Top Green Building Trends Worldwide

transparent-solar-windowsWith green building movement sweeping across the world, innovative technologies are being developed to keep pace with increasing shift towards sustainability. Integration of biodegradable, recycled, recyclable and renewable materials in the construction of buildings is attracting great attention worldwide. Natural paints, recycled steel, cellular concrete, clay bricks, wood, bamboo etc. are getting huge popularity in construction of green buildings.

Another interesting innovation is zero-energy building which utilizes solar cells/panels, wind micro-turbines, fuel cells and biofuels, among others, to meet electricity and HVAC requirements of the building. Likewise, net-zero-water-use buildings make use of water conservation systems to efficiently manage water consumption, rainwater harvesting, waterless toilets, greywater reuse, smart landscaping and on-site sewage treatment.

Low-emitting windows, coated with metallic oxide, to block sun’s harsh rays during summer and keep the heat inside in the winter are also gaining popularity. Such windows have the potential to significantly reduce heating and cooling costs of buildings.

According to Dubai-based green buildings expert Sunanda Swain, “Transparent solar window panels can also be incorporated into awnings, curtain walls, glass facade or as overhead glazing units.” She explains, “These increase access to direct sunlight while providing additional architectural benefits such as passive shading.”

Net Zero Energy Buildings rely on exceptional energy conservation and on-site renewable generation to meet energy requirements..

Net Zero Energy Buildings rely on exceptional energy conservation and on-site renewable generation to meet energy requirements..

Another promising innovation is in the form of cool roofs which is made of special tiles and reflective paints to reflect sunlight. Cool roofs have high levels of solar reflectance and thermal emittance, and help in reducing the heat island effect in urban habitats, especially in arid areas like the Middle East.

To sum up, green buildings can not only contribute towards environment protection but also bring loads of advantages to building occupants and users. Lower development costs, reduced operating costs, healthier indoor environment quality and less maintenance costs are major benefits associated with green buildings. To sum up, green building technologies can serve as catalysts for smart urbanization and sustainable development of urban centers, besides ensuring energy security, climate change mitigation, and opening new economic and job opportunities. 

Mitigating the Effects of Sand and Dust Storms

Sand and dust storms cause significant negative impacts on society, economy and environment at local, regional and global scale.  There are three key factors responsible for the generation of sand and dust storms – strong wind, lack of vegetation and absence of rainfall. The environmental and health hazards of such storms cannot be reduced permanently, however its impact can be reduced by taking appropriate measures.

As the dust cloud rises, it reduces the horizontal visibility which can impact human life in many ways. The fine suspended particles also contain contaminants, bacteria, pollens, which cause negative health impacts such as allergies and respiratory diseases. Dust also carries air borne pollutants such as toxins, heavy metals, salt, sulphur, pesticides etc which cause significant health impacts when people inhale the contaminated dust.  Dust can corrode buildings and other built infrastructure as it contains high level of salts, especially in the GCC countries. The major impacts of sand and dust storms are listed below:

Environmental and Health Impacts

  • Poor air quality – This is due to increase in contaminant loads and dangerously high level of breathable suspended particles in the air during sand and dust storms.
  • Increase in environmental hazards relating to transportation, building and health.
  • Dust deposition on landscape can cause drying of leaves, retard the growth of plant and cause damage to crops.
  • Suspended dust particles in water can obstruct the penetration of sunlight into the sea floor and hence affect marine life cycle.

Social Impacts

  • Ill heath from inhalation of fine suspected dust particles and pollutants present in the dust
  • Road accidents and aviation hazards due to poor visibility
  • Delay in landing and take-off of air flights and restricted ship movement
  • Increase in stress associated with crop damage

Economic Impacts

  • Damage to physical structures such as buildings, roads, swimming pools etc. due to dust deposition
  • Costs associated with cleaning of infiltrated dust inside the house and building and cleaning of vehicles
  • Cost of removing sand from road and buildings
  • Costs associated with accidents, material loss, delay in flights, delay in movement of vehicles,
  • Costs associated with clearing of buried construction infrastructure such as oil pipelines due to sand and dust during the storms

Reducing the Effect of Sand and Dust Storms

The effects of sand and dust storms can be reduced by using a number of health & safety measures and environmental control strategies.  Large-scale sand and dust storms are generally natural phenomena and it may not be always practicable to prevent it happening. However, control measures can be taken to reduce its impacts. Localised small-scale dust emission due to human induced activities can be reduced by using temporary mechanical methods such as concrete barrier, mulching, tree buffer etc.  

