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Active Solar Air Heating. By: Mitchell French. Objective. Give the class enough knowledge to make intelligent decisions regarding this heating system. Collection. Solar Collectors Gather heat Air is the absorbing fluid Air moves directly into house or stores in rock storage bin
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Active Solar Air Heating By: Mitchell French
Objective • Give the class enough knowledge to make intelligent decisions regarding this heating system
Collection • Solar Collectors Gather heat • Air is the absorbing fluid • Air moves directly into house or stores in rock storage bin • Air circulated through house using ducts • If excess heated air, stored in container • If not enough heat, backup heating system activates (traditional system)
Panels • Must be pointed towards true south • Point where sun is at its highest • This usually equates to your latitude +15° • Leniency of about 20° • Should not be placed in shaded area • Do not have to be placed on roof
Distribution • Fans move air through ducts in house • Large ducts allow the air to move slower and therefore feel warmer • An “Air Handler” decides where the air will go • From collectors to house • From collectors to storage container • From storage container to house
Ducts • Large due to lower temperature of air • Must move more air to make up for lower temperature • Must maximize the efficiency of fans • Requires insulation so no heat is lost (R-16) • Average system moves air at a speed of 1.5 to 3 m/s
Storage Container Build • Lined with rocks on the bottom to absorb heat • Quartz most common type of stone • Larger than required for fluid system • Can be stored inside, basement, or underground outside
Storage Container System • Heated air enters through plenum at top • Rocks absorb heat from air • Air enters through bottom, heats as it rises and gets distributed to house • If air going to house: • Enters through bottom plenum • Absorbs heat as it rises • Fans circulate air through house
Properties of Container • Materials: Cinderblock, Concrete, Wood • Must be sealed to preserve efficiency • Usually installed in crawlspaces or basements • Should have ½ to 1 ft3 for every ft2 of collector • Should be 5 to 7 feet deep • Temperature: top-140°F (60 °C) bottom-70°F (21.1°C)
Advantages / Disadvantages • Advantages: • If there is a leak in the system, it is less important than if one occurs in a liquid system • More effective during the day than the liquid system • Can heat air earlier and later in the day • Air systems do not freeze like is possibly with liquid systems • Disadvantages • Much more space required
Maintenance • Check ducts for leaks that could reduce performance • Make sure collectors are clear • Clean air filters for more efficient flow of air • Lubricate pumps and fans • Empty Storage Bin in summer
Installation • Depends on Container location • Hard to upgrade existing house • Must plan to use air solar heating from beginning
Partial Systems • No storage container • Collector panels not as large • Collector Panels placed directly on wall • Same principle as full system, but no storage • Collectors are relatively small • Simpler to install • fits in existing window
Conclusion • Size makes it cumbersome • Requires precise installation
References • http://www.healthgoods.com/Education/Energy_Information/Renewable_Energy/heating_with_active_solar.htm • http://www.newenergy.org/sesci/publications/pamphlets/active.html • http://www.solarenergysociety.ca/2003/active.asp • http://www.canren.gc.ca/programs/index.asp?CaID=60&PgID=141 • http://bathrooms.bobvila.com/Article/743.html