Net-Zero Hero

Net-Zero Hero

Designing Electrical Systems for Net-Zero Carbon at the UofC’s MacKimmie Complex Redevelopment

December 04, 2020 by Eleni Christos

The MacKimmie Complex Redevelopment will be one of the first buildings in the country of its kind. Originally constructed in the 1960s, the existing structure has been completely encased in an innovative, fully mechanized glass building shell; the building responds to changing weather conditions by automatically opening and closing windows across the façade, adjusting the internal air quality, temperature, and daylight to optimize energy use and occupant comfort. Striving for Net-Zero Carbon, the project is focused on reduced emissions and power consumption, while also generating green energy to offset its carbon footprint. The complex is one of the first being designed to the new Canada Green Building Council’s Net Zero Carbon Standard.

A significant amount of consideration had to be taken to reduce power consumption throughout the complex. Each workstation is provided with a local occupancy-controlled power bar which turns off after a few minutes of inactivity. Other receptacles throughout the space are provided with plug controllers at the branch circuit level which cut power when occupancy is no longer detected by the local lighting control occupancy sensor. This reduces phantom electrical loads on things like computer monitors, local desk fans, desk lamps, and other small devices that have a consistent electrical draw, even when not in use. While this might seem insignificant at first glance, the compounded energy usage over a year-long period is huge! Uncontrolled receptacles were also provided so critical loads (like a computer tower or laptop) could be plugged in and remain on without interruption of power.

The communications portion of the project is also one of the first of its size in the country. The complex will have a full GPON (Gigabit Passive Optical Network) installed. This means all the backbone and horizontal cabling throughout the complex will be fibre optics, with a small amount of copper patch cables. This reduces the amount of active equipment required in the communication riser rooms, in turn significantly reducing/eliminating the need for cooling that would normally be required in a typical copper installation. The fibre is extended from the communications room to an Optical Network Terminal (ONT) which replaces the traditional copper data device. This increases the network speeds and future-proofs the building for many years to come.

Another significant portion to the electrical Net-Zero design is the lighting and lighting control system. We provided a granular, adjustable low voltage lighting control design to allow maximum flexibility in the spaces, but also reduce power consumption. The open office areas were zoned in small clusters and each luminaire was provided with an on-board combination daylight/occupancy sensor. Each individual enclosed office space has a dedicated occupancy sensor and wall dimmer to promote a lower, more comfortable setting when possible. All sensors in the building are set to the minimum time-out setting of 7 minutes. All of the luminaires in the complex will be LED and have a performance of 100lm/W or better. Every component of the lighting design plays its own part to reduce energy consumption.

You can’t have Net-Zero Carbon without Green Energy! Reducing energy consumption is important, but net-zero isn’t achievable without contributing energy back onto the grid. While the mechanical systems throughout the building were significantly reduced by utilizing the double façade for climate control, it was still important to consider energy generation to ensure a net-zero target could be achieved. Once the complex redevelopment is complete, you will find a vertical integrated building façade solar array on the Phase II Block, and a horizontal roof top solar array on both the Tower and Block portions of the project. Combined, the complex will have upward of 600kW of green solar power.

The MacKimmie project has a been a learning experience for all involved. The level of collaboration between the consultant team and the construction team is ongoing and has been essential to the success of this project. Integration of systems and controls has been important to ensure proper functionality of things like the complex building façade. We are excited to see Phase II take shape as the Block portion of the project begins construction this summer, with estimated completion in 2022.