  • Take appropriate control of dust raising factors such as increasing the vegetation cover where possible. It helps in stabilization of the soil, sand dunes and form windbreaks.
  • Use of native plants and trees as buffer can reduce wind velocity and sand drifts at the same increase the soil moisture
  • Design buildings appropriately and conduct air infiltration testing during building commissioning.

Some health and safety measures that should be taken to minimise the adverse impacts due to the dust storm are:

  • Take extra precautionary measures for vulnerable population group such as children, elderly and sick people.
  • Use dust masks – Dust masks have filters which can filter out small particles and contaminants. Hence, mask should be used during the dust storms. Put a wet towel or tissue on the nose and mouth and drink lots of fluid.
  • Clean your face, nose and mouth frequently to prevent any dust entering into lungs and inhale some water through your nose in order to clean the nose of dust particles.
  • Close the doors and windows tightly, pulling all curtains up and put wet towels on the small holes that may be round windows
  • Restricting outdoor activities and staying inside the house.

 

References

  • Speer MS (2013) Dust storm frequency and impact over Eastern Australia determined by state of Pacific climate system. Weather and Climate Extremes, Vol 2, page 16-21.
  • Shivakumar MVK (2005) Impact of sand storms/ dust storms on agriculture.  Natural Disasters and Extreme Events in Agriculture. Publisher – Springer eBook, page  159-177.
  • Mohammad, Mohammad-Shafi Abdullah (1989) Dust storm phenomena and their environmental impacts in Kuwait, PhD thesis, University of Glasgow.

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Green Roof Potential in Arab Cities

Urban green roofs have long been promoted as an easy and effective strategy for beautifying the built environment and increasing investment opportunity. The building roof is very important because it has a direct impact on thermal comfort and energy conservation in and around buildings. Urban green roofs can help to address the lack of green space in many urban areas. Urban green roofs provides the city with open spaces that helps reduce urban heat island effect and provides the human population on the site with a connection to the outdoors. However, we must differentiate between two types of urban green roofs and assess their adaptability to Arab cities. This article provides an insight on green roofs and roof farming in Arab cities.

What are Green Roofs

Green roofs are essentially sustainable and passive design features of vegetation surfaces applied to a waterproofing layer of a suitable conventional roof build-up in rainy climates. In rainy countries such as Austria, Germany and Belgium green roofs are recognized as a significant source-control feature,contributing mainly to storm water management and drainage control. Green roofs not only store water at roof level, but also reduce the run-off rate from the roof, which in turn reduces the underground drainage network requirements. It is also possible to use or harvest rainfall from a green roof, although the amount of rainwater that can be used may be reduced depending on the type of green roof implemented.

Generally speaking, there are no green roofs in hot arid climates. In Arabia it is hardly to find any examples of successful green roofs. According to European norms the minimum annual precipitation rate for a green roof should be more than 450-650mm. Therefore, it is impossible to grow a green roof in Cairo (26mm), Amman (276mm), Riyadh (20mm) or Dubai (10mm). Even coastal cities like Alexandria (190mm), Tunis (450mm) or Casablanca (425mm) witness extreme summers and drought periods that almost eliminates the sedum plants from recovery during the winter season. Facing these facts, there are many voices in Arabia that surprisingly continue pushing the idea of green roofs claiming to sustain it through artificial irrigation. An idea that make us lose the whole point of sustainability in an already water scarce region.

Unfortunately, across the Middle East there are large numbers of students, architects, clients and even researchers who have a wrong perception and a defective understanding of semantic of green roofs,which are essentially associated with the presence of renewable rain water. This is due to the unfamiliarity with word Green Roof in our region and the huge influence of the Northern imaged media. Moreover, there are many researchers who talk about the positive side effect of green roofsthat significantly save energy, enhance the thermal performance and comfort of buildings, particularly in terms of summer cooling, based on readings and studies made in countries with latitude higher than 40o with temperate or cold climates. What is missing here is local evidence based experimentation and practices that address green roof in the warm and hot climate not from a theoretical copy-paste approach.

