Passive Solar Design
3 key elements
I. Maximizing Heat Collection in the Winter
by means of a thermal mass.
–
–
–
Direct Solar Gain
Trombe Wall – indirect solar gain
Sunspace – combines both direct and indirect
solar gain
II. Minimizing Heat Loss in the Winter
III. Preventing Overheating in the Summer
Thermal Mass-collection essential
Any material in the home that absorbs and
stores heat such as: concrete, brick, tile and
other masonry materials.
These materials absorb the sun’s energy and
radiate it slowly into the house at night or on
cloudy days.
They are most effective when dark colored
and are located in direct sunlight.
Direct solar gain
is radiant heat
from the sun admitted directly into the
living spaces, through south-facing
windows, which is then absorbed by
thermal mass.
-
A side view of a direct gain passive solar house
(Design by Dennis Holloway, Architect)
Trombe Wall schematics
•http://www.builditsolar.com/Projects/SpaceHeating/SolarWall/SolarWall.htm
Trombe Wall Essentials - indirect solar gain
• Thermal Mass
Solid masonry wall works well . The more massive the
better.
• Selective Solar Exposure
Collect in winter, protect in summer. Conceal with
overhang that blocks summer sun but not winter sun.
• Dark Color
Painted on or natural pigment, to absorb the sun's energy.
• Glass Interface
Glass lets through the optical energy from the sun. On an
exterior wall, install double-pane (or even triple in very
cold regions).
•http://www.allanstime.com/SolarHome/Trombe_Wall/index.html
Passive Solar Residence for Gerald and Betsy Loffredo,
Lyons, Colorado, 1979
One of the largest residential Trombe walls ever built. The
Trombe wall provides 90% of the required space heating in
this residence. The sunspace "crystal" in the front of the
house provides vegetable year-round
This
trombe
wall covers
the whole
side of the
house
http://www.dennisrhollowayarchitect.com/html/Loffredo.html
Trombe wall –with partial window
shown from the inside and the
outside
http://www.aspencore.org/sitepages/pid67.php
“…I painted
the uninsulated
plastered masonry wall
dark green, attached
a flat 1x3 frame with
masonry screws
and foam from a can,
then added
1 layer of Dynaglas clear
corrugated polycarbonate
greenhouse glazing
with corrugated foam
strips on the vertical
edges…”
Trombe wallwithout window
YO,
check
out my
wall!
http://www.builditsolar.com/Projects/SpaceHeating/nicksthrombe.htm
Sunspaces-use a combination of
direct and indirect solar gain
Sunlight entering the
sunspace is absorbed by a
thermal mass.
Heat is brought into the
house by means of
conduction through a
shared mass wall in the
rear of the sunspace, or
by vents that permit the
air between the sunspace
and living space to be
exchanged by convection.
II. Protection from heat loss
The heat you collect isn’t much good to you if
you can’t hold onto it!
• Insulation: R35 in walls, R50 in attics
• Landscape – to create wind blocks
• Careful room placement
• Sloping land (berms) and roof lines
• Earth
Sheltering:
achieve a low
profile that
provides
insulation and
energy savings.
• cold winter
winds just blow
right over the
house
Berms
N
http://www.sunterrahomes.com/homedesignconcepts.asp
Landscaping-as part of your design
A windbreak
on the northwest side
can shield the home
from prevailing
'
winter winds.
During the summer,
'
tall deciduous trees
planted close to the
home shade the
roof. Broad, shorter
trees on the west side
block afternoon solar
heat.
http://www.builditsolar.com/Projects/Cooling/Shading/EB%20Landscaping%20for%20energy%20efficiency.pdf
III. Preventing Overheating – a good
solar design allows you to collect a
lot of energy…but you don’t want it
in the summer!!
There are a
variety of
things that can
be used to
prevent over
heating….
http://www.builditsolar.com/Projects/Cooling/passive_cooling.htm#Shading
Use of Overhangs – allows the sun to enter
in the winter but keeps it out in the summer.
Solar Chimney - draws air through a
geothermal heat exchange to provide passive
home cooling.
As warmed air in the
chimney rises, air
near the ground is
pulled into the pipe,
is cooled as is flows
underground, and is
therefore cooler
when it enters the
home. This system
simply sets up a
convection current.
Overhangs prevent
overheating by the high
summer sun. The house
works as a cooling
tower when windows
are opened by venting
hot air out of a hatch on
the roof deck. This
pulls cool air into the
lower floors.
http://www.backwoodshome.com/articles/heckeroth63.html
Keeping the sun out in the summer
can include use of solar screens
• http://www.sunbloxsol
arscreens.com/solarscreens/Gallery/solarscreens-portfolio.html
Awnings can also be used to keep
sun off a window
http://www.builditsolar.com/Projects/Cooling/passive_cooling.htm#Shading
A house that incorporates a variety
of passive solar elements
• The house, which will be built in
pumicecrete, features several
Trombe walls and an interior
courtyard with sunspace.
• The Great Room (under the large
blue roof) has a sunspace on the
south and an array of large low-E
windows on the north that face a
spectacular view of the 600 foot
deep Rio Grande Gorge.
• The courtyard provides an windsheltered outdoor micro-climate
extension of the Great Room.
http://www.dennisrhollowayarchitect.com/html/PateByrd1.html
Cornell’s entry into the Solar
Decathlon 2007
Solar Decathlon in Washington DC
2007
http://www.inhabitat.com/2007/10/19/germany-wins-the2007-solar-decathlon/