200 Queen Street construction was completed in 1980 with significant areas of the building plant including the air-conditioning controls and computer head end, variable air volume boxes and fans being subject to refurbishment and upgrade since that time. The building now offers a high standard of accommodation that provides for the strenuous requirements of its Commonwealth tenants yet achieves a high level of energy efficiency. The slab shape allows for easy subdivision of the floors with a unique ceiling coving to all office areas providing additional sun shading.
At 200 Queen Street the particular issues addressed by the building structure include.
· The creation of a building envelope that allows the latest facilities at any time with minimal disruption.
· The selection of building systems capable of being on call at any time, responding to the increasing trend towards extended and/or irregular working hours.
· The creation of an energy efficient building both in the design of the building envelope and the engineering systems.
· Providing for maximum lift and fire safety.
· The inclusion of effective security systems and building monitoring facilities.
· Provision of facilities to ensure that all occupants of the building can be offered connection to an integrated array of communications and building services system.
Features of the building include:
· Duct spaces and additional service rooms that allow for the installation of extra communications facilities.
· Service rooms in the core on each floor to facilitate connection of riser cables to floor cables on each floor.
· Operational availability 24 hours per day.
· Zoning of air-conditioning to cater for normal office sub-division plus provision to add further zones for boardrooms and the like.
· Valved condenser water connections on all floors for installation of special cooling equipment to high heat load electronic equipment such as computers.
· On-site standby power generation, which will allow continued operation of the building except during a complete loss of power.
· Riser space to allow installation of cabling for uninterrupted and other special power supplies.
· Provision to allow modification of fire services for inclusion of delayed action sprinklers over delicate equipment.
The features described make possible the incorporation of fully integrated businesses in the building as well as connecting with other premises and buildings is possible. Tenants will operate their own systems but, in future, as centrally managed facilities are developed, the possibility of being able to connect to these will become a reality.
The overall performance of the building and its services are directed to satisfying the requirements of the major tenant with facilities and provisions substantially beyond that provided in alternative developments.
State-of-the-art building control and security systems are installed to supplement the basic building facilities.
(a) Building Control
The functions provided include:
· Management of energy consumption.
· Central computer based control of mechanical systems and equipment to maintain an optimum working environment.
· Operation of standby generator including after hours, brown out, black out sequences.
· Control of public area lighting systems.
· Monitoring of lift installation.
· Monitoring of fire systems operation.
· Managing out of hours operations.
· Managing systems’ maintenance activities.
The first line of security is at the building perimeter. 200 Queen Street incorporates a number of security systems, all of which are monitored by on-site guards. The guards also undertake random inspections of the building perimeter as well as internal inspections.
Normal tenant after-hours access is obtained through MIL key facilities at the main entrance and at the car park entries. Additional facilities include:
· On-site guards that monitor all systems and undertake physical building patrols.
· Monitoring of all plant, communications and electrical room doors.
· Card key readers on main entry points and in the lifts, which will provide after hours access to authorised floors.
· Extension of the card readers to tenancy entrances.
One of the major design criteria for the refurbishment and upgrade of 200 Queen Street was to improve building function and maximise energy efficiencies for the benefit of all tenants.
As an integral part of the overall building design strategy, all windows are double-glazed, allowing for a massive reduction of the effect of both solar heat gain and the transfer of heat from within the building. Other elements of the building facade and internal ceiling coving design also help limit heat transfer.
The building air-conditioning system operates with an economy cycle which compares the internal temperature requirements with the outside air temperatures. The system then automatically adjusts the air-conditioning plant operation by utilising the outside air for heating, or more commonly, the cooling of the building. The new Building Management System (“BMS”) is configured to provide optimum building conditions while minimising energy consumption.
The air-conditioning installation is fully operational during normal business hours and can be energised out of hours on any one floor or group of floors. Chilled water connections allow extension to local supplemental cooling plant, which may be made to cool computers or other equipment.
