It’s been quite some time hearing new Green Buildings around with new green technologies and impressive numbers and statistics reflecting on how low the carbon footprint of the new construction will be. But certainly, there’s a need a focus towards the existing buildings too, accounting for the larger amount of carbon footprint for many inefficient appliances such as chillers and lighting equipment. Simple retrofits and advice on routine green practices by the office staffs can show you how quick a payback period can be done.
So What’s the hype in Singapore?
In Singapore, the Inter-Ministerial Committee on Sustainable Development IMCSD has set a target to achieve 80% Green Mark Certification for all buildings by the year 2030, in which includes existing commercial buildings particularly. And this has a lot of aspects to deal with, and you have new solutions to overcome budget constraints such as ECPS Energy Savings Performance Contract. (View NEA’s Mr. Tan Kok Kwong’s Presentation HERE) But along the sides of regulations of policies for such initiative, there should be a physical model for people to look at what they are talking about. This brings to the idea of Zero Energy Building, located within BCA Building Construction Authority campus in Singapore, being the first zero energy building retrofitted from an existing building.
THE ESSENTIAL OF “TESTBED”
It’s part of the overall BCA campus. Converted from a three-storey former workshop, the building houses offices, classrooms, and a resource center. The ZEB aims to serve as a test bed for integration of Green Building Technologies into existing buildings and to be a hub for practitioners and students in the study of energy efficiency and green buildings. Such examples are extremely critical for people to experience themselves while being in it, related examples are Sime Darby’s very own IDEA HOUSE that has a very good documentation on the good practices from the design phase towards post commissioning period, and also Panasonic’s Econation Center that displays on how it’s the latest technology can integrate into a retrofitted home to be more energy-efficient. All these ‘test beds’ or examples are to prove that it’s not hard to go after green buildings and to beat all the skeptics on payback period in investing Renewable Energy and Energy Efficient items.
AWARDS ON THE RECORD– ZEB has grabbed various accolades for its innovative approach, including BCA Green Mark Platinum 2009, BCI Green Design Award 2010, IES Prestigious Engineering Achievement Award 2010, 2011 ASEAN Energy Awards, Minister for National Development’s R&D Award 2011. The challenging part of this retrofitting is that the unfavorable orientation of the building itself, having its main facades to be facing east and west.
This visit was made recently, November of 2012, almost after 3 years since it’s official opening 26/10/2009. Like any Green Building, the aim is not only focusing on cutting down the carbon footprint of the building but improving working environment by ensuring good internal air quality. Generally, there are 3 highlight zones, The Visitor Centre at the Ground Floor, the Office level, and the Solar Energy Panorama. Each of this area tested different approach of innovation according to the activity purpose and location within the building. I shall try my best to describe the highlights here, with the availability of the photos I have.
1. Shading Devices- The basic fundamental of any green building is to have low overall thermal transfer value, in which shading device plays a crucial role at the first step to preventing any unnecessary heat gain. In ZEB, it seems that the study is done extensively on various options to design a sun shading device that is not only effectively prevent heat gain but allowing the maximum amount of day light to be harvested.
2. Low-E Glazing – When it comes to glazing, there are a lot of aspects to look at rather than U-Value, U-Value is the thermal transfer rate, glazings are known to be prone to heat gain compared to wall surfaces. However, the important aspects are to choose one based on VLT Visible Light Transmission level which shows how much light is permissible and also SHGC Solar Heat Gain Coefficient. Double Glazing Unit is known to have a better LSG Light to Solar Gain ratio and performs well in preventing heat gain and yet allowing visible light without the harmful UV rays. ZEB is also a test bed for glazings when you have 4 different chambers with different glazings side to side to observe their performances.
3. Vegetation Skin – Well it is also part of the strategy to reduce heat gain of the wall, whether it could be done vertically or planted on roof top, the benefit of vegetation as building skin offers much more than reducing the overall EETV Envelope Thermal Transfer Value , but also emphasizing on the significance of ensuring our next generation survive from nature deficit order. The three kind of vegetation systems is also tested out in ZEB to study the effectiveness and efficiency over the time. You have Panel System, Cage System, or Mini Planter Box.
The office is truly a test bed itself to understand ergonomics better, one of the main challenges, when consultants try to create the best indoor environment quality for office space, is to understand the user’s occupancy pattern. The key to understanding is that there is never a system that can fulfill everyone’s satisfaction in terms of lighting and ventilation/temperature, so does ZEB do is to allow users to personalize their own space usage.
