Another heat wave has just been declared in Canada. It may be hard to believe, but we aren’t getting too far away from what Canadians know best — our winter season. We may not have had the types of winters that we were used to as children. But with climate change, anything is possible, and we must be prepared.
At the Royalmount shopping centre in Montréal, Qué, the safety of its customers was top of mind when designing and installing its geothermal heating system. One of the more interesting elements of this project is its snowmelt design.
“In the heart of Montréal, Royalmount is redefining urban living, but with its harsh winters ensuring year-round comfort and accessibility was a challenge,” shares Sébastien Pion, senior technical sales representative for GF Building Flow Solutions. “This technology melts snow and ice, preventing falls and keeping pathways clear. It also supports Royalmount’s commitment to sustainability by removing the need for harmful de-icing chemicals.”
Formally opened in September 2024, the shopping centre currently holds 170 stores and 60 restaurants. The project is aiming for LEED Gold and LEED-neighbourhood development certifications. It is reported that it will be a 100 per cent carbon-neutral development. LEED Gold is the second-highest level of LEED certification a building can achieve. The project must earn between 60 and 79 points within the LEED rating system.
Utilizing 253 loops of 3/4-inch helioPEX by Uponor, the entire outdoor walkway, stairs, and terrace are heated to melt any snow. In addition, the project utilizes 37 commercial stainless-steel manifolds and 74 10-ft. lengths of 1-1/2 inch Wirsbo hePEX piping.
The developer of the project, Carbonleo, designed the pedestrian-oriented space that prioritizes mobility. The pipe is embedded in the concrete of the sidewalks and staircases and circulates a mixture of water and glycol.
The project began planning back in 2017, with the installation of the snowmelt system beginning in March 2024 and finishing in late August 2024, just in time for the formal opening. As of the beginning of 2025, the snowmelt system was still in its commissioning phase, as the engineer fine-tunes the temperature control operation for the circulating fluid, a 50 per cent glycol mixture.
Project challenges
One of the major application challenges with the Royalmount shopping centre was due to the fact that the plaza was on two levels. Beneath the main level is a parking lot. The roof of the parking lot features a concrete slab, designed like a sandwich structure with a bottom and top slab. The top layer is where the Uponor PEX piping is located, while the electrical conduit and other components are found in the bottom layer.
Additionally, the plant life posed an issue for design due to the required drainage and water needed for the landscape aesthetic.
The glass walls around the project also posed issues for the manifold stations, making it impossible to hide them. In addition, some manifolds were originally supposed to go in the garage space. This would have required multiple slab penetrations for the radiant loops, which is not ideal.
“That saved lots of install time, considerably limited the risk of water infiltration, and made the manifolds easier access for future service,” shared Pion. “Our knowledge and experience anticipated potential challenges before we had to face them. For example, we requested the structural joints plans to help us plan with gbi the placement of the PEX loops in the snow melt system to minimize the number of transitions through joints, which is not recommended.” The mechanical building engineer on the site was gbi.
Why snowmelt?
A snowmelt system was chosen for this project to make it easier to remove snow, as no vehicles are permitted to enter the plaza. This is also anticipated to boost the life expectancy and lessen the maintenance of the concrete and pavers. In addition, it allows the shopping centre to reduce its need for de-icing chemicals.
As the source of heat for the project, a ground-source heat pump was installed, which incorporates around 90 pipe loops that are buried approximately 300 ft. in the ground. The loops were fabricated off-site and were required to be brought in, which made things a bit tricky due to the sheer size of the loops. The thermal loop system provides a high enough temperature to meet most of the snow melting demand.
A cascading heat source was also chosen for the project. Farming heat from the ground through the heat pump’s piping is only the second priority for warming the thermal loop. The loop’s priority is to capture heat from various sections of the mall that need to be cooled. If that is not sufficient enough, the thermal loop taps the heat pump system, while the third source is several electric boilers. More than one mechanical room was required and was hidden within the parking lot structure.