Efficiency in Home Heating and Cooling: Key Strategies for Energy Conservation
Learn how we heat and cool homes, the efficiency of different methods, heat transfer mechanisms, and ways to enhance energy efficiency in heating and cooling systems.
Efficiency in Home Heating and Cooling: Key Strategies for Energy Conservation
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Presentation Transcript
Key Questions: How do we heat/cool our homes? How do we get our heat? How does heat transfer? How do we increase energy efficiency? Why increase efficiency?
How do we heat/cool our homes? • Forced Air Heating and Cooling • What? • Air heated/cooled • Distributed through ductwork • How? • Natural Gas/Electricity • Why? • Can be used for heating and cooling • Relatively inexpensive • High Annual Fuel Utilization Efficiency (AFUE) • Efficiency of converting fuel to energy.
How Does Heat Transfer? • Second Law of Thermodynamics • Heat goes from a warm place to a cold place. • In homes: • When heating, heat is lost to the outside. • Hot objects will cool to room temperature. • When cooling, heat is gained from the outside). • Cool objects will warm to room temperature.
Conduction • Heat is transferred through materials by direct contact (transferred to adjacent molecules). • Ex. Putting a spoon in hot water
Thermal Conductivity Conductors vs. Insulators
Convection • Heat is transferred by mass motion fluids such as air or water. • Ex. Forced air by fan • What happens to particles when you heat them? • They spread out less dense. • Hot air rises, cool sinks down and takes it place
Radiation ? • Heat is transferred by electromagnetic waves. • The source heats an object but not the median in between. • Ex. The Sun heating a house.
Radiation Absorption vs. Emission