1. Energy efficiency in buildings Monga Mehlwana Tuesday, 05 October 2010

2. Global view of energy efficiency Energy use and GHG emissions data for residential and commercial sectors can be difficult to quantify Indoor combustion of biomass & coal is a significant health concern Energy consumption by commercial buildings is projected to be highest-growing end-use sector for energy in developing countries Motivation for EE in buildings focus: reduced energy costs to consumers, security of energy supply; cheaper option than investing in increased energy capacity; improved comfort; lower GHG emissions, thus contributing to climate change strategies and helping to achieve the Kyoto Protocol targets; contribution to the rehabilitation of certain building types Emissions from residential & commercial sectors, incl. direct emissions & end-use electricity consumption can traced to energy use in buildings

3. Energy use in buildings Primary end uses of energy vary between residential & commercial sectors In res sector HVAC account for 39% of total energy use Electronics, water heating, refrigeration, computers, and lighting use significant quantities of energy in the commercial sector

4. Theoretical potential - lowest amount of energy needed to perform a service if all energy losses, frictions and other inefficiencies could be eliminated Technical potential uses best commercially available technology available at the time regardless of cost Economic potential achievable where externalities are accounted for and prices send the right signal Social potential is saving achieved at a net positive economic effect to society as a whole. Achievable potential (market/maximum achievable potential) is amount of energy use that efficiency can realistically be expected to displace, assuming most aggressive programme scenario possible Programme potential is the efficiency potential possible under given specific program funding levels and designs Defining potentials for EE in buildings...

5. Methane-capture systems in landfills prevent GHGs from being released into the atmosphere Selecting low carbon materials (e.g. local materials, materials that sequester carbon, & products manufactured at efficient industrial facilities Using building design & construction techniques to maximize the use of natural light & ventilation can minimize the need for artificial light and HVAC equipment Using efficient appliances can minimize energy consumption and concomitant GHG emissions from electricity and direct fossil fuel combustion Adherence to conservation guidelines & making personal choices to reduce the use of appliances, artificial lighting, and HVAC equipment Heat pump hot water systems use heat from the air to heat water. Residential & commercial sector mitigation opportunities

6. Reducing heating and cooling by using passive design Insulation reduces the need to use mechanical heating and cooling systems Switching to renewable energy reduces environmental impact Renewable Energy Certificates (RECs) if small-scale energy systems are installed Benefits of solar hot water outweighs upfront cost as difference in cost will be paid back quickly, as less is spent on heating water, & results in reduction in the amount of GHGs produced Residential & commercial sector mitigation opportunities

7. Structural insulated panels are high performance building panels used in floors, walls & roofs for residential & light commercial buildings. They provide superior and uniform insulation compared to more traditional construction methods offering energy savings of 12% to 14% Insulated concrete forms are rigid plastic foam that hold concrete in place during curing and remain in place afterwards to serve as thermal insulation for concrete walls Geothermal heat pumps Heat recovery ventilation – using equipment HRV employs a counter- flow heat exchange between the inbound and outbound air flow. Radiant floor heating – concrete an ideal heat because of its thermal mass - radiant heating systems warm floors to temps of 75°F to 80°F Energy-efficient windows – windows account for about 25-30% of heat loss in residential & commercial buildings increasing energy use & costs & decreasing comfort EE technologies & measures in buildings...

8. Daylighting windows or other openings & reflective surfaces so that during the day natural provides effective internal lighting Solar home design and orientation – correct orientation makes significant difference to liveability & energy costs associated with heating & cooling House orientation – sustainable design use natural heat of the sun & cooler temperatures of the evening to maintain high standard of liveability Material selection & insulation – dense materials preferable in temperate climates (able to release heat), lighter materials are quicker to cool & preferable in tropical conditions. Thermal mass within insulated building envelope reduces extremes in temp inside resulting in average moderate internal temperature Efficient lighting and appliances deliver high quality long-life performance with energy & cost saving benefits...EE technologies & measures in buildings