PRESENTATION BY….

R.RAGHAVENDRA I/II M.Tech, CTM

121568

CONTENTS :1. Introduction

2. Climate change & Potential Impacts

3. Optimizing the Design Process

4. Conceptual Design

5. Preliminary Design

6. Detailed Design

7. Energy Efficient Models

8. Conclusion

9. References

INTRODUCTION : New challenges for the construction industry

• Impacts of climate change• Design to reduce GHG emissions

Engineering has the lead responsibility• For determining the technical feasibility and cost

Set of standard documents• Standard design detail drawings, standard design

criteria, standard specifications• Design guides and work process flow diagrams

Climate change & Potential Impacts:

Climate Change

How Will Climate Change

The Contribution of Buildings to Climate Change

The Impact of Climate Change on Construction

Potential Impacts On Development

Climate Change:

IPCC declared that ‘warming of the climate system is unequivocal’

– Changes in temperatures

– Hot extremes, heat waves and heavy precipitation events

– Tropical cyclones with larger peak wind speeds

– Heavy precipitation associated with ongoing increases of tropical sea surface temperatures.

– Decreases in snow cover

?

How will Climate Change:

All parts of the world will experience significant changes in climate over this century. These changes can be summarised as:

– Hotter, drier summers

– Milder, wetter winters

– More frequent extreme high temperatures

– More frequent extreme winter precipitation

– Significant decreases in soil moisture content in the summer

– Net Sea level rise and increases in sea surge height

– Possible higher wind speeds

?

The Contribution of Buildings:

Today, buildings are responsible for more than 40 percent of global energy used, and as much as one third of global greenhouse gas emissions, both in developed and developing countries.

In absolute terms:•8.6 billion metric tons CO2 eqv in 2004•15.6 billion metric tons CO2 eqv. by 2030 (expected)

Furthermore, the Buildings and Construction Sector is also responsible for significant non-CO2 GHG emissions such as halocarbons (CFCs and HCFCs) and hydro fluorocarbons (HFCs) due to their applications for cooling, refrigeration, and in the case of halocarbons, insulation materials.

The Impact on Construction:

Climatic factors Impacts

Soil Drying Increase will affect water tables and could affect foundations in clay soils

Temperature Maximum and minimum changes will affect heating, cooling, air conditioning costs and thermal air movement. Frequency of cycling through freezing point will affect durability.

Relative Humidity Increase will affect condensation and associated damage or mould growth

Precipitation Increase and decrease will affect water tables (foundations and basements); cleaning costs will be increased in winter, with associated redecoration requirements.

Gales Increase will affect need for weather tightness, risk of water ingress, effectiveness of air conditioning, energy use, risk of roof failures

Radiation Increase may affect need for solar glare control

Cloud Increase in winter will increase the need for electric lighting; reduction in summer may reduce the need for electric lighting for certain buildings

Components,sub-structures andwhole buildings

Impacts

Air conditioning Need to upgrade airtightness

Basements(sub-structure)

Increased risk of heave or subsidence, water ingress, consequential damage to finishes and stored items

Materials Plastics life is reduced due to increased radiation Increased salt spray zone in marine areas will reduce life duration

Roofs Increased fixing costs and risk of failures due to gales, wind and Precipitation

Whole building Increased cleaning costs due to wind, gales, relative humidity, precipitation. May alter construction costs and period owing to wet weather and associated loss of production.

