What is Building Automation System and What are its components?

What is a Building Automation System?

Building Management System (BMS) or Building Automation System (BAS) is a computer-based network system that monitors, regulates, and maintains building equipment and systems such as electrical lighting, HVAC, Access Control, Security Systems, and other related systems.

BAS is an example of a Distributed Control system (DCS) since it is an intelligent system that includes both hardware and software.

Building automation systems (BAS) is a group of tools used by building operations staff to give more effective and efficient control over all building systems.

Basic Components in Building Automation System

Building automation systems consist of 5 components. They are

  • Sensors
  • Controllers
  • Output Devices
  • Communication Protocol
  • Terminal interface

In this article, We are discussing how these components interact and communicate with each other.

1. Sensors

A sensor is a device, module, or machine that helps to keep track of environmental changes such as humidity, temperature, lighting levels, smoke in the rooms, and other parameters like people count. After gathering this information, sensors transmit them to other electronics, usually to controllers.

2. Controllers

The brain of the building automation system ((BAS) is the controller. They collect all of the data from the sensors and transmit commands to all connected systems, such as HVAC systems, lighting systems, and more, based on that data.

3. Output devices

When a command is sent out by the controller, the relays and actuators in the individual systems respond by following the new instructions, if necessary, or requirements.

4. Communication protocols

Each component of a building automation system is connected using a specific language. BACnet and Modus protocols help each component to transmit and receive data in order to alter settings and execute commands change parameters and run commands

5. Terminal interface

Building and facility operators can access the BAS using a user interface or terminal. This terminal assists users in understanding the information exchanged between each component and provides the ability to make manual adjustments.

The displays are visual with photo-realistic graphics.

Major types of Building Management systems

Major types of Building Management systems are listed below

  • Access control system
  • CCTV
  • HVAC
  • Lighting Control system

Access Control System

It is electronic safety equipment used to control access to a particular location. The term “access” can relate to both entering and using something. The term authorization refers to the ability to gain access to a resource.

Architecture of Access Control System

Components of an Access Control System

The kind and complexity of access control systems vary widely. However, the majority of card access control systems have fundamental components:

  • Access Cards
  • Card Readers
  • Access Control Keypads
  • Electric Lock Hardware
  • Access Control Field Panels
  • Access Control Server Computer

Access Cards

The access card is used to control the access or permission to premises or buildings which is secured by the access control system. Most of the access cards are small in size which helps us to carry in our wallet or purse just like any other debit/credit card. Each and every access card is encoded uniquely, so we can control the limitation individually.

Card Readers

A card reader is an electronic device used to read access cards of an individual and grants access to the user if the company permits. Card readers come in a variety of shapes and sizes, with some requiring card insertion others requiring swipes, and others requiring cards to pass in close proximity to the scanner.

The number of card readers depends upon the number of restricted doors. Card readers are normally positioned on or next to the door that they control.

Access Control Keypads

It is another type of entry restriction method which can be used along with access cards or instead of access cards. In this method, the user needs to enter the number on the numeric keypad of access control keypads instead of scanning or swiping an access card.

For additional security, we can add an access card along with the keypads. In this case, we need to enter the secret code after or before swiping the access card it depends on the program installed.

The numeric keys on the access control keypads are like touch-tone telephones.

Proper numeric code is required to gain access if we are using only access control pads.

Electric Lock Hardware

It is the equipment used to lock and unlock each and every door electrically if it’s controlled by the access control system.

This system is mainly designed to control the entrance of a building or a premise. The electric lock system won’t restrict the ability to exit the building freely.

Access Control Field Panels

The access control field panels are connected to equipment such as card readers, electric lock hardware, and other access control devices.

It is also called "Intelligent Controllers”.

The access control field panels are utilized at the building level to process access control activity. The number of access control field panels required in each building is determined by the number of controlled doors. Access control field panels are typically found in the phone, electrical, or communications closets.

Access Control Server Computer

The access control server computer serves as the system’s “brain.” The access control server computer serves as the access control system’s central database and file manager, as well as documenting system operations and information distribution to and from access control field panels

The large number access of cards can be controlled by a single access control server. Usually, we can make the normal computer an access card server computer by installing access control software.


