Tune up or rip and replace?

Rip and replace or invest in tuning existing systems? The temptation can be to assume that newer is better and that a major upgrade is needed to maximise building performance. Certainly with major systems such as HVAC, there can be a fairly straightforward return on investment calculation - current running costs against the capital cost of replacement and operating costs of a more efficient system. But the decision on other systems, such as control systems at the building or plant level, is less clear-cut.

Older control systems can limit flexibility - for example, by not supporting programming for different levels of building use across the day or the week. Take an office building whose control system doesn’t support different programming for different days. It is necessarily going to waste a huge amount of resources - and money - lighting and climate controlling the building on weekends when there are likely to be few workers present. Does this mean you need to replace the control system entirely?

Not necessarily. Jonathan Clarke, senior associate and controls group manager of Norman Disney Young, notes that building management systems run on ‘invisible’ software and updating this software, not the entire control system, can open up more tuning opportunities to deliver better building performance.

The issue of maximising performance of existing building stock will be a theme at this year’s ARBS technical seminar series, when a variety of speakers will discuss the issues and share current research and lessons learnt from a range of recent projects.

Andrew Smith, leader of building technologies at A.G. Coombs, is a retro-commissioning specialist who says that huge improvements are possible with the application of technology and knowledge developed in the last 5-10 years. In a showcase project at 100 Pacific Highway, North Sydney, Smith and his team moved a building from a 2.5 star NABERS rating to 5 stars - with no new equipment.

His approach starts with an audit of a building’s existing performance, ideally with 3-9 months’ data, including summer, winter and a shoulder season data. Armed with this knowledge and a detailed understanding of the building’s current plant, equipment and control systems, he can develop a building tuning strategy.

Meanwhile, AECOM’s technical director - buildings, Chris Beck, is on a mission to make the link between installed information, facilities management and building management system data - the sweet spot where these systems combine to deliver high-performing, low-running-cost buildings. Currently researching the confluence of these areas on behalf of major international clients, Beck is working with designers, control systems manufacturers and everyone in between to understand the issues.

“There are so many parties who have to collaborate to ensure we can maximise building performance management,” says Beck. “Building control systems vendors need to get on board to understand the requirements for data exchange between their systems. Practitioners at every stage of a building’s life from concept through to decommissioning need to understand the part their data plays in managing the building across its whole of life.”

This means that in many cases facilities managers need further education and training, and building owners likewise need education to empower their facilities managers to take steps to improve performance. Clarke also notes that benefits accrue when building managers involve building occupants. A regular part of his building management review and tuning process is to consult tenants. “On a recent project, we allowed every zone in the building to vote to get buy-in from the tenants,” he says. “Occupant comfort was a key driver for the project, and that involvement was critical in achieving the desired outcomes.”

With current efforts working from both ends - the front-end design and build and the back-end tuning and performance management - it would seem that we can make significant improvements to the performance even of old building stock.

Chris Beck will reveal more about his research in a seminar at ARBS 2014 and Jonathan Clarke will present an informative seminar about the current state of building controls and how to make tough decisions like ‘new system or recommission?’ Andrew Smith will share learnings from a variety of recent retro-commissioning projects. ARBS 2014 will be held at the Melbourne Convention and Exhibition Centre from 20-22 May 2014