Towards Zero Energy, Pearl River Tower

Net zero energy concept is one of the hot topics in today’s green building industry. There has been a lot of research, modeling and optimization to achieve a building that is environmentally responsible and friendly. Pearl River Tower is a 71-storey building in Guangzhou, China with an area of 212,165 square meters. As Guangzhou experiences some of the worst air pollutions in China, Chinese government set the goal of reducing carbon emission by 10% by the end of 2010. The goal of constructing such a building was to build a transformed, integrated, high performance, environmentally responsible design. 

The energy saving systems of this building would work together efficiently to consume approximately 60% less energy than a conventional building. This high performance building is designed in such a harmony with its surrounding environment that it extracts energy from the natural wind and sunlight. Furthermore, it has been considered as the largest radiant-cooled office building in the world and the most energy efficient super tall building in the world (1016 ft) since completion in March 2011.

There are 4 strategies that had been taken for achieving net zero energy which are Reduction, Reclamation, Passive Absorption and Generation. For instance in reduction strategy, instead of normal air conditioning and ventilation systems, chilled radiant ceiling through perimeter chilled beams is utilized. It functions with pumping cold water (58˚F) through copper pipes in the slab which cool curved metal plates used for the ceiling system and metal fins for the perimeter, consequently cooling the surrounding air. Also, the displacement ventilation function provides cooled fresh air and delivers it via a raised access floor. High performance glazing systems, daylight responsive controls, high efficacy lighting and high efficient office equipment are the other features that have been used for the reduction strategy.

Reclamation is another strategy that has been used for seeking net zero energy. Chiller heat recovery, generator heat recovery and exhaust air heat recovery are other features that utilized for providing a pleasant indoor air quality for the building in four seasons of year with different temperature and humidity conditions. Also, condensate reclamation system harvests water from chilled surfaces to control interior humidity. Water is filtered and used for interior plantings and toilet flushing. Furthermore, Solar energy is collected within the double wall facade. The energy is transferred to the mechanical floors and is used as heating for the dehumidification system.

Another useful strategy is passive absorption. Advanced wind and solar technologies were incorporated into the design of this skyscraper in order to generate or “absorb” the natural energy from the building’s surroundings. The Tower is positioned so that the broadest side of the building faces directly into prevailing winds. In addition, Photovoltaic cells were utilized into the mechanized shade system to capture the sun’s energy in the eastern and western facades.

Furthermore, in order to implement generation strategy, this tower needed to use a comprehensive micro-turbine system to fulfill its excess energy demand. These small, highly efficient turbines would run off of anything from biodiesel to natural gas, making the Pearl River Tower a mini power plant. However, Guangzhou authorities did not warm up to the idea. Their reluctance coupled with the faulty electrical grid led to these micro-turbines being put on hold.

Also, if you are interested, you can watch these two videos about the tower.

http://ctbuh.org/TallBuildings/VideoLibrary/ConferenceVideos/2009_Chicago_S8_Gilchrist/tabid/1968/language/en-GB/Default.aspx/

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

Introducing Four Interesting Green Products

1. Green Product Sub-category: Insulating Concrete Forms

            In general, Insulating Concrete Forms (ICFs) are used to make insulated concrete walls in a more efficient way than normal forming. ICFs can’t be disassembled after curing of the concrete which means that they are permanent forms. This product is typically made from expanded polystyrene (EPS) foams, extruded polystyrene (XPS) or a composite of wood waste or EPS beads and Portland cement. Also, we can stack them together without mortar before pouring concrete. This can help in reducing the amount of concrete that is needed for the final wall. Furthermore, their insulating performance can be considered as their best environmental benefit. Regarding the tests that have been conducted, it has been shown that most of them have R-values around R-20. However, there may be some exaggerations about the thermal mass benefits of ICFs.

Among different types of insulated concrete forms we can use Boost-R panels which have more R-value (R-30 and above). Reward Wall Systems provides this type of ICF. Also, we can choose between a variety of densities and thicknesses as well as EPS with neopor. Furthermore, special notches and tapered edges that are implemented on the panels can provide better locking and easier installation for the labor. Below is a table that shows the R-values for different Boost-R panel sizes.

