storeys or more: 6 W/m2 7 W/m2 8W/m2 Leaks through the building shell is equal to heat loss. Therefore, there is also requirements for leakage must be limited to a maximum of 1.5 l / s per. m2 for a pressure test at 50 Pa. The average of the existing housing in Denmark, has an air exchange through the leakage of about 2.5 l / s per. m2.

7 When the energy needs for a building is to be calculated in Denmark, you can use calculation module Be06, BuildDesk or similar. Calculations are performed using the method of SBI anvisning 213. In Sweden you can apply for funding for construction of passive houses. Support for expert help, quality management process and measurement, evaluation and dissemination. It is important to consider the following facts included in the calculation: The building's location and orientation. Interior daylight/sun. Constructions/details. Windows/doors. Installationer. Heating system/heat pumps. Ventilations/heat recovery. Solar heating Photovoltaic. Sun shelter. Natural ventilation.

8 The correct placement and orientation of the building on the site are critical for exploiting heat contribution from the sun. For optimum heat and daylight into the house it must be such as by passivhuse/0 energihuse plan with south as the primary main direction. When we place our windows, there are various advantages and qualities depending on whether we will convey them to the north, east, south or west. North facing windows: Incoming light from the space, plain light intensity, uniform color reproduction. East facing windows: Daylight far into the building, breakfast/ morning. South facing windows: Sunlight much of the day, plenty of opportunity for passive solar heating. West facing windows: Daylight far into the building, afternoon/ evening. The buildings location and orientation. Interior daylight/sun. Constructions/details. Vindows/doors. Installationer. Heating system/heat pumps. Ventilations/heat recovery. Solar heating Photovoltaic. Sun shelter. Natural ventilation. Passive? The concept Passive describes a building where the heat loss is reduced dramatically while using the sun as well as residents and house appliances heat to warm the building. There is in a passive house no need for an actual heating installations. It requires : well insulated walls, roofs, floors and windows. Dense structures. Avoidance of cold bridges. The annual need for added heat should not exceed 15 kwh/m2. Total Energy needs may, according to Cepheus projektet1) not exceed 42 kwh/m2/year for habitation. 1) Cost Efficient Passive Houses as European Standards

9 The buildings location and orientation. Interior daylight/sun. Constructions/details. Vindows/doors. Installationer. Heating system/heat pumps. Ventilations/heat recovery. Solar heating Photovoltaic. Sun shelter. Natural ventilation.

10 It's important that structures is designed in a way that provides the necessary insulation and density, to avoid condensation inside the structure. But because energy requirements demands increased requirements for the density in our houses, we must be more aware of this than ever before. This is especially true for structures of organic materials. The buildings location and orientation. Interior daylight/sun. Constructions/details. Vindows/doors. Installationer. Heating system/heat pumps. Ventilations/heat recovery. Solar heating Photovoltaic. Sun shelter. Natural ventilation. There is also increased attention to thermal bridges. Partly due to the risk of condensation and partly due to heat loss. Here, for example be aware of metal fittings which penetrate the insulation, foundation solutions and details by the windows. Several thousand examples from Germany Austria, Switzerland, Sweden, Belgium and Luxembourg demonstrates good experience with the passive house concept. Examples includes many different types of buildings as offices, schools, kindergartens, factories, nursing homes, dormitories, gymnasiums, detached houses, townhouses and apartment rentals.

11 By design and execution we shall pay extra attention to the densities to ensure the necessary performance. Examples where there is increased attention: Ventilation channels through the steam block. Electrical installations in walls and ceilings with steam block. Electrical installations through holes of the back wall. Joints around the windows. Collections in the steam block. The buildings location and orientation. Interior daylight/sun. Constructions/details. Vindows/doors. Installationer. Heating system/heat pumps. Ventilations/heat recovery. Solar heating Photovoltaic. Sun shelter. Natural ventilation. One reason for that in low energy houses has so great demands on the density, is because otherwise it would be difficult to control the air distribution between the individual rooms with ventilation/ heat recovery.

