Those of you from Sydney will probably be familiar with the former pink façade of the Australia Post building on Cleveland Street.

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1 Buildings account for almost half of annual worldwide energy consumption and green house gas emissions. They are, therefore, perhaps the most important target area for any strategy to address climate change. Since the late 1990s new commercial office buildings in Australia have increasingly addressed sustainability considerations and incorporated green technologies in their design. However achieving similar efficiency and sustainable design in older building stock still has the perception of presenting many technical, financial and social challenges Cleveland street is a prime example of a building where a major refurbishment to achieve best practice sustainability would encounter the full gamut of refurbishment challenges. 1

2 Those of you from Sydney will probably be familiar with the former pink façade of the Australia Post building on Cleveland Street. Constructed in 1989 NSW headquarters of the Australia Post Corporation Single tenant, owner occupied building. But as Australia Post s requirement for space in the building diminished various areas were tenanted out. In 2009 Australia Post engaged NDY to determine an upgrade plan for the replacement of end of life plant equipment. Then with the introduction of Commercial Building Disclosure (CBD) in 2010 this engagement developed into a NABERS improvement pathway and eventually a full refurbishment of the building. 2

3 SO WHAT ABOUT THE BUILDING ITSELF? It holds a prime position in Sydney s south with approximately 26,000m 2 of NLA over 5 levels, it provides parking for 245 vehicles, and has a a ground floor combining lobby, child care, gym, cafe and retail space. For a building designed in the late 80 s it benefited from a good quality façade with: Double glazing Well insulated walls, A well considered floor plate that allowed light into the space while managing heat gain Insulated spandrel panels (not full floor to ceiling glazing), and External shading on sections of the north and west facing part of the facade 3

4 NDY commenced work on the project by liaising with Australia Post to create a sustainability roadmap. This aimed to both reduce energy consumption and increase the capacity of the existing system while creating a strategic plan for HVAC end of life replacement. As this process developed Australia Post noted the potential for repositioning the building in the rental market through sustainability improvements. With the introduction of the Commercial Building Disclosure program, NDY s engagement was expanded to create a pathway to an improved NABERS Energy Rating. In 2012 Australia Post undertook a review of their property strategy, making the decision to sell the building. In order to maximize the sales price and update their facilities, a full building upgrade was initiated with a completely new tenancy fitout. Targets to achieve a minimum 4.5 star Base Building NABERS Energy rating and reposition the building as an A grade office space were set. Australia Post opted to remain within the space as renovations were completed thereby adding additional complexity to the project brief. 4

5 WHAT DID WE DO? Firstly, we developed a road map of potential upgrade options with a list of opportunities and cost estimates. Then we sat down with the client and prioritised these initiatives, and then carried out energy modelling on the preferred options and verified the impact of each of the upgrades. The base building energy model was able to achieve 5 stars with a reasonable confidence buffer without a major redesign of the building mechanical, electrical, fire and hydraulic systems. With the final report including a prioritized list of projects with approximate costs and star improvement steps for each. Getting to 4.5 Stars was achieved through building services upgrades and fabric improvements including new double glazing. However, it was a rooftop PV system that was crucial in reaching the 5 Star NABERS target. In addition to energy efficiency and renewable energy systems, the Upgrade works also included specifications for sustainable materials, waste minimisation and management, water efficiency and rainwater harvesting, ecological considerations in the landscape design and improved occupant comfort & health through indoor environmental quality initiatives. These outcomes assisted Australia Post to reposition the building to meet current best practice sustainability benchmarks and deliver a PCA A Grade quality space, which substantially improved the capital value of the building, and made it a more attractive space for Australia Post and the other building tenants. The work transformed a tired, dated underutilised office asset into a modern, efficient, attractive space which meets best practice standards of sustainability performance. 5

6 The initial Asset improvement plan created by NDY covered most of the easy wins including sub metering, system recommissioning and upgrades to lighting and BMS infrastructure. Mapping further improvements to the building raised other issues frequently encountered on refurbishment projects. These included issues around staff and social acceptance of the alterations, discussions about what economic payback is acceptable and whether potential technological risks were palatable. 6

7 The main improvements implemented included; Metering o We separated the Base Building from Tenant energy consumption, which allowed for a Base Building NABERS energy rating to be assessed, thereby providing a more useful metric that the building manager has more control over; We completed a full BMS Upgrade; o Which improved the resilience of the buildings systems the old BMS system was at the end of its life and provided limited control over the building; o And the upgrade improved the controls functionality the updated system provided much better programmability and allowed the implementation of an advanced controls system for optimised energy efficient operation; We then conducted a full re-commissioning & tuning of the building s mechanical systems which optimised their operation; Common area lighting upgrade and controls; A VAV system upgrade and optimization; Changes to the Economy cycle to Enthalpy control; Outside air damper replacements; The installation of VSDs on all pumps and fans and implementation of energy efficiency strategies; Solar heat gain reductions through improved glazing shading coefficients on all facades; and The installation of a roof-mounted photovoltaic solar power generation system with at least 275 kw capacity, the final system was 283kW. 7

