Download Tensile Structures as Microclimate Modifiers

Tensile Structures as Microclimate Modifiers
TS3 – Tensile Structures as Microclimatic Modifiers
What Materials are
used in Tensile
Structures?
• A tensile structure is a
construction of elements
carrying only tension and no
compression or bending.
• Fabric for clothing was the
first material used in tensile
structures. Modern
manifestations include other
forms of fibrous material
such as Fiberglass,
Polyesters and Polymers
such as ETFE.
• Such structures are classified
as thin-shell structures since
there’s only a thin layer of
material separating indoors
from outdoors
TS3 – Tensile Structures as Microclimatic Modifiers
Thermal Flows On ThinShell Structures
•
Thermal flows are important
to any architectural design and
have been for centuries.
•
As an inhabited structure a
Thin-Shell Structure must be a
comfortable environment
•
However, whilst the structural
design can be approached
with almost total confidence,
the environmental
performance of the spaces
they enclose is still relatively
poorly understood.
TS3 – Tensile Structures as Microclimatic Modifiers
Thermal Flows On ThinShell Structures
TS3 – Tensile Structures as Microclimatic Modifiers
Thermal Flows On ThinShell Structures
•
•
The thickness of the fabric
membrane, typically around
1mm permits the skin to
function as a passive filter,
capable of modifying both
thermal and light levels within
the enclosed space to
minimise reliance on
conventional energy sources
to control the internal
environment.
Selection of materials with
appropriate optical properties
offers a means of creating
spaces where daylight levels
are accentuated or creating
more protected shaded
spaces.
TS3 – Tensile Structures as Microclimatic Modifiers
Use of Materials and
Topology to Manipulate
the Internal Environment
•
Tensile structures can be used
as microclimate modifiers in a
number of different ways
•
Selection of materials with
reflective properties and
strategically defined openings
offer a means of creating
spaces where heat can be
retained, or dissipated within
the enclosure.
TS3 – Tensile Structures as Microclimatic Modifiers
Example:
Khan Satyr - Astana,
Kazakhstan
•
Temperatures in Astana can
drop to -35 degrees Celsius in
winter and climb as high as
+35 degrees in summer.
TS3 – Tensile Structures as Microclimatic Modifiers
Example:
Khan Satyr - Astana,
Kazakhstan
•
Temperatures in Astana can
drop to -35 degrees Celsius in
winter and climb as high as
+35 degrees in summer.
•
The three-layer ETFE envelope
is designed to shelter the
enclosed accommodation
from weather extremes and to
allow daylight to wash the
interiors.
TS3 – Tensile Structures as Microclimatic Modifiers
Khan Satyr - Astana,
Kazakhstan
•
Temperatures in Astana can
drop to -35 degrees Celsius in
winter and climb as high as
+35 degrees in summer.
•
The three-layer ETFE envelope
is designed to shelter the
enclosed accommodation
from weather extremes and to
allow daylight to wash the
interiors.
•
A unique ventilation system
utilizes buoyancy forces to
drive hot air out of the
structure in summer months,
whilst retaining heat in winter
months.
TS3 – Tensile Structures as Microclimatic Modifiers
Example:
Denver International
Airport, USA
•
Temperatures in Denver can
drop to -8 degrees Celsius in
winter and climb as high as
+30 degrees in summer.
•
The two layer fiberglass
envelope is designed to
shelter the enclosed
accommodation from weather
extremes. The internal surface
is highly reflective to prevent
re-radiation of heat absorbed
in the daytime to the night sky
.
•
A clever ventilation
mechanism utilizes natural
stack effect to effectively
remove heat build up over
warm periods
TS3 – Tensile Structures as Microclimatic Modifiers
Rules of Thumb to
Microclimatic Modifiers in
Thin-Shell Structures
•
•
•
•
•
•
Every enclosed structure needs
adequate levels of fresh air to
ensure a healthy and
comfortable environment
Use low level openings on
multiple orientations, combined
with high level openings
Use the natural form to drive
ventilation airflow via natural
means – i.e. stack ventilation
Select the “reflectivity” and
“transmissivity” properties of
the tension material carefully,
based on the local
climate/microclimate
Warmer climates should have
large openings at high level
combined with low reflectivity
materials, to flush the heat out.
Colder climates should have
smaller openings at high level
combined with highly reflective
materials, to keep the heat in.
TS3 – Tensile Structures as Microclimatic Modifiers
THANK YOU !
Ioannis Rizos / AA Tutor