Heating and Ventilating

Stephen Payne looks at future-proofing integrated control systems
Whether you are designing a whole new building or refurbishing a single floor of an old one, if the project is a single home or a whole new business district, open control protocols make sense because they give designers a wider choice of solutions from an open marketplace ¡V and their adoption has meant that more leading edge technology has trickled down from prestige projects like the Media City development at Salford Quays to individual dwellings in private and social housing sectors.

Another key advantage of the open systems approach is that it is opening minds so that, at last, heating and lighting are integrated for optimum efficiency, rather than being viewed as two completely different installations.Domestic premises are the main contributors to our national carbon footprint, as has been recognised by the government¡¦s commitment to Green Deal funding, so it makes sense that the best thinking in control and energy efficiency should be applied to domestic premises.

The way people use homes has changed since the early days of central heating. Instead of congregating in one living room, family members are now more likely to be in separate rooms using multiple televisions, computers and tablets.

So it also makes sense for heating controls to be catering for optimum comfort and efficiency in all areas of the home.

In recent years, housing managers have realised the potential benefits of zoned control systems in even modest homes. If installers and developers opt for a proprietary bus system, rather than an internationally agreed open protocol, then they will be limiting their choices, and the benefits of market forces. Specifiers are demanding more and are now looking beyond stand-alone controls.

Now they are going a step further and turning their attention to intelligent building control.

They see that broadband throughout the home, surround-sound and cable television in several rooms are becoming the norm.

Meanwhile the heating, ventilation and lighting is left to chug on in its old fashioned way ¡V when all that is needed is intelligent building controls.

Open thinking
Installing a KNX standard bus cable is as easy as any other cable, so it¡¦s clearly not such a big deal to install it to make new levels of automation possible.

This is true not just for new-build but also in older homes ¡V any refurbishment should include KNX network cabling as well to provide a truly future proof solution.

It can be installed next to mains cable, so why be chasing two lots of wiring into the wall when installers can do it all at once?

Some building managers are faced with local authority owned housing stock that has fallen lamentably far short of modern standards, and so out-of-the-box solutions like the Belfry EcoPod clearly have a place.

The EcoPod arrives on site fully commissioned and ready to be lifted by crane into position.

The KNX EcoPad display allows tenants to simply read their energy usage ¡V for example, how much is left on their prepaid meter.

They can even call for emergency credit if required.

However, where housing managers want to build more flexibility into their programmes, KNX open protocol is the way forward as it allows the installation of some smart products immediately and then the ability to build on the system gradually as requirements change.

In addition, there is no absolute need to upgrade a whole development immediately: single blocks, floors or wings can be upgraded and the project extended as resources allow ¡V safe in the knowledge that future compatibility will never be an issue.

The key to having this flexibility, and all the benefits of market forces, is to opt at the outset for a truly open and scalable protocol, so that products from different manufacturers can be chosen on merit and added to the central bus network.

The only way is KNX
The KNX stable offers 100% guaranteed compatible products from over 300 different manufacturers, with thousands of products, all of which can be commissioned as part of a single installation.

Installers use the KNX ETS software to set up each device and integrate the system together. On completion of the project KNX Association members will hand an electronic copy of the building program to the building owner or manager.

Heating (electric, underfloor, radiator), lighting (LED, fluorescent, low energy), music, television, door entry and metering, for example, are all installed on one common network cable and are programmed to work together.

The devices that you want to work together to control the environment in each room communicate through the KNX bus cable, so that increasing temperatures turn the heating down or bright sunlight turns artificial lights off, for example. The KNX bus cable is designed to allow for future configuration changes and addition of more devices.

A KNX installation will typically include a fixed or removable control panel or head-end for control and monitoring.

The LV bus power supply and DIN rail mounted devices such as actuators and dimmers for the lights, heating controls, door and window actuators will be housed in one or more panels throughout the building. One example of the use of KNX in the home is the Theben Varia thermostatic room controller and multifunction display, which shows how easy intelligent control is for the occupier to use.

Room profiles for heat, light and ventilation are programmed by the installer using the KNX software and the user can control or monitor as many as eight rooms or areas and select the right lighting scene for activities such as reading, working or watching television at the touch of a button.

The Varia can even display weather information by accessing data from the weather station if installed. Voted as KNX product of the year in 2011, a version of the Varia was developed into the EcoPad, which is an integral part of the EcoPod system.

Across the board, technology is changing and evolving, but KNX as a truly open protocol does offer some certainty.

KNX installation in a nutshell
Products are installed on a KNX bus cable, and this pair of wires provides the signalling information and power for devices such as the Theben PresenceLight presence detector. Other devices, such as heating actuators will need a 230v power supply.

All KNX devices are connected to the KNX cable through a twisted pair, radio frequency, power line or IP/Ethernet, and are able to exchange information.

Devices on the bus can be sensors, actuators or displays needed for the control of building management equipment.

Almost all building functions can be controlled, monitored and signalled through a uniform system without the need for extra control centres.

In larger buildings there will be a permanent head-end, but nothing more demanding on the budget than a dedicated PC. For smaller buildings or family homes, the integrator will simply plug in his laptop to programme or adjust the system.

The family will access the system from a fixed touch panel or their tablet device.

Programming of the installed KNX-compatible devices is then managed using a single software tool ¡V currently ETS 4 ¡V available from www.knx.org. KNX leaves building owners and managers in complete control.

KNX products are all tested for compliance, ensuring they operate seamlessly together on the KNX network. KNX-compliant products are available for control of systems such as:

Lighting
HVAC
Intruder alarms
Audio visual systems
Blinds
Awnings

// The author is KNX systems manager at Theban AG //