ABB synchronous reluctance motors and drives enable reduced carbon emissions in an energy efficiency upgrade for Hobart CBD building
- The equipment upgrade has enabled a 5.1 tonne reduction in annual CO2 emissions.
- For the supply air fan application energy consumption was reduced by a staggering approximation of 40%.
- For the chilled water pump application, energy consumption was similarly reduced by around 35%.
- The building property managers have experienced significantly lower operational costs and energy bills.
The Sypkes Group’s property at 85 Macquarie Street is a multi-tenancy commercial building that features corporate office spaces including those occupied by government and parliamentary officials. It is situated in the heart of Hobart’s Central Business District (CBD), in Tasmania. The ten floors are occupied by approximately 250 workers on any given workday.
Stuart Davey Sypkes, Director of Property of the building recognised issues with aging equipment used to manage the heating, ventilation, and air conditioning (HVAC) operations, and consulted Enginuity Power Solutions, who collectively engaged ABB Authorized Value Provider A1 Electric Motors, to conduct an in-depth analysis of the existing system’s process performance.
The HVAC application that underwent the analysis incorporated motors and drives responsible for powering and managing the chilled water for 85 Macquarie Street, and others that were depended upon for powering the supply air fan for the entire building.
Solutions identified
Tom Green, Managing Director at Enginuity Power Solutions, together with Chris Cheong, Director at A1 Electric Motors, conducted an analysis which recognised that 85 Macquarie Street was eligible to bring their existent motor selection down a size. The supply air fan was originally powered by a 15kW motor but it was determined that the necessary motor that would be adequate to drive the load was instead an 11kW motor. In turn this would enhance their system, reduce operating costs and increase energy efficiency.
ABB synchronous reluctance motors (SynRM) and ACH580 variable speed drives (VSD) were ultimately selected for this project.
The difference made when upgrading to a high-efficiency IE5 SynRM motor
HVAC systems worldwide rely on millions of low-voltage (LV) electric motors to run pumps, fans and compressors. However, these motors consume on average about 50% of the energy used in buildings. Most of the motors in our buildings today are only efficiency class IE1 or IE2.
Rory Paltridge, Division Manager for Motors at ABB Australia says, “Climate change and environmental responsibility are propelling changes across all industries. These SynRM motors offer industrial users a great opportunity to reduce their electricity usage and CO₂ emissions while also benefiting from increased productivity and lower life cycle costs.”
Energy efficiency, cost effectiveness, and reliability without compromising on comfort
The ACH580 is a drive that stands out for its ability to guarantee air quality in the most energy efficient and cost-effective way in both normal and critical situations.
Because HVAC systems run at partial loads close to 99% of the time, VSDs can save energy by an average of 20 to 60% compared to traditional damper or valve control methods. It’s possible because drives can adjust the motor speed of equipment directly to meet the current building needs.
When asked about the asset replacement at 85 Macquarie Street, Stuart Davey-Sypkes, Director at SFO Property said, “It just made sense every way I looked at it. Reducing energy consumption in the building by upgrading the foundation that underpinned the plant and where equipment played a pivotal role, was the logical first step in a broader strategy to reduce the running costs of our building. The ROI calculations looked compelling and it was backed with sound logic, which resulted in an easy ‘yes’ to undertake these upgrades.”
12 months strong and data that radiates positive results
It’s been found that the equipment upgrade has enabled a 5.1 tonne reduction in annual CO2 emissions. To offset this much carbon you would have to plant approximately 2.5 hectares of trees every year for the life of the asset. That’s equivalent to an area the size of 1.5 Melbourne Cricket Grounds (MCG), or five return trips between Paris and New York by plane.
A look at the supply air fan application shows energy consumption was reduced by around 40%. Thanks to the implementation of the ABB ACH580 VSD inrush currents have been reduced by over 140A per phase and kVA demand has been reduced by over 100kVA. This has the potential to further reduce the energy costs at 85 Macquarie Street by over $12,000 AUD annually.
With the chilled water pump application, energy consumption was reduced by around 35% with a reduction in line current of approximately 43%. Owing to the new VSD inrush currents have been reduced by over 92A per phase and kVA demand has been reduced by over 65kVA. This has the potential to further reduce the energy costs by over $8,400 AUD annually giving the project’s capital investment an ROI of approximately 18 months.
By the numbers — a comparison of then and now
Figure A demonstrates the significant reduction in inrush current on start-up (the old system showed around 155 Amps per phase, versus the new system of around 14 Amps per phase). The old system required 109 kVA to start the motor and following the implementation of the ABB SynRM motor and drive package, this was reduced to just 9.74 kVA. This is substantial as most commercial customers in Australia are charged for peak kVA demand. A reduction in kVA demand, therefore, equates to significant operational cost savings.
Figure B is again a revealing comparison of the benefits of the new supply air fan system and highlights the current draw/inrush current during system start. It demonstrates the load profile of the current draw of the system when the motor starts. Notice the massive peak in current draw in the top graph when the old system was using Direct On Line motor starting (DOL).
In comparison, Figure C which profiles the performance of ABB’s SynRM motor and ACH580 drive package shows the load ramp rate increase gradually signifying more managed control of speed and power. This results in reduced mechanical stress on the system and equipment as a whole which extends equipment lifetime, reduces the need for service downtime, and emphasises the reduced energy consumption in the application and associated costs.
Tom Green says, “We focus on supporting industry and bridging the gap between intangible ideas and delivering evidence-backed innovative, future-proof solutions.
Our partnership with Chris and his team at A1 Electric Motors and our collaborative approach cements our ability to consult, design and deliver on projects such as these.”
Chris Cheong says, “We’re always thrilled when we’re able to see potential energy savings from equipment upgrades with the use of the ABB EnergySave calculator coupled with ROI data such as that provided by Enginuity Power Solutions.”
Learn more about ABB’s SynRM motors
Learn more about ABB’s ACH580 drives for HVAC applications
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