Breathing Walls Research Articles

Phytoremediation of Indoor Air Pollutants: Harnessing the potential of Plants beyond Aesthetics

Indoor air pollution has emerged as a major threat to human health worldwide that needs to be dealt urgently. The present review is an effort to overview the different indoor air pollutants (CO2, volatile organic compounds (VOCs) like formaldehyde, benzene, nitrous oxide, trichloroethylene, fluorine, ammonia, radon, aldehyde, hydrocarbons etc.) their hazardous effects on human health, potential of indoor plants in their remediation and their practical utility. Besides providing oxygen to breathe, multifaceted roles of indoor plants have been well documented. Plants were used since decades for indoor decorations based on their aesthetic value, but now studies are focused on screening plant species for their efficiency in absorption of indoor air pollutants. The basis for phytoremediation is the potent efficiency of some plants to assimilate, degrade, or modify toxic pollutants into non-toxic ones. Phytoremediation seems to be the key solution to improve indoor air quality as it has many potential advantages (simple, potentially cheap, and easily implemented) in comparison to other traditional or latest methods. Breathing walls, portable air filters for rooms or whole house filtration through heating, ventilation and air conditioning systems are some of the technologies developed, to reduce indoor air pollution and improve indoor air quality but all these are costly, resource consuming and still there is question on their efficiency. Detailed account of morphological, anatomical and molecular mechanisms underlying plant leaves and leaf associated microbes in reduction of pollutants have been reviewed that could help in developing cost effective and eco friendly remediation technologies. This review gives a brief discussion about air phytoremediation to improve effectiveness of this technology in practical use.

An Experimental Study of Indoor Air Quality Enhancement Using Breathing Walls

Recently, many studies have focused on studying indoor air quality, especially with the outbreak of COVID-19, which is one of the reasons for the increased need to improve indoor air quality. Many ideas and applications are available to incorporate nature into buildings to improve indoor air quality (IAQ) and thus secure a higher percentage of natural ventilation and pollution reduction. One of these ideas is to use "breathing walls" (BWs), which are envelope components based on porous materials. They decrease energy consumed for heating, ventilation, and air-conditioning of buildings. The study discusses the effect of using the BW approach on thermal comfort in buildings. Moreover, the improvement in the IAQ when using two models - one using BWs (applying natural and industrial materials together on the BWs, which are composed of wooden concrete hollow bricks (WCHBs)), and the other model built with solid traditional bricks (STB) - was studied through an experiment to compare air temperature, carbon dioxide (CO₂) concentration, indoor relative humidity and thermal behavior. The experiments were conducted on the two models for five months in the summer of 2019, and the results of both models were compared. From the results, it may be concluded that the model with BWs exhibits improved thermal behavior than the model with traditional bricks by recording on average three to five degrees lower than the outside temperature. Moreover, the relative humidity is lower in the WCHB model than in the STB model by ~41.66% in the same conditions; however, the CO₂ concentration (ppm) in the WCHB model was lower than that in the STB model by ~28.5% in the same conditions.

Breathing Artifacts of Urban BioClimatic Layers for Post-Anthropocene Urban Environment

This article seeks the qualitative synthesis of schools of thought from extreme climate regions that could support urban biodiversity and climate change adaptation through architectural design. It proposes that climate comfort and biodiversity are closely related. This article suggests a possible systemic urban metabolism within a built environment that can support a transition to post-Anthropocene, where humans and other species live together in synergy. This article exemplifies and seeks systemic relations and reflections of gathered field studies documentation of case studies of breathing walls, envelopes, and screens generating bioclimatic layers in the cultural landscape, selected for their penetrability and performance. The samples from diverse study journeys that were codesigned through vernacular cultures and the author’s research by design speculations on the responsive screen ‘Ray’ are investigated and speculated upon through gigamapping (visual complexity mapping). This gigamapping is not to present any hard data model but to relate, inform and speculate on the investigated field that is grounded in research by design on cross-species coliving. This is approached through possible architectures and architectural and urban design parasites, transitioning towards synergetic landscapes of our envisioned colived and cocreated futures.

