Sustainable Building Designs and Smart Systems Brief Introduction & Illustration 27th Jan 2023

Net-zero Electricity Generation

Energy Saving and Green Buildings

Green Transport

Waste Reduction

Vision Net-zero Electricity Generation

To achieve Carbon Neutrality before 2050, the HKSAR Government has launched the “Hong Kong’s Climate Action Plan 2050”, setting out the

Energy Saving and Green Buildings

Green Transport and FOUR Major Decarbonization Strategies. Waste Reduction

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Energy Saving and Green Buildings

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Background In Hong Kong, buildings account for about 90% of total electricity consumption, and over 60% of our carbon emissions is attributable to generating electricity for our buildings. This supplement “Sustainable Building Designs and Smart Systems” aims to enrich audience with generic information about ordinary building designs and systems in Hong Kong, covering the FOUR Major Decarbonization Strategies.

The proposed designs and systems in this booklet can be adopted for NEW buildings and/or EXISTING buildings through retrofitting. Retrofitting

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Renewable Energy Photovoltaic (PV) System is composed of one or more solar panels combined with other electrical and mechanical hardware that use energy from the sun to generate electricity.

Solar Water Heating Systems harvest the heat in solar radiation to produce hot water. Domestic solar water heating system usually comprises of solar collectors and a water tank.

Building-integrated Photovoltaic (BIPV) is solar power generating product or system that is seamlessly integrated into the building envelope and part of building components such as façades, roofs or windows.

Bio-gas Heating/Electricity Generation System is to make use of anaerobic digestion of organic waste (e.g. food waste) to generate bio-gas for power.

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Daylight

Skylight

Permeable Design

Adequate natural light reduces the need for artificial light and can improve the performance, well-being, and mood of occupants. Good daylight designs can also connect interior spaces to nature, such as skylight, high window-to-wall ratio and high ceiling height.

Light Pipes are highly reflective tubes that capture light from domes on the roof. They help bring light to windowless areas inside the building.

Light Shelves are a passive architectural device used to reflect natural daylight into a building. 'Bouncing' sunlight off a horizontal surface distributes it more evenly and deeply within a space, whereas direct sunlight can cause glare near an opening, whilst leaving dark areas further in.

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Natural Ventilation Stack Effect or Chimney Effect is a phenomenon that occurs because of the natural heat transfer. The warm air has a lower density rather than the cold air and raises to the upper part of the building, chimney, towers, etc. stack ventilation can be an independent system in constructions or as a supporting ventilation system boosted by many different devices or ventilation strategies. Permeable Design

Stack Ventilation Design

Wind Catcher is a device that ventilates a building by the use of wind. A small tower on the roof contains an opening that faces the prevailing wind, which is at a cooler temperature than the interior of the building. Because the wind velocity at this opening is greater than it is at the lower windows of the building, air in the shaft of the tower is forced down the shaft to cool the building.

Airflow Driven by Window Locations

Wind Catcher 6

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Passive Cooling Green Wall/Roof can reduce the heat flux through a building envelope since the growing medium acts as an insulating layer, the plants shade the roof and are believed to provide transpiration cooling. The higher thermal mass of a green roof system also improves the thermal performance of the roof. It also mitigate the heat island effect.

External Shading Fins help maintain the indoor temperature by minimizing heat and direct sunlight penetrating into the main building. This saves energy by requiring less air conditioning to keep to the room temperature.

Insulated Glass Units – Double/Triple Glazing High Performance Glass wall system offers good thermal and optical performance to lower cooling load, reduces the reliance on artificial lighting and hence reduce energy consumption.

Tinted Glass

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Passive Cooling Chilled Beams deliver cooling to rooms primarily by using cool water in coils that exchange heat with room air, so reducing the air dry-bulb temperature. The principal advantage of using a chilled beam – as opposed to an ‘all air’ air system – is that moving heat around a building can be undertaken far more efficiently by pumping cool water in pipes than by moving the same amount of heat in ducted air. Chilled Ceilings differ from chilled beams in that they rely more on radiant as opposed to convective heating and cooling. A chilled ceiling is a metal sheet with water pipes running above it. The pipes heat or cool the metal panel, which then radiates that energy toward the building occupants. Since they rely on radiant properties, chilled ceilings must be aimed at a building occupant to be most effective.

Indirect Evaporative Cooling takes advantage of evaporative cooling effects, but cools without raising indoor air humidity. Usually, two airstreams are involved – the air supplied to the indoor spaces and a secondary stream that is exhausted outside. In operation, an indirect evaporative process cools air or water on one side of an impermeable heat-exchange surface such as a thin plastic plate or tube. The wet side cools the dry side without adding moisture (because there is no direct contact between the water and the airstream to be cooled).

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Passive Cooling A Double Skin Façade is a traditional façade that has a second cover on the outside that is normally made of glass. The two facades, often called “skins”, are separated by an empty space (air gap).