12 Windows has 3 main functions: Providing access to daylight. Allow for ventilation. Serve as rescue opening. Furthermore, they can contribute positively to the heat balance of the solar flow. But also negatively by the loss of heat occurs through the window. The buildings location and orientation. Interior daylight/sun. Constructions/details. Vindows/doors. Installationer. Heating system/heat pumps. Ventilations/heat recovery. Solar heating Photovoltaic. Sun shelter. Natural ventilation. The optimal window will have the following characteristics: High sound transmittans of the pane. High sun heat transmittans (g value) of the glass. Low U value for glazing and frame. Restricted area of the frame contra glass surface. Low ψ value for the distance profile between the glasses. In planning of the window area in a dwelling you can in principle put the area to approx. 25% of the brutto area. And 40% of those placed in the south facade. With respect to windows U value, the frame part of the construction is the "weak" part.

13 What we need is a broad knowledge of all construction parties also on counterparties" discipline. Craftsmen are often the client advisors in renovation! Architects, engineers and technical professionals must know and take account of current energy limitations design of new buildings and renovation of existing buildings which is constantly reinforced. There is a demand for minimizing the surface of the building to minimization of thermal bridges. The location and quality of for example windows. The location of technical equipment and electrical wire within the steam block and more. Energy efficient lighting is absolutely necessary. If we use the best devices now we could saved around 50% of its consumption.

14 Comfortable living for all, without moisture problems. Less noise, dust and pollen from outside. Chance of 80 95% lower operating costs for electricity and heat (That means a cheap way to reduce CO2 and other discharges!). Economically sustainability for both private industry and public. New jobs (An Austrian study showed an 8% increase in number of jobs vs. current building). More secure energy supplies due to reduced oil, natural gas and coal dependency.

15 Compact construction Optimal insulation including windows and pipes and engineering. Dense buildings and good ventilation No cold bridges the energy and indoor climate Avoid overheating by building constructive true Use materials with low embedded energy Take account of the available heat supply form Plan with low transportation needs. Minimize use of chemicals, optimize green space. Minimize the circulation of hot water. Give details on the operation and maintenance to users. Ensure good daylight and energy optimized artificial lighting. Heavy materials to store heat in the floors and the walls. In Germany they have make political decisions to provide cheap loans for energy efficient new construction and renovation. And in Austria since the year 2000 there have been an ambitious research and development program, which also offered support for energy and environmental optimization.

16 Optimize Supplementary insulation rather exterior than interior. Makes building close and optimize ventilation Find out whether the existing windows can be optimized or switched to the best of today's windows. Go for the best solutions even if they are slightly more expensive now. Set the heating and ventilation system. Find cold bridges and try to get them removed it also gives benefits of indoor climate. Avoid harmful chemicals and optimize natural content Remember that an energy efficient building offers good indoor climate, good health, high learning capacity and high productivity

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19 Cooperation from the beginning is crucial for building Passive Houses. Evaluation of the economics of Passive houses show that they cost between 0 and 10% more to construct. 0% where the low energy was going into the concept from the start. 10% where the low energy was put on afterwards. SBI says between 3 and 6% more expensive, and calculations show that it may be 0% more expensive. In Germany, Passive Houses is cheaper. per. m2 than German standard when looking at total costs.

20 Untrendy: Low energy lose to new kitchens and bathrooms! Aversion: The rules for social housing makes it difficult to focus on low energy Disinclination : It gives a lot of hassle energy savings must wait until we get more time. Unengagement in economics: There is too small savings to drive the engagement? Insecurity: Pigeons energy efficient buildings and can designers and contractors in general do it properly? And can we count on the craftsmen? Invisibility: We do not know our energy consumption "Products" is not on the shelves and savings may not be visibly to others. Ignorance by user: There are many other "unknown" factors of energy optimization indoor climate, comfort, maintenance no fresh air in an airtight box, noisy air. Ignorance by guides: Knowledge of energy efficient and cost effective construction and renovation methods are too small in building operators "Very few buildings is built or renovated in a sustainable manner, although there are proven techniques. The biggest obstacle is lack of interest from builders and buyers who erroneously believe that sustainable construction is expensive... "

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