How to retrofit a buildings to smart home using KNX platform?

Introduction

Smart home environments enrich living experiences by offering an attractive blend of convenience and sustainability. The introduction of IoT, sensors, and Artificial Intelligence in modern building has transformed them into intelligent infrastructures with improved energy management capabilities, cost savings, safety measures, and accessibility features. Retrofitting existing structures for automation helps to optimize energy consumption, improve occupant comfort, reduce environmental footprint, and boost overall productivity. This article delves deep into the world of Smart homes and prospective developments in retrofitting automation within existing building using the KNX platform.

KNX Platform

KNX is a well-established open standard communication protocol for building automation in residential and commercial settings. It is a fusion of earlier protocols, such as the European Installation Bus (EIB), Batibus, and European Home Systems (EHS), to create a mature and reliable system. KNX is the world's only open home and building control standard and complies with EN 50090, EN 13321-1, and ISO/ IEC 14543 standards. KNX users can control various building functions through a single platform. Lighting, blinds, HVAC systems, security, audio/video, appliances, and energy management can be integrated for seamless operation. Such centralized control enhances convenience, efficiency, and improved energy utilization.

KNX offers flexibility in its implementation. Communication can be established through twisted-pair wiring, powerlines, radio frequency, or I.P. links. Using a standardized data model allows these interconnected devices to communicate and operate as a distributed application seamlessly. A notable KNX application is room automation, where a central hub controls lights and shades and coordinates with heating/cooling valves to maintain individual room comfort. This allows for intelligent adjustments, such as automatically shutting down the HVAC when a window is opened to prevent waste of energy. KNX extends its influence to energy management, where users can gain valuable insight into connection patterns by connecting the various energy meters and pinpointing areas for optimization. Submetering at the circuit level can be achieved with certain KNX products, providing an even more granular view of energy usage.

KNX integrates seamlessly with solar inverters, energy storage devices, and battery management systems (BMS), helping manufacturers create comprehensive solutions for renewable energy management within Smart homes.

The KNX market is enjoying considerable growth, driven by its versatility and focus on critical areas like control and connectivity, lighting, energy management, entertainment, smart appliances, and security. Statistics reveal that the global KNX product market size was valued at USD 6178 million in 2022. It is projected to touch an expected value of USD 19314.81 million by 2031, growing at a CAGR of 13.5% during the forecast period (2023–2031).

Figure 1: KNX energy management system

Implementing KNX solutions in building

With KNX, a wide range of devices can communicate with each other, even if they are from different manufacturers. It even allows them to be integrated with other automation systems. The KNX communication protocol supports wired and wireless communication with advanced features such as scene control, scheduling, and energy management. KNX devices can be programmed and configured using specialized software, allowing customized deployment of automation and control systems in lighting control, heating and HVAC network management, security system monitoring, and more.

Regarding Smart home solutions, both wired and wireless KNX automation systems can retrofit existing building. You must select the right Smart home automation solutions for your home. The primary decision lies in choosing whether to use a wired KNX infrastructure or a wireless one. When recommending a Smart home option for a newly built property, it is preferable to have a wired KNX system installed. Wires perform better than wireless signals and are highly reliable. Green KNX bus cables connect devices without direct connections to the switches in a wired solution. The core cabling infrastructure is improved by integrating appropriate actuators, sensors, and displays with the specific functionality of each switch or pushbutton defined during the parameterization stage. Once installation and parameterization are complete, these devices can seamlessly communicate. Retrofitting becomes expensive if the existing building needs cabling. It is recommended that during new construction or a comprehensive renovation, the bus cable be placed along with the conventional power lines to interconnect the various KNX-capable elements. If many empty pipes were laid during construction, a later retrofit with KNX cables can be easily implemented. In circumstances when the installation of new wires cannot be justified, there is a wireless alternative like KNX RF, which is often easier to implement. KNX-RF wireless connectivity offers a secure and stable communication network that can be easily integrated with various automation and control systems devices. KNX-RF operates in the sub-GHz, unlicensed, ISM band and employs frequency hopping spread spectrum (FHSS) and channel hopping to ensure coexistence with other wireless technologies sharing this often-crowded portion of the R.F. spectrum.

Figure 2: Wired and wireless KNX connectivity for smart building

KNX Wired solution from MEAN WELL

Figure 3: KNX wired solution for intelligent lighting control

In Figure 3, a wired KNX-based solution consists of sensors, KNX devices with LED drivers, and lamps. You can use this setup for Intelligent lighting control. The users can choose a KNX presence detector with a KNX actuator connected to a Constant Voltage (C.V.) LED driver to automatically control a Constant Voltage (C.V.) driven panel light. Similarly, to compose a dimming lighting system, they can select a KNX touch panel, matched with a KNX dimming actuator, and connect to a dimmable C.V. LED driver to dim and control a C.V. driven LED strip. The role of the KNX actuator is to convert the commands received from sensors, automatic control switches, or timers into actions and form the interface between the KNX system and the electrical devices typically implemented for lighting, blinds, and heating applications.

Here, KAA-4R4V from MEAN WELL is used to light switches and control LED drivers with a DC 0(1)-10V dimming function. It is a 4-channel device with an independent latching relay that can turn on or off and is suitable for all kinds of LED drivers. Based on the KNX architecture, this actuator can easily be programmed through the ETS system as needed during planning or use or manually through the physical buttons on the panel. The KAA-4R4V dimming actuator features an individual configuration with a green LED on each channel, indicating a clear switch status. Its compact design and 72mm width modular build make it ideal for placement within distribution boards on 35mm mounting rails in EIB/KNX applications.

Conclusion

KNX protocol has significantly shaped the home automation industry. Retrofitting existing building for automation is vital for achieving energy efficiency, sustainability, occupant comfort, and productivity. Farnell offers a variety of components like power supplies, actuators, and Transceivers based on KNX protocols for intelligent building applications.