A look at passive design principles. Useful resource for teachers of Construction Studies in Ireland.

1. Passive Housing
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2. What is passive design?
Passive solar design refers to the use of the sun’s
energy for the heating and cooling of living spaces. In
this approach, the building itself or some element of
it takes advantage of natural energy characteristics in
materials and air created by exposure to the sun.
Passive systems are simple, have few moving parts,
and require minimal maintenance and require no
mechanical systems.
(http://passivesolar.sustainablesources.com/)
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3. Passive Housing Principles
Orientation/ layout
Natural lighting
Thermal mass
Heating
Airtightness
Air quality
Glazing
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4. Sun Path
In Northern
hemisphere nations
the sun is
positioned in the
south.
The sun rises in the
east and goes down
in the west.
In summer the sun
is higher in the sky
than in winter (as
shown in diagram)
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5. Orientation/Layout
Note: Storage rooms placed
As sun is in south, to provide to north side of house
natural light the rooms that
are busiest should be on the
southerly façade of the
home (kitchens, living area)
Rooms which are used less
frequently and need little
lighting should be placed on
northerly façade of home
(utility, bathrooms etc.)
Note: Living room, kitchen,
Barry Mattimoe 5 dining room to south of
house

6. Orientation/Layout
As the sun rises in the
east it is best practice to
have bedrooms on the
south east side of the
home.
This will provide light to
the room in the morning
when the sun rises.
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7. Natural lighting
To provide natural light
from the sun, large glazed
areas are used to let the
suns rays enter the home.
To maximise the light
from the sun, these large
glazed areas should be on
the south facing façade of
the house.
This will let the sunlight
into the home Note: Larger overhang on roof to
throughout the year. prevent overheating in summer
months.
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8. Shading
During the summer months
there is a high chance of
overheating in a passive home.
This is due to the high levels of
exposure to the sun.
In order to combat this a large
roof overhang can block the
rays from the sun from
entering the home.
This overhang will prevent
overheating during the
summer and still allow all
winter sun into the home.
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9. Thermal Mass
Thermal mass is the ability
of a material to store heat
produced from sunlight.
This concept is important in
passive design as changes is
temperature need to be
controlled.
Materials with good thermal
mass store the heat from
the sun and let it out slowly
as the day progresses.
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10. Thermal Mass
During the day the thermal
mass materials absorb the
heat from the sun.
These materials release the
heat slowly throughout the
day and night.
This keeps the house at
comfortable temperature
Good thermal mass
materials: concrete, water,
clay brick, natural
rock/stone
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11. Heating
Solar heating panels can
be used to provide hot
water for the home.
Panels are placed out
southerly facing roof to
absorb the heat from the
sun throughout the year.
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12. How Solar Panels Work
The solar panels are made of
specially designed material that
absorbs the suns rays extremely
efficiently and when the sun
heats the solar panels, a fluid is
pumped from the hot water
cylinder in your hot press up and
around the solar panels.
The fluid is then heated in the
solar panels and returns to the
hot water cylinder to heat the
water in the cylinder.
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13. Airtightness
An important aspect in
passive design to prevent
heat being lost in the
home.
All elements of the
dwelling should have high
levels of insulation to
prevent heat loss.
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14. Wall Insulation
In traditional building
systems there is a chance
of cold bridges in the wall
area between small gaps
at joints.
As shown in the diagram
warm air is being lost
around the window and
at the eaves.
In passive homes this
needs to be eliminated in
order to trap all the heat
in the house.
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15. External Wall Insulation
Insulating walls externally
is system suitable for
passive homes.
This system prevents any
cold air from outside
entering the building.
It provides a full cover on
the external surface of
the building trapping in
the heat inside the home.
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16. Viking Timber Frame
Insulation
Timber frame construction
is suitable for passive
design.
Between the stud work of
the timber frame it is
packed with insulation.
The insulation is packed in
tight in between the studs
to prevent any cold
bridging.
Insulation is usually 200-
300mm depending in
thickness of wall.
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17. Roof Insulation
Eaves ventilator insures ventilation in
roof space to prevent timber rotting.
This detail shows high
levels of cellulose
insulation which has been
sprayed between the
joists.
The insulation goes down
to eaves level and insures
no cold air can travel
through to the living area
of the home.
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18. Roof Insulation
This detail shows the
insulation between the
roof rafters.
This system is used if the
roof space is to be used
as a living space.
The insulation is rigid
board and is cut to fit
between the rafters of
the roof.
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19. Foundation Fig 1
insulation
Heat can be lost through the
ground in a house.
In traditional foundation
systems there is a high Fig 2
chance of cold bridges
coming from the earth into
the house as shown in Fig 1.
By using a modern insulated
slab as shown in Fig 2 the
bridge is prevented from
occurring.
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20. Viking insulated
slab
In this foundation cold
bridges are prevented.
The foundation is
insulated on the internal
as well as external
surfaces.
The foundation is made
up of polystyrene
insulation which when
joint forms a ring beam to
which the concrete
foundation is poured into.
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21. Air quality
Indoor air quality is a
important concern to take
into account when
designing a passive home.
Due to the high level of
insulation in passive homes,
stale air can be trapped in
the home if it is not
released.
This can lead to mould
growing in the home and
creating uncomfortable
living conditions
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22. Heat Recovery Ventilation (HRV)
HRV units provide the
clean air necessary to
create comfortable living
conditions.
These systems take the
stale air within the house
out and let fresh air into
the house.
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23. Heat Recovery Ventilation (HRV)
Hot air from inside heats cool air
When the hot stale air is coming into house in heat exchange
extracted from the home, it core.
is used to heat the cool
fresh air coming in.
The air from inside and
outside pass through the
same system however they
never come in contact with
one another.
As the hot stale air leaves it
heat the cool air coming in.
this keeps the house at a
comfortable living
condition.
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24. Triple Glazing Note: Insulated
window frame
Triple glazed systems are
often used in passive
homes.
Triple glazed systems have a
high conservation of heat
and also eliminate drafts in
the house.
The main disadvantage of
this system is the distortion
of light between the panes
of glass.
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25. Double Glazing
Don’t have as high
thermal efficiency of the
triple glazing system.
However the double
glazed system wont
distort the light coming
into the home to the
same extent as the triple
glazing system.
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26. Balance between glazing systems
As both systems have good
thermal efficiency it is suitable
to use both types in the ne
home.
As the north facing façade will
experience the cooler/stronger
conditions it would be suitable
to use triple glazing system on
this façade.
To the south/east/west facing
façades it would be suitable to
use the double glazing system
as these sides of the home will
take in the sunlight. This
system wont distort the light
as much as the triple glazing
system .
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