BAS - Building Automation Systems
The Building Automation System is an intelligent network to control and manage building operation including all building mechanics and electronics infrastructure, building air quality and temperature, lightings, occupancy, monitor infrastructure performance and physical security (CCTV) inside and outside buildings and IT network. BAS also includes people management and work orders addressed to building engineering and maintenance and operation costs. Building with an intelligent system is called a Smart Building.
What does the BAS system do?
Building automation control mechanical, electrical, and plumbing (MEP) systems - the heating, ventilation, and HVAC system elements such as chillers, boilers, air handling units (AHUs), roof-top units (RTUs), fan coil units (FCU), heat pump units (HPU), variable air volume boxes (VAVs), lighting.
Other systems that are often controlled and are under a complete automation system include: power monitoring, security, close circuit monitoring system (CCTV), ID cards and keypad access, fire alarm system, elevators and escalators, plumbing system, and water usage.
BEMS - Building Energy Management Systems integrates four systems:: Building Automation System (BAS), Telecommunications System (TS), Office Automation System (OAS), Computer Aided Facility Management System (CAFMS).
In the early 1980s, BEMS consisted of a simple workstation storing data related to buildings management. Today’s large BEMS has a central station and a number of outstations that collect signals from sensors monitoring building , operates actuators, controls air quality and a temperature in a building. All of these information is securely stored in a database to use in control and operation of a building infrastructure. All parts of the BAS system communicate with each other through a Local Area Network (LAN) network. The main segments of the BAS systems are energy management systems, lighting control systems, and fire detection and suppression systems.
Building placement: A buildings location and surroundings play a key role in regulating its temperature and lighting. Trees, landscaping, and hills can provide shade and block wind, for example. In cooler climates, designing buildings with an east-west orientation to increase the number of south-facing windows minimizes energy use, by maximizing passive solar heating.
Building shell: Tight building design, including energy-efficient windows, well sealed doors, and additional insulation of walls, basement slabs, and foundations can reduce heat loss by 25 to 50 percent. Highly insulated buildings may require ventilation, and heat recovery ventilators can provide airflow with minimal energy use.
Cool roofs: Dark roofs become up to 70°F hotter than the most reflective white surfaces, and they transmit some of this additional heat inside the building. Studies by the US EPA in Sacramento, CA and by the Florida Solar Energy Center in Florida found that lightly colored roofs use 40 percent less energy for cooling than buildings with darker roofs. White roof systems save more energy in sunnier climates, and a study by the Lawrence Berkeley National Laboratory found cool roof systems have net energy savings in colder climates as far north as Chicago, Illinois.
Heating and cooling: Advanced heating and cooling systems can reduce energy consumption and improve the comfort of the buildings inhabitants. For example, programmable thermostats automatically raise or lower temperatures at night or during the day when no one is present. Zone heating and cooling systems allow the temperature of specific rooms or different floors to be controlled independently. Air-source and geothermal heat pumps can provide both heating and cooling efficiently. Evaporative cooling in dry areas and desiccant cooling in more humid areas are also generally more efficient than conventional cooling systems. Integrated space and water heating systems are often energy efficient in larger buildings
Lightings: Several methods reduce the need for artificial lighting: proper placement of windows and skylights and use of architectural features that reflect light into a building, such as light shelves. When lighting is required, compact fluorescent light bulbs use two-thirds less energy and last 6 to 10 times longer than incandescent light bulbs. While early fluorescent lights produced stark white light, newer florescent lights produce more natural light, and they are cost effective, despite their higher initial cost. Task lighting, lighting sensors and dimmers also reduce the power needed for lighting. Increased use of natural and task lighting have been shown to increase productivity in schools and offices.
Home and office appliances: The energy-efficient appliances, including refrigerators, freezers, ovens, stoves, dishwashers, and clothes washers and dryers with its Energy Star label use significantly less energy than older appliances. For example, current Energy Star qualified refrigerators, use 40 percent less energy than conventional models did in 2001. Modern power management systems also reduce energy usage by idle appliances by turning them off or putting them into a low-energy mode after a certain time.
Energy Management Systems for Buildings
Energy Consumption by U.S. Buildings
Source: ENVIRONMENTAL AND ENERGY STUDY INSTITUTE, Energy Efficiency Fact Sheet, Release: May 2006
Source: Andy Jefferson “Home Sealing Improving Energy Cost”, EPA T0958_DIY_Guide 2006new.indd
Key Features for a Energy Efficient Building
The United States produces 25% of global greenhouse gas emissions, the buildings are responsible for 48% of the U. S. greenhouse gas emissions. The majority of these emissions come from burning fossil fuels where 40% of non-industrial waste is produced by buildings (136 million tons annually). Buildings are responsible for 31% of the Mercury (Hg) in municipal solid waste. 40% of total annual U.S. energy consumption is by the buildings, the transportation sector consumes 28%; industry consumes 32%. Over $80 billion dollars are spent every year on electricity and natural gas in buildings. Of all the U. S. resources buildings use about 70% of electricity, 12% of potable water, 30% of raw materials, 8% of petroleum, 53% of natural gas. Only for buildings lightings nearly a quarter of a total energy is used. The life cycle of a typical non-residential facility is over 75 years, public schools have a life span about 60 years. With rapid increase of energy cost in a short time spending for energy can easily surpass the initial cost of the building.
(Sources: U.S. EPA, http://www.epa.gov/epaoswer/hazwaste/sqg/c&d-rpt.pdf ; http://www.p2pays.org/ref/03/02026.pdf )