London Shard

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The Shard located in London England

The Shard is the tallest building in Europe. This irregular pyramidal structure, clad entirely in glass, consists of ninety-five stories and stands at a height of 1,016 feet. The building was finished in July of 2012 and was designed by the architect Renzo Piano. He designed the building to be extremely environmentally friendly and economically sustainable. The building even was given a BREEAM Excellent rating.

Piano designed the Shard to use renewable natural resources to reduce the depleting of nonrenewable resources. For example, the 11,000 glass panels that make up the outside of the structure are designed to reduce heat from the sun by 95%. As these panels approach the top, they form a spire. The final nine levels of the building consist of the spire and are open to the elements which allow the building to breathe. On the inside of the glass panels, there is also a ventilated inner cavity housing a solar-control blind, and a double-glazed unit. The glazing on the panels reduces infrared radiation.  An intelligent blind control system is used which tracks the position and intensity of the sun to deploy the blinds only when required. These aspects, that were incorporated into the design, minimize the use of power for air conditioning which requires the use of nonrenewable natural resources. The panes of glass also allow for natural illumination which reduces the use of electricity to light the building. Another way that the Shard uses renewable natural resources to help the environment is that it has two natural winter gardens per floor that are used to naturally ventilate the workplaces with clean air instead of using electricity and filters.

The Shard is economically sustainable by having its own power plant and through the functions of other high technology systems. Installing its own power plant on site at the Shard was very expensive, however the extra expense will be recovered in due time. By the plant using natural gas, they will save money. Today natural gas only costs $2.50-$4.00 per thousand square feet whereas oil is $3.64 per gallon (Gripper). Even though oil burners burn hotter, they are less efficient than natural gas burners, so when comparing prices and efficiencies the natural gas is more cost effective. Also, when the natural gas is converted to electricity it creates heat. The designers of the Shard cleverly installed a heat exchanger to transfer heat from the power generation system to the building heating system so not as much money must be spent heating the building.  Another benefit of the power plant on site is that they are able to install their own unique sophisticated technology that increases the efficiency within the plant. This saves money because the plant does not require as much utilities.

These are only some of the reasons of what makes the Shard a green building, but they some of the most important and also ideas others should take into consideration when designing green buildings.

Eliminating Thermal Bridging (Residential)

I came across an article that describes a slightly different way of framing a standard 2×4 wall that eliminates thermal bridging.  There is nothing extraordinary here, no technological innovations, but the more I thought about this framing addition, the more it made sense.  It will add to the first cost of the construction slightly (materials and labor) but it will save on yearly air conditioning costs, paying itself back over time.  I am a firm believer that a building, especially a home, should function passively when it comes to energy so that smaller MEP systems can be fitted without the need to expensive renewable that will effectively never pay themselves back.

The “Mooney Wall” adds extra interior furring and spray insulation.  Picture a standard 2×4 wall with added 2×2 16″O.C. but running in the perpendicular direction (see pictures in article).  These 2×2’s extend beyond where the 2×4 ends since they are mounted and screwed into the structural studs.  Once the wall is sprayed solid with insulation, thermal bridging is virtually eliminated.  The various parallel paths are as follows:  Exterior sheathing and cladding -> A) full depth insulation, B) insulation meeting the back of a 2×2 C) through a 2×4 stud then through insulation -> interior finish.  There is no direct flow through a stud directly to the interior finishes.  This assembly focuses on conductive flows through these materials.  The convective and re-radiated flows would be very similar to the standard 2×4 construction.  There is a decent amount of added mass so the re-radiation, if any, would be reduced.

Still the weakest point of this assembly, conductively, is when the flow goes through the 2×4 stud and then through 2″ of spray insulation (C above).  This would be worse than 4″ of insulation thickness meeting a 2×2 stud or even the full 6″ of insulation (assuming a 6″ nominal insulation layer from the 2×2 mounted on the 2×4).  The only thermal bridging left is when the 2×2 is mounted onto the 2×4 at various locations.  Instead of the standard 2×4 framing when you get linear slices of bridging, this solution gives you point sources of thermal bridging.  The founders claim an R19 to R21 value for the wall versus R13 to R14.  Such a simple way to solve such a common issue.

http://www.builditsolar.com/Projects/Conservation/MooneyWall/MooneyWall.htm

Wave Powered Desalination Plant

Carnegie Wave energy is planning to open the worlds first zero-emission wave powered desalination plant in Australia. The two megawatt pilot project will operate will multiple submerged buoys tethered to pumps that funnel pressurized water to turbines onshore. There the water can either be harnessed to create electricity or to run and supply water for a reverse osmosis desalination plant.

Now with that being said, there are some questions I have in mind.

Firstly, I would like to admire the people who worked on this design to make this possible. It seems there are technological advances I’m not caught up with, and did not think something like this was (effectively) possible yet. And its about time somebody started harnessing the power of waves for something more than just energy.

