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Lesson 2 Introductory Lecture
Lesson 2 Introductory Lecture
Lesson 2 Introductory Lecture
Lesson 2 Introductory Lecture
Lesson 2 Introductory Lecture
Lesson 2 Introductory Lecture
Lesson 2 Introductory Lecture
Lesson 2 Introductory Lecture
Lesson 2 Introductory Lecture
Lesson 2 Introductory Lecture
Lesson 2 Introductory Lecture
Lesson 2 Introductory Lecture
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Lesson 2 Introductory Lecture

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An Introduction to Energy Efficiency (Ventilation) by Team G-Power [4-086]. Copyright Team G-Power (Hwa Chong Institution, Singapore) 2011.

An Introduction to Energy Efficiency (Ventilation) by Team G-Power [4-086]. Copyright Team G-Power (Hwa Chong Institution, Singapore) 2011.

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  • 1. Darrel Long Ong Xin Jie Teo Zheng Jie Team G-Power Energy Efficiency (Ventilation) Lesson 1 Introductory Lecture
  • 2. Lesson Objectives Lesson 1 Introductory Lecture
  • 3. Thermal Energy Transfer Lesson 1 Introductory Lecture
  • 4. Conduction <ul><li>Definition: </li></ul><ul><li>Transmission of molecular movement/thermal energy through an object or between objects in direct contact </li></ul><ul><li>Magnitude of heat flow depends on </li></ul><ul><li>Area of section perpendicular to heat flow direction </li></ul><ul><li>Thickness of object(s) </li></ul><ul><li>Difference in temperature </li></ul><ul><li>Conductivity of material </li></ul>Lesson 1 Introductory Lecture
  • 5. Convection <ul><li>Definition: </li></ul><ul><li>Heat transfer from the surface of a solid body to a fluid (gas or liquid) or the inverse through a cycle </li></ul><ul><li>Magnitude of heat flow depends on </li></ul><ul><li>Area of contact </li></ul><ul><li>Viscosity and velocity of the fluid </li></ul><ul><li>Difference in temperature between solid and fluid </li></ul><ul><li>Whether the fluid flow is laminar or turbulent </li></ul>Lesson 1 Introductory Lecture
  • 6. Radiation <ul><li>Definition: </li></ul><ul><li>Thermal energy that can be transmitted through space from one body to another </li></ul><ul><li>Emission wavelength spectrum depends on: </li></ul><ul><li>Nature and on the temperature of the surface of the body </li></ul><ul><li>Amount of radiant heat flow depends on: </li></ul><ul><li>Temperatures of emitting and receiving surfaces </li></ul><ul><li>Emissivity and absorptivity of these surfaces </li></ul>Lesson 1 Introductory Lecture
  • 7. Conduction, Convection and Radiation Lesson 1 Introductory Lecture CHALLENGE: Can you identify the processes of conduction , convection and radiation here?
  • 8. <ul><li>The higher the temperature , the more energy these atoms and molecules have, and the faster they move , hence occupying more space </li></ul>Hot Air and Cold Air RECAP: Hot objects occupy more space than cold objects despite having the same weight As hot air takes up more space than cold air, hot air has a lower density  hot air will rise, cold air will sink Lesson 1 Introductory Lecture
  • 9. Hot Air and Cold Air <ul><li>APPLICATION </li></ul><ul><li>Where should ‘openings’ in a house be positioned? </li></ul><ul><li>In the bottom and top of the house </li></ul><ul><ul><li>Bottom for cool air to flow in </li></ul></ul><ul><ul><li>Top for hot air to rise out of </li></ul></ul>Lesson 1 Introductory Lecture
  • 10. Cross-Ventilation <ul><li>Relies on wind to force cool exterior air into the building through an inlet (window, door, etc.) and to force warm interior air out of the building through an outlet (window, door, etc.). </li></ul>Lesson 1 Introductory Lecture
  • 11. Cross-Ventilation <ul><li>Benefits: </li></ul><ul><li>Passive cooling ; reduced reliance on air-conditioning </li></ul><ul><li>Allows for lighting of area </li></ul><ul><li>Case Study: </li></ul><ul><li>Edgedale Green in Punggol East </li></ul><ul><ul><li>Carpark block </li></ul></ul><ul><ul><li>Sides of lift lobby </li></ul></ul>Lesson 1 Introductory Lecture
  • 12. The End <ul><li>Any questions? </li></ul>Lesson 1 Introductory Lecture

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