With ever increasing population density and growth, human kind is facing critical challenges like including climate change, food scarcity, water scarcity, etc. Catering the increasing demands of the society has led us to come up with solutions which can be harmful for the environment. A sustainable approach is the need of the hour.
Today sustainability is of highest significance in building and construction sector. Availability of land, has become a major concern especially, in countries like China or India, where population has reached its highest peak. Maximum settlement, with minimum land use is prioritized. Architects and designers are always in a search of a solution which achieves both environmental sustainability and caters the increasing demand. With the development in the field of building materials, we have materials which fit this category. They are alternative materials, an alternative to the conventional building material and are eco-friendly.
These alternative building materials are developed or customized according to a certain requirement or is mass customized as a solution to a generalized issue. They are developed with respect to the current environmental condition, prioritizing the climate, which makes them a smart choice, to otherwise widely used conventional building material.
Pollution absorbing bricks
Air pollution is one of the growing concerns with respect to climate change. It has severe effects on human health. Carbon emission due to manmade activities and excess presence of carbon in the atmosphere traps heat on the surface of the earth and causes global warming.
Architects and designers are taking measures regarding reduction of carbon footprint while and after construction, which will eventually result in minimizing the harmful effect of air pollution.
Pollution absorbing brick is a brilliant alternative to conventionally used bricks, and curtails air pollution caused by a building. These bricks are also known as ‘Breathe bricks’.
They were developed by Ar. Carmen Trudell, an assistant professor at Cal Poly San Luis Obispo’s School of Architecture and is also the founder of Both Landscape and Architecture.
Concept: Breathe bricks work on the basic principle of air filtration. It filters the outside air and provides it to the interior of the structure. These bricks filter the air and separate the pollutants and other particles like dust. The inspiration behind this genius innovation was the concept of ‘cyclone filtration’ that one can see in vacuum cleaners.
Material and components: The bricks are in the form of porous concrete block. They are specifically designed and shaped in a faceted manner, so as to direct the air flow inside the system. Shafts are provided for structural reinforcement. A coupler made of recycled plastic is provided between two bricks and a hopper is provided at the base for the collection of particles.
Function: Breathe bricks functions as a passive filtration system installed in the exterior of the structure. It consists of a cavity wall, which is a double layered construction with the breathe bricks on the exterior so as to absorb and filter the pollutants and the internal which provides insulation and a vent for air movement. The cyclone filter is cast into the air filtration brick. This cyclone filter enables the air from outside to swirl like a cyclone, separating the pollutants and dust particles, and inducing filtered air into the internal structure. The filtered air is then directed by the brick coupler. The major component of this system is the ‘brick coupler’. It is made of recycled plastic. It functions as an agent directing the airflow from outside into the air filtration bricks for cyclone filtration. It acts as an outlet for the filtered air into the interior. It sends the distilled particles to the hopper at the base of the wall. The hopper needs to be cleaned regularly. But due to its size (approximately equal to the length of two adjacent bricks), one need not clean it frequently. Brick coupler helps in aligning the bricks by accommodating the structural reinforcement through one of its shafts. The filtered air from the coupler passes through the cavity and into the vent or the window. If the structure has operable opening or window then the air is directly passed into the interiors through it, in absence of inoperable window opening the air is passed through the HVAC system.
According to the test, which was carried out to detect the filtration capacity of the brick, it was inferred that the brick, filters 30% of particles spanning up to 2.5 microns or smaller in diameter, which is equal to smoke or haze, and it filters 100% of coarse particles with diameter more than and equal to 10 microns.
The energy used in production of this system is less as it does not use any mechanical components. Breathe bricks is considered to be an innovative alternative material. It is inexpensive in comparison with the mechanical air filtration techniques used in large scale. It is environment friendly and is sustainable.
It is a low-tech material. No complicated technology or mechanism is applied while manufacturing these bricks. There is no requirement for skilled labourers to construct the system, making it cost effective. Hence, this material is considered to be an excellent alternative in developing countries. Small municipalities and developing regions can use this solution to curtail the air pollution, while providing a healthy environment to the residents.
A significant characteristic of a sustainable alternative material is its adaptability in terms of mass customization. It is when a certain material is suitable to be used in every part of the world irrespective of its macro climate, micro climate, end users, etc. and is mass produced is known as Mass customization. As per the aforementioned advantages of Breathe bricks, it can be considered as a strong participant in mass customization of building materials and construction techniques.
The disadvantage of the breathe brick passive filtration system is that the exterior wall takes as much as double the original space, which leads to contraction of the interior space.
Breathe brick can be used in load bearing structures up to one or two storey height. It is mostly used in regions with poor air quality. It is beneficial in areas with heavy particulate outdoor matter.
The alternative materials like breathe bricks, serves as a potent aspect for a greener tomorrow.