Airborne Infection and Breathing Walls

Airborne Infection and Breathing Walls

A numerical model to simulate the dynamic performance of Breathing Walls

A one-dimensional Finite Difference Model for Breathing Wall components under time dependent Dirichlet boundary conditions is presented. The algorithm undergoes a comprehensive validation against a dynamic analytical model, under either sinusoidal and generically periodic boundary conditions, adopting different airflow velocities and in relation to capacitive and resistive materials alternatively. It is found that the accurate prediction of the temperature profile inside the wall is influenced primarily by the timestep, whose optimal value can be identified through a preliminary frequency analysis of the boundary conditions. Moreover, for a better prediction of the surface heat flow density, and especially in insulating materials, refining the space grid below 1 mm is recommended, as well as the adoption of a 3-point numerical scheme. The numerical model is finally tested against experimental data on a porous concrete wall, showing that numerical errors may compare to other sources of uncertainties, regarding materials properties and boundary conditions.

SMART BREATHING WALLS FOR INTEGRATED VENTILATION: HEAT EXCHANGE AND INDOOR AIR QUALITY IMPROVEMENT

There are many ideas and applications for incorporating nature into buildings to improve the quality of the indoor air and to achieve a higher percentage of natural ventilation with pollution reduction. One such idea is to use the Breathing Walls built on porous materials. The energy used in air-conditioned buildings is reduced by these materials. BW suggests a conceptual design suitable for hot climates and capable of controlling airflow across the entire surface and refrigerating internal spaces in various cooling ways. BW forming all or part of an air-permeable building envelope or exterior provides a comprehensive solution to that and severe issue of self-inflicted environmental harm that many cities now face. BW are the walls that have pores inside them and are capable of spreading water vapor and helping to get rid of moisture and raise indoor air quality (IAQ). In both a social and economic context, IAQ is a significant issue. The definition of breathing walls, their characteristics, and the environmental problems that the BW solve will be discussed in this paper, as well as their impact on the improvement of the indoor air quality.

Measuring a Breathing Wall's effectiveness and dynamic behaviour

Breathing Walls are building structures based on porous materials crossed by an airflow, which act both as building envelopes and ventilation system components. In climates where both heating and cooling are needed, a pro-flux configuration (heat and air mass both flowing in the same direction) might be alternated with a contra-flux configuration (heat and air mass flowing in opposite directions) during the year or even on a day. Understanding and modelling the Breathing Walls' stationary and dynamic behaviour is thus fundamental, in order to optimize their design and to fully exploit their energy-saving potential. In this experimental study, a small-scale no-fines concrete Breathing Wall was investigated. The steady-state contra-flux tests performed in a Dual Air-Vented Thermal Box laboratory apparatus were used to derive the heat recovery efficiency of the sample as a function of the cross airflow velocity. The effectiveness of this technology was then evaluated in a virtual case study. An optimal airflow velocity across the Breathing Wall was found, leading to energy savings between 9% and 14%. Dynamic tests were performed assuming a sinusoidal variation of the operative temperature on one side of the sample. They showed how airflow velocity affected the Breathing Wall inertia and dynamic behaviour.

Lucy in the sky with ketamine: Psychoactive drugs have potential for a major breakthrough in treating depression.

EMBO Reports (2018) e47118 “It felt like being in a pod […], like a little boat, going along through rooms [that had] white breathing walls.” This is how American standup comedian Neal Brennan described his experience with ketamine, a psychoactive drug also known as Special K in the club scene, in an interview with fellow comedian Joe Rogan. “I just couldn't get over the fact that this was happening in a doctor's office,” he said about taking ketamine as a medication against depression. > One may argue that treating psychologically unstable patients with an addictive drug that has psychedelic side effects is not a good idea. Ketamine was introduced commercially in the United States in 1970 as an anesthetic. At lower doses, it causes dissociations, out‐of‐body experiences, and hallucinations, which explains its career as club drug. But during the past two decades, it has also gained attention as a fast‐acting antidepressant. Its antidepressant effect was first noted by researchers at Yale University in the 1990s, and the effect was reproduced in a larger double‐blind, placebo‐controlled trial at the US National Institute of Mental Health, published in 2006. A number of studies have since shown the effectiveness of ketamine in treating patients with depression, suicidal ideation, and post‐traumatic stress disorder [1]. Researchers have called it the biggest breakthrough in depression research in half a century. Ketamine is not yet approved by regulatory agencies, but is widely used off‐label by private so‐called ketamine clinics. New medications to treat depression are urgently needed. The last significant innovation—Prozac, the first selective serotonin reuptake inhibitor (SSRI)—is now 30 years old, and SSRIs and many me‐too drugs of similar structure and function still dominate the treatment of depression. They are, however, anything but satisfactory. It takes 6–8 weeks for their effect to kick in, and …

English

‘Breathing walls’ concept is an innovative construction procedure that can help improve thermal comfort in houses utilising local material. The author designed this concept based on teaching civil engineering procedures, observations and understanding of construction practices in building industry through research and practice. One such accommodation was developed in 1992-93, another in 2000 and more in 2005. The practices were progressively improved and proved that a temperature drop of 10-15 degrees Celsius can be achieved by breathing walls concept without cost exceeding 5-10% for the overall project. Breathing walls concept can help develop comfortable eco-friendly low cost housing in the developing as well as in developed countries.

