Passive Solar, Passive Cooling and Daylighting
OBJECTIVES Learn about :
The history of Passive SolarEnergy efficient designEnergy end usesPassive Heating and Passive CoolingDaylightingRenewables
The History of Passive Solar
5th Century BC Greece
Community Planning employed passive solar design.
Diminished fuel sources brought design changes.
Passive Solar in Ancient Greece Aristotle noted, builders made sure to
shelter the north side of the house to keep out the cold winter winds.
And Socrates, who lived in a solar-heated house, observed, "In houses that look toward the south, the sun penetrates the portico in winter" which keeps the house heated in winter.
Cross section of a Roman heliocaminus. The term means "sun furnace."
Roman heliocaminus The Romans used the term to describe
their south-facing rooms. They became much hotter in winter than similarly oriented Greek homes because the Romans covered their window spaces with mica or glass while the Greeks did not.
Solar Greenhouses from Ancient Rome to 18th Century
Europe
Canvas covered the glass in the evenings to hold in heat.
With the fall of the Roman Empire, so too came the collapse of glass for centuries in either buildings or greenhouses.
19th Century Solar Remodel with attached greenhouse
American Solar Heritage:
Anastasi Indians
Pueblo Indians’ Sky CityContinuously inhabited since the 12th century
Southwest AdobeOrientation, control & thermal mass
Adobe = Thermal Mass
The colonial "salt box" house, typical of New England architecture of the 18th century.
Maximizes Southern Exposure
The solar-heated Rose Elementary School in Tucson Arizona. It obtained over 80% of its heat from solar energy for an entire decade, beginning in 1948.
Village Homes subdivision built in the late 1970s in Davis, California. The layout of the subdivision allowed every house to face the winter sun.
Today
Generation and use of energy (electric, gas, oil, coal) are major contributors to air pollution and
global climate change.
And pollution of our rivers…….
MOUNTAIN TOP REMOVAL
Improving energy efficiency and using renewable energy sources are effective ways to improve air quality and reduce the impacts of global warming
Energy efficiency is a cornerstone of any green building project.
Passive Solar
Passive solar buildings aim to maintain interior Thermal comfort.
Passive solar building design is one part of green building design, and does not include active systems such as Mechanical ventilation or Photovoltaics
.
Passive Solar Design
The 47-degree difference in the altitude of the sun at solar noon between winter and summer forms the basis of passive solar design.
Passive solar building design revolves around 5 main aspects;
Aperature: The set of windows and overhangs that determine how much sun enters the building.
Absorber: The material that the sun’s ray come into contact with.
Thermal Mass: The material that stores the sun’s thermal energy for re-release after sundown.
Distribution: The means by which the thermal energy is released to the living/working spaces.
Control: The techniques used to control the collection and distribution of the sun's thermal energy.
Design Aspects:
Passive Solar Design Themes: Direct Gain: Sunlight shines into and
warms the living space. Indirect Gain: Sunlight warms thermal
storage, which then warms the living space.
Isolated Gain: Sunlight warms another room (sunroom) and convection brings the warmed air into the living space.
Passive Solar Heat Passive solar design can reduce heating
temperatures by 30-50% Windows need to be incorporated within
30 degrees of due south
indirect gain systems In the indirect gain, a storage mass
collects and stores heat directly from the sun and then transfers heat to the interior space. There are several indirect gain passive solar systems :
Indirect Gain Water Wall
Trombe Wall
Isolated Gain Space:
Sunroom
Passive Solar Design Aspects
PASSIVE COOLINGPlant deciduous trees for shade
Natural ventilation is a key cooling strategy
Install window overhangs and awnings
Deciduous Shade Trees Primarily shade windows and paved areas Keep trees an appropriate distance from the
house and utility lines
Deciduous shade trees offer the best solution for keeping out low-angle sunlight from west and south windows in summer.
Shade trees can reduce summer air-conditioning costs by 25 – 40%.
Trees can create a microclimate that is up to 15 degrees cooler
than the surrounding area.
Trees also clean the air, create habitat and play areas for children as well as add aesthetic beauty to the neighborhood.
Overhang and Awnings
Overhangs are important parts of passive solar heating and natural
cooling.
Awnings and Overhangs
Help keep the heat of the sun out during the summer.
Wood trellises
Arbors
Adjustable or demountable awnings made of fabric or metal
Allow heat to enter during the winter.
DAYLIGHTING
• What is Daylighting?• Energy Savings• Productivity, Health and Well Being
This?
Or This?
Clerestory Windows
Modeling with the Heliodon
Heliodon at PG&E Energy Center
Daylight modeling with Heliodon
Daylight after construction
Daylighting Saves Energy and Improves Productivity
Deck Mounted Skylight
Sun tracking systems
Skylights
Solar Tubes:Inexpensive, Easy to install …
And very effective
Daylighting on a large scale
REVIEW OBJECTIVES Learn about :
The history of Passive SolarEnergy efficient designPassive Heating Passive CoolingDaylighting
WE DID NOT INHERIT THE EARTH FROM OUR PARENTS. WE ARE BORROWING IT FROM OUR CHILDREN.
CHIEF SEATTLE