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Fantech TechTalk newsletter Issue 66, December 2009

Transcript of TechTalk Issue 66

  • Manager John Grimwade said the rocks had chilled water coils constructed from had chilled water coils constructed from PVC Nitrile material embedded within PVC Nitrile material embedded within the Glass Reinforced Concrete (GRC) the Glass Reinforced Concrete (GRC) rock. Chilled water enters the rock at 6C rock. Chilled water enters the rock at 6C and aims to maintain the surface of the and aims to maintain the surface of the rock at 12C on a 25C ambient day. rock at 12C on a 25C ambient day.

    When the weather is too warm, 25C When the weather is too warm, 25C or above, the Pandas will stay inside or above, the Pandas will stay inside their day rooms where chilled water their day rooms where chilled water air handling units complete with heat air handling units complete with heat recovery modules air-condition the room to recovery modules air-condition the room to maintain a maximum indoor temperature of 18C, he said.maintain a maximum indoor temperature of 18C, he said.

    To help facilitate the air flow and cooling Fantech supplied a range To help facilitate the air flow and cooling Fantech supplied a range of products including five in-line centrifugal fans and two in-line of products including five in-line centrifugal fans and two in-line mixed-flow fans.mixed-flow fans.

    The Panda enclosure is due to be opened to the public on 13 December. The Panda enclosure is due to be opened to the public on 13 December.

    Two Giant Pandas will soon be on display at Adelaide Zoo. Three year old Two Giant Pandas will soon be on display at Adelaide Zoo. Three year old Wang Wang and his two year old mate Funi left China in late November, Wang Wang and his two year old mate Funi left China in late November, bound for a 10 year stay at Adelaide Zoo. bound for a 10 year stay at Adelaide Zoo.

    To accommodate its new guests Adelaide Zoo has undergone a major To accommodate its new guests Adelaide Zoo has undergone a major construction project. In addition to the new Panda enclosure, the zoo construction project. In addition to the new Panda enclosure, the zoo has a new ticketing area and a function centre known as the Santos has a new ticketing area and a function centre known as the Santos Conservation Centre. Conservation Centre.

    Giant Pandas are on the endangered species listing with only 1600 left in Giant Pandas are on the endangered species listing with only 1600 left in the wild. To protect the species and secure its long term survival, breeding the wild. To protect the species and secure its long term survival, breeding pairs of Giant Pandas are loaned to zoos outside China. pairs of Giant Pandas are loaned to zoos outside China.

    Adelaide Zoos Panda enclosure cost $8 million and includes a separate Adelaide Zoos Panda enclosure cost $8 million and includes a separate enclosure and day room for each Panda as well as sleeping dens and a nursery.enclosure and day room for each Panda as well as sleeping dens and a nursery.

    Native to the high mountains and deep valleys of China, the Giant Pandas Native to the high mountains and deep valleys of China, the Giant Pandas will be kept cool in Adelaide by chilled rocks. Haden Engineerings Project will be kept cool in Adelaide by chilled rocks. Haden Engineerings Project

    December 2009Newsletter Number 66

    The newly completed Melbourne Convention Centre has been fully integrated with the Melbourne Exhibition Centre to create a modern, user-friendly and versatile environment that makes an architectural statement on the banks of the Yarra River.

    It is the first convention centre in the world to be awarded a 6 star Green Star environmental rating. It also won the Banksia Environmental Foundation Built Environment Award; an award presented for buildings, infrastructure, services and technologies that incorporate significant sustainable development principles and practices.

    The buildings innovative water management system captures and uses all rain water and is complete with its own black water treatment plant. Solar hot water systems and energy efficient lighting have also been incorporated to reduce energy consumption.

    Mike Reid from James L Williams Pty Ltd, a leading mechanical contractor in Victoria, said an energy efficient HVAC system was achieved by conditioning an occupied area up to 2.5 metres above the floor in open spaces through low velocity systems and high efficiency motors. He said 149 Fantech fans were selected for their high efficiency and there was extensive use of primary and secondary pumping systems incorporating variable speed drives to help limit energy consumption.

    The main foyer, with its 18 metre glass faade fronting the Yarra River, has radiant slab heating and cooling to keep the occupants comfortable, while efficient chilled beams are used in the ground/mezzanine offices.

