Sustainability - incorporated in lightweight construction. Aarhus School of Architecture 15. november 2011

Transcription

1 Sustainability - incorporated in lightweight construction Aarhus School of Architecture 15. november 2011

2 Presentation Jørgen Lange Nielsen Engineer 1987, Aarhus Technical College Partner in the firm Ellehauge & Kildemoes Practical and theoretical experience with indoor climate and energy through Associate engineering, Professor development of Engineering and College of Aarhus teaching and intermediation. Areas of focus are integrated energy design, low energy buildings, sustainable energy sources and sustainability in construction. Experience in quality development and innovation projects, and teaching / learning.

3 Presentation Ellehauge & Kildemoes We carry out development projects on energy renovation supported by: We work with networking and information / intermediation:

4 Today s program 1. Challenges for Construction 2. Sustainability what is that? 3. Integrated energy design 4. Tools 5. Your case what to do?

5 Challenges that require sustainable solutions Limited ressources > energy supply and building materials Environmental problems -> Global warming Health -> Toxicity and particles Productivity -> Comfort and fewer sick days

6 Challenges Global energy crisis The world faces a growing energy demand. Energy ressources are limited We all have to contribute to the reduction af the global energy demand > In our buildings we have the opportunity to do something!

7 Challenges Global warming

8 Challenges CO2 emissions Numbers in Gigatons CO2/year

9 Challenges Effectivity and health + = bad economy for both communities, company and individual

10 Sustainability Concepts - definition We need balanced solutions they have to be sustainable! Social (Tolerable) (Just) Environment Sustainability (Viable) Economy The total solution is a weighting / balance based on prioritization

11 Sustainability Concepts what is sustainable?

12 Sustainability Concepts - subtopics Environment Life cycle assesment of building materials and energy consumption in the building Assesment of choice of material based on their effect on the environment and their toxicity. Energy consumption Water consumption Recycling Economy Total economy calculations which take into account: Construction costs Operating costs Maintenance og the building Assesment of: Flexibility of the third party user. Effect on the value of the building. Social Atmospheric comfort Thermal comfort Acoustics Visual comfort User influence Building structure and outdoors areas Architecture and art

13 Concepts - subtopics Life Cycle Assessment (LCA) LCA is a method to evaluate the potential environmental impacts and resource use associated with a product or service. LCA is based on life cycle thinking, ie. that you consider the entire product / service life cycle from cradle to grave in the environmental assessment.

14 Concepts - subtopics Evaluation of materials 1. Use building materials with environmental declarations (avoid materials which emit gasses) 2. Use reusable materials 3. Use durable materials 4. Choose solutions with low maintenance costs 5. Reduce material wastage 6. Use materials with the lowest possible energy use for manufacturing

15 Concepts - subtopics Energy consumption in buildings Average energy consumption in existing building, and future demands for new buildings in Denmark.

16 Concepts - subtopics Thermal indoor climate Optimum operating temperature CLOTHING

17 Concepts - subtopics Thermal indoor climate Clothing [CLO]

18 Concepts - subtopics Thermal indoor climate Level of activity [MET]

19 Concepts - subtopics Atmospheric indoor climate

20 The principle in Integrated energy design - IED The starting point is the user's use of the building in relation to the climate Optimal daylight must be ensured without overheating the building Thermal and atmospheric comfort must be ensures through the entire year Utilize all the passive properties to create a good indoor climate Using installations in a minimal extent to complement the building with light, air and heat / cold when the building itself cannot create this

21 Integrated energy design The Danish climate Average annual temperature = 7,7 C Highest measured temperature = 36,4 C (1975) Lowest measured temperature = -31,2 C (1982)

22 Integrated energy design Building heat balance

23 Integrated energy design Optimizing the building

24 Integrated energy design Passive tools Spatial organization and climate zones Building geometry and orientation Daylight and solar energy Sun protection and heat storage Insulation and density Additional passive and active tools

25 Tools Spatial organization

26 Tools Climate zones 1 climate zone Indoor Outdoor Several climate zones Climazones With different climate zones, you get a more versatile building, requiring less energy to heat up. Bæredygtighed i let byggeri 26

27 Tools Building geometry A lean building receives more daylight A compact building retains heat

28 Tools Building geometry A building's heat loss gets smaller, the smaller the surface area is, compared to the heated floor area. In this context, we talk about building compactness.