Analytical modelling of Breathing Walls: experimental verification by means of the Dual Air Vented Thermal Box lab facility

Breathing Walls are air permeable envelope components based on porous materials. In contra-flux operation air flows opposite to conductive flux, while in pro-flux they have the same direction. The Breathing Wall behaves either as a ventilation heat exchanger or as an active insulation.In literature an analytical model describing steady state heat transfer across a Breathing Wall can be found. Since it lacks an exhaustive experimental validation, a facility developed at the Energy Department of Politecnico of Milano was used to investigate the thermo-physical behavior of a no-fines concrete based Breathing Wall in steady state Dirichlet conditions and contra-flux operation.

Experimental investigation of the steady state behaviour of Breathing Walls by means of a novel laboratory apparatus

Breathing Walls are envelope components, based on porous materials, crossed by a natural or forced airflow. Since they behave both as recovery heat exchangers and active insulation, reducing the conductive heat flux, they represent a promising envelope technology, allowing to reduce energy consumption in buildings.From the modeling point of view, an analytical model can be found in literature, describing heat and mass transfer across Breathing Walls in steady state conditions. However, to the best of the authors' knowledge, the model lacks an exhaustive experimental validation. Therefore, in this paper, the novel laboratory apparatus named Dual Air Vented Thermal Box developed at Politecnico of Milano is presented. The apparatus is used to experimentally investigate the steady state behaviour of a 1 m2 Air Permeable Concrete sample, crossed by an airflow at different velocities up to 12 mm/s.The temperature profile inside the sample, measured in different positions, is compared with the model predictions. While in the central portion of the wall a very good agreement is found, the experimental results at the top and at the bottom of the wall suggest a non-uniform velocity field entering the sample. A qualitative confirmation of this hypothesis is provided by CFD simulations on the apparatus, clearly showing a mixed convection regime on both sides of the wall. The results lead to state the validity of the one-dimensional analytical model in literature, although a careful application should take into account adjusted boundary conditions, consisting in an airflow velocity possibly variable with height.

Breathing walls: The design of porous materials for heat exchange and decentralized ventilation

This study demonstrates how to design pores in building materials so that incoming fresh air can be efficiently tempered with low-grade heat while conduction losses are kept to a minimum. Any base material can be used in principle, so long as it can be manufactured with millimeter-scale air channels. The channel-pores are optimized according to the thermal conductivity of the base material, the dimensions of the panel, and the suction pressure sustained by a given fan or a chimney. A water circuit is integrated at the interior surface to ensure direct thermal contact and prevent radiant discomfort. Correlations from the thermal sciences literature were used to optimize the size and distribution of channel-pores in wood, glass, and concrete test panels. The measurements showed good agreement with theory and were presented in a general form so that designers can predict the steady-state performance of any optimal design in sensible heat-transfer mode. Schlieren imaging was used to characterize the different regimes of mixed convection at the interior and exterior surface. The data explain the discrepancy between prediction and measurement in the dynamic insulation literature, and how the integrated water circuit overcomes these problems. Surface heat-flux measurements were correlated in a general form so that designers can account for convection at the interior and exterior surface.

Energy conservation and renewable technologies for buildings to face the impact of the climate change and minimize the use of cooling

Facing the climate change is a common priority, due to ethical issues related to general concept of sustainability and livable future for the next generations. Moreover, ethical aims for contrasting energy poverty, heat-related diseases and deaths, availability of food and water, infections and viral-bacteriological risks, meteorological extreme phenomena, such as floods and intense and destructive precipitations, are stringent and pressing targets. All serious and independent investigations reveal future scenarios of an overall global warming that surely make worrying the evolution of quality of life on this earth. Each one has to do his part. In this study, the research is focused on renewable technologies for the passive cooling of buildings. Indeed, the space cooling is a strongly increasing use of energy and induces a vicious circle, being, at the same time, a cause and an effect of the anthropogenic overheating of the planet. The paper mainly reviews techniques for suitably governing the energy interaction between buildings and surrounding environment. The energy efficiency concerns the building envelope design, the use of efficient HVAC systems, adoption of renewable energy on-site. On the other hand, every energy conversion process determines waste heat, so that also a ‘free of operational cost’ solar cooling system however causes dissipation of heat into the ambient. Finally, renewables cannot be the unique solutions for supplying the energy required for the building use. Conversely, strategies for reducing the building cooling are needed, and these are reviewed in this study. In thermodynamics terms, the building is seen as part of the system and not the mere control volume. Greenery of facades and roofs, phase change materials, nocturnal convective cooling, evaporative and ground cooling, solar systems such as chimneys for improving the building ventilation are here discussed, as well as emerging technologies such as breathing walls and dynamic insulation. The reviewed studies, selected on the basis of more recent progresses concerning the investigated technologies, revealed potentialities but also criticalities in the design.

