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Blow Fill Seal air handling rooftop plant room

Drug therapy Accurate and consistent climate control is paramount in all pharmaceutical environments. This is especially so in a blow-fill-seal manufacturing facility such as that found in Melbourne’s outer east, as Sean McGowan reports. At the foothills of Melbourne’s Dandenong Ranges sits one of the largest pharmaceutical production facilities in Australia. 20

ECO L I BR I U M • M AY 2017

The GSK (GlaxoSmithKline Australia) production plant in Boronia produces a range of respiratory products, including Ventolin, Flixotide and Relenza, which

are used in the treatment of asthma, influenza and other respiratory infections. These products are delivered in various forms, including the well-known Ventolin puffers and nebules. GSK’s nebule products are manufactured using a state-of-the-art blow-fill-seal (BFS) manufacturing technique at the Boronia facility. The BFS area of the facility was built in 2000. Here, a container is formed from a polymer, which is then filled and sealed in a continuous process in a sterile, enclosed area inside a machine – without human intervention. This technique can be used to aseptically manufacture sterile pharmaceutical liquid dosage forms. It is considered to be the superior form of aseptic (sterilised, basically) filling. In order to support this process, a Good Manufacturing Practice (GMP) Grade C Clean Room environment needs to be achieved and maintained by the facility’s HVAC systems.

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Additionally, maintaining adequately high air-change rates, levels of filtration and room pressures are an essential requirement of the air-handling systems.

END OF LIFE Having operated 24 hours a day, seven days a week for all but a few brief shutdown periods over a 15-year period, the existing air-handling units (AHUs) serving the Boronia facility had either reached, or were well past their economic life expectancy when GSK sought to replace them in June 2015. “The existing AHUs had reached the end of their economic life and were having pressure fluctuation issues as well as major failures that caused significant interruption to the production,” says Jason Pleaner, M.AIRAH, associate director – mechanical for Irwinconsult. Having been involved in the original design and construction of the facility at the turn of the millennium, Irwinconsult was familiar with the site and the issues associated with the aging AHUs.

Accurate and consistent climate control is extremely important because temperature and humidity can greatly affect the polymer extrusion process

In such environments, accurate and consistent climate control is extremely important because temperature and humidity can greatly affect the polymer extrusion process and product quality.

As well as their age, Pleaner says the units were located in a very tight roof space, which was accessible only via crawlways in a confined ceiling void above the clean rooms. This made access for maintenance quite limited, and became a key driver for the project. Following a “request for proposal” from GSK, Irwinconsult was engaged to fully design and document a new dedicated plantroom above the existing facility roof to house the new AHUs. The successful tenderers, Kane Construction and D&E Air Conditioning, were then contracted to construct the new plantroom and mechanical services. Irwinconsult remained to oversee the construction administration tasks. “The new plantroom and the new AHUs needed to be constructed over a live clean room environment, with no disturbance to the production facility,” Pleaner says. “Maintaining the operation of the existing facility was a major challenge. It required us to plan the project in such detail so as to facilitate a rapid cut-over from old equipment to new, and commissioning new equipment in under a week.”

A limited amount of time was allocated to plant shutdown and cut-over. Very careful planning was therefore required to ensure a smooth changeover, as well as re-commissioning of the pharmaceutical productions suites, including re-validation of the GMP space.

MEETING REQUIREMENTS Like all pharmaceutical companies, GSK prescribes a set of design requirements for all of its facilities and HVAC plant. In the case of the Boronia facility, the company placed unique requirements on all systems. This includes preconditioning all outside air to reduce the energy costs associated with dehumidification and reheat. The company also requires that HEPA filtration be applied to the outside-air intakes during bushfire events. “Given the site’s close proximity to the Dandenong Ranges, bushfire smoke has been a significant issue in the past – causing false smoke alarms and unscheduled plant shutdowns,” says Pleaner. These unscheduled plant shutdowns are then further exacerbated by the need for time-consuming and costly GMP clean room re-validation procedures to be carried out. The environmental parameters for the facility’s filling rooms are based around achieving a GMP Class C clean room environment at 60Pa absolute pressure. Temperature requirements are 19°C +/- 1°C. Humidity requirements are 50%RH +/- 10%RH. In order to satisfy GSK’s stringent energy-efficiency requirements, a number of options were investigated. These sought to minimise the plant’s energy consumption. Also considered were methodologies for dehumidification, bushfire smoke control, AHU capacity and filtration, and future proofing of the plant. Eventually, the final design settled on individual preconditioning fan-coil units (FCUs) serving each of the new main AHUs. “This assisted in minimising dehumidification energy consumption, which had previously been a major M AY 2017 • ECO L I BR I U M

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Highly accessible and maintainable plant area to house BFS filling room air handling equipment.

energy consumer due to the need for dehumidification and re-heat in the old system,” Pleaner says. A total of 13 AHUs were identified for replacement – nine AHUs serving the BFS filling rooms, as well as an additional four units serving ancillary spaces.