CCTV is an abbreviation for closed-circuit television, which is also known as video surveillance. Video cameras are used in CCTV technology to transfer a signal from one location to another and display it on a restricted number of displays or on a computer screen.

CCTV surveillance is very common in many parts of the world for the surveillance. CCTV technology may be used in industrial plants to monitor several stages of a process from a central control station. CCTV systems can be set to run continuously or only when a specific event is being monitored. A more recent version of CCTV, which employs digital video recorders (DVRs), enables long-term recording with a variety of quality and performance options, as well as other capabilities (such as motion detection and email alerts).

Architecture of a CCTV System

Top 10 CCTV Manufacturers

  • Samsung
  • Hikvision
  • Honeywell
  • Sanyo
  • Sony
  • Bosch
  • Axis
  • Dahua
  • FLIR Systems
  • Avigilon


An HVAC is a system that stands for Heating, Ventilation, and Air Conditioning. It is equipment or technology, which helps to monitor and regulate the temperature of a commercial or residential property.

Examples of HVAC Systems are

  • Air conditioners
  • Heat pumps
  • Furnaces
  • Air handlers
  • Ductwork
  • Ventilation lines
  • Filters
  • Other air quality products

Function of HVAC

The main function of an HVAC system is to provide healthy and comfortable interior conditions for occupants.

How does HVAC work?

We know that the main function of an HVAC system is the movement of air. The HVAC system is a combination of AC and central heating systems. It has a single blower to circulate air in a residence via internal ducts, or a ductless system for multiple rooms or zones in the house.

Furnace and heat pump in the home’s air conditioner either capture or creates the heat, then moved by the blower and ductwork.

Selection of HVAC Equipment

Climate conditions in most parts of the country require the heating and cooling of outdoor air to ensure sufficient thermal comfort for building occupants, demanding the installation of HVAC systems. The equipment for heating, cooling, and ventilation a building is a complex design decision that must take into account a number of elements, including:

  • Heating and cooling needs
  • Energy efficiency
  • Humidity control
  • Outdoor air quantity and quality
  • Indoor air quality
  • Cost

Why HVAC System is needed?

The following are the reasons for the need for the HVAC system.

  • Improvement of air quality
  • Regulation of moisture
  • Maintaining constant temperature throughout the year
  • Conservation of energy

Top HVAC Manufacturers

Top HVAC manufacturers are

  • Daikin
  • Johnson Controls
  • LG Electronics
  • United Technologies
  • Electrolux
  • Mitsubishi
  • Samsung Electronics

Lighting Control System

A lighting control system is an intelligent network-based smart lighting device that can regulate the brightness, quality, and properties of light in a defined space with the help of various inputs and outputs relevant to lighting control. Lighting control systems can be used for both indoor and outdoor lighting. Lighting control systems ensure that the right amount of light is available at the right time and in the right place.

Types of Lighting Control System

The main types of lighting control systems available in the market are

  • Occupancy sensors
  • Dimmers
  • Integrated lighting controls

Occupancy sensors

Occupancy sensors can regulate lighting devices by sensing the presence of people in an area. We can program occupancy sensors to turn on the lights automatically when they detect motion and turn them off after a set length of time if the space is not occupied.

Occupancy detectors are also another name for occupancy sensors.


A dimmer sensor is used to control and change the light’s intensity according to user preferences. By using dimmer controls, users can lighten or darken the room easily. Furthermore, dimmers can be programmed to turn off the lights after a set amount of time. This not only saves energy but also extends the life of Led lamps.

Integrated lighting controls

Users can adjust the lighting scenarios in a specific space using integrated lighting controls. It also allows users to customize and configure a lighting scene based on their mood. Several LED lighting manufacturers provide IoT-enabled control solutions that enable customers to control lighting with mobile phones and other internet-enabled devices.

Benefits of Lighting Control System

  • Change room appearance
  • More energy efficiency
  • Alter room according to the atmosphere and mood of the end-user
  • Convenience and safety