News & Updates

A Cutting-Edge Zero-Carbon Hot Water Plant Is in the Works for Vienna House

An engineer works on the electrical and control panel for one of three Vienna House Droplet hot water plants.

Vienna House will be the first building in Canada to feature a new type of modular climate-friendly hot-water plant. The innovative system is currently being assembled off-site and will eventually be installed on the building’s roof, where it will produce endless zero-emissions hot water for residents.

It’s called the WaterDrop Droplet, and it’s the brainchild of Albert Rooks, CEO of Small Planet Supply, a Vancouver B.C. company.

As part of its commitment to sustainability—and in compliance with the greenhouse-gas requirements of the Vancouver Building By-law—the Vienna House design team agreed early on that electric air-source heat pumps would heat the water that the building’s residents will use in their sinks and showers.

But it wasn’t enough to simply choose electric over natural gas, a fossil fuel. The team also wanted to steer clear of heat pumps that rely on hydrofluorocarbons—a family of chemicals that, if accidentally released to the atmosphere, would exacerbate climate change.

Some newer-generation hot-water heat pumps instead use carbon dioxide as a refrigerant. Should carbon dioxide somehow escape the otherwise-sealed system inside one of these heat pumps, it would create far less harm to the climate and the Earth’s protective ozone layer than hydrofluorocarbons would.

Vienna House’s mechanical engineering consulting firm then undertook a rigorous assessment of three carbon-dioxide-based heat-pump hot water systems. The company, Introba (formerly Integral), considered numerous factors, including performance and reliability, annual energy and carbon, electrical requirements, and both up-front and operational costs.

In 2021, Introba ultimately recommended the Sanden SANCO2 system for Vienna House. Sanden heat pumps are manufactured in Japan and distributed in British Columbia by Small Planet Supply, a Vancouver, B.C. based company. The machines have a solid track record: Millions of SANCO2 hot-water heat pumps are reliably operating around the world, and were first installed in British Columbia homes back in 2016.

In the years following Introba’s assessment and recommendation, Small Planet Supply launched WaterDrop Systems, a spin-off company it set up in Tumwater, Washington. The firm developed and launched the WaterDrop Droplet—a modular all-in-one climate-friendly hot-water plant built around an array of Sanden SANCO2 heat pumps.

WaterDrop Droplets are manufactured off-site and designed to be craned onto a building’s roof. Vienna House will receive three Droplets, and serve as the technology’s debut Canadian installation.

Left to right: WaterDrop Systems engineer Tom Murgatroyd, Small Planet Supply CEO Albert Rooks, and WaterDrop Systems engineer Bryan Perkins.

WaterDrop Systems is assembling Vienna House’s three Droplets at its facility in Tumwater, Washington—just south of Olympia. Once complete, the company will ship them up to Small Planet Supply’s headquarters in South Vancouver.

Small Planet Supply will hold the Droplets in Vancouver until the Vienna House project team schedules them for delivery and installation via crane, likely in mid-2025. The company will then connect the three droplets to one another, to storage tanks, control valves, the building’s electrical supply, and to cold water supply and hot water lines. The team will then confirm and adjust controller functions to make sure everything is working as expected.

Though storage tanks, valves, and other components will be housed in a rooftop mechanicals room at Vienna House, the company offers a weatherproof self-contained housing for its Droplets, such as this example that it assembled for a project in the United States.

Small Planet Supply CEO Albert Rooks says that WaterDrop Droplets will consistently produce potable water at 65ºC / 150ºF in all climate conditions—even in Northern British Columbia.

Because the Droplet uses multiple heat pumps in an array, it is designed for redundancy. Should something go wrong with one heat pump, the rest will continue producing hot water for residents without interruption.

While WaterDrop Systems assembled the Vienna House Droplets in the United States, future hot-water plants for other buildings could be built closer to home.

That’s because in 2022 the provincial Ministry of Energy, Mines and Low Carbon Innovation awarded Small Planet Supply funding from its CleanBC Building Innovation Fund to build a WaterDrop Systems manufacturing plant in Richmond, British Columbia. The funding is also supporting R&D on a next-generation Droplet that could potentially store thermal energy much like a battery stores electricity.

Down the road, WaterDrop Droplets could potentially use the on-board storage technology to help reduce demand on the electricity grid during peak times, Rooks says.