Intelligent use of Controls in Buildings
by Doug Robins of AES Control Systems and President of the Building Controls Industry Association
Appeared in ACR
More and more building users are installing air conditioning systems in order to satisfy the demands of their facility and the type of user is on the increase. Where it was the province of the commercial office, retail and leisure markets, air conditioning is being more commonly applied to educational establishments and throughout the health sector. Alongside this growth, the ac industry has been expanding its own markets with VRF/VRV systems being specified for a wide range of building types and not just commercial developments. This has led to the need for air conditioning companies to co-operate with controls installers to enable all building services to be co-ordinated and managed in a sensible manner through system integration.
Building design is at the forefront of this new co-operation, making sure that all of a building's systems can in fact communicate with one another. It is fact that many building services systems still maintain their own proprietary networks.
To achieve interoperability, the designer will need the advice of an experienced and knowledgeable control systems specialist to ease the process of establishing a coherent structure in order to allow the different systems to connect to a common interface. Interoperability also provides the building owner with total control over the systems being installed, which in turn can help reduce the management, maintenance and energy costs over the lifetime of the building.
'Open protocols'
While many air conditioning systems are more than capable of working in isolation, there is a growing need for them to form part of a building management system (BMS). The controls industry is demonstrably moving towards 'open' communications standards, as are many air conditioning manufacturers, thus enabling both to be seamlessly interfaced.
The close control capability of the air conditioner is maintained by the system's integral controls, allowing it to be commissioned and tested without the need for a central supervisory platform. The BMS controls the remaining HVAC plant, such as toilet extract, boilers, hot water services, etc., with the connection between air conditioning system and BMS achieved at management level. Of course it need not stop there, this approach can extend to fire, security, lifts, and lighting systems which also take their primary operating instructions from integral controls.
This methodology allows each installed system to be fully tested and commissioned before the BMS interface is connected; system integrity is maintained and allows the greatest choice of different systems to be incorporated within the building services architecture. The building user gets the benefit of the widest choice of the building services systems together with improved interoperability. This in turn leads to increased efficiencies in alarm and data logging and enables energy consumption to be compared against known benchmarks, all from one supervisory platform.
Commonly, the platform used is based on IP (internet protocol) technology, giving users control over their personal environment through their own PC. In addition, management and maintenance can be undertaken remotely using standard web browser technology. This single platform approach enhances energy management by adjusting all of the systems to match required conditions. A simple example of integrated systems working together is a local PIR sensor advising the BMS of a room or area becoming vacant, allowing the BMS to lower space temperature and reduce light levels achieving percentage savings that accrue day-on-day, week-on-week to produce dramatic savings.
Realizing anywhere near these reductions is extremely difficult, if not impossible, when systems are operating in isolation. For example, a pre-programmed energy efficient air conditioning routine can so easily be negated by allowing the heating system to run unchecked.
IP Simplicity
An added bonus of integrated systems is training. BMS operatives need only to be trained on one software solution, not separate systems, and if using IP technology then training and support could be carried out remotely.
In fact, IP technology eases a raft of support services. Remote specialists can access the operating system via IP, pro-active maintenance can be achieved by actively monitoring the conditions of the plant and generating alarms before maintenance checks are due, and alarms can be routed to the relevant maintenance provider, thereby saving downtime.
BCIA members are at the forefront of such technology having been involved in the implementation of building services integration. Its members are working within the Comité Européen de Normalisation (CEN), which has been tasked with standardizing ".system neutral data transmission methods between products and systems for HVAC applications..to develop HVAC specific applications of existing communications methods, one for each level required". Few disagree that open protocols are the future of intelligent buildings.
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