The Real Problem

Arab cities suffer from serious problems that are similar to most other large cities in the developing countries. Among the most visible manifestations of the challenges posed by rapid urbanization are many environmental problems, such as pollution, dense urbanization, urban heat island effect and inversed greenhouse effect during winters. In fact, the dense concentration of automobiles and polluting buildings created a negative impact on the environment. In fact, the rapid urbanization not only created environmental problems but also economic problems. For example, air conditioners are running, over the whole summer period, trying to deliver an endless demand for cooling. This leads to increasing prices of electricity bills. This is due to the lack of energy codes, which means that roofs are without or with very poor insulation. Additionally, cities suffer from constant desert sand depositing together with disappearance of green spaces which lead to deprivation of open space.

During the last decade many Arab cities witnessed several times inefficient food production and distribution, inaccessibly high food prices and above all locally grown food, loaded with toxic contaminants. The fast-growing population and the failing government approaches to housing and spatial planning policies contributed to the growth off informal settlements within and around the center. For example, 8 million Egyptian live in informal settlements in Cairo with problems of unemployment, pollution, transportation, inadequate drainage and sewerage, and lack of usable urban open spaces. In Cairo, the amount of green space per inhabitant is roughly equivalent to 0.33 square meters per person (3.5 square feet), one of the lowest proportions in the world. Among the above listed problems stands out a common denominator. It is the building roof.

Roof Farming as an Alternative

Under the influence of the all those issues emerges the idea of roof farming. Urban roof farming has long been promoted as an easy and effective strategy for beautifying the built environment and increasing investment opportunity. Roof farming can help to address the lack of green space in many urban areas. Urban roof farms provides the city with open spaces that helps reduce urban heat island effect and provides the human population on the site with a connection to the outdoors. Challenged by environmental and pollution, Cities suffer from locally grown food, loaded with toxic contaminants that threat the health.

In the last couple of years, Cairo suffered from an inefficient production and food distribution and inaccessibly high food prices. The population explosion and the tendency to build on agricultural land have acted to limit the resources of city families and their access to healthy edible products. With a little effort and money, roof farming can contribute in improving the families quality of life and provide them with healthy food and raise their income, this is besides the environmental and aesthetical role it plays. For example, Cairo citizens and some governmental authorities acknowledged the problem of food contamination & distribution and are mapping measures and methods that can guarantee safe food.While it is not new, the notion of planting rooftops in Egypt has only recently been implemented. In the early 1990s at Ain Shams University, a group of agriculture professors developed an initiative of growing organic vegetables to suit densely populated cities of Egypt. The initiative was applied on a small scale; until it was officially adopted in 2001, by the Food and Agriculture Organization (FAO).

There are several case studies that represent successful projects implemented by different non-governmental organizations (NGO), public institutions and private civil initiatives. For example Ibn Kassir foundation, in Al-Zawya Al-Hamra, Cairo, created a roof farm from wooden containers (barrels) with plastic sheets filled with peat moss or perlite used as substrates. The drainage is driven through small plastic hoses to buckets. This system is producing leafy crops such as parsley, radish, and carrots. A square meter using this method would cost around 400 Egyptian pounds (LE).

Finally, in many Arab cities, where many environmental social and economic problems exist, a beam of light emerges to contribute in solving many of these interrelated problems. Planting our roof with different kinds of vegetables and fruits or even any kind of green plants will change lots of things. It is certain that roof gardening and farming have measurable qualitative and quantitative benefits. The techniques for implementation are simple and doable and above all cost efficient. However, no roof gardens can be created without the knowledge of the factors affecting the creation and design. The most important factors are the climate, the constructional and economic factors.

