How tuning can lead to big performance gains in old buildings
8 May 2014
By Andrew Smith, A.G. Coombs
8 May 2014 — You don’t need to invest in new equipment to get savings from older buildings. It’s possible to get up to a 50 per cent performance improvement in old building stock by tuning alone, A.G. Coombs’ Andrew Smith says.
Many people hear “retrofit” as a big rip-and-replace operation, but you don’t need to replace all your existing building systems to achieve substantial energy savings. With landlords on a quest to attract tenants in an environment where “green is good”, being able to tune older buildings for substantial energy savings and improved performance is a big win.
Buildings with higher NABERS ratings attract a premium and are sought after by tenants committed to basing themselves in 4.5- and 5-star premises. In an exemplar project in North Sydney, A.G. Coombs moved a building from a 2.5-star NABERS rating to 5 stars – with no new equipment.
With advances in technology and knowledge in the last 5-10 years, these results are possible for older buildings. An essential first step is an audit of a building’s existing performance. Ideally a minimum of 3-9 months’ data, including a summer, winter and a shoulder season, provide a basis for analysing current performance and understanding trends. Armed with this knowledge – and a detailed understanding of the building’s current plant, equipment and control systems – a building tuning strategy can be developed.
This may include simple changes such as making a building’s morning start-up time later, or more complex programming changes to take into account dynamic parameters such as building load and ambient conditions.
Today’s technologies allow strategies to be tested in a proof of concept phase, where some manual programming of the building’s systems allows monitoring of changes to prove their effectiveness before building control systems are reprogrammed. A proof of concept also provides data to build a business case for the changes, with a clear understanding of costs, benefits and time to return on investment.
ROI can be rapid, and recent experience tuning a portfolio of buildings in the Melbourne CBD shows payback can be achieved in timeframes as short as nine months.
It’s not only technology advances that help us achieve better building performance. The industry is learning all the time, and strategies developed in the last 5-10 years can be applied even to older building stock.
As long as the building owner and building manager are on board, you can take a look at what can be done even with 20-year-old buildings. It’s possible to achieve 25-50 per cent performance improvement from tuning alone. Performance improvements cover not just hard savings in energy costs, but also softer savings such as improved occupant comfort.
For the majority of buildings, hard energy savings deliver payback in something over 18-24 months, depending on the changes in strategy that are applied and the time taken for those to reach maximum effect. But the maths stacks up also in lengthening building equipments’ useful life and potentially improving rent/lease outcomes.
Tuning the building’s existing energy consuming systems to be the best they can be is the best first investment you can make in lifting your buildings environmental rating, extending the life of its plant and reducing your energy bills.
Andrew Smith is leader – building technologies at A.G. Coombs. He will deliver a seminar on building tuning/retro-commissioning at ARBS 2014, happening in Melbourne 20-22 May.