1.2.3 Reducing Unwanted Energy Transfers

• Conduction is the transfer of energy through direct contact
• Reducing unwanted energy transfers improves energy efficiency
• Air leaks in buildings can cause both heat loss in winter and heat gain in summer.


  True
• How does radiant heat from hot surfaces transfer energy?

  Through radiation
• Match the source of unwanted energy transfer with its description:

  Heat loss through walls ↔️ Poorly insulated buildings

  Air leaks ↔️ Gaps and cracks in buildings

  Inefficient appliances ↔️ Older or poorly designed devices

  Friction in moving parts ↔️ Mechanical systems like engines
• What is the role of insulation in reducing heat loss?

  Creates a barrier
• How does optimizing system design reduce energy loss?

  Minimizes friction
• Acoustic panels are examples of sound absorption
• Steps for reducing energy loss due to heat in a building:

  1️⃣ Install insulation in walls and roof

  2️⃣ Seal air leaks around windows and doors

  3️⃣ Optimize design of heating systems
• What is the purpose of sound absorption?

  Convert sound into heat
• What are energy transfers in physics?

  Movement of energy
• How does convection transfer energy?

  Movement of fluid
• Why does poor insulation lead to heat loss in buildings?

  Reduces energy efficiency
• Friction in moving parts of mechanical systems can cause energy loss due to heat
• Conduction, convection, and radiation are all types of energy transfers.


  True
• Insulation materials help minimize heat transfer through conduction
• Sealing air leaks in buildings improves energy efficiency.


  True
• Match the method for minimizing energy loss through sound with its description:

  Sound absorption ↔️ Converts sound waves into heat

  Sound insulation ↔️ Blocks sound from passing through

  Vibration isolation ↔️ Minimizes transfer of vibrations
• What type of material is used for sound insulation in buildings?

  Dense materials
• Methods to minimize energy loss through sound:

  1️⃣ Use sound absorption materials

  2️⃣ Apply sound insulation techniques

  3️⃣ Isolate vibrations from machinery
• Sound insulation is achieved with dense materials like concrete
• Why are sound absorption, insulation, and vibration isolation essential?

  Improve energy efficiency
• Match the type of energy transfer with its description:

  Conduction ↔️ Direct contact between objects

  Convection ↔️ Movement of a fluid

  Radiation ↔️ Electromagnetic waves without a medium
• What is a common source of heat loss in buildings?

  Poorly insulated walls
• Addressing unwanted energy transfers conserves energy resources.

  True
• How does insulation reduce heat transfer?

  Creates a barrier
• Optimizing system design reduces friction in mechanical systems.


  True
• Sound insulation blocks sound using dense materials like double-glazed windows
• Match the light energy technique with its benefit:

  Reflective Surfaces ↔️ Reduces the need for more light fixtures

  Energy-Efficient Light Sources ↔️ Conserves energy and lowers bills

  Optimized Lighting Design ↔️ Enhances illumination and reduces waste
• Vibration isolation uses rubber mounts or spring isolators.


  True
• Energy transfers refer to the movement of energy from one place or form
• Reducing unwanted energy transfers improves energy efficiency.


  True
• Air leaks in buildings lead to heat loss in winter and heat gain
• Reducing air leaks involves sealing gaps and cracks
• What type of energy does sound absorption convert sound waves into?

  Heat
• Reflective surfaces increase brightness without needing more energy.


  True