Regarding green roofs, we shall only address this issue based on experimental and monitored cases. More importantly, a vision is required to be drawn together with long term strategy, adopting the holistic approach of roof farming and providing support and sustainability. It is this holistic approach that can solve many problems of different background and aspects, and can contribute to improving the quality of life of the dense Arab cities. By exploitation of such roofs, their development and planting; a reasonable ratio of green areas can be reached in the near future. A ratio of 4 square meters per person can be provided once the suitable green framing roofs have been developed and exploited.

Source: Attia, S., Mahmoud, A., (2009) Green Roofs in Cairo: A Holistic Approach for Healthy Productive Cities, Conference Proceeding on Greening Rooftops for Sustainable Communities, June, Atlanta, USA http://orbi.ulg.ac.be/handle/2268/167604

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Introduction to Green Roofs

Green roofs are emerging technologies that can provide a wide range of tangible and intangible benefits to communities interested in enhancement of their environment.  Green roof development involves the construction of a vegetative layer on top of a human-made structure or building adding green space to areas that would otherwise be unused.  The major benefits of green roofs are reducing energy use as well as air pollution and greenhouse gas emissions, enhancing stormwater management and water quality, decreasing heat island effect by regulating temperature for the roof and the surrounding areas and providing aesthetic value and habitats for many species. 

What are Green Roofs

Green roofs mainly consist of a vegetation layer consisting of trees, plants, and other shrubs, a substrate layer where water is retained and in which the vegetation is secured, and a drainage layer which helps to evacuate excess water. The depth of the substrate layer is how the two main types of green roofs are differentiated.

Green roofs can be intensive or extensive. Intensive roofs are thicker, more than 15 cm deep, which allows for the growth of a wider variety of plants including trees and shrubs.  However these roofs are heavier, more expensive and require more maintenance and irrigation.  Extensive roofs, on the other hand, are covered in only a light layer of vegetation, less than 15 cm, and are primarily made up of shrubs, low-growing sedums, and herbs.  Unlike the plants on an intensive green roof, the extensive vegetation is typically self-sustaining apart from the bi-yearly maintenancewhen the beds need to be weeded and fertilized.

Because of their weight and function intensive roofs are usually used on commercial buildings.  Commercial buildings tend to be made out of concrete and can support heavierweight loads than traditional homes.  Once the plants are installed and the soil is moist these rooftop green spaces can weigh as much as 150 pounds per square foot. They also tend to have more room to include benches, tables, greenhouses, fountains and walkways that travel between different features of the green roof and provide space where people can interact with the natural surroundings. Intensive roofs tend to be more attractive than extensive roofs and can offer people a place to relax, eat or work in park-like settings.

Extensive roofs on the other hand because of their low weight tend to be more often suitable for residential type buildings or sheds and barns.  Extensive green roofs are the simplest to install and are very often added to existing roofs. Depending on the source you look at these roofs may add 10 to 35 pounds per square foot to a roof’s load.  Drought-tolerant plants and grass are the most common used vegetation on an extensive green roof due to their low water requirements and the shallowness of their roots.

Unending Benefits

Green roofs can be placed on both old and new buildings.The green roof system can either be modular, with drainage layers, filter cloth, growing media and plants already prepared in movable, often interlocking grids, or loose laid/ built-up where each component of the system may be installed separately.  Reports vary on installation costs but on average extensive green roof range between $8 and $20 per square foot and intensive green roofs range between $15 and $50 per square foot.  This compared to a traditional roof installation which averages about $16 dollars per square foot the green roof installation costs tend to be much higher. Although a higher installation cost is required, the green roof undoubtedly offers more benefits than a traditional roof may offer.

Green roofs have the potential to reduce energy demands two ways: absorbing heat and acting as insulators for buildings.  Adding a layer of soil and plants to a roof adds insulation to the building it covers.  Since roofs are the site of the greatest heat loss in the winter and the hottest temperatures in the summer, the greater insulation offered by green roofs can decrease the amount of energy required to moderate the temperature of a building.

Furthermore, reducing the demand for energy consequently reduces air pollution.   By lowering air conditioning demand, green roofs can decrease the production of associated air pollution and greenhouse gas emissions such as CO2, coming from power plants.  Additionally, because plants through photosynthesis convert atmospheric CO2 into oxygen, the plants on green roofs can help filter harmful noxious gases in the air and reduce CO2 emissions in the atmosphere.  

