PASSIVE SOLAR ENERGY

1. PASSIVE SOLAR ENERGY ME 100 TUTORIAL PRESENTATION By Aaron Zhou ID#: 20193983

2. 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:

3. 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:

4. 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

5. Indirect Gain Picture taken from www.eere.energy.gov/RE/solar_passive.html • 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

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

7. 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

8. Day lighting Picture taken from www.rupages.com/ Rock-n-Roll_Hall_Of_Fame.jpg Rock and Roll Hall of Fame • 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 Picture taken from ap-expo.com/HK%20show/ Hongkong_Show.html

9. 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.tucacas.info/ sunfirecooking/fatimajim.jpg Picture taken from www.ekosbuild.com/ CaseStudies/Overhangs.jpg

10. 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