Solar Properties and Passive solar Flashcards
How is solar availability applicable to buildings?
The sun is high in the summer = Shading devices.
Sun is low in winter = Below shading device results in free heat
Fixed or tracked Solar pannels
Tracked solar panels collect more sunlight as they move to absorb the most of the suns rays
What is diffuse solar Radiation
Radiation that is diffused by the earths atmosphere.
Total Solar Irridance Equation
G = G(Direct)+G(Diffuse) (W/m2)
What are the units for solar irradance?
W//m2
What is Passive Solar Heat?
Heat thaat is stored in building materials and released later.
- No mechanical Parts
- No external power
What is active Solar heating?
External Power is used to run the system while hardware and mechanical equipment are used to collect and transport solar energy.
3 solar energy components
Diffuse
Direct
Reflected
Trombe wall
South facing glaze then thick building materials in order to absorb heat
Green House Effect
Short wave energy is collected through the glazing
The radiation is absorbed by the opaque or solid elements and re-admitted
The long wave cant leave due to the glazing
Issues with Solar space heating for buildings
- Less reliable as there is less sun in winter
- Not all solar energy can be collected
- Heat storage needs to be high enough to be useful
Double skin facade
Like the Gherkin
Sunlight passes though the glass. Internal convection heat up the air and allows for the heat to rise. Windows can be opened or closed to let in warm air as well as ventilate the building.
