Passive Design Elements

Passive building design allows us to use heat from the environment or the occupants to create a comfortable environment in a building. This will reduce the need to create heat from the combustion of fossil fuels or electrical resistance heating.

Walls

• Conductive heat flow

Insulation

• Conductive heat flow

Windows

• Reflectivity

• Emissivity

• Spectral response

Water Heating

• Heat capacity

Refrigeration

• Metrics for CDD

• Metrics for volume

• Thermodynamic cycle

Heat Pumps

• Thermodynamic cycle

Spectrally Selective Materials

In a cold climate, it would be advantageous to be able to absorb sunlight very efficiently, but radiate heat very inefficiently. What properties would such a material have?

Maximum Temperature

• Given a heater emitting a constant power, what is the equilibrium

  temperature for a home?

• For simple cases, we can estimate this from the UA product

$q = U A \Delta T$

$\Delta T = T_{inside} - T_{outside} = q/UA$