4. Day lighting Harvesting – The possibilities of harvesting natural lighting is studied extensively. Whether it is light shelves, or skylight, or Light Pipes or Light trough, these concepts are used in different spaces in trying to harvest every bit of possibilities of day lighting. The skylight opening at the top of the office space is adjustable via a butterfly pivot system located above the entrance, in which users can control the shading preference too to adjust the light level. . Light shelves are placed extensively to the office layout too. And Light trough are used to harvest direct sunlight instead of the only skylight to the groundfloor conference room
There are a lot of strategies to harvest daylight, however, a few things I have noticed of is that maintenance is crucial to clean the light shelf to maximize the efficiency, and there are concerns on aluminum reflectors can oxidize over a period of time. Another issue is that the light trough install here is only able to harvest sunlight half the day because it’s the only position at one side of the building.
5. Efficient Task Lighting – On top of daylighting, here we have task lighting to allow office occupants to personalize their space. Having a flexible , extendable, and efficient LED task lighting, this can satisfy user’s preference of brightness and convenience. The benefit of the combination of daylighting and task lighting is extensive, Read More HERE.
6. Photo Sensors – Sensors in this office measures the light intensity within the office space. When light levels are sufficiently provided for by natural light, the artificial light is switched off. There is a master switch to overwrite the sensor as well, in which rather than deciding to switch on or off the lights, you are directing if the lux sensor system should control the decision.
7. Displacement Cooling – Instead of the typical air conditioning coming down from air vents above. Cool air is supplied from the floor level at low velocity. This cool air mixes with the warm air in the space and rises towards the ceiling where it is extracted. this approach requires less energy than a conventional air-conditioning system.
8. Personalized Ventilation – To adjust to everyone’s satisfaction of air conditioning, just like the task lighting allowing occupants in their individual cubicle to adjust their brightness, there is also a personalized blast of fresh, cool air. This ventilation system delivers fresh air directly to each occupant through pipes attach to a desk, in which is also connected to the overall Air Conditioning system as illustrated above.
9. Sensors equipped Single Coil Twin Fan Ventilation System – One innovation highlights of ZEB is the function of single coil twin fan ventilation system. In which it separately cools the fresh air and recirculated air, resulting in efficient use of energy. The presence of occupants is detected by sensors and the cooling required is supplied accordingly.
10. Solar Systems– High-performance solar panels are installed to supply energy for the building. Bigger than an Olympic sized swimming pool when laid out side by side, these panels generate about 207,000kWh of electricity per year. This is enough to power 45 four-room HDB flats a year. There are three generations photovoltaic systems used to integrate into ZEB, whether it is monocrystalline silicon, polycrystalline silicon, amorphous silicon, copper indium selenide, the PV cells are not only integrated into the building but the car park shelter too.
As much as it is Zero Energy Building, in which we could see from the reading below that the cumulative energy production is more than the cumulative consumption, however, it does not mean that it could be independent of the energy grid. The harvesting of solar energy has a lot of aspects to look at, whether frequency is also crucial to study at as there are training seasons that will give lower harvesting too. Image is taken from BCA Website.
11. Solar Chimney – Specially developed for the tropical climate, solar chimneys are made of metal that absorbs solar radiation. Place on top of the roof or up high in a non-air conditioned room, they suck out warm air from the room. Through convection, cool air will then rush into the room. It works on Convection and Buoyancy, where vertical shafts are heated by sunlight to enhance the natural ventilation in a building.
12. Active Control and Management – Afterall, above all these features, the important brain of all is the Building Energy Management System. The ZEB has an advanced Building Management System to control, monitor, and manage all the equipment installed in the building. With close monitoring of usage and occupancy patterns, energy use can be optimized while maintaining comfort and functionality.It is essential to study on how a building performs across time and a continuity in calibrating the sensors after studying the various user preference and perhaps a change in activity or interior equipment in the building. The purpose of this system is more than monitoring but must be flexible to adapt and fix to changes as time goes.
THE ROAD AHEAD
The most important aspect of any green building is the continuity of effort after its completion, which lies on two main elements, occupants and also energy management system. It is essential to ensure occupants understand their building and their surrounding that relates to their work performance. It is once said that,
Stupid Technology, Smart People, Makes Smart Building ; while, Smart Technology, Stupid People, Makes Stupid Building.
Credits to BCA website for giving extensive information and some pictures via their web. Credits to IEN Consultants making this trip possible. Looking forward to the rise of Building Automation systems paving the path to smarter buildings with Energy management systems.
Or lazy to read all the details? well then just watch the video of ZEB 😉 OR ALSO, Feel Free to view more picture via FACEBOOK.