2. Green Product Sub-category: Metal-Framed Skylights

            There are a lot of energy waste issues for the conventional metal-framed skylights such as high thermal loss of glazing or non-thermally broken frames, undesirable heat gain that increases the demand for cooling functions. Generally, prismatic and active skylighting systems utilize implanted prisms, reflectors or sun-tracking systems to increase daylight entry in different day times. Specifically during early-morning or late-afternoon hours that the sun beams have low angle and lower direct sunlight enters the building from skylights.

In addition, some skylights can provide high performance glazing (triple-glazing), low-conductivity gas-fills, low-e suspended films, low-e coatings, etc. Some skylights also include translucent insulation materials such as translucent fiberglass, silica aerogel and thermochromatic, electrochromatic or photochromatic covers to change and improve the solar transmission specifications due to heat, electric current or sunlight. Also, some skylights implement thermally broken frames that considerably reduce thermal bridging. 

Furthermore, a few skylights utilize advanced fiber-optic technology to lead daylight to spaces that cannot be benefited from direct skylight or several stories below the roof level. However, this technology is not yet on the market widely. We can see the general function of these devices in the picture below.

3. Green Product Sub-category: Recycled Paints

            As we know, the main component of recycled paints is leftover paint from other consumers. Although, recycled paint has less reputation in the market, there are different levels of recycling content and quality that might be suitable and can be used for specific jobs. Besides the environmental benefits of using recycled paint, there are also some financial benefits for the projects as it can be found with a quite cheap price ranging from $0 to $10 per gallon.

            This product is usually made by regional waste management agencies which generally gather leftover paint, categorize it by depth and type of color, filter the impurities and make it ready for use. Therefore, the agencies are free of paying more for the leftover paint disposal. However, the biggest issue with using recycled paint is the limitation in color selection (typically brown, beige or white).

            Furthermore, using recycled paint needs to take appropriate examination procedures so that the final product has the minimum criteria of a suitable paint. Also, it may need to add extra virgin materials to reach the specifications needed. Kelly-Moore Paint Company provides recycled paint since 1992 and it has a good quality among the others in the market. Typically, their products are made from at least %50 leftover recycled paint. Also, they provide sixteen different standard colors.

4. Green Product Sub-category: Vapor-Retarders

            Vapor retarders are some equipped sheets that can be added either to interior or exterior parts of a building to prevent moisture moving due to diffusion into roofs, walls, foundation, etc. Also, it has three different types which are vapor impermeable, vapor semi-impermeable, vapor semi-permeable. Typically, materials with vapor permeability greater than 10 perms are considered to be vapor permeable.

In addition, it should be taken into consideration that vapor retarders placement should always be done in the context of the vapor permeability of the other materials used. So, the whole system can provide an appropriate vapor retarding function for the building. Therefore, for functioning more efficiently, it needs a comprehensive design of vapor retarding for the whole system.

Energy Efficiency Problems in Some LEED Certified Buildings

Nowadays, Energy Efficiency is one of the most important issues that world is trying to solve. Building construction industry is involved in a major part of total annual energy consumption of every country. Consequently, finding new approaches to provide more energy efficient procedures in building construction has been taken into consideration. Therefore, the concept of green buildings came up and different green building rating systems have been developed in many countries all around the world.

In year 1998, United States Green Building Council (USGBC) developed a nationally accepted benchmark for green building industry named as Leadership in Energy and Environmental Design (LEED). Generally, the main purpose of implementing LEED for assessing buildings was to assure the energy efficiency and environmentally sustainability of them. However, it has been observed that some LEED-certified buildings consume much more energy than similar non-certified ones. So, what is the point in implementing such rating system when there is no guarantee for the building to be more energy efficient? Why do some LEED-certified buildings consume more energy than the anticipated model?

For answering this question we may compare the energy consumption data of some LEED-certified buildings with each other. It seems that these inconsistencies are not completely caused by the suggested reasons such as lack of inter-operation between parties, changes in construction, Climate or equipment induced differences, etc. We think that there might be a problem in implementation practices. Finding the solution for this question needs more categorized comparison of the actual versus anticipated energy performance data, using statistical approaches. So, by comparing the data achieved from different buildings and comparing them in each dividend of energy consumption (such as plug loads, air conditioning, lighting systems, etc.) we can find were the implementation problem could be.

