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_In
formation/Renewable_Energy/heating_with_activ
e_solar.htm
• http://www.newenergy.org/sesci/publications/pam
phlets/active.html
• http://www.solarenergysociety.ca/2003/active.asp
• http://www.canren.gc.ca/programs/index.asp?CaI
D=60&PgID=141
• http://bathrooms.bobvila.com/Article/743.html
Diagram