Trial / Demo
Working in partnership with IES Consultants, the Sisk Dublin Head Office retrofit project delivered a remarkable 49.92% total energy cost saving over the ASHRAE 90.1 baseline, one of the strongest performances achievable under the LEED framework.
For this retrofit project, IES Consulting used IES Virtual Environment (IESVE) to model an existing commercial office development with upgraded building service systems and a total serviced floor area of 3,241msq, including plant and storage areas. It was vital that, as the main hub for the Sisk business in Ireland, this three-storey office building reflected the values of its owner by ensuring that every element of the retrofit was focused on the people using the building.
It features a coffee shop, workshop and gym on the ground floor that all had to be taken into consideration for energy modelling, but more importantly it showed the benefits of using data and insight to repurpose an existing building to an even higher standard.
Operating around usual office hours and closed on the weekends, variations in lighting, occupancy and receptacle building loads were accounted for within the building energy model using ASHRAE 90.1 user guide best practice schedules.
Modelling methods
To accurately model complex HVAC, lighting and hot water systems, streamline LEED PRM documentation, and demonstrate exceptional energy performance, IES Consulting created an energy model of the proposed building at the following stages:
• A preliminary model based on concept/detailed design – this model was used to provide feedback to the design team in terms of the current LEED performance and impact of any additional energy conservation measures.
• A final model based on tender documentation which will be issued to the GBCI as part of the LEED design submission.
How IESVE made a difference
To address ASHRAE 90.1 2010 criteria, IES Consulting applied the Building Performance Rating Method (BPRM) using IESVE software. As mentioned, this involved creating an ASHRAE 90.1 2010 PRM compliant baseline model which the proposed model was compared against. This determined the ‘proposed’ building energy consumption when compared against the energy consumption of a specifically defined set of ‘baseline’ models. The final result was calculated based on an energy cost saving between the proposed and baseline models. These baseline models were automatically generated by the IESVE in line with ASHRAE 90.1 Appendix G 2010. The benefits of this are that the VE software is accredited in the US under EPACT, and also exceeds all criteria within the ASHRAE 140 standard.
Fully compliant
IES Consulting also carried out HVAC systems modelling for the building, and simulated the completed model to produce output reports using the IES PRM Navigator which was used as part of the design submission to the GBCI. This not only demonstrates compliance with LEED v4’s stringent energy performance requirements, but also ensures modelling transparency for any GBCI review.
Results
A total energy and cost savings of 49.92% were achieved over the ASHRAE 90.1 2010 baseline mode. And this means at 49.92% cost savings, it translates to 25 LEED ID+C optimised energy performance points scored.
• Interior lighting energy savings of 33.8%
• Heating energy cost saving of 59.8%
• Space Cooling: An 82.4% saving in cooling energy
• Fans-Interior: A 19.3% saving in fan energy
• Domestic Hot Water: An 81.6% saving in DHW energy due to low flow fixtures
Why IESVE?
“IESVE is perfect for detailed dynamic simulation. The software’s comprehensive toolset, from HVAC simulation and LEED reporting, enabled the team to manage the entire modelling process within one environment. It also illustrates that when you use the right people with the right tools, you can repurpose, retrofit and transform existing buildings into a more efficient and effective built environment.
And by leveraging IESVE's fully integrated modelling environment to manage everything from HVAC simulation to LEED reporting in a single platform, IES Consultants demonstrated that even a complex, mixed-use commercial building can achieve exceptional energy performance when our software is applied from the outset.”
Mark Tiernan, Senior Design Manager – Strategic Projects
MCIOB, MIDI
