There is no Getting Around the Smart Home
Wired or Wireless Technology: Which is Better for aConnected Home?
By Julia Winkler (B.Eng.), Prof. Dr. Michael Kroedel, Marketa Sidlikova (M.Sc. in Finance)
Smart Home is “in”. Networking your own four walls is becoming easier and more userfriendly than ever with the increasing number of corresponding end devices andprofessional system solutions. The hardware alone however does not make a homeintelligent. It depends on the type of networking: wired or wireless. A new study by theTechnical University of Applied Sciences Rosenheim compares the common smart homestandards KNX and EnOcean in different living scenarios.
We spend around 90 percent of our life in buildings, a good part of it in our own four walls.
Regardless of whether in an apartment or in your own villa: Smart Homes increase thecomfort and safety of their residents. They ensure more efficient use of energy, save costs
and are therefore an absolute “must” when it comes to climate efficiency. So it's no wonderthat the trend towards intelligent homes is continuing, as a look at the smart home market
shows. According to Statista, penetration of smart home products will increase from 41,6%
to 85,7% in 2025. This corresponds to an annual sales growth of 11.8 percent.
What is a Smart Home?
Smart Home means professional building automation for your home. Technical devices ofvarious types are connected in a network, they interact and can be controlled from theoutside. For this purpose, the information from the network is communicated by means of acentral control unit. Alternative terms are smart living, connected home, home automation
or eHome. Automation solutions especially for seniors are also referred to as modern
ambient assisted living (AAL).
How Does a Smart Home Work?
A professional smart home is an intelligent system that networks individual products(sensors and actuators). This forms the technical basis for automated control and flexible
operating options for building technology in various areas. In addition to lighting, shadingand heating / air conditioning / ventilation, the most important are security, entertainment
electronics and information technology / telecommunications. Sometimes charging stations
for electric cars are also integrated into the smart home system. Individual intelligent
products such as voice assistants or smart meters, on the other hand, do not yet make ansmart home.
Spoiled for Choice: Wired or Wireless?
Digital networking is a prerequisite for the smart home. It is this that enables the smoothcommunication of the individual components in apartments or residential buildings.

This can be done in two completely different ways, with or without wireless technology. In
addition to proprietary solutions from individual manufacturers, there are also open
standards for both variants. KNX (wired) and EnOcean (wireless) are each representative intheir segment.
KNX (Konnex) is a widely used wired bus system for building automation. As a further
development of the EIB (European Installation Bus), KNX is an open, manufacturerindependent standard that is supported by a large number of manufacturers. As astandardized standard, KNX leaves a lot of scope for design and is considered to beparticularly secure.
EnOcean was defined in March 2012 by the International Electrotechnical Commission (IEC)
as a global wireless standard (ISO / IEC 14543-3-10) for decentralized building automation.
In the meantime, more than a million buildings have such radio networks. The EnOcean
ecosystem of self-powered wireless sensor solutions currently consists of 5,000 productvariants based on 1,500 basic products. The products can be combined with one anotherusing standardized interoperable sensor profiles.
Wired or Wireless: Who is Ahead in the Smart Home?
The study by Julia Winkler and Prof. Dr. Michael Krödel compares smart homes of different
sizes based on KNX or EnOcean technology in two equipment variants with regard to costs,
sustainability and health and well-being. In both cases, a conventional building withoutintelligent networking serves as a guide.
In detail it concerns:• A one-room studio apartment (450 sq. ft.) with a total of 33 or 42 products (basic or fullequipment)• A two-bedroom apartment (900 sq. ft.) and a total of 70 or 89 products• A single-family house (2300 sq. ft.) and a total of 162 or 186 products
The equipment in conventional buildings is based on the international standard DIN 18015RAL-RG678 for the installation of electrical systems in residential buildings (three-star
comfort equipment). The differentiation of the smart home variants is based on internal
university research results. The basic equipment includes typical entry-level functions for
comfort, safety and energy saving. In addition to the basics, the full equipment includes
additional functions such as brightness and presence detectors, central switch for heating
control, as well as weather stations and the complete security package.
The cost calculation for the individual equipment options is based on the calculation aid forelectrical and information technology trades (KFE, as of 2020) as well as the current
publically available product catalogues from representative providers such as Hager (forKNX) and Eltako (for EnOcean).
Invest in Smart Living
A comparison of the conventional “dumb” installation with the smart equipment reveals anunsurprising picture: Smart costs initially more. According to the study, the surcharge forelectrical installation is between 64% in a one-room studio apartment with basic equipment
based on EnOcean and 385% in a fully equipped two-bedroom apartment based on KNX.

GRAPHICS

Caption: Example of full equipment in various home types. The wired smart home requires
30% more total initial investment than the wireless solution.

Caption: Example of basic equipment in a one-room apartment: The smart versions are
initially more expensive than the conventional equipment. The wired smart home requires
the highest total initial investment.

The smart additional functions make living space initially more expensive. In the medium
and long term, however, the investment is well worthwhile. Because immaterially, a higher
quality of living has an impact on comfort and safety from day one. And in concrete terms,
up to 10 percent of heating energy costs can be saved through intelligent heating. A
significant potential when you consider that heating accounts for around 60 percent of theenergy consumption of private households and is mostly heated continuously, especially inwinter.
Wired or Wireless Technology in the Smart Home?
When comparing the smart home variants "wired" (KNX) or "wireless" (EnOcean), wireless is
significantly lower in terms of costs. With comparable functionality, the difference is 20 to30 percent. This applies to all buildings and equipment variants. This is due to the higher
expense of cabling and the cost of the wired devices and their installation.
Switches and sensors based on EnOcean do not need cables. They can be simply attached
and implemented as required - a big plus in terms of flexibility, for example whenretrofitting or converting. The use of fewer cables also saves PVC - according to the study,
up to 8.5 kg per smart home - and improves the overall environmental balance of theconstruction project.
What about Electro Smog in Wireless Smart Homes?
The radiation exposure is 700 times lower than that of WLAN or Bluetooth connections and1.6 million times lower than conventional smartphones. The so-called SAR value is decisive
for this. SAR stands for Specific Absorption Rate and indicates the maximum amount oftransmission power the human body can absorb.
Conclusion
The intelligently networked home initially costs more. But these investments are well
worthwhile in terms of the intangible gain in comfort and safety as well as lower energy
costs. The installation costs of the wireless smart home are up to one third less than thewired version. Wireless also scores in terms of flexibility and environmental protection.

Sources:https://www.buildinggreen.com/blog/we-spend-90-our-time-indoors-says-who
https://ec.europa.eu/commission/presscorner/detail/en/IP_03_1278
https://de.statista.com/outlook/dmo/smart-home/deutschland
https://www.statista.com/outlook/dmo/smart-home/united-kingdom
Winkler, J. (2021). Comparison – Building Automation: With and Without Wireless
Technology. Study performed as part of Bachelor Thesis by Julia Winkler at the Technical
University of Applied Sciences Rosenheim. English translation and adaption by Marketa
Sidlikova.
https://www.enocean-alliance.org/wp-content/uploads/2021/07/Comparison-BuildingAutomation-with-without-wireless-KNX-vs-EnOcean.pdf