Skin, Clothing, and Dwelling

Gottfried Semper is often credited with originating the concept of the building as skin in architectural theory, but an alternative trajectory of this idea can be found in the mid-nineteenth-century science of hygiene. In Skin, Clothing, and Dwelling: Max von Pettenkofer, the Science of Hygiene, and Breathing Walls, Didem Ekici explores the affinity of skin, clothing, and dwelling in nineteenth-century German thinking, focusing on a marginal figure in architectural history, physician Max von Pettenkofer (1818–1901), the “father of experimental hygiene.” Pettenkofer's concept of clothing and dwelling as skins influenced theories of architecture that emphasized the environmental performance of the architectural envelope. This article examines Pettenkofer's writings and contemporary works on hygiene, ethnology, Kulturgeschichte (cultural history), and linguistics that linked skin, clothing, and dwelling. From nineteenth-century “breathing walls” to today's high-performance envelopes, theories of the building as a regulating membrane are a testament to the unsung legacy of Pettenkofer and the science of hygiene.

Experimental and numerical assessment of breathing walls performance for theimprovement of air quality and comfort indoors

The construction of airtight building envelopes within nearly Zero Energy Buildings is likely to generate thermo-hygrometric discomfort indoors, that needs to be managed with airconditioning and ventilation systems. In countertrend, some researches developed in northern Europe countries focused on the construction of “breathing” building envelopes that let in the air (passively or with mechanical devices) through dynamic thermal insulations able to preheat and filter it from possible pollutants. This study reports the results of experimental and analytical assessments of dynamic insulation systems, aimed to the design of a breathing wall system for the application in building renovation interventions.

PASSIVE VENTILATION SYSTEM THAT INCORPORATES A PITCHED ROOF CONSTRUCTED OF BREATHING WALLS FOR USE IN A PASSIVE SOLAR HOUSE

This paper describes a natural ventilation system that incorporates a pitched roof constructed of Breathing Walls for use in a passive solar house. The Breathing Wall is expected to solve the inherent contradiction that exists for a building that is open to the outside air, in which a balance in the indoor air/moisture conditions is maintained, but energy efficiency is low. In other words, the use of Breathing Walls can provide a healthy and comfortable environment at higher energy efficiency in a passive solar house. In the present study, we experimentally evaluate the effects of roof pitch on the heat recovery capability and the occurrence of internal condensation within the Breathing Wall, using a simulation of the ventilation rate of a natural ventilation system. The effective opening area per unit area required to provide sufficient air change capability, i.e., 0.5 ACH, even for zero wind velocity, was determined to be 10 and 5 cm 2/m 2 for pitches of 26.5° (Pitch 1) and 45° (Pitch 2), respectively. Furthermore, at the maximum predicted wind velocity of 10 m/s for Pitch 1/2, even though the outdoor air temperature is 5°C, the temperature of the indoor-most air reaches 13.2/12.5°C, corresponding to a heat flux of ≈128/158 W/m 2. No internal condensation occurs, even at the maximum pressure differential, which corresponds to a wind velocity of 10 m/s across the wall of the Pitch 1/2 model, when a Breathing Wall having an opening area per unit area of 11.3 cm 2/m 2 was installed in the ventilation system.

天然ゼオライトの表面処理とその特性

The adsorption of dyes (direct, acidic, basic, reactive and disperse) on Itaya zeolite consisting mainly of clinoptilolite and mordenite was investigated.The adsorption isotherms were found to be approximately expressed by the Freundlich equation. The order of adsorption selectivity was basic dye>acidic dye>other dyes.The Itaya zeolite surface-treated by the disperse dye and binder has less adsorbing power to nitrogen than the untreated zeolite, but has about the same hydrogen and ammonium ion exchange capacity. Therefore, it is useful for soil for gardening, an ornament rock for cleaning of water in an aquarium and for building materials (for example, breathing walls).