Filling room air handling units with outside air pre-conditioning fan coil units mounted above.

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The final design prescribed that the new units serving the BFS filling rooms comprise of an outside air preconditioning FCU, cooling coils and variable-speed fans.

individual air-handling systems without affecting others. It also allows redundancy and maintenance requirements to be met.

The decision to use individual preconditioning FCUs over a centralised system provides the ability to maintain

The outside air in-flow rate is modulated in response to room pressurisation requirements.

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capital costs, and was less efficient than the condensing boiler system provided,” says Pleaner. Despite the existing AHUs requiring replacement, the original ductwork was considered to be in good condition and was deemed suitable for reuse. The need to have it removed at the expense of further plant shutdowns was therefore avoided.

COORDINATING SUCCESS Coordination was critical to the success of the GSK Boronia project. Bushfire smoke is controlled using HEPA filtration (as prescribed by GSK) and ember guards on outside air intakes, which prevent the ingress of smoke into the system and fault alarms.

supply-air fan. A new, dedicated heating hot water (HHW) system was provided to service the new plant; this was a departure from using the site’s existing steam system.

The main AHU comprises secondary filtration, cooling and heating coils and

“The use of steam for heating was found to be considerably higher in terms of

“The need to keep manufacturing uninterrupted was the centrepiece of the design,” says Pleaner. “It significantly influenced the positioning of units within the plantroom, as well as the location of new ductwork to align with the existing ductwork below the roof.”

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Careful positioning of the new ductwork also ensured the best connection into the existing, reused ductwork. To this end, D&E Air Conditioning spent considerable time and effort ensuring good connection detailing and transitioning while minimising the cut-over time. 3D modelling also played an important and positive role in coordinating with the existing services and structure. “An extremely thorough site condition survey, as well as measurements and preparation of shop drawings undertaken by the mechanical contractor were critical to the achievement of the required criteria,” says Pleaner.

External ductwork arranged for connection into existing filling room supply and return air ductwork below.

Every effort was made by the design and construction teams to minimise disruption to the existing production processes. This included consideration of how the new plantroom platform structure could be tied into the existing building

structure to transfer the load into the ground. Since new structural columns could not be installed within the operating clean rooms, the plantroom spans a significant distance between the existing structural columns located in corridor spaces.

All new AHUs, boiler plant and chilled water components were tested and commissioned prior to cut-over. This ensured that once the changeover occurred, the units would operate to maintain the required criteria without issue. In all, just three shutdown periods were required to complete the project.

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Dedicated condensing boiler plant for BFS facility.

Dedicated condensing boiler plant for BFS facility.

Initially, two brief periods were used to install new spigot connections to the existing ductwork, in preparation for cut-over of the new units. Then a five-day Christmas shutdown period was used to remove the old AHUs from the roof space, make final connections, and complete air balancing,

PROJECT AT A GLANCE The equipment ■ AHUs: Colair ■ Boilers: Baxi (Hydroheat) ■ C onstant air volume dampers: Trox ■ FCUs: Colair ■ Filters: Camfil ■ Pumps: Grundfos ■ VSDs: Danfoss

The personnel ■ C lient: GlaxoSmithKline Australia (GSK) ■ Contractor: Kane Construction ■ M echanical services contractor: D&E Air Conditioning ■ M echanical services design: Irwinconsult

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final commissioning and automatic controls tuning and verification. “The key to the project’s success was the ability to pre-commission the new plant, and install the spigot connections earlier in the construction phase,” says Pleaner. “This made cutting over to the new system a fast and seamless process during the Christmas shutdown period.”

POSITIVE OUTCOMES Pleaner says the completed project has delivered outstanding results. Other than the marked minimisation of production downtime, the upgrade has resulted in substantial improvements in energy efficiency, maintenance accessibility, room pressure and condition stability. It now also allows for future expansion of mechanical systems. Although no quantitative assessment has been carried out, it is expected that the dehumidification energy associated with maintaining close-control clean room conditions will be in the order of 23 per cent less for cooling compared to the original system. Re-heat energy has been virtually eliminated, due in large part to the high heat loads inherent within the filling rooms being served. Fan energy has

also been reduced, with high-efficiency, variable-speed plug fans replacing the original belt-drive centrifugal fans of the existing system. Importantly, room pressure has been found to be considerably more stable than was the case with the original airhandling systems, as are temperature and humidity conditions. Pleaner says plant maintainability has also been significantly improved. “The previous AHUs were located in a confined ceiling space, requiring maintenance personnel to traverse over crawlways and requiring bump caps to avoid potential head injuries – all the while having to carry filters and their required tools,” he says. The new plant provides safe and comfortable access to all the maintainable equipment, with sufficient plant space to store spare parts. Plant safety is also improved through the inclusion of “Lock Out Tag Out” valves, power isolators and access panels to moving parts. There is automatic plant shutoff in case of unauthorised access to operating fan components. Since completion of the project, GSK has reported that the new air-handling system has operated without incident and has surpassed expectations. ❚