8 RESULT OF THE UPGRADE The project was completed in May 2014, on time, and under budget without disruption to Australia Post operations. The building is on track to achieve its commitment to a NABERS Base Building Energy Rating of 5 Stars The building achieved a 5 Star Green Star Office v3 Design rating and is currently undergoing Assessment of both 5 Star As Built and Interiors ratings Cleveland street was also a finalist in the Heritage and Sustainability category and was highly commended in the building and structure categories at last months Engineering Excellence Awards 8

9 The mechanical services upgrade works included the following: AIR CONDITIONING ZONING AND AFTER HOURS OPERATION The air conditioning system was re-configured to match the PCA Grade A zoning requirements. The standard hours of air conditioning services were programmed via BMS in accordance with the lease agreements. An interactive internet capable interface was installed to be used by the tenants to request the air conditioning services during afterhours occupancy and provide reports on each tenants after hours air conditioning usage. BUILDING MANAGEMENT AND CONTROL SYSTEM (BMCS) UPGRADE A new Open Protocol BMS which incorporating a Zone Voting Control Strategy with Dynamic Demand Response (DDR) was installed to maximise the efficiency of the building. Incorporated lighting control, and interfaces with other systems such as Fire and Hydraulic Services. Plant load shedding is also controlled by the BMCS. The new Energy Monitoring System (EMS) also provides metering, monitoring and reporting of all of the building services with dynamic reporting, benchmarking and real time NABERS rating estimates. CHILLER REPLACEMENT AND CENTRAL PLANT UPGRADE The existing Trane chiller was deemed to be at the end of its economic operating life and was replaced with a new high efficiency Powerpax chiller, to operate together with an existing recently replaced Powerpax machine. The remaining Trane water cooled centrifugal chiller was retained as a standby chiller. Spare parts from the redundant chiller and its refrigerant (R123) have been stored on site for future maintenance of the remaining Trane stand-by chiller. New chilled water buffer tanks were installed in the chilled water by-pass line to improve after hours and low load chilled water system operation. New motorised valves were installed to the condenser water system to improve staging of the cooling towers. New chilled water and heating hot water differential pressure switches were added to control the system operation. The new chilled water system provides flexibility for low load conditions, partial occupancy and after hours air conditioning. The chilled water system is designed for a stable operation at 10% of the maximum cooling load of the smaller chiller. The chilled water pumps will be designed to reduce their speed down to 50% during the part load conditions to enhance system energy efficiency. To maximize the efficiency of the mechanical plant the control system incorporates a number of setpoint reset strategies. 9

10 VAV OPTIMISATION CONTROL STRATEGY Typically, VAV systems are controlled using averaging or high select calculations that regulate supply air pressures and temperature to cater to the worst zone. Trim and Respond Zone voting control strategy dynamically resets the control setpoints using a zone voting technique. To handle the increased data associated with this more dynamic and responsive control strategy, the controls network and the BMS server hardware was upgraded. Zone temperature sensors are used to incrementally reset the plant setpoints The more requests there are for a change in temperature, the quicker the response. As the requests reduce, the system trims back its reaction time. The control strategy only responds when there are requests for a temperature change from multiple zones, rogue individual zones are ignored. In a conventional system the building can cycle between heating and cooling modes because the system is attempting to be too responsive, wasting energy. The trim and respond control strategy t ignores the first 10% of zone requests to reduce sensitivity. The result reduces energy and produces more stable internal conditions with the same level of tenant complaints as before. 10

11 BUILDING TUNING NDY were engaged to carry out the building tuning. This typically involves meeting with the controls and commissioning contractors and the building management to discuss the performance and tuning requirements on a monthly basis. For this project, NDY had remote access to the system and are caring out the tuning process by monitoring the performance via the BMS trend logs and instructing the BMS contractor to make adjustments to the control parameters. To record the tuning process, tuning reports were generated which identified the time and date, parameter changes and reasons for change to audit the process and keep all parties up to date with the status. Initially, the system was observed to be sensitive and responded too quickly to the zone requests. Having adjustable minimum request parameters allowed for quick and effective tuning to take place to stabilise the system. The system is currently set up to ignore approximately the first 10% of zone requests, a significant amount which would not have been envisaged from the initial design. This value has proved to be optimum, resulting in stable conditions and few tenant complaints. 11