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Trends in Sustainable Housing

There has been large-scale proliferation in construction of buildings worldwide due to population growth, economic development, urbanization and migration. According to UN Habitat, there has been a migration of the world's population from rural areas to cities or smaller urban areas. In fact, this trend is expected to continue and cities within the developed as well as developing nations are expected to grow in terms of population. As a result all forms of construction activities are expected to become more intense than ever in the years to come.

Usually the development of urban areas suffers from weak process of planning and control which lead to bad housing conditions, poor sanitation system, limited electricity and water supply, and often poverty.  These issues coupled with high population growth rate, environmental degradation, global warming and limited non-renewable resources highlights the importance of sustainable housing for the survival of humankind.

Sustainability in Buildings

Building construction and operation have extensive direct and indirect impacts on the environment. Buildings use resources such as energy, water and raw materials, generate a variety of wastes and emit potentially harmful gases. Basically the environmental impacts of buildings take place within six stages of building lifecycle:

  • Design process
  • Material or product manufacture
  • Distribution
  • Construction phase
  • Operation
  • Refurbishment or demolition

In terms of energy consumption, 60 percent of the world’s electricity is consumed by residential and commercial building. Space heating accounts for 60 percent of residential energy consumption and water heating for 18 percent in developed countries. Therefore radical changes must be made in design and performance of the buildings to reduce energy consumption and its corresponding environmental impact.

In many countries, sustainable construction methods are being adopted to lead the building industry towards sustainable development and provide better quality living environment. Basically sustainable building design and construction intend to diminish environmental impacts of building over its entire lifetime by paying attention to environmental, socio-economic and cultural issues.

Trends Around the World

The developed and developing world is facing sustainable housing and urbanization challenge in different ways.  Currently industrialized countries are the highest contributor in CO2 emissions. However it is expected that developing countries will take the lead in global warming in the near future. Developing countries are experiencing fast-paced urbanization and at the same time slums and informal settlements are also expanding rapidly which makes development of sustainable housing a difficult proposition.

Countries around the world are taking steps towards implementing sustainable design in the building sector. However most of them are still far from reaching the intended targets.  The major barriers in implementing energy efficiency in the building sector include:

  • Economic and financial issues;
  • Structural characteristics of political, economic and energy system; and
  • Lack of awareness and information

However different countries adopt different approaches for sustainable construction and set different priorities, depending on their economic condition. Nations with high economic growth are developing sustainable buildings making use of latest technologies and innovations. In case of developing countries, social equality and economic sustainability are foremost considerations. In fact, developing countries are moving slowly or even negative towards adopting sustainable housing strategies.

As far as Middle East is concerned, economic considerations dominate for oil and gas-rich GCC countries as they protect their oil and gas export reserves by investing in new ways to boost energy efficiency and lower energy consumption. However for less-affluent countries, such as Jordan, lack of indigenous energy resources and high energy costs are the primary reasons for implementation of sustainable design strategies in buildings.

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Water Conservation Strategies for Middle East

To deal with freshwater management challenges in the Middle East, it is important to bring a balance between both water supply and demand side. This can be done by employing strategies to increase water efficiency and conservation. Water conservation strategies for the Middle East include reducing the use of potable water where possible, find alternative source of water for various water usage and increase the water efficiency of fixtures and equipments. 

Efficient strategies along with water monitoring that tracks water consumption and identifies problems can significantly reduce both indoor and outdoor water consumption in water-scarce GCC countries like UAE, Qatar, Kuwait and Saudi Arabia. Most of the water conservation strategies have no additional cost implication and/or provide rapid payback while other strategies such as wastewater treatment systems and graywater plumbing system often require substantial investment. 

Reduce Indoor Potable Water Consumption

Consumption of potable water  in indoor uses can be reduced by installing water-efficient low flow fixtures for water closets, urinals, lavatories, showers, kitchen sinks and by using non potable water for flush functions. The sources of non-potable water are mainly captured rain water, gray water, municipal treated sewerage effluent (TSE) or reclaimed water. Waterless urinals are available in the market, which can be used in commercial buildings. Flow restrictors, electronic controls and compositing toilets can also help in achieving indoor water reduction targets.

