UVic District Energy Plant Consolidation, efficient equipment, and passive design bring big energy savings

Consolidation, efficient equipment, and passive design bring big energy savings

By Esteban Matheus

Site plan

N The University of Victoria’s new district energy plant (DEP) replaces a system of outdated and inefficient boilers scattered throughout the campus with a consolidated system serving 32 buildings, and a 27.5 MW capacity of thermal heat.

1. The new DEP consolidates operations into one location: a glazed box open on the north and east sides to allow people to look inside. 2. Intake louvres are visible on the north facade of the plant. The three stacks are tied to the three boilers inside.

ARCHITECT DIALOG STRUCTURAL ENGINEER RJC Engineering ELECTRICAL ENGINEER AES Engineering MECHANICAL ENGINEER FVB Energy Inc. CIVIL ENGINEER Westbrook Consulting Ltd. CONSTRUCTION Farmer Construction LANDSCAPE ARCHITECT HAPA Collaborative COMMISSIONING AGENT C E S Engineering PHOTOS Martin Tessler

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Energy Intensity 135 KWhr/m2/year Reduction in energy intensity 72% based on ASHRAE90.12007. Recycled materials content 16% by value Water consumption from municipal source 40,970litres/occupant/year Reduction in water consumption 33 % Construction materials diverted from landfill 96%

The new plant also allows for future expansion, as well as integration of renewable energy sources. The district energy system as a whole will result in an overall reduction in energy use by the university of approximately 10%, and greenhouse gas (GHG) reductions of 6,500 tonnes/year, thanks to efficiencies created by consolidating heating facilities, improved equipment and infrastructure, and reduced losses in the system.

The DEP is built on a former parking lot in the southwest corner of the campus adjacent to a forest and publicly accessible botanical gardens and interfaith chapel. This site was selected for several reasons: - the most appropriate location in a new campus plan, - minimized the plant’s effect on sensitive campus ecosystems, - has adequate space for future renewable energy expansion, - connections to nearby buildings, - not part of the district energy loop, are easy to facilitate, directly linked to municipal streets for easy access, and - allows the university to showcase its infrastructure investments to the broader public.

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Floor plan indicating path of public tours

1 DE Campus system overview 2 Building input/output 3 Architectural feature: form, material 4 Mechanical feature: pumps 5 Mechanical feature: boilers

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6 Mechanical feature: economizer 7 Mechanical feature: stacks 8 Land feature: rain garden 9 Electrical feature: Ev charging 10 Fuel type, system and input 11 Building system overview 12 Digital display content 13 Control room operation

3. The sloped roof directs rainwater into the bioswale on the south side of the building to help manage stormwater. 4. The rain garden, located on the west side, adds to the natural beauty of the site while also serving as an important resource conservation measure. 5. Glulam columns, CLT panelling, and structural steel bracing ensure that the post-disaster facility will survive a major seismic event, and last for at least 50 years.

Diagram showing potential removeable heat graphed against the height of the building.

The building includes an electric vehicle charger, and bike racks and shower for the operators. The main occupied space is the plant’s control room, which is 100% daylit by operable windows that also provide a beautiful view of the forest to the shift engineers that are present 24 hours a day. All spaces are within five metres of these windows. The space undergoes 26.7 air changes/hour.

Large north-facing glazing allows views into the plant and brings in daylight, with a smaller curtain wall strip at the south. All lights are LED fixtures and work with daylight and occupancy sensors to achieve an overall projected consumption of 26.7 KWhr/m2. On the exterior, water runoff from the DEP roof and the surrounding landscape is conveyed via a bioswale that runs behind the building into a newly established rain garden. Water is held and filtered by the garden soil, and surplus amounts infiltrate into the surrounding native sub-soil.

During heavy rainfall, water is held in the upper tier of the garden and then spills over a weir to the garden’s lower tier for absorption into the sub-soil. This action slows the entry of storm water into the municipal system at a time when the system is under the most pressure. Within the building, a 33% water use reduction, or 19.23L per m2 per occupant per year (compared to a baseline reference building as per LEED 2009) has been achieved through the use of low-flow fixtures.

6. Operators are able to work in a spacious, naturally lit facility that has a warm, biophilic ambiance thanks to exposed CLT panels throughout the plant.

Recoverable heat is used to enable natural ventilation.

The building employs passive energy strategies starting with organizing all equipment by height clearance to create a building form that slants from the north east towards the south west. Intake louvres on the north and east facades, and exhaust louvres on the south and west elevations, maximize natural ventilation when cooling is required, eliminating the need for mechanical fans. Residual heat from the boilers warm the building in winter.

The high-efficiency burners in the plant are expected to result in a 6,500-tonne annual reduction in greenhouse gases (GHG). There are also future opportunities for the DEP to be retrofitted as a low-carbon fuel plant through the use of electric boilers, or expanding the plant to accommodate biomass fuel, which would further reduce GHG emissions.

The project team calculated a baseline EUI for this building typology at 376 kWh/m2. Anticipated EUI for the new DEP is 135 kWh/m2, representing a 64% reduction.

The main structural material of the 710 sq.m building is cross-laminated timber (CLT) for the roof and wall panels, and glulam columns. As this is a post-disaster building, additional steel structure was added for lateral forces associated with the high seismic zone in Victoria. The building is designed to last at least 50 years and survive a major seismic event.

The timber structure helps to reduce the embodied energy of the building, and imparts a warm and comfortable environment to the interior. A higher-quality metal standing seam roof was chosen to provide extended durability.

One of the most innovative aspects of the DEP is the educational component of the project. It was a priority for the university to showcase its investment in sustainable infrastructure while also educating students and the broader public about energy usage on campus. Signboards and digital dashboards describe the sustainable design of the building and the vital role the plant plays in reaching the University’s GHG emission reduction goals. The DEP has recently achieved LEED® Gold certification.

ESTEBAN MATHEUS IS ASSOCIATE ARCHITECT AND PROJECT LEADER FOR THE PROJECT AT DIALOG. MARTIN NIELSEN WAS THE PARTNER ON THE PROJECT, AND GEOFF COX WAS PART OF THE ARCHITECTURE TEAM.