Now, there are some problems with the current “Natural Harvesters” in use today, namely the solar panels and the wind turbines. The main problem I’ve read about them is that their net energy is relatively really low. Oil, the substance nations are dropping bodies over, has an incredibly high net energy. And what that means is that the ratio of the amount of ‘work’ it gives out compared to the amount of ‘work’ that it takes to gather high. Oil can produce so much energy compared to other resources. Going back to the natural harvesters, they may have the ability to generate their own power to operate, but whatever power is left over to give is low. They use almost all of the energy they gather. Not to mention the aesthetics behind it all. Although they themselves are not too much of an eye sore to me, there are countless others who would say otherwise.

While the application of this technology is relatively new, there is no telling if the design will live up to its promise. How much net energy will it produce, and will that be enough for a bigger population? Can this be something that gets incorporated at the States? Although there are other wave energy processing plants already in the works, this seems to be a right step towards sustainability.

http://www.youtube.com/watch?v=mhDl5HG6vOQ

Chicago’s Battle of the Roofs: Green vs. White

Green roofs are commonly associated to the idea of energy efficiency, environmental friendly architecture, and proficient economic decisions. Nevertheless a 2001 green roof competition had some shocking results. This was established by then-Chicago’s Mayor Richard Daley with the purpose of finding out which building in Chicago could reduce their electricity bill the most.

The great battle was set between the Cook County buildings against the Chicago City Hall. Both buildings located in the Loop, the Cook Country building featured a white roof top while the Chicago City Hall designed and built a green roof, this featured 20,000 plants of more than 150 native to the Chicago region species from shrubs, vines to even two trees [1].

The Chicago City Hall takes pride of its green rooftop for the distinctive improvement of the city’s air quality, energy conservation, storm water runoff reduction, and urban heat island effect. The garden was able to achieve 75% rainfall retention, a temperature reduction on averaged 50 to 70 degrees during summer, and an annual $22,000 electricity bill reduction [2].

To win the competition, the Cook County building decided to cover the building’s roof and side facade with white-coated roofing membranes. This application not only resulted in a longer roof life cycle, but it reflects solar radiation and ultraviolet waves resulting in a lower energy cost; so low, that it allowed the Cook Country Building to beat the Chicago City Hall by reducing the summer building temperature and extra 2 degrees over the Chicago City Hall’s, moreover it was also able to save up to an annual $65,000 on their electricity bill, $43,000 more savings than the City Hall’s savings count [3].

But not only can a white roof help save a lot more energy and money than a green roof, it is also much more affordable to install and a lot less time consuming to maintain. While green roofs are great for reflecting heat, tackling air pollution, collecting rainfall water, and processing greenhouse gas emissions, they don’t come anywhere near the amazing results that white-coated roofs have accomplish. Green roof cost up to $30 per square foot to maintain [3].

Even though economics are a very important part of any building architectural decision, green roofs brings some hard-to-ignore facts to the table. For the most part, green roofs are open to employees and or the public, provide pocket habitats for urban birds, quiet areas of parkland in the middle of the city density, and work as extremely efficient rainfall collectors.

So which is better — white or green? From an economic stand point of view white is the undoable choice, but if you do happen to not care so much about money and more about statics, functionality, and human and natural advantages, green is definitely the way to go.

[1] Daigneau, Elizabeth. (2012) Chicago’s Battle of the Roofs: Green vs. White. Online: http://www.governing.com/topics/energy-env/gov-battle-of-roofs-chicago.html

[2] City of Chicago. (2013) City Hall’s Rooftop Garden. Online: http://www.cityofchicago.org/city/en/depts/dgs/supp_info/city_hall_green_roof.html

[3] Cook County Government. (2011) Facilities Management. Online: http://www.cookcountygov.com/portal/server.pt/community/facilities_management/294/facilities_management

Rainwater harvesting system

Rainwater harvesting system

Rainwater harvesting system is used for water efficiency in Green Building. Rainwater harvesting captures, diverts, and stores rainwater for later use. Implementing rainwater harvesting is beneficial because it reduces demand on existing water supply, and reduces run-off, erosion, and contamination of surface water. Home systems can be relatively simple to install and operate and it may reduce your water bill.

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First of all rainwater is captured off rooftops and other surfaces, sent through an inlet filtration device designed to remove debris before storage in a tank. Inlet filters can be located in a variety of locations depending on site constraints.

Roof Catchment: Your roof accounts for a large surface-area, and when it rains, this water is typically routed through a system of gutters and pipes and dumped unceremoniously into your yard, where it washes away valuable topsoil. Roof catchment systems, which are the most common type for residential applications, collect this water by routing it through a system of gutters and pipes into a cistern, usually located on the ground level. The choice of roofing material is extremely important as some types can contaminate the water, such as those with coatings or metallic finishes or asphalt. Acceptable roofing materials for catchment systems include aluminum, tiles and slate or galvanized corrugated iron.

Ground Catchment: A ground rainwater harvesting system is a more simple approach than the rooftop version and offers the possibility of a wider catchment area. Water may be collected via drain pipes or earthen dams and stored above or below ground in tanks. The quality of water may be lower at the ground level, rendering the captured water suitable for landscaping needs only.

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Secondly, collected rainwater is stored in a tank or cistern which can be located above or below ground. Depending on the project’s requirements, tanks are available in a variety of materials, with plastic (polyethylene), fiberglass, or galvanized steel the most common.

