Montreal has promised heated sidewalks along part of the 2.2-kilometre stretch of Ste-Catherine St. that is to be rebuilt in the downtown core. If it succeeds, it will become the first municipality to do so on a broad scale in Canada, and will join the few northern cities with similarly inclement weather to make the attempt.

Details on cost or what form of heating technology it plans to use are still under study. Heated sidewalks are planned for the first phase of work, which involves rebuilding 670 metres of Ste-Catherine from Bleury St. to Mansfield St. The construction is scheduled to begin in 2017 and be completed in 2019.

Proponents say the city will save in snow clearing, wear and tear on its infrastructure, and health costs linked to falls, while economic activity and tax revenues should increase as people are more inclined to go downtown in winter.

Detractors worry the technology, installation and operating costs could be excessive, and the heating system prone to expensive breakdowns.

Costs: Because it’s still studying plans, the city of Montreal does not have a final cost yet. Of the $95-million budget for Phase 1, $15 million has been set aside for “extra needs,” which include heated sidewalks, as well money for “smart city upgrades,” like free Wi-Fi and parking indicator signs, and money to offset construction costs for merchants.

Technology: The cities of Sapporo, Japan, and Oslo use electric coils beneath their sidewalks as heat sources. Reykjavik uses hot water running through plastic tubing beneath the surfaces to melt snow on some of their roads, sidewalks and parking lots, which comes from naturally heated geothermal groundwater pumped up from the earth’s crust. Saskatoon is looking into using solar panels or energy from water dumped into the river from the province’s power station. The city has given itself five years to study the project.

In Montreal, the city could easily tap into excess heat often wasted by large buildings that vent extra heat vapour through their chimneys or pour used hot water into the sewage system, said Jean-Claude Michel, general manager of the CCUM (Climatisation et chauffage urban de Montréal). The thermal heating company has been in operation since 1947, providing heat to one-third of the city’s downtown core via steam or heated water. The excess heat wasted by buildings could be instead rerouted into polyethylene piping the size of a garden hose embedded in loops in the concrete of the sidewalks.

“It’s like operating a skating rink, but easier,” Michel said. Laying the pipe is simple, but operating the pumping systems, automatic sensors that can detect cold and snow, and the condensers will be more complicated. In his opinion, electric wiring systems would be risky due to the threat of water leaking through corroded concrete and frost heaves cracking the wires. The CCUM could also supply energy, he noted. The system would only have to supply heat during snowfalls or icy periods, reducing costs, Michel said.

How Holland does it: The city of Holland, Mich., (pop. 33,000) decided to install a hydronic snow and ice melting system under the streets and sidewalks of five city blocks in 1989, in conjunction with a $3-million downtown renovation project. It uses waste heat from its municipally owned power plant, running excess hot water that was previously dumped into a lake through kilometres of underground polyethylene pipe. The system cost roughly $1 million to institute, paid through private donations, city budget and a tax on downtown merchants.

In service for almost 26 years, the system has been running well and proved a boon for the town, said Dana Kollewehr, downtown manager for the city of Holland.

“It’s been extremely positive, a really great asset from a safety and promotional aspect, in extending the walkable environment within downtown,” she said. Factoring in capital expenses, operations and maintenance, the system costs about $200,000 a year to operate. Less wear and tear from snow clearing meant the city could install brick pavers instead of asphalt, which makes it easier to open the road for occasional repairs, and the piping has aged well. But she adds the concept is feasible in Holland because the city has a free heat source. Some communities would need to install boilers to provide hot water, which would be costly and environmentally unfriendly, she said.

Holland gets more snow than Montreal each year, on average. Its heating system is able to handle the heavy snowfalls and extreme cold, Kollewehr said.

rbruemmer@montrealgazette.com

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