12 ELECTRICAL UPGRADES The existing tenant area lighting was replaced with single 28W T5 linear fluorescent ceiling recessed troffers with high frequency DALI electronic ballasts to meet the requirements. The luminaires were fitted with semi-specular louvers for visual comfort (i.e. to provide some ceiling illumination) and the reduction of glare. The lighting was designed such that lighting levels within 95% of the net lettable area were not greater than 400lx. Additionally, the lighting power density was designed to be less than 2w/m 2 /100lx. The new luminaires are individually addressable via a DALI control system which allows for future flexibility. Most areas are controlled via motion sensors with separate settings for trading hours and after hours modes. Lighting within daylight zones have been separately zoned and programmed for daylight harvesting (i.e. automatic dimming based on lighting levels from daylight). Lighting control zones are less than 100m 2. Soft wiring has been installed for lighting with PVC best practice cabling. 12

13 THE SOLAR SYSTEM NDY carried out detailed energy modelling of the building in order to determine the possible NABERS rating resulting from the building upgrades. It was found that even with the mechanical, controls, lighting and building fabric upgrades, the base building areas would still consume excessive energy required to obtain the 5 star NABERS rating desired by the client. NDY proposed a photovoltaic system to offset this excessive base building energy consumption. Utilising the ample roof space, a 283kW system was designed which included vertically mounting of panels to North facing walls. The 1048 solar panels at Australia Post will produce MWh of electricity per annum; enough electricity to reduce the base building electrical load by 25% at peak times. The strings of panels were set up to minimise the impact of shading due to existing roof mounted structure and equipment. This system was the largest roof mounted photo-voltaic system in Sydney at the time of installation. In order to reduce the cost of installation and use the power generated efficiently, the photovoltaic system was connected to the main mechanical services switchboard located within the plant room on level 6. This retained the power generation close to the major base building energy user. 13

14 HYDRAULIC INFRASTRUCTURE UPGRADE The existing amenities have been replaced with new water saving fixtures. The hand basins have been replaced with 6star WELS rated mixer taps rated at 3.5L/ min, the WC s with 4star WELS rated 4.5L (full flush) and 3L( half flush) and Urinals with 6star 0.8L flush. The existing 2,000L break tank for Irrigation has been removed and in its place 15,000L of rainwater re-use. The rainwater re-use / Irrigation water tank has been located within the level 6 plant room, in order that no energy be used to pressurize the irrigation main, gravity will perform this task. Energy (Gas) metering has been provided to the cooling towers and hot water plant in order to observe energy use for continued feedback to assist with the creation of energy efficient building management protocols and provide relevant data for the implementation of future upgrades. The fire services upgrade works included the following: Fire Hydrants Fire Hose Reels Fire hydrant and hose reel protection for effective operation by building occupants and fire fighters were provided throughout the building. A new fire storage tank has been provided allowing the recirculation of test water within the building. This tank has been sufficiently i sizes to promote the complete capture and recirculation of water during fire sprinkler and hydrant pump run testing and the reuse 99.78% of water used for fire system testing. 14

15 The building has undergone a complete facility upgrade along with a full fitout of half the building. It is estimated the building will achieve annual electricity cost savings of over $340,000 from an energy reduction of at least 1.7GWh per annum, which is over half of the buildings consumption before upgrade. Some of the key issues that were addressed during the works included; Demonstrating code compliant fire safety, especially as the addition of amenity stairs across two floors doubled the floor plate to show compliance over; Ensuring that retained components of the HVAC and Electrical systems were adequately protected, cleaned and/or refurbished; Understanding the performance of the building fabric where it is largely existing; Adapting the space to be able to change as occupant behaviour changed; Communicating change to an existing building occupants; and Involving the community in the refurbishment. The result of all upgrade works has been to improve energy efficiency of the building. Which will save operational costs, as well as significantly improving the buildings NABERS rating, which helped reposition the building for sale. The services upgrade also improved occupant comfort and satisfaction through improved control and indoor air quantity. 15

16 So what provided the most significant impact on the energy reduction? the controls modifications are the clear differentiator. Buildings are dynamic with constant changes in ambient conditions and occupancy levels. The logic behind Trim and Respond makes sense to track the behaviour of the building and provide just enough conditioning to meet the zone requests, always trying to trim back when the requests are satisfied. The fan efficiency is now being maximised and the tuning process is further streamlining the buildings performance. Considering the existing infrastructure of the building, the outcome has been very successful. Australia Post Refurbishment project proves that a well engineered services upgrade can provide substantial energy savings and overcome many design challenges. 16

17 Following on from the refurbishment project Australia Post as a tenant have continued to make changes to the way that they operate in the building, Cleveland Street will be taking delivery of new electric delivery vehicles by the end of 2014and the site has completed blower door testing on areas of the facade to establish the buildings air tightness. This highlights how with an involved and engaged client a focus on efficiency in refurbishment can have a much broader effect outside the simple energy and water savings. 17