Building Automation is Key to Green Buildings

Building automation (BA) is defined internationally by ISO 16484 and in Germany nationally by VDI 3814 as the automated control, regulation, monitoring, optimization and operation of technical building equipment (TBE) – primarily including HVAC, lighting and shading.

A distinction must be made between building and home automation for residential buildings, commonly known as smart homes.

It's important to know that “smart building” is an undefined term that leaves room for interpretation. However, “smart building” presumably includes advanced building automation anyway. WAGO defines a “smart building” as a non-residential building operated sustainably and energy-efficiently over its entire lifecycle. With the functions of a system-wide building automation and control system and other services, a “smart building” supports the user and offers maximum comfort in optimum climate and lighting conditions.

With well-thought-out building automation, building technology processes can be designed automatically, intelligently and efficiently. Therefore, BA plays a key role in constructing sustainable non-residential buildings, such as office or administrative buildings, kindergartens or hospitals. BA also increases occupants' safety and comfort by relieving them of tasks such as switching the lights on and off or regulating the temperature.

A sophisticated room automation system ensures optimal room conditions and efficient energy use without any occupant effort. This requires leveraging synergies, e.g., between HVAC, lighting, and shading:

The ISO 52120 (previously known as EN 15232) lists potential savings depending on the automation class.

• Demand-driven shading
  For example, before cooling rooms in summer, closed shades prevent sunlight from heating the rooms. In winter, rooms can be warmed by opening the shades.

• Optimal and efficient use of space

• Optimum room temperature control

• Intelligent lighting control

• Presence-dependent air conditioning

An open system is characterized by the use of standardized communication technologies and support by many manufacturers. The components are thus interoperable, can be networked and can exchange information independently of the manufacturer. This simplifies using the synergistic effects of different systems.

In contrast, a proprietary system is manufacturer-specific. Generally, only devices from one manufacturer can communicate with each other. Therefore, communication between different proprietary systems requires significant technical and financial resources. In fact, using proprietary systems means that users largely depend on the manufacturer – especially when it comes to maintaining and expanding the system.

There are many different protocols or communication technologies that must exchange data in a BA system:

IP-based communication, which is characterized by flexibility, is increasingly gaining ground – e.g., via BACnet IP (BACnet SC), Modbus TCP and MQTT for cloud connections.

Additionally, protocols such as Modbus RTU, KNX TP1, DALI and SMI still exist; these are transmitted via twisted pair technologies. Use of these technologies is decreasing as IP communications increase. Nowadays, these technologies are used to build shorter and shorter routes, which are integrated into IP networks with suitable routers.

In addition, wireless technologies are becoming increasingly popular on the market. Especially for revitalizing existing buildings, wireless technologies offer the necessary flexibility. For example, EnOcean is an established wireless technology. Other technologies are also developing, such as LoRaWAN, Thread with KNX RF and Matter, as well as Zigbee, for which a final market impact can not yet be estimated.

Don't underestimate this: When it comes to communication within a BA system, it is vital to focus on IT security to protect the systems from unauthorized access.

BACnet stands as the data transmission protocol for “Building Automation and Control Networks” in building automation and is standardized with ISO 16484-5 worldwide. The BACnet protocol can be transmitted over various transmission media such as IP and two-wire networks. BACnet enables standardized data exchange for building automation and, thus, a cross-system integration of devices from different manufacturers and sectors into a uniform overall system. Extensions or changes in buildings can be implemented with BACnet regardless of manufacturer and across systems.

A data point in BA is an information unit that can be physical or virtual. Physical data points refer to directly connected or networked field devices in a system. Virtual data points (also called communicative or fictitious), on the other hand, are software-based or come from a transmission protocol. Data points are uniquely identified in a building automation system via a data point address or user address (asset identification key).