Transcript Passive Solar Energy

ME 100 TUTORIAL PRESENTATION
PASSIVE SOLAR ENERGY
By Aaron Zhou
ID#: 20193983
Intro to Passive Solar Energy
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Raw energy from the Sun
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The term “passive” signifies that there are no additional mechanical equipment
required, other than the normal building elements
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All passive techniques use building elements such as walls, windows, floors and
roofs, in addition to exterior building elements and landscaping, to control heat
generated by solar radiation.
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If used carefully it could provide us with many benefits which would otherwise cost a
lot more
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Solar energy is useful for heating, cooling, cooking, lighting, electricity, water pumping
and purification
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Incorporating passive solar designs can slash bill by half!
3 common methods and additional strategies of utilizing this renewable resource:
Passive Solar Heating
• In cold climates, it is very important to obtain and
stored the maximum amount of heat to sustain
comfort
• Passive solar heating makes use of building
orientation, windows, and building materials
• South-facing windows are designed to let the sun's
heat in while insulating against the cold.
• Open floor plans allow more sun inside
There are 3 main methods of passive solar heating:
Direct Gain
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System where heat collection, storage and
distribution all occur within the same
space, without any interference
Use of south-facing windows, to receive
maximum solar exposure during the winter
months
Solar heat passes straight into the room
where it heats up a thermal mass
Heat absorbed by thermal mass and
continually distributes collected heat at
night
Effective thermal masses consist of dense,
heavy materials that will retain heat
whether of not in direct sunlight. Eg.
usually an internal wall or floor made of
concrete, stone or masonry, especially if
painted a flat, dark color; dark-colored
cylinders, tanks or drums filled with water,
or bins of rocks.
Picture taken from www.eere.energy.gov/RE/solar_passive.html
Indirect Gain
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Uses the same materials as direct gain system
but thermal mass is placed between Sun and
space that is heated
Use of flat plat collectors positioned below the
mass and space to be heated
Solar heat is transferred to the thermal mass
where it is absorbed
The heat air rises and enters room through
vents at the bottom of the walls
Convection brings the heat into room and cool
air down to ducts at the bottom to be sent back
to the thermal mass where it is heated and
circulated
During the hot summers, the process is
reversed, so since the thermal mass is not in
direct sunlight, it absorbs heat from inside the
room and radiates it out
Very effective as it usually takes around 6-8
hours for the heat energy of the thermal to
totally dissipate, so it can supply heat to the
home throughout the night
Picture taken from www.eere.energy.gov/RE/solar_passive.html
Isolated Gain
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System where the space that is
Picture taken from www.sunenterprises.com/images/sunroom_1217_large.jpg
passively heated by the Sun is
isolated from the rest of the building
space
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South-facing sunrooms are
commonly fitted to a home to take
advantage of the sun's heat and
light.
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Using sunrooms to ventilate a house
is also possible
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Lower vents from the sunroom to the
interior rooms draw air through the
living space to be expelled out the
upper vents to the outside along the
top of the sunroom.
Sunroom
Passive Solar Cooling
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Passive cooling minimizes the effects of solar
radiation through shading or generating natural
air flows with convection ventilation
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Thermal chimney, which can be designed like a
smoke chimney to vent hot air from the house
out through the (metal) roof
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Sun heats up the space in the roof, air warms
up and rises up the space, escapes through
vents at the top
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At the same time, cool air from outside is pulled
into the room from fresh air vents at the bottom
of the wall
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Warm air inside is also pulled by vents into the
roof space to be released
Picture taken from the.honoluluadvertiser.com/. ../Feb/27/ln20a.gif
Day lighting
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Providing interior building with
natural sunlight
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South and north-facing windows
and clerestory windows are all
possible options
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Daylight benefits include
electrical savings, better health,
and improved light quality
(especially in commercial
buildings)
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Research has showed that
student grades and attendance
in schools also improved
Picture taken from
www.rupages.com/ Rock-nRoll_Hall_Of_Fame.jpg
Rock and Roll
Hall of Fame
Hong Kong
Exhibition and
Convention
Centre
Picture taken from apexpo.com/HK%20show
/ Hongkong_Show.html
Other Technologies
Solar Cookers
• Sun can be focused to heat of water and
food
• Used in undeveloped countries but modern
designs are available to the general public
Picture taken from www.tucacas.info/ sunfirecooking/fatimajim.jpg
Others
• Shadings and overhangs also reduce the
hot summer sun, while still allowing winter
sun
• The optimal window-to-wall area ratio is
25-35%.
Picture taken from www.ekosbuild.com/
CaseStudies/Overhangs.jpg
References
Information:
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http://www.eere.energy.gov/RE/solar_passive.html
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http://www.newenergy.org/sesci/publications/pamphlets/passive.html
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http://www.canren.gc.ca/tech_appl/index.asp
Pictures:
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www.google.ca