Structure/cladding/ renders/Membranes

Increased risk of cracking due to different thermal or moisture movements

Timber-framed Construction

Increased risk of failure due to increase in relative humidity, depending on design

OPTIMIZING THE DESIGN PROCESS:In many respects designing to meet climate change challenges is

sustainable design. A project execution approach integrating the following concepts for sustainable engineering, procurement and construction (S-EPC) is directly relevant to designing for climate change:

•Site master planning and design for ecology•Process design to conserve water, energy and other natural resources•Passive design of facilities to save energy in plant and building operations, e.g. Energy Star® roofs or green (vegetated) roofs; adequate insulation of building walls, roofs, pipes, ducts and vessels, to minimize fossil-fuelled power consumption and emissions•High-efficiency HVAC and electrical systems including high-performance lighting systems integrated with daylighting and smart controls•Onsite renewable energy with energy storage for peak use, meeting the power demand that has been reduced by all of the above concepts, and resulting in reduced fossil fuel demand / emissions.•Eco-purchasing and contracting: “greening” the supply chain to minimize climate change impacts of the supply chain.

CONCEPTUAL DESIGN:

The conceptual design phase is when sustainable design, climate change mitigation and adaptation features can be most easily incorporated into a project.

During conceptual design, the integrated sustainable design team evaluates design alternatives. Project facilities, process and mechanical equipment, and building components or features should be evaluated based on their sustainability as well as feasibility and cost-effectiveness. The team should consider the maturity of the technology of the building, facility or process feature; the capital expenditure (i.e., first cost) required to procure, install, and implement the facility, building or process feature under consideration.

Consider alternatives to:

•Maximize energy efficiency and minimize GHG emissions:

•Maximize water efficiency:

•Minimize the embodied energy and carbon content of materials:

PRELIMINARY DESIGN:

During preliminary design develop the facility energy model to confirm the design meets the established performance goals; calculate facility operations GHG emissions and materials embodied carbon content; develop a facility life-cycle cost estimate; include building information in the 3-D model. Periodically update these calculations and verify the project continues to meet the sustainable design performance goals as design progresses.

The following tasks are included in this design phase:•Include sustainable engineering concepts in system design descriptions and facility design descriptions. Right-size systems and facilities using software models (not conventional rules-of thumb), avoid over-design.

•Identify energy consumption by category, e.g., internal loads from the processes, building envelope loads (heat losses / gains through walls, roofs, etc.), ventilation requirements, and others.

• Identify energy interactions between systems and opportunities for reductions in energy requirements and cost savings through energy efficiency measures.

• Develop alternative design solutions to reduce energy loads and evaluate systems as a whole.

• Iterate these optimization steps and refine the system selection / design to arrive at the optimized combination of systems for energy efficiency and emissions reduction.

• Update the energy model, emissions calculations, cost estimate and 3-D model to reflect the design, as it develops.

Conduct a second review of progress toward meeting energy and emissions goals on the project, after the design concept is developed. This review can be concurrent with other required design reviews and is intended to confirm continued progress toward meeting the established sustainable design criteria.

Contd…

DETAILED DESIGN & CONSTRUCTION :

Continue to promote an integrated work process among all disciplines to assure continued implementation of the established energy efficiency and emissions reduction goals. Specify low embodied CO2 and energy content materials. Include embodied energy and CO2 evaluation criteria in technical bid evaluations. Specify materials available locally.

Consider construction waste management options, construction vehicle options, etc.

Finalize the:

•Energy model

•3-D model with building information

•GHG emissions calculations

•Life-cycle cost estimate

Conduct a third and final review of the design relative to the energy efficiency and emissions reduction goals.

THERE ARE DIFFERENT LOGICS in pursuing the energy efficiency of buildings, ranging from lower to higher technological approaches. These are models that can be applied to improve energy efficiency in buildings;

• Low- and zero-energy buildings

• Passive housing de-sign

• Energy-plus buildings

• EcoCities

• Refurbishment aspects

• Commissioning processes.

ENERGY EFFICIENCY MODELS:

Low Energy Buildings:

The Definition of low-energy building can be divided into two specific approaches:

The concept of 50% & The concept of 0%

A building constructed using the 50% concept consumes only one half of the heating energy of a standard building.

The low energy consumption is based on an increased level of thermal insulation, high performance windows, airtight structural details and a ventilation heat recovery system.