Reduce Outdoor Potable Water Use

Landscape irrigation consumes huge amount of potable water. The water use for outdoor landscaping can be reduced significantly through an integrated approach. This includes employing combination of water-efficient irrigation technology, mulching, reduced turf or no turf grasses, using non-potable or recycled water, installing sub-meters to track and log irrigation trend and choosing native and adapted plant species in landscape design and using xeriscaping methods. High performance water efficient irrigation systems such as drip irrigation, bubbler distribution systems, scheduled irrigation and weather-based irrigation controlled can be used to increase the water efficiency.  

Reduction in Process Water Use

The typical building systems that use process water include cooling towers, boilers, chillers, dishwashers and washing machines. The volumes of water used in these systems are quite significant. The strategies to reduce process water use include; use of non-potable water such as rainwater, graywater or TSE in building processes and systems such as cooling towers. Metering of process water system can be done to collect information on water consumption and to identify leaks.

Recovery and Reuse of Condensate Water

Condensate produced from air conditioning equipment can be recovered and reused within the building. The condensate can be collected by installing a collection pan and then transferred to different systems through drainage pipes for various reuse purposes such as irrigation, toilet flushing, or other onsite purposes where it will not come in contact with the human body. For buildings with a cooling load equal to or greater than 350 kilowatt, a large volume of condensate can be recovered and reused.

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Green Building Rating System in Jordan

Building consume 21% of the primary energy and 43% of the electricity generated in Jordan, according to a recent report by the Ministry of Energy and Mineral Resources. Efforts started in 2009 to develop a rating system for buildings that will reduce the energy and water demand and provide an efficient and healthier environment.

Jordan has several LEED registered buildings since 2009. One of them is LEED Silver and two are LEED Gold, and around 20 more building are registered online and are in the process of applying for LEED. The energy crisis started in Jordan in 2008 after the sharp increase in energy prices. Subsequently the attention to the energy consumption in building increased, and the building officials started implementing the local building codes related to energy. About twenty seven National Building Codes in Jordan are directly related to building envelop, natural ventilation, natural lighting, mechanical and electrical systems.

The Ministry of Public Works and Housing (MoPWH) has the Jordan National Building Council (JNBC) division which is responsible for the development of the Building Codes in Jordan. The Jordan Green Building Guide (JGBG) technical committee was established in 2009 to develop the Green Building Rating System in Jordan with the help of specialist in the public and private sectors under the leadership of the technical arm at the Construction and Sustainable Building Center (CSBC) at the Royal Scientific Society. International references from leading sustainability rating systems were used as references such as LEED and BREEAM, with emphasis on the local conditions in Jordan pertaining to energy and water scarcity.

The JGBG was issued in 2013, and it became available to everyone to use. An incentive program for the adoption of green building in Jordan based on the JGBG rating system was approved in 2015 and it was launched on the 3rd of September 2015.  And the first building under the JGBG requirements is under development.

Owners and developers that adopt the JGBG rating system will be entitled to an increase in the Floor Area Ration (FAR). The JGBG has four levels;

  • Level A (25% increase in FAR allowed)
  • Level B (20% increase in FAR allowed)
  • Level C (15% increase in FAR allowed)
  • Level D (10% increase in FAR allowed)

The Greater Amman Municipality (GAM), Green Building Unit, is in charge of managing the registered buildings under the JGBG. After the Owner or Developer registers the green building with the CSBC for the implementation of the JGBG at certain level, the Issued for Construction drawings are forwarded to the GAM. GAM has developed a one stop shop to process the registered buildings under JGBG and it follows up with the different entities like the Civil Defense Department, Jordan Engineers Association, and others until the building permit is issued. Periodic visits and reviews are done by the CSBC throughout the project until the team achieves the requirements of the JGBG. Subsequently the certificate of compliance is issued for the new green building.

