Simon Buddle looks at the four factors affecting the quality of a KNX installation and underlines the importance of specialist KNX programming skills.
I don’t know about you, but I’d like to think of myself as a bit of a handyman. I can generally fix most things around the house; putting up shelves, changing the shower cartridge, electrics, or replacing a bit of guttering. But there are some jobs that I never undertake – plastering and tiling are two that spring to mind. On the surface, these are simply repetitive and monotonous tasks, but there is a real skill to both that require years of practice to get right. And when I say ‘right’ I mean perfect. In either case, any imperfections are very obvious to the human eye.
Likewise, back in the day, I was very happy to tinker around with my car engine, but when it came to something difficult, you’d trundle off to the local garage and some bloke with oily hands and a boiler suit would most likely tell you that “It’s gonna cost ya”. But over the last ten years, that person has become two people, one with oily hands and one with a laptop and a USB cable. They have specialised.
For me, the quality of any KNX installation is defined by four factors:
• Products used.
• Quality of installation.
• Programming of devices, user interfaces and logic.
• Ongoing support for the customer.
Let’s look at these individually, and how each might affect the quality of a KNX installation.
One of the great accomplishments of the KNX Association is the requirement for all KNX products to be vetted by the organisation and approved for use in the KNX world. That, by definition, means that we’re all working with a known standard of product, irrespective of manufacturer. The deciding factor in which products to choose may therefore be a simple matter of small differences in specifications, for example, minimum load for the output of a lighting dimmer. Or it might be how easy they are to wire up and/or retrofit, or it could be the profit margin, or just familiarity.
The modular nature of KNX, coupled with the requirement to adhere to national electrical regulations, by and large, also means that the quality of installation is pretty much a given. I’m sure we’ve all seen a few horror shows in our time, but for the most part, they are of a good standard. You might argue that the labelling is poor or cables aren’t as tidy as they could be, but electrically-safe? Absolutely they need to be. Most electricians can put together a KNX system without too much difficulty. For custom installers, this is the very meat and drink of their world.
Programming can be broadly broken down into three areas: KNX actuator parameterisation; user interface design; and logic controls. And this is where we begin to see wildly different quality levels. As we know, for group addresses (GAs), there are two schools of thought: either we set up as a function-based or a room-based layout for the GAs.
When I started, I was taught to do it by function. After a few jobs, I changed to room-based and still use that to this day. And here’s the thing; I have the luxury of doing KNX programming on a near day-to-day basis all year. Most people are not programming full time. And whereas building a KNX panel is broadly the same as building a Lutron panel, the same cannot be said for the programming. It is a very different way of working. Add to the mix novices at heating and cooling, and any contractor or new-to-KNX custom installation company can quickly get into deep water. Likewise, setting up user interfaces and logic engines can be daunting to the newcomer. I have seen programs of varying qualities; some I have had to start again, and others that are great. For example, each time I see a program (which is not often) from my colleague Jim Fairburn, I know that the job has been done well and to a good standard.
Not only is this a must for all installations it should, in my opinion, be embedded into the project costs from the outset. By their very nature, these systems require a layer of technical knowledge that homeowners simply don’t possess (and nor should they). As a minimum, telephone support, so that you can direct a client to a button on the front of an actuator to turn on a light, open a blind, or garage door, surely has to be the most basic service level agreement that you should offer.
I have said this before and I’ll say it again now, there needs to be more training for the programming of KNX systems in all three areas, namely KNX actuator parameterisation; user interface design; and logic controls. Badly-programmed systems reflect badly on the industry. Moreover, if this isn’t a world that you work in day-to-day, maybe it’s worth hiring in that skillset in order to either do the first few jobs until you’ve cut your teeth, or to provide some training and guidance. Professional programmers provide the same level of quality, job after job. They work in a streamlined and efficient way, and by that, I mean financially. That in turn makes KNX and your business, look professional and relevant to modern living.
Simon Buddle CEng MIET, is a consultant for Future Ready Homes, a specialist in BMS and ELV services system design.