Simon Johnson of Theben answers some common queries regarding the KNX “open protocol” building control system.
Q. Isn’t this type of solution only for Premiership footballers?
There is a misconception that KNX is only for the super-rich, living in 10 bedroomed homes with mind-blowingly expensive touch panels in every room. It’s time to dispel that myth.
With over 400 manufacturers of KNX enabled devices and a growing number of KNX wholesalers, the product range, accessibility and pricing is on par with many proprietary smart home systems.
Q. It looks like a complicated system to wire?
From an installer’s point of the view the first fix cabling is simple. In the majority of cases it’s quicker to install than a traditional 230V wiring system and, with point-to-point wiring, final testing is easy. The green 4 x 0.8mm bus cable runs to every KNX device in the building: actuators, switches, room controllers, push buttons, PIRs, multi-function displays and room thermostats.
You can daisy chain, star or spur up to 64 devices on one bus cable alone, easily enough for a standard four bedroomed home. The bus cable is screened, twisted and mains-insulated so you can even run it alongside the mains cabling with no extra containment, no extra holes in the joists and no separate clipping runs.
Imagine a scenario of a kitchen-living-dining area with three entry doors, up to 10 lighting circuits (all of which are LED), with switching and dimming. The client would like each circuit to be three-way controlled or, even worse, they can’t make up their mind which switch will turn on which lighting circuit. It’s a situation we’ve all been in!
That would require some serious cable runs and modular switch plates and cabling connections, but with KNX it would be one single green cable daisy chained to each switch and taken back to the distribution board.
Q. Do I need an IT degree to program KNX?
You need a laptop, a version of the ETS software, a USB interface and some training. It’s like anything new, at first it seems odd to be programming the switching and dimming of light fittings with a laptop, but it soon becomes second nature and the flexibility it gives you and your clients is worth the investment. As qualified electricians we work with calculations, specifications and technical drawings every day – it’s no more difficult than learning the BS7671 wiring regulations.
There are now a number of KNX training centres across the UK and the KNX Organisation in Brussels also offers an online training course. Most training providers offer KNX introduction courses, partner courses and FREE manufacturer specific training days.
Q. Is the software expensive?
Good software isn’t free, take a look at any professional software package. The KNX Organisation offers three different versions of the latest ETS5 software to suit the size of projects you’re most likely to be involved in:
Demo – this version is FREE and will allow you to use up to five KNX devices, possibly enough for an open plan kitchen-living-dining extension or conversion.
Lite – allows up to 20 devices to be programmed.
Professional – is totally open with no restrictions on the number of devices in your project.
Q. Could I not get the same functionality from an app-based smart home device?
A mobile app doesn’t make a building an intelligent building; an RF switch doesn’t make a home a smart home.
KNX offers a robust wired backbone that can be added to, amended and updated as your client or your client’s buildings needs change. KNX isn’t restricted or compromised by your Wi-Fi router or the foil-backed insulation in your roof and it is backed up by a vast number of multi-national manufacturers, all spending millions on R&D.
Q. What types of projects and properties can KNX work for?
KNX is infinitely scalable – from six lighting circuits in a kitchen extension to the BBC Media City in Manchester or Terminal T5 at Heathrow. Whatever the requirement, KNX can accommodate.
Q. Will it integrate with DALI or BACnet or a traditional BMS system?
An enormous range of gateways are available to interface just about any building system with KNX. But why not fully implement your BMS with KNX and benefit from a worldwide standard fieldbus with thousands of KNX compliant devices and peripherals available from over 400 manufacturers and a wide range of logic controllers supporting a vast library of building control functions?
Q. Why KNX? What’s in it for me?
1. We need to start building more intelligent buildings; ultimately legislation, energy costs and CO2 emission reductions will start to drive this. Being involved in KNX will allow you to offer the solution that will control every system in your client’s home or office intelligently and energy efficiently.
2. The increase of IoT devices is promoting smart homes, but many of these devices are plug-and-play that the homeowner can install them themselves. As an electrician you need to be a step ahead of the game by offering a specialist smart building solution.
3. Ultimately you need to separate yourself from the competition. Winning a commercial contract or residential job is often down to the cheapest quote; why not offer something your competitors can’t?
Q. How do I find out more?
There is a dedicated KNX UK association, which runs as a partnership of UK manufacturers, integrators, wholesalers, training establishments and other interested parties whose goal is to promote the KNX standard within the UK. This provides support to those already in the industry as well as those just coming into it.
The association, KNX UK, is governed by an elected board, whose experience reflects KNX activities throughout the UK. There are four membership levels: manufacturer, integrator, wholesaler and professional.
KNX UK helps to provide businesses of all sizes access to big business ideas through a shared community, forum and voice.
