Introduction
Nowadays air pollution has become a huge problem at some
cities which tends for causes such as global warming, heat island effect. The
countries closer to equator have inherited the problem of hotter climates. They
receive comparatively lesser rainfall. Many of them are developing countries
including Sri Lanka. As a result, buildings that help to reduce this problem
are all the range. In past few years though, designers and architects have
started to move beyond simply reducing building’s emissions and started to work
with techniques that actually remove pollutants from the air. However, in most
incidents, these new technologies have been effecting air, chemically or physically
by comes into contact with them.
What if buildings could work a little more like a vacuum cleaner? What if they
could take a more effective role in pulling in pollutants from the sky? This
was exactly the concept of inspiration behind the developing of Breathing
Brick.
Breathe Brick is a masonry system which is designed and
constructed to constitute and be a part of ventilation system of buildings. It
filters polluted outdoor air so that it becomes healthy enough to bring directly
into occupied spaces. It acts as a pollution absorbing brick where the design
is very similar to a vacuum. The pollution vacuums in bricks were developed by
assistant professor Carmen Treadle at Cal Poly College of Architecture and
Environmental design. The brief brick sucks pollutants in the air and releases
filtered air. The innovative material is designed to be a part of a building
standard violation system. In short, it is a technology that can be easily
applied to the current construction process by performing wind tunnel tests.
Product / Material
The Breathing Brick is designed to form a part
of a building’s regular ventilation system, with a doubled-layered facade of
the specialist bricks on the outside, complemented by a standard internal layer
providing insulation. At the center of the Breathing Brick’s function is
cyclone filtration, an idea borrowed from modern vacuum cleaners, which
separates out the heavy pollutant particles from the air and drops them into a
removable hopper at the base of the wall.
The system is composed of two key parts: Concrete bricks and
Recycled plastic coupler.
1. Concrete Bricks
Breathe Brick unit is a structural masonry component within
which is embedded with a cyclone filter. The concrete brick is featured with a
faceted surface which helps to direct airflow into the system, and a separate
cavity for inserting steel structure. The brick is designed in a way that it
can be replaced some exterior.
2. Recycled Plastic Coupler
It helps to create a path from outside into the brick’s
hollow center and to align bricks.
It has a two layer facade system
with the specialist bricks on the outside and standard insulation on the inside
in the center is a cyclone filtration system that separates out the heavy air
particles from the air and collects them in a removable hopper.
How “Breathe Brick” Wall Operates ?
By the help of the
faceted surface of the Breathe Brick, the air outside the structure is directed
into rectangular inlet ports. The air that comes into the system is spinned by
cyclone filter winnowing out particles.
The cyclone filter is cast
directly into the concrete form. The filtered air that passes into the cavity
of the double-Wythe wall system could then supply an HVAC system or an adjacent
interior space directly. (Breathe Bricks – Operation Mechanism, Applications,
Advantages (online))
The Breathing Brick can function
with both mechanical and passive ventilation systems, as the brick simply
delivers filtered air into the wall plenum; this air can be delivered to the
building interior through mechanical equipment or through trickle vents driven
by passive systems such as stack ventilation.
Importance as a sustainable product
• Cheap.
• Sustainable.
Breathe Brick is a clever way of
taking the heavy particulates out of the air as a byproduct of making a
building
• Environmentally friendly.
• Low Embodied Energy.
• Ease of handling and
construction.
• Low Carbon construction. (using
of natural construction material)
• Lightweight. (Technique for
modification of breathe brick)
By replacing sand in concrete by EPS, the
brick can be formed into a lightweight brick. Discussed further under Physical
properties of Breathe Brick.
• Help to improve thermal
comfort.
• Energy efficient. Since it operates without electricity and
makes part of ventilation system. It works with pressure and temperature
differentials
• Passively filter outdoor air
prior to introduction to an indoor environment.
• Can operate through existing
HVAC system or passive as independent system.
• The design of breath bricks can
be configured in a wall with window and the cooling system as well.
• It was proven that the system
can filter 30% fine particle pollutants and 100% course particles such as dust.
In wind tunnel tests, the system
was found to filter 30% of fine aggregates such as airborne pollutants and 100%
of course aggregates such as dust. As the entire system is relatively
expansive, the Trudell posits the Breathing Brick is a way to lower the pollution
level in developing countries, where rapid expansion of industry and less stringent
environmental regulations often cause problems. (Rory Stott, www.archdaily.com)
Applications
• Breathe Brick is optimal for
one or two story structures in areas with poor air quality.
• It can be used to construct
exterior walls (plenum or courtyard, sound walls along freeways, school
playground enclosures)
• It is specifically designed for
regions with elevated outdoor particulate matter.
Physical properties of Breathe Brick
“Breathing Walls” concept is an
innovative construction procedure that can help improve thermal comfort in
houses utilizing local materials.
Breathe brick is made up of
concrete and plastic couplers made from recycled plastic. The concrete part can
be made out of user’s choice. As a technique the brick can be constructed to
have light weighted characteristic. By the
introduction of expanded Polystyrene (EPS) which is a replacement for sand, the
brick is lightweight and contains various properties of strength and water
absorption. EPS has been frequently used in construction industry in production
of lightweight building materials such as wall panel and lightweight concrete
blocks. Replacement of sand by EPS is based on volume. The replacement
percentage of EPS was 0%, 20%, 30%, 40% and 50%.
Based on experimented results,
the density and compressive strength of the brick was decreased as the
percentage of the replacement increased. Meanwhile for water absorption
properties, it was found that water absorption of the brick was decreased as
the percentage of EPS increased. However the properties obtained have been
satisfied the requirement where the brick density for lightweight should be
less than 1680kg/m3. The strength of load bearing and non-load bearing brick is
11.7MPa and 3.45MPa for each individual unit. Meanwhile, for water absorption,
the percentage of water absorption of brick should be less than 12%. From
researches it was found that replacement of sand by EPS give significant impact
towards strength and water absorption performance of concrete.
Unfortunately the strength is
limited to one or two story buildings. The strength limitation is the major
weakness in lightweight breathing brick. But it is more suitable for houses in
Sri Lanka.
E. Dilmi D.Z. Abeysekera
Department of Civil Engineering
University of Sri Jayewardenepura
REFERENCES
- Admin, (17 December 2017), Breathe Brick (online) [Accessed on 25/09/2019],Available at : http://transmaterial.net/breathe-brick
- Madeh Izat Hamakareem, Breathe Bricks – Operation Mechanism, Applications, Advantages (online) [Accessed on 24/09/2019], Available at: https://theconstructor.org/building/breathe-bricks/29216/
- Rory Stott, (12 August 2015), This Innovative Brick Sucks Pollution From the Air Like a Vacuum Cleaner (online) [Accessed on 25 September 2019],Available at: https://www.archdaily.com/771767/this-innovative-brick-sucks-pollution-fromthe-air-like-a-vacuum-cleaner
·
This is great. Thank you for sharing valuable information
ReplyDeleteVery informative.Keep it up ����
ReplyDelete