The Jordan Thermal Insulation Code, Jordan Energy Efficient Building Codes and the Jordan Green Building Guide are all working towards improving the energy use in buildings. The table below shows the development of requirements in the thermal transmittance (U-value) for walls in buildings. The Thermal Insulation code and the Energy Saving Building Code calls for the mandatory requirements of U-value = 0.57 W/m2.K for walls and U-value = 1.60 W/m2.K for the overall U-value for walls with all openings. The Jordan Green Building Guide will give one point for the buildings with walls U-value below 0.50 W/m2.K and two points for buildings with walls U-value = 0.40-0.50 W/m2.K

The CSBC started a training program in the JGBG as well, and the first training course will be conducted at the Royal Scientific Society starting November, 2015.

Unending Benefits of Natural Ventilation

Natural ventilation is a method of allowing fresh outdoor air into indoor living spaces by natural means without the use of air conditioning units and other types of mechanically driven devices. It  is the process of changing or replacing stale or noxious air with fresh air in any space to provide high indoor air quality to control temperature, replenish oxygen, remove moisture, odors, smoke, heat, dust, airborne bacteria and carbon dioxide.

Ventilation is important as it reduces unhealthy air pollutants, such as formaldehyde and radon. It reduces excessive moisture and humidity levels, which can lead to mold growth and can cause structural damage. Ventilation reduces naturally occurring odors in the house from pets, cooking, smoking, and other everyday living activities.

While buying or moving to a dwelling, we often consider factors like exterior and interior of building, paint, space, location, building finishes, tiles, ceramics, bath room and electrical fittings etc, but we never ponder on the ventilation aspect. Perhaps this is due to having air conditioners in almost all buildings of the country.

Ventilation is provided through openings such as windows, ventilators and doors. Because of central cooling systems, most people don’t open windows and doors as often. Therefore, air conditioning has become the only principal mode of ventilation in urban surroundings.

A home’s natural ventilation rate is unpredictable and uncontrollable due to the openings, depending on dwelling location, size and number of openings in wind direction. Thus, one cannot rely on natural wind only to ventilate a house uniformly.

Ventilation is needed for removing water vapor produced by respiration, burning, and cooking, and for removing odors. If water vapor is permitted to accumulate, it may damage the structure, insulation, or finishes. In the absence of adequate ventilation, irritating or harmful contaminants can build up, causing occupant discomfort, health problems and reduced performance levels.

Harmful pollutants from a variety of sources can contribute to building-related illnesses. Ventilation systems that are improperly operated or maintained can contribute to sick building syndrome (SBS) which may cause symptoms like dry mucous membranes, eyes, nose and throat irritation. These disorders lead to increased occupant sickness and reduced work efficiency.

The advantages of natural ventilation are many and can have a tremendous positive impact on its occupants, building and the environment. It is suggested that natural ventilation is to be used on optimum basis keeping following aspects in mind:

  • Use fans at appropriate locations to blow air from the cool side of the dwelling to the hotter side.
  • Don’t keep your windows closed.
  • Do occasional air wash of your dwelling.
  • Open windows for durations, depending on the sunlight and its intensity.
  • Cross ventilation in a dwelling will enhance air quality and will avoid it to become a sick building.
  • Provide fountains, pools or swimming pools outside the dwelling which can act as transition spaces where air is naturally cooled before passing through interiors.

A proper design, operation and maintenance of the ventilation system is essential in providing indoor air that is free of harmful concentrations of pollutants. Improvements in indoor ventilation may substantially increase an individual’s health, moral and productivity.

Sickness of Buildings – Causes, Risks and Solutions

Environment is not only important for its own sake, but also as a resource for healthier living conditions and well-being. Poor environmental quality and its current and future impact on human health is a significant concern worldwide. Air pollution causes significant health problems. In fact, knowledge about the links between health and air quality has considerably improved in the last few decades. According to a WHO report, more than 30% of new and renovated buildings worldwide may generate severe complaints related to indoor air quality.

What is Sick Building Syndrome

Sick Building Syndrome (SBS) is used to describe situations in which building occupants experience acute health and comfort effects that appear to be linked to time spent in a building, but no specific illness or cause can be identified. SBS occurs mostly in office buildings however, it may also occur in other public buildings such as schools and libraries. According to the US Environmental Protection Agency (EPA), SBS is highly suspected when the following conditions are present:

  • Temporal symptoms related to time spent in a specific building or part of a building.
  • Symptoms disappear when the individual is out of the building.
  • Seasonality of the symptoms (heating, cooling).
  • Similar complaints among co-workers.

