Active systems refer to the electrical and mechanical systems, such as the HVAC (heating, ventilation and air conditioning) systems and lighting systems.
The energy efficient active systems in ZCB result in a 25% of energy saving compared to a similar building of the current standard design.
High-volume-low-speed fans can generate high volume of air flow at a low speed. The noise associated with the movement of the fan blades is low.
These huge ceiling fans move large volumes of air effectively by using their patented blade design, which enhances evaporation for comfort. The fan can effectively reduce the necessary duration of air conditioning.
High Temperature Cooling System
A high temperature cooling system does not need to overcool the air to achieve the comfort humidity level, thus saving energy for air conditioning. This is mainly achieved through a separate cooling and humidity removal system.
The high-temperature cooling system in the ZCB is comprised of chilled beams, underfloor displacement cooling and desiccant dehumidification.
A chilled beam is a type of air conditioning system designed to cool buildings. Pipes of water are passed through a "beam" (a heat exchanger) suspended a short distance from the ceiling of a room. As the beam chills the air around it, the air becomes denser and falls to the floor. It is replaced by warmer air moving up from below, causing a constant flow of air movement and cooling the room.
Underfloor displacement cooling is an air distribution strategy for providing ventilation and space conditioning in buildings. The systems use the underfloor plenum beneath a raised floor to provide conditioned air through floor diffusers directly to the occupied zone.
A desiccant dehumidifier uses chemicals to remove moisture from the air. The Desiccant dehumidifier works by passing high relative humidity air over a desiccant such as a silica gel that attracts moisture. Then a low relative humidity air stream is run back over the desiccant to remove the water molecules from the desiccant.
In conventional systems, cooling and dehumidification are done at the same time. At the ZCB, desiccant dehumidification is a separate process, improving efficiency compared to the combined cooling and dehumidification system.
The cool and dry air is supplied from the floor up – it gathers heat from the occupants and begins to rise. A vertical flow is generated near each occupant, creating a healthier environment as germs are less likely to spread, and stale air is exhausted near the ceiling.
Intelligent Lighting Management
Intelligent lighting management refers to the automatic control of the lighting based on occupancy, individual needs and natural lighting level.
The ZCB is divided into zones according to their natural lighting potential and use. In each zone, the lighting levels and the occupancy are monitored by sensors and the lighting is adjusted accordingly.
The active skylight is a roof window frame set with inclined shading fins.
The skylights can be shaded if necessary to optimize daylighting and solar control. The shading fins are controlled by computer software and sensors by adjusting their shading angles to cut out direct sunlight at different angles as the sun passes over the building. They diffuse daylight into the interior as needed, greatly reducing the heat gain from direct sunlight.
Task-lighting gives high levels of illumination in an energy efficient and controllable way. Using the warm white-coloured LEDs with high luminous efficacy, it puts light where it is needed, reducing the energy use of ambient lighting.
A regenerative lift is a lift equipped with a regenerative converter to provide a feedback path for energy generated arising from the braking mode of the motor. Power is also regenerated when the lift is in up-operation with no / little load or down-operation with full / heavy load. The amount of regenerative power depends on loading condition, travelling distance, starting frequency, and efficiency of the lift system.
Bio-diesel Tri-generation System
A tri-generation system is a system that combines cooling, heating and power generation. The Biofuel Tri-generation in the ZCB uses biofuel made from waste cooking oil.
The waste heat from the electricity generation is harvested for cooling and dehumidification, leading to a high utilisation rate of 75% for the fuel source, as compared to 40% in a conventional power plant.
Adsorption chillers are a heat-operated refrigeration unit. It is driven by hot water rather than from large amounts of electricity like conventional air conditioners. Hot water used comes from recovered heat of the Biofuel Tri-generation System.