A Double Skin Façade can be either mechanically or naturally ventilated, depending on the type of ventilation system used in the air gap. These are known as active and passive (interactive) ventilated facades. Active systems have an outer skin of airtight insulation glass in front of the ventilated inter space. Air exchange is artificially induced and takes place inside the building via heat exchangers. In winter, this has the advantage that energy required for heating can be saved via heat recovery. Passive ventilated façades are the more common type in Europe, particularly on commercial buildings. Here, the air exchange takes place between the inter space and the environment. A natural convection is created via defined openings, which are normally located above and below the outer glass. Suspended glass walls in front of a conventional construction are also possible, as are punctuated facades, as well as box-type windows or compound windows.

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Displacement Ventilation System

Displacement Ventilation/Underfloor HVAC system is a room air distribution strategy where conditioned outdoor air is supplied at a low velocity from air supply diffusers located near floor level and extracted above the occupied zone, usually at ceiling height. High occupancy applications such as schools or offices can implement displacement ventilation to provide a superior indoor environment improving the air quality, reduce noise levels generated by air delivery systems and offer additional flexibility using air that is driven by the heat sources and not by the high velocity mixing of the space. This system can be beneficial to occupant health and performance. 10

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Active Building Systems – Cooling High Efficient Oil-free Centrifugal Chiller The non-contacting magnetic bearing technology has less lubrication loss and higher energy efficiency. Air bearing technology also has less friction loss and greater overall efficiency.

Chiller Plant Control Optimization System The manual control of chillers or fixed chiller sequencing systems often results in energy wastage. Unexpected breakdowns of chiller units can lead to costly and ad-hoc repair. After the installation of the chiller plant control system hardware that connects to the BMS, sensors and associated equipment in existing plant, its software will run a continuous performance feedback loop powered by sophisticated control algorithms. By collecting data from the plant equipment and subsequently comparing actual efficiency of each chiller unit against the benchmark, the system will be able to provide a complete, reliable and easy to access measurement of key components of the plant room. After running diagnostics of the plant’s operational efficiency, the system will make real time adjustments, which lead to immediate cost savings.

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Active Building Systems High-volume Low-speed Fan A high-volume low-speed (HVLS) fan is a type of mechanical fan greater than 2.1m in diameter. HVLS fans are generally ceiling fans although some are pole mounted. HVLS fans move slowly and distribute large amounts of air at low rotational speed– hence the name "high volume, low speed."

Smart Meter Smart meter is also known as advanced metering infrastructure (AMI) system. They can read and send meter readings automatically through wireless network. With the smart meter, users can join CLP’s Peak Demand Management to reduce their building energy usage during peak demand hours to earn rebates.

Lift Regenerative Power For conventional lifts, the power generated by the traction machine is dissipated as heat in the building. Whereas, lift with regenerative function obtains power from electrical supply network, when it travels downwards with heavy load or upwards with light load, the traction machine will be act as power generator and the lift is running at “regenerative mode”. Compared to conventional lifts, regenerative lifts are 20% to 30% more energy efficient.

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Smart Building Systems

A Building Management System (BMS) is a computer system installed in a building that will communicate with the building's equipment. Allowing its owner to monitor and control its installations, such as air conditioning, heating, ventilation, lighting, or energy supply systems (electricity, gas, solar panels, etc.)

Digital Twin is a digital representation of an intended or actual real-world physical product, system, or process (a physical twin) that serves as the effectively indistinguishable digital counterpart of it for practical purposes, such as simulation, integration, testing, monitoring, and maintenance. The application of virtual modeling in a software for facilities management – digital twin facility management software – adds an extra dimension to traditional 3D Building Information Modeling (BIM), with real-time data harvested from connected sensors and smart IoT devices. Digital twin modeling enhances traditional smart facility management software with highly accurate, as-is digital descriptions of every aspect of a built asset. They enable hyper-realistic simulations of dynamically changing facility conditions, showing differences between the original design and actual operations. Armed with comprehensive, real-time virtual facility models, planners, owners and contractors can identify current faults, anticipate risks and visualize future changes with unprecedented accuracy. 13

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Smart Building Systems Smart Space Utilization System can optimize space utilization, move towards agile working, and support the productivity needs of corporate workforce in today’s modern working environments. The analytics tools allow corporate to compare space allocations to measured workplace utilization for each operation unit with high-quality visualization tools, such as charts and heat-maps displaying areas of high and low utilization overlaid on a floor plan.

Smart Parking System uses touchless systems with automated license plate recognition technology, which allows a camera to read registered plate numbers. Users can also utilize a smartphone application to register their plate number to gain access. The system then calculates time spent in the parking area, and automatically charges the user. Such systems eliminate the use for any form of physical contact.