10 Amazing Recycled Building Materials

Today, the use of recycled materials as building materials is rapidly growing. Although, the structural issues should be taken into consideration, using these kinds of materials for constructing building seems to be quite acceptable. There are a lot of examples of using recycled materials in building construction. Here I want to introduce some of them with some examples.

There is a Buddhist temple in Thailand that is made of almost one million beer bottles. This temple can be a proof that we can use recycled and reclaimed materials beautifully in building construction. Also, it reminds us the huge amount of waste that we produce in our daily life. Because of their translucency and ability to hold thermal mass, glass bottles are also often used in cob building to enhance natural daylighting for a stained glass effect.

Here is a grain silo that is purchased and moved to create an unusual circular home. We can use silos for constructing a quick environmentally friendly home. They also have the potential for being used in durable inexpensive pre-fabricated housing. Besides, they look so luxurious, too.

We also can use aluminum cans as small bricks in Earthship buildings, stacked and mortared with lime on earth. When John Milkovisch retired, he got bored – but he didn’t turn to golf for entertainment. He began adding ‘aluminum siding’ to his Houston, Texas home in the form of flattened beer cans “for both practical and decorative reasons”, he says on his website. The house is now covered in 50,000 cans.

There are some examples of using shipping containers in building construction. Some creative designers turn these usual rectangular boxes into considerably beautiful buildings, apartments, offices, etc. Shipping containers can be stacked with crane and build up a building. Also, they are really easy to transport from one place to another one.

Every day, thousands of tires are being thrown away. As I mentioned in my previous blog, we can use tires as building components in earthship structures. Packed with rammed soil, tires can provide an incredibly solid building material. Also, they can absorb heat in winter and keep the building cool in summertime. (for more information, read my previous blog)

Some people recycle boats that are no more seaworthy. Huge ships like the Great Lakes Shipping Boat (top), now known as the ship residence on an island in Lake Erie at Put-in-Bay, Ohio, make incredible seaside mansions that are quite a sight when seen from the water.

Can we use wood pallets as building materials, too?! The answer is yes. As they are plentiful and thrown away every day and also we can easily nail them together, we can use them to build some small buildings. And while they may not be a great load-bearing material for anything other than a shed, they do make a fantastic addition to building exteriors to filter sunlight.

A cardboard building may sound like the most temporary of structures – something you expect to find in a shantytown, not a suburban neighborhood. That it is, but imagine how such a material could be put to use for inexpensive emergency shelters that set up ultra-fast. Architects Stutchbury and Pape developed a $35,000 flat-packed prefab cardboard house made from 100% recycled materials with a waterproof outer membrane made of HDPE plastic.

Surrounded by industrial scrap metal every day for years, a former scrapyard owner saw a lot of potential for reuse – and put those ideas to work in his own home, a modern metal masterpiece 90 minutes northwest of Toronto. A rusted metal gate made from an old truck chassis, old galvanized steel siding and I-beams rescued from a demolition job are just a few elements of the mostly recycled home. And what will happen to this recycled home when it’s finally due to be demolished?
“With most houses, when they’re torn down, everything goes into a bin,” homeowner S. J. Sherbanuk told Dwell. “When this house gets pulled down 60 or 80 years from now, they won’t even need a bin. It’s all gonna get reused.”

As the last one, here is a 727 Fuselage Home at the Costa Verde resort in Costa Rica, a two-bedroom suite made from a refurbished vintage 1965 Boeing 727 airframe. Retired from its former hectic life as part of South Africa Air’s fleet, the salvaged airplane serves as a cozy and unique lodging perched atop a 50-foot pedestal for the feel of being in the air.

Earthship Biotecture, another step to be more sustainable

    Today, while I was searching about new methods for green building construction, I came to a very interesting method named Earthship Biotecture that I want to write this blog about it. As I understood, earthships are passive solar houses that are made from natural recycled Materials and can perform the role of an environmentally friendly building very well and they are going to be more widely used these days. The Most Versatile and Economical building design in the world developed over 40 years around the world by Earthship Biotecture. Earthships which can be used in any part of the world and in any climate, provide you all the needs to survive, with modern amenities and utilities, if desired.