    With a total building capacity of 22,000 people, you need to make sure there are no hiccups with the ventilation system, Mike said. To ensure a high level of reliability we have standby fans, pumps and air handling systems.

    A major feature of the centre is the 5000 seat plenary hall with its gala seating system. This unique spiral lifting device allows flexible seating configurations in a 510 square metre room that can be divided into three self-contained, acoustically separate theatres.

    Visitors to the convention centre breathe comfortably thanks to under-floor displacement air systems fitted with carbon dioxide monitoring and control in the plenary hall and foyer.

    Mike said the technical complexity, large scale and tight construction program of the project had combined to make the convention centre a huge challenge. At the peak of the project there were more than 1000 workers on site, and we were able to deliver the project on time, he said.

    The Melbourne Convention Centre and integrated Hilton Hotel were designed by Joint Venture Architects Woods Bagot and NH Architecture for the Plenary Group consortium.

    The Melbourne Convention Centre opened in April 2009.

    M J h G i d id tthh kM J h G i d id h kZoo panders to new guests GZoo panders to new guestsZZoo pandders to ne g ests

    Melbourne Convention & Melbourne Convention & Exhibition CentreExhibition Centre sets the standard

    sets the standard

  • Technically SpeakingWith Jack Pirie

    Fan Total EfficiencyGlobal concern about the level of carbon dioxide (CO2) production and links to climate change have led to increased demand for more efficient equipment and systems that consume less energy. The building mechanical services industry accounts for about 20-25% of the worlds energy consumption, with fans representing a substantial share of that. This is an area where well-engineered fan selections and systems can be made, providing substantial cuts in energy consumption, much of it with an immediate cost benefit.

    Fig. 1 shows that the efficiency of a single fan varies greatly over its performance envelope. If a fan is selected too far from its sweetspot energy may be unnecessarily wasted. Not only is energy saved by selecting near the sweetspot, but noise levels are typically quieter, and there is less chance of the fan entering stall.

    An early step in improving energy efficiency in Australia was the establishment of AS/NZS1359.5 2004 Three-phase cage induction motors High efficiency and minimum energy performance standards (MEPS) requirements. The minimum efficiencies of MEPS motors are now between 80% and 96% for the majority of motors which will make further efficiency gains difficult to achieve.

    Section J of the Building Code of Australia (BCA) legislates minimum performance targets, W/L/s, for fans and air handling equipment in Section J5.2, while allowing AS1359.5 2004 to handle the minimum motor efficiencies. Even with the BCA requirements, further reductions in consumed power of up to 40-50% can be obtained using best practice principle and careful, well considered fan selections.

    It stands to reason that, with regards to fans, major efficiency gains, and therefore power savings, are possible both now and in the future.

    The efficiency of a fan impeller is generally rated in terms of total efficiency. This definition measures how well a fan impeller converts the power output from an electric motor into useful mechanical energy in the airstream, based on total pressure. It is NOT a measure of the overall efficiency of a fan, as losses through the motor or other elements such as belt-drives, are not considered.

    When this formula is applied to a particular fan size, the fan with the highest efficiency will be the one

    consuming the least power. However, if the selection is made over a range of sizes, a different picture can emerge.

    Consider an axial flow fan required to meet BCA Section J5.2 W/(L/s) ratings, handling 40m3/s @ 600Pa static pressure.

    From the Fantech Product Selection CD, for fans in the 1400 to 1800mm dia. range, the two fans with the highest total efficiency are the AP1404CA9/31 at 80% efficiency and the AP1806FA12/19 at 73% efficiency; both fans meet the BCAW/(L/s) requirement.

    Interestingly, although the AP1404CA9/31 fan has the higher total efficiency, it requires 50.36kW shaft power to drive the fan whilst the AP1806FA12/19 requires only 40.50kW.

    The reason for this is because a fans total pressure is the sum of the static and velocity pressures and, as the 1400 dia. fan is smaller than the 1800 dia. fan, its velocity pressure will be higher when handling the same airflow.

    Fig. 2 illustrates the differences in the total pressures of the 1400 and 1800 dia. fans; in this instance the 1400 dia. fan having to develop 1005Pa and the 1800 dia. fan only 748Pa.

    To generate the higher total pressure the 1400dia. fan has to do more work than the 1800 dia. fan therefore usi