29 Tools Orientation of the building It means a lot to the utilization of the solar energy how the glass sections are oriented towards the sun.

30 Tools Passive solar heating Passive solar heating covers more than all the solar energy a building can absorb and utilize, without further action than the design and construction choices made when designing the building.

31 Tools Areas of glass What is good solutions?

32 Tools Sunscreening In summer overheating of buildings may be be a problem because there are large areas of glass. That is why solar shading is important. The best solution is an external solar shading, which can be activated when needed and deactivated when you want the sun / heat.

33 Tools Sunscreening

34 Tools Heavy or lighweight construction Heavy constructions may be better to distribute the heat throughout the house, while lightweight constructions provide a higher heat unbundling. Heavy construction keeps the heat for longer than lightweight constructions. This means that the summer heat can be harder to ventilate away than in lightweight structures where the structure is cooled down quickly. In turn, the heavy constructions store some heat during the day and deliver it at night.

35 Tools Thermo active constructions By placing hoses in concrete slaps, buildings can be heated and cooled with temperatures which are close til the indoor temperatures. It is possible to save up to 75% of the electricity used to cooling compared to traditional coolingsystems.

36 Tools Thermal mass with PCM A lightweight construction, such as a timber building, has a low thermal mass. This may be raised by so-called PCM (Phase Change Material). A PCM layer can be placed within wall constructions to increase the thermal mass of the house. The room air temperature results more comfortable and less varied. The energy consumption for both air conditioning and heating will decrease.

37 U-værdi Tools Insulation Doubling the insulation thickness = half of heat loss When can additional insulation is no longer worth it? When is has a negative influence on LCA When it has a total economic disadvantage (net area) Isoleringstykkelse [mm]

38 Tools Insulation compact types Special insulation - up to 5 times better.but expensive Vacuum insulation

39 Tools Natural ventilation Principper Bæredygtighed i let byggeri 39

40 Tools Natural ventilation Advantages: No electricity consumption for air Low maintenance costs Limited space needed for engineering Restricted materials requirements Disadvantages: No heat recovery Imposes requirements to architecture Not stable climate control The solution: Hybrid ventilation by combining natural and mechanical ventilation Bæredygtighed i let byggeri 40

41 Tools Additional tools (active) Mechanical ventilation - can be performed in many ways Microventilation - require less electricity

42 Tools Additional tools (active) Preheating of air in ground channels

43 Tools Additional tools (active) Energy from the ground or the air

44 Tools Solar energy (active) Solar heating Solar photovoltaics

45 Tools Additional tools (active) Solar walls

46 Tools Additional tools (active) Double facades

47 Tools Additional tools (active) Rainwater harvesting to conserve drinking water

48 Integrated Energy Design The final result of IED! Bæredygtighed i let byggeri 48

49 Your case what to do? 1. What are users doing in the building? - how many types of users?, for how long do they stay?, what are the activity? 2. How do the users fill comfort? - do all need the same temperature? - and fresh air? 3. What are the weather challenge? - what is most important to take care of - heating or cooling? 4. How do we exploit the solar energy and the daylight? - what is the best orientation? How do we place and what are the best size of windows? 5. How do we reduce the operation energy? - can we reduce the needs for heating, lightning and ventilation? 6. How do we reduce the energy for deployment? - do we know anything about the products? can we optimize the construktions? 7. How do we reduce indoor air impacts from materials? - can we find informations about materials? 8. How do we ensure a good working environment for the contractors - must it be pre-fabricated? how do we ensure air tightness? 9. How do we reduce the environmental impact of disposal?