In USA-Arizona, USA-Grand Canyon (California), Belgium, Canada, Denmark, Finland, Germany, Italy, Japan, the Netherlands, Norway, Sweden and Switzerland zero energy buildings were built.

Zero Energy Buildings:

Zero-energy buildings(an ultra-low-energy buildings) are buildings that produce as much energy as they consume over a full year.

Energy can be stored on site, in batteries or thermal storage. The grid can be used as seasonal storage via net metering, as some buildings produce more in the summer and use more in the winter, but when the annual accounting is complete, the total net energy use must be zero. Buildings that produce a surplus of energy are known as energy-plus buildings.

The Worldwide Fund for Nature (WWF) zero-energy housing project in the Netherlands & The Malaysia Energy Centre (Pusat Tenaga Malaysia) headquarters are zero-energy office (ZEO) buildings.

Passive Houses: A passive house is a building in which a comfortable interior climate can be maintained with-out active heating and cooling systems. The house heats and cools itself, and is therefore ‘passive’.

Compact form and good insulation: U-Factor <=0.15W/(m2K)

Orientation and shade considerations: Passive use of solar energy

Energy-efficient window glazing and

frames:

U-Factor <=0.80W/(m2K) {glazing and frames, combined}

solar heat-gain coefficients around 50%

Building envelope air-tightness: Air Leakage <=0.61/hour

Passive pre heating of fresh air: Fresh air supply through underground ducts that exchange

heat with the soil. This preheats fresh air to a temperature

above 5oC, even on cold winter days

Highly efficient heat recovery from

exhaust air:

Heat recovery rate over 80%

Hot water supply using regenerative

energy sources:

Solar collectors or Heat pumps

Energy-saving household appliances: Low energy refrigerators, stoves, freezers, lamps, washers,

dryers, etc. are indispensable in a passive house

Characteristics of passive houses

Eco Cities:

In order to render the building energy efficient, the whole energy chain has to be considered, including the local environmental conditions, community issues, transportation systems and working and living structures.

Eco Cities are settlement patterns for sustainable cities, which were developed in a project supported by the European Union. The energy chain for buildings in Eco Cities includes the following items:

> Low-energy houses;

> Low-temperature heating systems;

> Low-temperature heat distribution system;

> Use of renewable energy sources whenever possible;

> Heat production as near as possible;

> Electricity production;

CONCLUSION : Designing to meet the challenges of climate

change does not require a completely new design

process. Incorporating sustainable design

considerations into the conventional design process

can result in more energy efficient and lower GHG

emitting designs if sustainable design performance

goals are set early in the project development and

regularly monitored to assure the evolving design

continues to support achieving the goals.

And when considered in the context of the

overall life-cycle cost of a project, sustainable design

will reduce life-cycle costs and produce significant

benefits for climate change.

REFERENCES : Dr. R. B. Draper, Dr. P Attanayake (2010),” DESIGNING TO

MEET CLIMATE CHANGE CHALLENGES”, International Conference on Sustainable Built Environment (ICSBE-2010).

Sylvie Lemmet, (2010), “SUSTAINABLE BUILDINGS AND CLIMATE INITIATIVE”, Sustainable united Nations.

“BUILDINGS AND CLIMATE CHANGE” - Status, Challenges and Opportunities by United Nations Environment Programme, 2007.

Gardiner, Theobald (2006), “ADOPTING TO CLIMATE CHANGE IMPACTS: A good practice guide for sustainable communities”.

Michael J. Holmes, Jacob N. Hacker (2007), “CLIMATE CHANGE, THERMAL COMFORT AND ENERGY: Meeting the design challenges of the 21st century”

N.J. Cullen BSc(Hons), “CLIMATE CHANGE –DESIGNING BUILDINGS WITH A FUTURE”, National Conference 2001

MarkSnow, Deo Prasad (2011), “CLIMATE CHANGE ADAPTION

FOR BUILDING DESIGNERS”, Australian Institute of Architects.

R.RAGHAVENDRA

?