Integrating systems at room level
Chris Irwin, Business Development Manager for Northern and Eastern Europe at Distech Controls discusses the benefits of integrated room control and the energy and cost savings that can be made.
Over the years much has been written about integrated systems and the term now means many things to many people. Even the term Systems Integrators has, for the most part, been something of a misnomer, since the majority of controls specialists install only HVAC controls from one manufacturer and do not get involved in integrating different functions or sub-systems. This is because the UK market has been surprisingly resistant to systems integration due to the strongly ‘siloed’ approach taken by UK manufacturers, contractors and the conservative thinking of many M&E consultants.
In general it seems that all parties involved in a project find it easier to specify, supply and buy separate systems for lighting, HVAC, security etc, rather than producing or using a single system that links the separate systems together in such a way that they work well together and can exchange data, typically with a common user interface at the supervision level. It has been hard for end-users to get the integrated buildings they would benefit from, even if they are aware of the potential benefits and attempt to steer the project that way. When integration gets specified, the plans often gradually unravel during the contract letting process and are further compromised by rushed commissioning or by the main contractor/client not enforcing full specification compliance.
Since the building operator is frequently unaware of the advantages of an integrated approach to building systems there is something of a ‘chicken and egg’ situation in the industry. The lack of demand for systems integration has allowed systems manufacturers to continue to sell separate HVAC, lighting, security and other systems, which has suited established players rather well. Integration has been viewed by many as complex, expensive and risky, a perspective fuelled by those whose systems are more proprietary and are technically difficult to integrate.
System integration has been technically complex in the past, due to the fact that proprietary systems require special gateway type products in order to exchange data, but this is changing. Some manufacturers have adopted open protocol standards for their network communications and the increasingly widespread use of multi-protocol platforms such as the Niagara Framework has made the engineering of integrated systems much easier. BACnet, LONWORKS, KNX, Modbus, M-Bus, EnOcean and various other standards are making the integration of different manufacturers’ products and systems much easier. It is now possible to buy building management systems which have the capability to integrate the various building sub-systems at no extra cost. Some even offer lower costs by combining functionality at a low level and avoid duplication of network and supervisory costs.
So why bother with systems integration functionality? Well, the answer depends on who you are, what type of building is involved, and how the building will be used. Specialist advice is necessary here as integration is no general panacea; there is only value in doing it if it delivers benefits. These come in various forms; reduced energy costs, reduced operational and maintenance costs, lower capital costs, and lower life cycle costs. Qualitatively an integrated building offers occupants a better experience as the functionality is enhanced. As a simple example, if the local ‘on the wall’ user interface allows you to adjust your lighting, sun blinds and local temperature in one device rather than two or three, it is both visually simpler and easier to learn. Having one occupancy time schedule for all services rather than having to change multiple calendars in separate systems is also clearly simplifying matters.
Some integrations are obviously beneficial: choosing to include metering within the BMS rather than installing a completely separate metering system offers significant cost savings and enables energy data to be seamlessly included in the overall system visualisation graphics and reporting. Other integrations, such as linking the fire alarm system to the lighting and HVAC control systems also offer benefits but these are less immediately apparent, mainly relating to better maintenance processes and enhanced life safety (e.g. better control of dampers and escape route lighting beyond what is mandatory). The biggest potential benefits of integration are energy savings and reduced capital costs; however, not all integration solutions are equal, as we shall see.
One way of achieving functional integration of the lighting and HVAC control within a building is to install two separate systems and then link them at a central point using a gateway or a supervisor level integration platform. This will enable sharing of data so that an occupancy detector on the lighting system can automatically adjust a temperature set-point in that zone to reduce energy use when no-one is present. Also status and alarm events from both systems can be viewed on a common screen.
However, two systems have had to be purchased and wired, and two separate maintenance contracts will be required, plus there is the issue of how the integration is engineered and how software upgrades to either system are managed so as not to disrupt the integration. Employing a common installer and subsequent maintenance contractor for both systems overcomes some of these issues, but the duplicated system costs mean that whilst there will most likely be operational benefits, there is no capital cost saving.
Another approach is to achieve the integration at much lower level. Many manufacturers now supply products that use one of the open standard protocols, as already mentioned, so that various devices from different manufacturers can be combined to achieve an integrated system covering all the main functions. However, there are relatively few controls specialists who are comfortable with this mix and match approach since it is more complex to troubleshoot and consultants are wary of it too.
This issue can be solved by choosing an integrated room control solution, which will control the HVAC and the lighting, and even sun blinds and other functions all in one system from a single supplier. This option offers the multiple advantages of achieving seamless functional integration, lower capital cost and clear contractual liability. By linking the lighting into the HVAC controls at room or zone level and using multi-sensors that include multiple functions in a single device, the wiring and networking costs of such a system are much reduced. Such an integrated system also offers a much simpler user experience as local adjustments can be made via a single wall or desk mounted interface for all functions, or a single mobile phone app.
Further significant savings due to improved space utilisation and productivity can be achieved by linking the room control to a suitable room booking system. For example, the occupancy detectors in each room can report whether the room is actually in use, and alert others of its availability; pre-setting of lighting and blind levels for different meeting times can save time for a meeting host, and rooms can be ventilated and conditioned according to the planned occupancy. Such optimisation of otherwise under-used meeting spaces can lead to some major capital cost reductions.
Few manufacturers currently offer such fully integrated room control (IRC) solutions, but they exist and they work. The deployment of IRC is already well established in other countries across Europe; there are plenty of reference sites that demonstrate the viability and advantages of this approach, so it
is hoped that more suppliers and specifiers will realise that single function networked systems are no longer the best solution for modern buildings, which need to be operated in more integrated and energy efficient ways than previously.
Negative perceptions regarding integration are lagging behind the current reality of what is achievable technically and economically. There is a clear need for the industry in the UK to adopt a more progressive attitude towards delivering control system solutions that fully realise the potential offered by today’s technology. This will involve not only a greater commitment to ‘getting things right’ technically from all those involved in specifying and procuring the system, but also a much greater effort on the part of Systems Integrators to embrace the latest open integrated products and offer their clients services, which focus on programming the installed controls to achieve maximum energy efficiency, not just adequate control.