Rethinking Building Electrification: Inside RRC Polytech Stevenson Aviation HVAC Upgrade

Electrifying existing buildings is one of the biggest challenges facing the construction and engineering industry today — especially in cold climates like Manitoba. Aging infrastructure, limited electrical capacity, high ventilation demands, and operational constraints can quickly make decarbonization projects feel financially or technically out of reach.

At SMS Engineering, we believe successful electrification requires more than simply replacing equipment. It requires a deep understanding of how buildings operate, careful coordination across disciplines, and practical solutions that balance sustainability, performance, occupant needs, and long-term cost.

That approach was recently recognized with an Award of Excellence from ACEC-MB for the HVAC Upgrade at RRC Polytech’s Stevenson Aviation Campus — a project that successfully electrified approximately 99.5% of the building’s energy usage while reducing annual CO2 emissions by roughly 121 tonnes, all without requiring an electrical service upgrade.

Modernizing a Complex Existing Facility

Originally constructed in the 1950s as a warehouse and aircraft hangar, the Stevenson Aviation Campus was later converted into an educational facility supporting aircraft maintenance training.

Today, the building includes hangar space, classrooms, labs, workshops, and administrative areas — all with unique ventilation and heating requirements.

The existing HVAC systems were nearing the end of their useful life and relied heavily on

natural gas-fired rooftop air handling units.

In addition to high energy consumption, the rooftop configuration created ongoing maintenance and accessibility challenges, particularly during Manitoba winters when rooftop servicing introduces additional safety concerns.

At the same time, RRC Polytech was looking to significantly reduce the building’s carbon footprint while modernizing the facility to better support students, staff, and long-term operations.

Rather than approaching the project as a straightforward equipment replacement, our team evaluated the building holistically — examining operational patterns, ventilation requirements, electrical infrastructure, maintenance access, occupant comfort, and long-term energy performance together.

While many decarbonization strategies focus first on reducing heating demand through envelope upgrades or energy recovery systems, those options were not ideal for this facility.

Due to the building’s ventilation requirements and contaminated exhaust air streams, traditional heat recovery opportunities were limited.

Instead, our team focused on transitioning the building’s primary heating source from natural gas to electricity through the use of air source heat pump technology.

Designing for Manitoba’s Climate

Electrification in Manitoba comes with unique challenges. System performance during extreme winter temperatures, electrical demand limitations, maintenance considerations, and long-term operating costs all needed to be carefully evaluated.

After analyzing multiple approaches, our team selected a variable refrigerant flow (VRF) air source heat pump system capable of providing both heating and cooling while operating efficiently in cold weather conditions.

At an outdoor temperature of -8°C, the installed system achieves a heating coefficient of

performance (COP) of approximately 2.5, meaning it uses only about 40% of the energy required by conventional electric resistance heating to provide the same heating output.

This efficiency was critical to making the project operationally and financially feasible. It also helped manage long-term utility costs while significantly reducing the building’s reliance on natural gas.

Importantly, the project demonstrated that effective decarbonization does not always require pursuing absolute perfection. By strategically retaining natural gas heating for one infrequently used system, the project achieved meaningful emissions reductions while remaining financially practical and achievable for the client.

Solving the Electrical Capacity Challenge

One of the project’s biggest challenges was achieving electrification without upgrading the building’s electrical service and internal distribution systems — a major cost driver for many retrofit projects. To solve this, our team took a detailed and practical approach to analyzing the building’s operational demands.

During site investigations, we identified that the paint booth ventilation system, one of the facility’s largest heating loads, only operated for approximately 40 hours annually.

By maintaining natural gas heating for this single unit, we were able to dramatically reduce peak electrical demand while contributing only a negligible amount of annual carbon emissions.

This strategic decision ultimately made the broader electrification approach feasible while helping the client avoid significant infrastructure upgrade costs.

To further optimize building demand, SMS Engineering designed a power metering and

load shedding system that continuously monitors total building electrical usage and temporarily sheds non-essential loads during peak heating conditions.

By carefully studying occupancy patterns and Winnipeg climate data, we determined these peak conditions would occur only during limited extreme weather events, often outside occupied hours. This allowed the project to remain within the existing electrical capacity while maintaining reliable building operation.

Engineering Beyond the Equipment

This project required innovative thinking well beyond the HVAC equipment itself.

While rooftop access is still available through a new concealed ladder system, routine maintenance activities no longer require regular rooftop servicing during winter conditions, improving overall safety and operational efficiency for facility staff.

Rather than replacing the existing rooftop configuration with new rooftop units, our team repurposed an underutilized mezzanine area within the building to house the new air handling units.

This significantly improved long-term maintenance accessibility by allowing the primary HVAC equipment to be serviced safely from within the building.

The mezzanine space also introduced several coordination challenges across mechanical, structural, and architectural disciplines.

To maximize the available footprint, two air handling units were vertically stacked — an approach that required careful consideration of loading, vibration, service clearances, and code requirements.

The final design allowed the units to remain fully serviceable from the mezzanine level while staying within the client’s spatial constraints.

The project also modernized the building’s ventilation system by converting existing bypass boxes to variable air volume (VAV) systems.

This reduced fan energy consumption while allowing much of the existing ductwork to remain in place, minimizing project costs and material waste.

In addition to improving energy performance, the upgraded systems brought the facility up to current ventilation standards while enhancing indoor air quality through MERV-13 filtration and improved containment within specialized learning spaces. These upgrades provide students and staff with a healthier and more comfortable learning environment while supporting the long-term functionality of the facility.

A Practical Path Forward

The Stevenson Aviation Campus HVAC Upgrade demonstrates that meaningful electrification is achievable — even within complex existing facilities and challenging climates.

For our team at SMS Engineering, this project represents the value of taking a practical, integrated approach to decarbonization. By carefully analyzing building operations, challenging conventional solutions, and collaborating closely with the client, we were able to develop a system that balanced sustainability goals with operational reliability, occupant needs, maintenance accessibility, and financial feasibility.

As more organizations explore pathways toward building electrification and carbon reduction, projects like this reinforce an important reality: successful outcomes are not driven by a single technology, but by thoughtful engineering, collaboration, and a willingness to approach every building as a unique opportunity for innovation.

Check out more project photos here.