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Rainwater Harvesting System

Rainwater Harvesting System Paved roofs with pervious materials can support rainwater collection. Harvested rainwater can be treated by sand filtration and ultraviolet (UV) disinfection for irrigation, water cascade and other non-potable uses, reducing water consumption effectively. In addition, the pumping stations are installed with the following devices to enhance the effective use of water:

• • •

Rainfall sensors to suspend irrigation on rainy days; Water retention layer to enhance irrigation efficiency; and Water consumption monitoring system to improve water conservation.

Incorporating the concept of water resources management into rain garden landscaping design in which rainwater can be filtered by garden plants and soil to improve run-off quality and reduce discharge into underground channels. Rain gardens can also beautify the environment and provide 15 habitats to enhance biodiversity.

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Greywater Treatment System Greywater Treatment System Water collected from baths, showers, wash basins, kitchen sinks and laundry machines etc. is known as grey water. Grey water is easier to purify and reuse as compared to wastewater since it generally contains much less concentrations of pathogen. For this reason, it always recommended to keep grey water separate from wastewater for sanitation purposes. Elevated levels of organic substances, are found in grey water from household and building appliances. Ultrafiltration (or other filtration methods) is required to eliminate these contaminants prior to being discharged into a grey water treatment system. The treatment of greywater usually include: • • • •

Pre-filtration Sedimentation Flotation Post-filtration or UV disinfection

Along with harvested rainwater, the grey water can be treated and reused for non-potable purposes such as toilet flushing.

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Smart Irrigation Smart Irrigation contains weather sensors, soil sensors and various controllers. The sensor monitors the current weather conditions and the actual ground humidity, and the controller controls the water valve to open or close. Realize automatic irrigation. Scientific judgment on whether, when, and how much water is needed.

Soil Moisture Sensor

Leaf Wetness Sensor

Rain and Snow Sensor

The smart irrigation system integrates technologies such as the Internet of Things, mobile Internet, LORA, and remote sensing monitoring. Remotely control valve switches wirelessly. Provide plants with the right amount of water according to soil type and weather conditions to save irrigation water. The smart irrigation system mainly includes various technologies such as sensor technology, automatic control technology and computer technology. Combined with garden irrigation methods such as sprinkler irrigation and drip irrigation. 17

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High Water-efficient Fixtures

Flow Restrictor

Dual Flush Toilet

Motion Activated Faucet

WELS Label showing the level of water consumption and water efficiency of the plumbing fixtures and water-consuming devices helps consumers to make choices of purchase. The Water Supplies Department (WSD) has launched the voluntary WELS since 2009 and implemented it in phases for six types of plumbing fixtures and water-consuming devices, viz. showers for bathing, water taps, washing machines, urinal equipment, flow controllers and water closets. It is recommended to adopt high water-efficient fixtures with WELS labels.

Water Efficiency Labelling Scheme (WELS) Label

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Indoor Environmental Quality and Filters High Efficiency Particulate Air (HEPA) filters can theoretically remove at least 99.97% of dust, pollen, mold, bacteria, and any airborne particles with a size of 0.3 microns (µm). Minimum Efficiency Reporting Values, or MERVs, report a filter's ability to capture larger particles between 0.3 and 10 microns (µm).

UV Air Purifier works from inside the heating, ventilation and air conditioning (HVAC) system, and utilizes ultraviolet light to disinfect air as it flows through the ductwork.

Indoor Air Quality Sensors and Real-time Display

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Green Transport

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Electric Vehicles

Medium Speed EV chargers The major benefit of electric vehicles are using electric motors to drive and involve no combustion of fuel. Therefore, electric vehicles are quite quiet and zero emission in operation. It helps to improve road side air quality. According to the Environmental Protection Department’s guideline, the power output of EV charger should be not less than 7kW. 20

Waste Reduction

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Materials, Waste Reduction and Management CIC certified green materials/products are assessed and certified by the CIC regarding their impacts on the environment throughout the different stages of the life cycle of buildings. Low VOC refers to volatile organic compounds that are not harmful to the environment and humans. It mostly refers to paints and other products that have a very low or zero VOC, e.g. sealants, adhesives and cleaners. Antimicrobial paint additives have the ability to resist unsightly mould and mildew growth, which prolong the shelf-life of paint products

FSC certification enables users to choose wood, paper and other forest products made with materials from wellmanaged forests which are managed in a sustainable way so there will still be plenty of them left for future generations of people and wildlife. Rapidly renewable materials are materials that are able to regenerate themselves in 10 years or less, such as bamboo. They include bio-based products made from plants harvested on a 10-year (or shorter) cycle.

Modular Integrated Construction (MiC) refers to a construction whereby free-standing integrated modules (completed with finishes, fixtures and fittings) are manufactured in a prefabrication factory and then transported to site for installation in a building.

Reverse Vending Machine (RVM) is an automatic device that allows users to feed in used beverage containers (e.g. plastic beverage containers) for instant rebate. 21