Potential Causes

The exact mechanism by which a building is causing illness to occupants is still unknown. However, sickness of buildings results from a group of factors associated with effects of high concentrations of toxic pollutants present inside the building. In many cases, occupant's behaviors such as closing windows while using ACs in summer or central heating system in winter leads to an unhealthy indoor atmosphere due to poor ventilation,. Furthermore, poor building design, maintenance, and/or operation of the structure's ventilation system may also be at fault.

The ventilation system is often found to be at the core of the problem, and can itself be a source of irritants .The poor ventilation system can result in accumulation of pollutants within the building, in this case the indoor environment can often have lower air quality in comparison with the outdoor air, even in a heavily polluted city with vehicle exhaust and other pollutants. Moreover, very low levels of specific pollutants, such as VOCs, that are present inside a building may act in combination, to cause symptoms of illness.

Major Symptoms

Building occupants complain of SBS symptoms such as sensory irritation of the eyes, nose, throat; neurotoxic or general health problems; skin irritation; nonspecific hypersensitivity reactions; and odor and taste sensations.  In most cases, SBS symptoms will be relieved soon after the occupants leave the particular room or zone. However, there can be lingering effects of various neurotoxins, which may not clear up when the occupant leaves the building. In some cases, particularly in sensitive individuals, there can be long-term health effects.

There is a wide array of factors which can contribute to making a building 'sick'. Sick Building Syndrome can be caused by inadequate ventilation, chemical contaminants from indoor or outdoor sources, and/or biological contaminants. Many volatile organic compounds, which are considered chemical contaminants, can cause acute effects on the occupants of a building

Chemical Pollutants

Indoor chemical pollutants such as ozone resulted from printers, VOCs, fresh painting, cigarette smoke, off-gasing of the carpets and furniture, and the frequent use of chemical cleaners or fresheners. Outdoor chemical pollutants such as motor vehicle exhaust and building exhausts.

Biological Pollutants

Poor sanitary and cleaning practices, especially in public facilities, lead to the accumulation of biological contaminants such as pollen and dust mites', fungi, mold, and bacteria from the toilet. Besides, insect body parts are particularly troublesome allergens and are commonly implicated as contributors to SBS.

Physical factors

Major physical factors involved are weakness of ventilation, high temperatures, fluorescent lighting and electrical equipment, change in temperatures during the day, low humidity, poor lighting, dust, and use of display screens for long hours.

Associated Risks

It is important to be able to recognize the symptoms of SBS and to take action immediately, since misdiagnosis is one of the most critical issues. If you are experiencing SBS symptoms which remain even after leaving the building, this might be an indication of Building-related illness (BRI). SBS have long-term psychological effects in the form of depression, anxiety or paranoia and also leads to negative employee efficiency.

Plausible Solutions

To ensure elimination of SBS-related problems, several measures must be taken including improving the indoor air quality, as building sickness will diminish once the pollutant source is removed or modified.  Another key measure is repairing or replacement of ventilation system to meet ventilation standards in the local building codes. It is also important to improve cleaning practices at public spaces, taking to consideration that detergents shall be stored in well-ventilated areas and isolated from other materials. Other practices include frequent checking of heating, cooling and air conditioning systems, avoiding synthetic fabrics, minimizing the use of electronic items and unplugging idle devices, smoking restrictions, allowing time for building material in a new building to off-gas pollutants before occupancy.

Fortunately, nature has very effective tools for air purifying, for instance sun's rays have a magical effect in cleaning the air. It is worthwhile to focus on efficient and periodic natural ventilation during the day, even during winter time. Additionally, specific species of plants not only purify the indoor air quality, but also have a positive effect on psychological health by increasing the concentration and relief of fatigue and stress. Indoor plants that are effective at air purification include Aloe vera, Boston fern, Chinese evergreen, Christmas cactus, Chrysanthemum and daisies.