• Index of this issue

No. 55, March 2006 Special topic: Features in the library building/facilitiy

INTRODUCTION

Opened in July 2005, the new National Library of Singapore is an innovative library designed for the tropics and is fast becoming an icon in Singapore and the region.

The library is a "green" (environmentally-responsive) tropical building that employs a holistic design approach to reduce the impact of the use of energy on the natural environment. This is achieved through several bioclimatic design techniques - passive low-energy systems, passive lighting concepts, climate-response building orientation and built form configuration, effective façade systems and bioclimatic use of landscaping – all of which help make the building remarkably energy-efficient.

In fact, the library building won an award for its "green" features – the Green Mark Platinum Award by the Building and Construction Authority in Singapore – even before it was opened to the public.

BUILDING FACILITIES

At approximately 58,000 square metres, the new National Library at Victoria Street spans 16-storeys and is more than five times larger than the old National Library at Stamford Road. The building consists of two main blocks connected by covered walkways. This two-block approach was adopted to address the issue of having a quieter space for the library and a busier area to facilitate the vertical movement of people attending programmes and activities through the building.

The first and larger block houses the Lee Kong Chian Reference Library (Levels 7-13) while the second block caters to the public for activity-based programmes and commercial spaces. The Central Lending Library in Basement 1, the car parks in Basements 2 and 3, the Drama Centre from Levels 3-6 and the National Library Board headquarters on Level 14 span across both blocks. The new National Library melds lifestyle and interactive elements together to create a holistic approach to learning. Beyond the library premises where the collections are housed are various conducive and dynamic spaces for experiential learning and interaction:

• The Plaza – an open area on the ground level with a café, staged area for performances and an internal street connecting North Bridge Road and Victoria Street. This area, which is accessible to the public 24 hours a day, has become a popular meeting point and a hive of activity for the community.
• Gardens – relaxing garden environments on Basement 1, Levels 5 and 10 for library-goers to escape from the hustle and bustle of the city.
• The Pod – a rooftop enclosed space for library programmes and corporate functions.

Generous pockets of spaces have been set aside for programmes and exhibitions, catering for both wet and dry weather occasions. In addition, the National Library building also houses a performing arts venue – the 615-seat Drama Centre, which spans four floors.

GREEN FEATURES

Architecturally, the Library has a number of prominent active and passive design features such as:

• A naturally ventilated public plaza on Level 1, ie the Plaza.
• Fully double glazed façade with low (heat) emissivity glass.
• Daylight sensors at the perimeter of the library areas that allow the lights to dim or switch off depending on the amount of natural light entering the building.
• Fixed sunshades that ensure direct sunlight does not enter the building during most of the day, thereby reducing the cooling load on the air conditioning systems.
• Automatic Blinds installed along the Victoria Street façade that are automatically activated in the evenings when the sun is low and fixed shades are ineffective.
• Rain Sensor installed as part of the automatic irrigation system, saving on both water and power consumption.
• Motion Detectors in staff toilets that switch on and off automatically when occupied.
• Integrated Lighting Control System that allows strategic programming of the internal and external lights. This helps to control the building's energy consumption. In addition, localized intelligent switches for the office floor provides after hours lighting only when required at the occupied areas.
• The Carbon Monoxide (CO) Monitoring system in the car park is programmed to operate during the morning and evening peak hours through the Building Management System. During these times, the CO sensors activate the fans when levels exceed 15 ppm.
• The building is equipped with an integrated Building Management System (BMS), which monitors and controls the mechanical and electrical (M&E) equipment, optimising the operation of the systems.
• The Variable Air Volume (VAV) terminal units of the Air-Conditioning and Mechanical Ventilation (ACMV) System means that the air volume supplied to each space is optimised to maintain the specified temperature in the building. Carbon Dioxide sensors also ensure that the percentage of fresh air is maintained in all areas.
• High efficiency chillers of 0.61 kw/RT are configured with larger non-essential centrifugal chillers and smaller essential screw chillers. The latter also functions as the night load chiller as well as a swing chiller in the day. This configuration ensures that the chiller plant is always running at its optimum levels.

Variable speed drives (VSDs) have been employed on the air handling units (AHUs) and pumps. VSDs allow the building loads to be accurately matched and ensure the systems consume less energy during part load conditions.  

Due to the tropical climate and the hygroscopic nature of the books in the library, the internal environment needs to be continuously controlled.  To save on energy, a night setback strategy is employed. This strategy results in a higher temperature in the building outside of operating hours. This helps to reduce the energy consumption of the chiller plant during this period.  Also, by employing such a strategy, less energy is needed to bring the building to the optimum temperature during the occupied periods.

An energy analysis study was conducted to establish the most efficient method of operating the escalators in the building. Based on this study the escalators have been installed with sensors, which detect pressure and operates only when someone uses them.