    Earthships as they exist today, began to take shape in the 1970s. Mike Reynolds, founder of Earthship Biotecture, a company that specializes in designing and building Earthships, wanted to create a home that would do three things; first, using native materials wherever possible, it would be sustainable architecture. Second, it would rely on natural energy sources and not be dependent on the “grid”.  So, it would be less vulnerable to natural disasters and independent from the electrical and water lines. Finally, it would be economically feasible for the average person with no significant construction skills to be able to construct.

   Designed and marketed by Earthship Biotecture of Taos, New Mexico, the homes are primarily constructed to work as autonomous buildings and are generally made of earth-filled tires, using thermal mass construction to naturally regulate indoor temperature. In addition, They have their own natural ventilation system. Earthships are generally independent from public utilities and fossil fuels which makes them more environmentally friendly. They are built to use the available local natural resources to function, especially the sun light. For example, windows on sun-facing walls admit lighting and heating. Another interesting thing that should be mentioned about them is that the buildings are often horseshoe-shaped to maximize natural light and solar-gain during winter months. The thick, dense inner walls provide thermal mass that naturally regulates the interior temperature during both cold and hot outside temperatures. Also, the internal load-bearing walls are o honeycomb structure of recycle cans and concrete and commonly named as tin can walls. They are usually thickly plastered with a stucco surface. Furthermore, the roof of the Earthships is generally insulated with two layers of four inch poly-iso insulation to make it more energy efficient.

First experimental house completed near Taos, New Mexico using empty steel beer and soft drink cans

    Also, this method is not limited to tires only. Any dense material with a thermal mass potential, such as adobe, concrete, dirtbags or stone could be used for these kind of construction. However, Earthship structures are known for the use of earth-rammed tires. As we know, rammed-earth tires are plentiful around the world. There are an estimated 2 billion tires throughout the United States. As of 1996, as many as 253 million scrap tires were being generated each year in the United States, with 70% being reclaimed by the scrap tire market (leaving perhaps 75 million scrap tires available for reuse as whole tires). Also, the method of using them is so simple and feasible for anyone to perform.

    Another benefit of the earth-rammed tires is the considerable load-bearing capacity and fire resistance. A fully rammed tire, which is about 2 feet 8 inches wide, is massive enough to surpass conventional requirements for structural load distribution to the earth. Because the tire is full of soil, it does not burn when exposed to fire. In 1996 after a fire swept through many conventional homes in New Mexico, an Earthship discovered in the aftermath was relatively unharmed. Only the south-facing wall and the roof had burned away, compared to the total destruction of the conventional homes.

   Also, in the economical point of view, earthships cost about the same as a conventional home, but a conventional home does not come with all the electricity and water you will use. A conventional home is bad for the planet, is not strong and uses materials that require a lot of fossil fuels to manufacture and get to your building site.

    Nowadays, Earthships are used in many states in the Unites States as well as many countries in Europe. Also, using the insulation on the outside of tire walls, which was not common in early designs, they are becoming more viable to every climate without compromising their durability. Therefore, we will probably see wider use of this method in future of the green building industry, as it is becoming more and more popular and inspiring more people because of its inexpensive matreials.

    Here is a video of this method used for construction of a building.

Green Roof Systems, Precious Technology

     In this blog I want to give some general information about Green Roofs and their considerable effect on reducing the energy consumption of buildings in Green Building industry. As we know, using green roofs in our structures has some positive effects on it such as reducing storm water runoff, attenuating roof temperature, reducing heat island effect, optimizing energy performance, etc. Nowadays, green roofs are going to be more widely used in different structures, but still it has to be improved in different aspects. (e.g. 20% of commercial roofs in Germany are green.)

     Although it seems that green roof construction need a set of skills and takes a lot of time, effort and money (comparing to conventional roof construction), It can considerably reduce the amount of energy usage in a building. Generally, green roofs are made of some typical layers such as waterproofing membrane, insulation, protection fabric, drainage and filter layers, soil media and vegetation. The typical layering of the green roof systems can be seen in the picture below. Also, beside reducing the Heat Island effect, this system can effectively be used for reducing of the water consumption of a building as well.

     As some of the good examples of green roof users in United states, I should mention Ford Motor Company (Dearborn, Michigan), Ballard Library in Seattle, the new California Academy of Sciences building (Golden Gate park, San Francisco), United States Postal Service's Morgan Processing and distribution Center (New York City), Zeckendorf Towers (New York City), etc which are shown in the pictures below.