The installation is designed to maintain internal temperatures in the range 21°C to 24°C summer and winter. Plant design limits are related to seasonal temperature variations between 5°C to 35°C with a relative humidity upper limit of 55%, there is no lower limit. There is provision for the installation of humidification equipment should this be required.
The plant design allowances provide for a total heat load of 120 w/m2 that includes the dead building load, electrical loads emanating from lights and equipment and solar heat gain.
Fresh air provisions are liberal and include 100% fresh air during cool weather via the systems economy cycle.
200 Queen Street provides floor by floor air handling units for optimum efficiency. The fans all incorporate variable speed drives that respond to ambient floor conditions and alters the operation of the air distribution fans to suit. The basic installation includes a minimum of 10 zones per floor, each with its own temperature controller to which additional zones can be added. The controllers in each zone are directly monitored by the BMS allowing for specific control of individual areas. The system can be monitored remotely and components of the plant interrogated to ensure optimum set points and operation are maintained. The contractors can undertake minor adjustments to the plant from off-site. This ensures that any discrepancies in tenancy conditions can be rectified even before a tenant is aware of any changes in floor condition.
Cooling for the building is derived from a central chilled water plant, incorporating two heavy and one light load chillers. The facility is on call 24 hours a day. Heating is provided via hot water generated in a gas fired boiler.
All facilities are linked to the central computer, which both monitors and controls the total facility.
Electrical power is supplied to each floor at the electrical services room. Connections to tenants’ meters and wiring will be made at this point. Provision is also made within this room to install separate risers for connection of equipment requiring a high quality power supply. Enhancement to uninterrupted power supply level is possible. The generator is housed in its own building that is located on the north western corner of the level 10 garden area.
The basic electrical supply is supported by a standby power facility, which incorporates a 1250 kVA generator. This will provide sufficient power to maintain all air fans, light load chiller and lifts during periods of limited power availability and to allow main functions to be maintained during complete black out. Change over to the standby power facility will be automatic. The building control systems will then select operating functions.
Lighting fittings are ultra low brightness units set out to achieve an average illumination in open office areas of 500 lux. There are two lamps in each luminaire to maintain illumunation levels. Addition of further fittings to suit sub-divisional layouts will be possible.
The lift installation consists of two sets of passenger lifts, which serve the office floors, one set of passenger lifts that connects the car park levels to the ground floor and level 10, one goods lift and a small shuttle lift that links levels 32 - 34.
Low Rise (Floors 2-21)
Four (4), 20 passenger units travelling at 3.0 metres per second.
High Rise (Floors 22-32)
Four (4), 20 passenger units travelling at 4.0 metres per second.
Car Parking (Ground – level 10)
Two (2) 20 passenger units travelling at 2.0 metres per second.
Goods Lift (Lower ground -Level 33)
One (1) 8 passenger unit travelling at 0.25 metres per second.
System performance levels have been developed in accord with the industry standard targets of 30 seconds average interval and 10-12% handling capacity in 5 minutes.
The building is protected throughout by an automatic wet pipe sprinkler system. This is backed up by hydrants/hose reels, fire detection and alarm facilities and communications systems, which provide for:
· Emergency warning and evacuation.
· Fire brigade contact.
· Smoke detectors are installed in all tenancy, storage and plant room areas as well as within the return air shafts.
The air-conditioning system is fitted with smoke exhaust modes of operation.
To facilitate tenant fitouts the sprinkler system is designed to accept a number of additional heads.
Proposing tenants should expect the regular statutory maintenance of the fire services facilities and the participation in regular fire evacuation training and drills.
Toilet facilities are in keeping with those for contemporary centre city developments. Tea rooms are provided on all floors with provision to fit cooling water units.
Wet stacks are provided at the southeast and northwest corners of the core for connection of additional tenant fixtures. In developing layouts tenants should check the suitability of proposed fixture locations with the project’s services consultants.