PASSIVE SOLAR ENERGY

By Aaron Zhou

ID#: 20193983

ME 100 TUTORIAL PRESENTATION

Intro to Passive Solar Energy

• Raw energy from the Sun

• The term “passive” signifies that there are no additional mechanical equipment

required, other than the normal building elements

• 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.

• If used carefully it could provide us with many benefits which would otherwise cost a

lot more

• Solar energy is useful for heating, cooling, cooking, lighting, electricity, water pumping

and purification

• 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• 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• 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• System where the space that is

passively heated by the Sun is

isolated from the rest of the building

space

• South-facing sunrooms are

commonly fitted to a home to take

advantage of the sun's heat and

light.

• Using sunrooms to ventilate a house

is also possible

• 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

Picture taken from www.sunenterprises.com/images/sunroom_1217_large.jpg

Passive Solar Cooling• Passive cooling minimizes the effects of solar

radiation through shading or generating natural

air flows with convection ventilation

• Thermal chimney, which can be designed like

a smoke chimney to vent hot air from the

house out through the (metal) roof

• Sun heats up the space in the roof, air warms

up and rises up the space, escapes through

vents at the top

• At the same time, cool air from outside is

pulled into the room from fresh air vents at the

bottom of the wall

• 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

• Providing interior building with

natural sunlight

• South and north-facing windows

and clerestory windows are all

possible options

• Daylight benefits include

electrical savings, better health,

and improved light quality

(especially in commercial

buildings)

• Research has showed that

student grades and attendance

in schools also improved

Hong Kong Exhibition and Convention Centre

Rock and Roll Hall of Fame

Picture taken from www.rupages.com/ Rock-n-Roll_Hall_Of_Fame.jpg

Picture taken from ap-expo.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

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

Picture taken from www.tucacas.info/ sunfirecooking/fatimajim.jpg

References

Information:

• http://www.eere.energy.gov/RE/solar_passive.html

• http://www.newenergy.org/sesci/publications/pamphlets/passive.html

• http://www.canren.gc.ca/tech_appl/index.asp

Pictures:

• www.google.ca