This clever radiator hack can make your 100-year-old heating system more efficient

Inside an 80-year-old apartment complex in Brooklyn, the steam heat system had always been chronically uncomfortable in the winter. Apartments on the top floors could be 90 degrees even with the windows open on a cold January day; apartments on the lower levels were never quite warm enough.

But over the past few years, the buildings have transitioned to a new system. The old radiators are still in place. But technology called a “Cozy” now encloses each of them with an insulated box that helps hold heat inside. When sensors detect the room getting cold, a small fan blows out warm air without forcing the boiler in the basement to run again. Heat is distributed more evenly through the building. Tenants can also use an app to adjust the temperature in their apartments—something they couldn’t control in the past. Because the buildings’ steam heat was especially inefficient, the change has helped cut energy use by 43%.

Kelvin, the startup that designed the technology, now plans to combine it with heat pumps in other apartment buildings that are trying to shrink their carbon footprints. “What I’ve tried to build at Kelvin are pathways for these buildings to decarbonize in a financially driven manner—what a business would decide to do even if there wasn’t some kind of big piece of legislation that was trying to force them to do it,” says Marshall Cox, Kelvin’s CEO, who designed the Cozy technology more than a decade ago to deal with his own overheated apartment.

A New York City law that went into effect for large buildings this year will require them to meet strict emissions limits by 2030. (D.C. has a similar law.) Still, Cox says that building owners are slow to make the switch from fossil fuels. “With a boiler, people don’t replace those until they die,” he says. When a boiler breaks in the middle of the winter—and tenants immediately need heat—landlords typically just buy a new gas-powered boiler. Installing heat pumps often requires more complicated and expensive steps like putting holes in apartment walls and upgrading wiring.

Instead, Kelvin wants to help buildings install Cozy units to reduce the energy use from boilers. At the same time, it plans to add low-cost window heat pumps that can be easily installed—and run them only when the temperature is above freezing, which means that it can be less expensive. (Freezing weather necessitates an additional system to protect the device from falling ice from condensation, so Kelvin’s approach avoids that).

The heat pumps will be paired with thermal batteries that can store power. In the summer, the heat pumps will provide air conditioning, and the thermal batteries can charge at night when there’s less demand for energy. That means that buildings can get paid by the local utility for reducing demand at peak times; that revenue can help cover the initial cost of installing the new equipment, Cox says.

In a climate like New York City’s, the apartments can rely on heat pumps throughout most of the winter. Then, only when it’s especially cold, the radiators turn on automatically. As the Cozy system runs, Kelvin will collect data about the building’s energy use to make a future plan for the owners to electrify completely. When the boiler later breaks, “you have a backup heating system in every apartment in your building, so it’s not an emergency,” says Cox. At that point, the building could add more equipment to fully decarbonize; as Cozy units run, Kelvin plans to use the data that it gathers to help buildings design final systems in advance.

Kelvin plans to begin rolling out the first pilots with its new “hybrid electrification” system later this year, while it continues to install more Cozy units. A new partnership will help accelerate the work: Kelvin announced today that ClearGen, a company that provides capital for energy solutions, has committed up to $100 million in financing to help apartment building owners install the technology. The cost of the hybrid systems isn’t yet available, but the Cozy is available for a zero-down, $15-a-month subscription per apartment.

Original article can be read here.