Ford Motor Company (Dearborn, Michigan)

Billard Library, Seattle

New California Academy of Sciences building (Golden Gate park, San Francisco)

United States Postal Service's Morgan Processing and distribution Center (New York City)

Zeckendorf Towers (New York City)

     Using this technology in the state of Florida has some issues such as intense rainfall, long drought conditions, hurricanes, wind uplift and scour resistance, viability of plants, biodiversity, fire resistance concerns, etc. After a lot of investigations in this field, researchers came to that the cultivation of Florida green roof must take some points into consideration such as heat flow, moisture residence, plant selection, depth of roots, weed suppression and wind uplift. Among these, wind uplift seemed to more critical in using green roofs which some useful researches had been done for obtaining better criteria in use of green roofs considering the wind uplift issue (“Wind resistance of green roof systems” David Prevatt, Glenn Acomb). Here, I should mention the Perry construction yard green roof on top of the Rinker school of building construction at the University of Florida, which was used as a case study for this research.

Rinker school of building construction, University of Florida

     In conclusion, I think although cultivation of green roofs in Florida has some issues, it can be really helpful for structures in this region to be more sustainable. Investing time and effort in researching in new ways of using this industry can lead us to a more sustainable future. Tough, there are a lot of new research topics in this field that should be taken into consideration.

The Importance of Being Sustainable

          Have you ever been thinking about the relationship between you and the environment around you? How much do you care about your natural habitat? Do you consider your life style to be environmentally friendly? Do we think about the future of our planet when we are spending its natural resources? Surely, many of us have been encountered to these kind of questions nowadays. But why do we have to find an answer for them? The answer is "Energy". As we know, our planet is functioning with all kinds of energy transformation each day. In a more precise view, every individual need energy to sustain his daily life. But how should we share these finite sources of energy to assure that all of us have the ability to sustain? Regarding to a well-known article named "The tragedy of the commons" by Garrett Hardin, population naturally tends to grow exponentially and the "tragedy" occurs when individuals and the society are locked into a system that rationally forces them to maximize his gain by taking without limit, in a world that is limited. So, how can we survive?

            The answer that is given to this question is being more sustainable. Regarding to the definition given in the world commission on environment and development report "Our Common Future"(1987), sustainability is meeting the needs of the present without compromising the ability of the future generations to meet their own demands. Lets be more familiar with this concept. A few months ago, I took an on-line "Carbon Footprint Assessment" survey. Carbon Footprint, as Wiedmann said, is “a measure of the exclusive total amount of carbon dioxide emissions that is directly and indirectly caused by an activity or is accumulated over the life stages of a product”. After completion of this survey I found that my carbon footprint on the environment is almost 2.7 times bigger than the average footprint for people in United States which was embarrassing and really surprised me. Then I found that it was because of the long-distance travel that I had taken from my country which is almost 8000 miles far from here. So I decided to calculate my carbon footprint in a two-week period in my home country before coming here. In the second assessment my footprint was calculated as 1.3 times larger than the average footprint for people in Iran.

My Carbon Footprint in a two-week period in the United States / Iran (Left side / Right side)

Although I think by increasing the time period to a year, the results would be less, the amount of carbon dioxide emitted from my normal activities in my life style is larger than the average. However, I think that my life style is normal and almost every individual around me has the same style and that’s the tragedy. Before this survey I thought that I might be normal but now I have to think about the correction of my style of living.

There are some practical ways that I can reduce my carbon footprint. First of all, I can reduce it by accommodating the use of residential energies in my home. It doesn’t mean that I have to decrease the use of energy. It would be just correcting the way of using the energy resources. The second way is to use public transportation instead of driving my own car which can be easily done. It needs just a little thinking about the terrible effect that I am going to put on the environment in my lifetime. After these, I can try to change my food preferences, garment preferences and many other aspects of my life style. Also Recycling plays an important role in this promotion.

           In a Nutshell, individuals must take the correction of their life styles into consideration immediately. To make a conclusion, I should mention the Matthew R. Simmons’s speech in the "Limits to Growth" article which is “It is time for the world to re-read Limits to Growth! The message of 1972 is far more real and relevant in 2004 and we wasted a valuable 30 years of action plans by misreading the message of the first book."