Chapter 6part 1 Passive Solar

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Chapter 6-part 1 Passive Solar

• Incident Solar Radiation-Effects of Latitude and
  Season
• Solar Heating through Time
• Uses of Passive Solar Heating Today
• Passive Solar Houses
• Solar Hot Water Heaters

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Energy in the News
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US Renewable Energy Use
Share in 1999 How is this mix Different from
that In Developing Countries? Brazil? India? Other
?
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Expected Growth in Renewables Bush Admin. 2001
Report
Is this right, especially given the relative
costs of different sources?
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Renewables Second Best Growth
Can nuclear continue to outstrip Renewables, why
or why not? What is the growth rate of wind
power In Europe?
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Solar Radiation vs Infrared Radiation
Why do the sun And the earth emit Different types
of radiation? Why does the mix of radiation
change from the top to the bottom of the
atmosphere? What is insolation? What are
absorption bands? What is albedo? What is the
greenhouse effect?
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Seasonal and Latitudinal Insolation Variations
Why does solar insolation at High latitudes
decrease during Winter months? What happens
between the Tropics of Cancer and Capricorn?
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Angle of Incidence of Solar Insolation
Why does the optimum Angle from horizontal for A
solar panel vary with the Season (at high
latitudes)? What happens near The equator?
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Seasonal Sunrise and Sun Angle at 40N
Why is this variation In angle important For
passive solar design? What happens at
the Equator?At South Pole station?
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Insolation on a Solar Collector 40N
What season does The flat collector Get the most
insolation? What season does the Vertical
collector Get the most insolation? What would
this graph Look like near the equator?
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Types of Solar Insolation
Physics of cloud Cover still not Well known Big
problem in Climate models How does
total Insolation depend on the Solar
constant? (Precambrian Equatorial Glaciations)
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Types of Solar Insolation

Direct Reflected Diffuse Where do you get the
most reflected insolation, on land Or on the
water? Why? What type of weather gives you more
diffuse insolation, Cloudy or clear? Why? How
much of the incident solar radiation reaches
the Earths surface?
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US Mean Annual Solar Insolation
Where is insolation greatest? Where is
insolation Least? What is the ratio of The
greatest to Least insolation In the US? Is this
surprising?
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Solar Printing Press
Invented by August Mouchat 1878 A Solar
Collector B Steam Engine C Water Tank Printing
Press turned By steam engine
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Parabolic Solar Collector
How does using water as the working fluid limit
the collectors efficiency? If outside air is
at 293K, what is the Theoretical efficiency?
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Solar Pot
Mouchots solar pot Could boil 3 liters of Water
in 1.5 hours. Based on your problem Set, about
how long would it Take to just bring the water To
100C?
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Adams solar cooking pot
Where in The developing World would these Pots be
easiest For people to accept? Least easy to
accept? (Think cuisine Not income levels)
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Telkes Oven
Why can this solar oven Reach higher
temperatures Than the previous oven? What
features of passive solar Design does it
incorporate That make it more efficient?
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Solar Water Distiller
Research vessels get water from evaporators. Why
is it so hard to distill water in the Red Sea?
Why does the ship need to be moving To distill
water? (Dredging leg in the Red Sea.)
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General Features of Solar Heating
What uses a fan Active or passive Solar heating
Systems?
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Flat Plate Solar Collector
How is this Solar collector like a
greenhouse? Why should it Absorb more heat Than
a typical Greenhouse (three reasons)
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Types of Solar Flat Plate Collectors
Which types are most Likely to be passive? Why?
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Active solar hot water system
Why is active solar more common at high latitudes?
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Types of Solar Collectors
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Thermosiphon Hot Water Heater
Passive Solar System Water Collection Tank Must
be above the solar Collector. Why? Very popular
in the Middle East. Why are these
systems Impractical at higher Latitudes?
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Bread Box or Batch Water Heater
Hot water is removed Whenever tap is turned
on. Payback time 5 to 10 years. Very
inexpensive for Preheating water. Solar shower
used in Gulf War very similar.
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Increasing Systems Energy Efficiency of Hot
Water Systems
Reduce water temperature to 120F (depends on
dishwasher) Insulate heater to R-19 Use low
flow showerhead and aerators (payback time 1
year) Reduce use by 50 Install a graywater
system (illegal in some areas) Special
detergents needed Install a timer on water
heater so is only on when being used. Install a
tankless water heater system (some use open
flame But so do gas driers).