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.