At last all rainwater harvesting systems require a rainwater control station to manage the system as well as treat and pump water. Water is distributed from the storage tank via pumps. Many applications also require filtering the water before pumping in order to safeguard non-potable water quality.

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Rain does more than simply provide drinking water. It also supplies homes with a renewable source of water that can be harvested, collected and stored for various purposes, including irrigating gardens, cleaning, washing clothes and more. Promotes both water and energy conservation. Rainwater harvesting has been around for decades, but only recently has it received national attention due to water shortages throughout the United States. However, that rainwater harvesting systems require regular maintenance, such as cleaning the roof surface, piping and storage container to prevent the water from becoming contaminated. Also, standing water is a natural mosquito breeding ground, so you must use netting or other devices to keep them out. Cisterns can be unsightly. It is possible to camouflage them, and if you are really concerned about the aesthetic impact, then opt for an underground version.

 

Natural Air Purifiers

The course on Building Science focuses on teaching students how to improve built environments and how to provide a clean and comfortable environment for the inhabitants or users of a building.  In our class, we have discussed ways to make energy efficient environmental friendly buildings.  This motivated me to find some naturals ways for air purification. Upon investigation, I gained knowledge on a couple of natural ways that can purify indoor air that I feel people with contaminated air in their homes and work spaces would benefit from because the current technologies on air purification come with their significant detriments and disadvantages.

As we make buildings with better insulation and energy efficiency, we tend to make buildings tighter with less ability for air to pass freely. Air quality can suffer due to that. Mechanical air purifiers and filters claim to be very efficient in cleaning dust particles, smoke and other contaminants. Now there are even ones that do not even require the filters to be changed, such as ionic or ozonolysis air purifiers. These filters are able to provide clean air without the noise of previous filters with older technology.  But these mechanical air purifiers are not the ultimate solution they appear to be. These machines are not only expensive but can pose a threat to the health of those exposed to the air pollutants it ironically creates. There are about 2.2 miligrams of ozone released per hour by Ionic purifiers and 200 miligrams per hour released by Ozonolysis purifier. These amounts can cause lung disease and shortness of breath as well as asthma and throat irritation.  There are four natural easy alternatives to this scenario. Image

The first of the natural alternatives is one that we learn about in high school biology. Plants have been shown in studies conducted by NASA to have the effect of eliminating toxic waste and cleansing the air of toxins. This is done when a plant emits water vapor which creates a pump action that pulls contaminated air down towards the roots of the plant where it is used by the plant to make food; this makes for a symbiotic relationship between the building inhabitant contributing to the pollution and the plants kept in the closed space. The second of the natural alternatives is Beeswax. Yes, Beeswax candles have the effect of cleaning the air of pollutants around it by negatively charging ions when it burns which cling to positively charged pollutants and allergens in the air. Yet another easy way to clean the air in an enclosed space is by using activated carbon. Installing activated carbon into the heating, ventilating and air conditioning HVAC systems can help purify the air because it has the ability to eliminate odors and trap pollutants in its pores. A final way to purify air that I discovered in my research was the use of salt lamps. Salt lamps are made by hollowing out large chunks of salt crystals; after hollowing it out, a light bulb or candle can be placed inside.  When the salt is heated by the flame or heat, it releases negative ions just like the beeswax candle and ionic air purifier, and the ions attach to the positively charged pollutants and allergen. These four techniques are inexpensive and require little effort to maintain yet can have a significant impact on the purification of the air we breathe in some poorly ventilated buildings. The alternatives are worth considering when finding a solution to polluted air.Image

For more information visit these links:

http://www.idealhomegarden.com/holidays-crafts/best-natural-air-purifiers/

http://www.naturalnews.com/035961_air_quality_indoors_purification.html

Bioreactor Façade

Renewable energy is receiving increased global attention as a potential sustainable. Algae bio-fuel is an alternative to fossil fuel that uses algae as its source of natural deposits. Many research study how to use this resource in industry as a sustainable energy and few months ago the first building covered with algae panels was unveiled in Germany.

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The bio-reactor panels that are mounted on an existing building are like storage contain algae that continuously supplied with liquid nutrients and carbon dioxide via a separate water circuit running through the facade. With the aid of sunlight, the algae can photosynthesize and multiply in a regular cycle until they can be harvested. They are then batch separated and transferred as a thick pulp to the technical room. There they are fermented in an external bio-gas plant, so that they can be used again to generate bio-gas. The whole building is intended to be completely self-sufficient.

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The algae panels are 8′ by 2′, with a total surface area of 2152 square feet at a yield of 15 g dry weight per square meter per day for the conversion of biomass into bio-gas, a net energy gain of approximately 4,500 kWh per year can be achieved. In comparison, a family of four consumes about 4,000 kWh per year. The algae facade could thus supply the entire household of the family with bio-electricity! However the system seems to be prohibitive due to the high cost and time needed to assemble also the maintenance but this kind of projects will be more efficient in the future when the fossil fuel will be depleted.

 

http://www.algaeindustrymagazine.com/algae-powered-building-to-open-in-germany/