DADANCO technology takes air conditioning to new heights

Revolutionary new air conditioning technology is not only saving older commercial buildings around Australia said to be "dying" from poor air conditioning, but could also influence the design of many future commercial multi-storey buildings.

The technology, which was developed in conjunction with the University of Adelaide by Professor Sam Luxton and Vladimir M. Petrovic (former PhD student), has been recognised in the scientific community and granted world-wide patents. The technology has been commercially realised by DADANCO Pty Ltd, a company set up by Professor Luxton and Mr Petrovic.

DADANCO's technology has extensive ramifications for building construction and commercial property maintenance industries, and has environmental spin-offs. It can improve by up to 50% the capacity of induction air conditioners, lower air-conditioner background noise by up to 15 dB, reduce maintenance and running costs, and lower environmental impact through reducing energy usage.

Successes with the new technology include reducing the air conditioner noise level in an 8-floor Brisbane law court by 10 dB; saving the 13 floor Capita Building (SA) from desertion by tenants because of air conditioning problems, and allowing a stalled building project in Sydney go ahead by showing the developer how to gain an extra floor for the same building height using a DADANCO Starline system.

The technology is also being incorporated into the $25 million upgrade of 360 Collins Street, Melbourne.

Vladimir Petrovic, DADANCO Managing Director, said the technology was specially developed to solve noise and capacity problems in perimeter air conditioning systems and uses "old science" principles in a novel configuration.

(Perimeter induction air conditioning systems are installed in thousands of commercial building constructed in the '50s, '60s and '70s. They work by discharging a stream of high-velocity, cooled and conditioned primary air from the main air conditioning plant through a set of nozzles in the room units that are installed throughout a building. The jets entrain air from within the unit, causing a pressure reduction that draws a secondary air stream - from the room - to flow into the unit through a secondary heat exchanger fitted into the unit's mixing chamber. The mixture of primary and secondary air is then discharged into the space to be conditioned through a short diffuser.)

"We developed a novel, patented nozzle design that greatly enhances turbulent mixing of the primary air jet and the secondary air flow by optimising the perimeter-to-area ratio of the nozzle outlet cross section.

"This more efficient entrainment reduces stresses within the jet and so reduces noise generation," Mr Petrovic said.

Further increases in efficiency were obtained by redesigning the internal profile of the mixing chamber and by critical alignment of the nozzles. The new mixing chamber profile creates a "Venturi throat" that boosts the efficiency with which the momentum of the flowing air can be converted to pressure as it flows into the room space.

Mr Petrovic said the combined effect of these two components raised the unit's entrainment ratio by up to 77% and reduced noise levels by up to 15dB.

He said the technology was originally developed as a "refurbishment kit" that could be retro-fitted into older buildings that use induction air conditioning systems.

Mr Petrovic said the technology was now incorporated into DADANCO Starline Perimeter air conditioning units designed for installation into new buildings or as replacement units in existing buildings where it formed the basis for a supremely low-noise, cost-effective air conditioning system.

He said another benefit of the new technology was that it also lowered the demand in primary air pressure in induction systems. "This means that, in new system installations, smaller ducting can be used which subsequently reduces the ceiling space required to about 350mm."

Mr Petrovic said that by applying DADANCO technology to new installations, architects, property developers and construction companies could add one extra floor for every 12 proposed in the same building envelope and reduce the size of plant rooms by about half for the same air conditioning efficiency.

"Existing systems with floor-mounted units can be replaced with the compact Starline ceiling-mounted units to provide up to 15% more lettable space in a building," Mr Petrovic said.

"And, as there are no moving parts in a Starline perimeter induction unit, maintenance is minimised to an annual inspection," he said.

DADANCO has recently embarked on a $2 million 3-year research and development program to further increase the efficiency and lower noise and energy usage of their Starline units. As well as exporting their technology interstate, DADANCO has set up a joint venture operation in Singapore, and is looking at Europe and the East Coast of America where there is a potential $20 billion market for the product.