Kelvin's Cozy smart device radiator cover can reduce heating costs by 45%

Kelvin founder Marshall Cox

COMPANY Kelvin, formerly known as Radiator LabsFOUNDED 2011MANAGEMENT Marshall Cox, founder and CEOFULL-TIME EMPLOYEES 22 and projected to grow to 33 by the end of the second quarterSYSTEMS SOLD TO DATE 15,000PRODUCT MIX Easily installed radiator covers that moderate the amount of steam heat that goes to each residential unit, keeping each apartment temperate and reducing heating costs by as much as 45%.GROWTH STRATEGY Kelvin plans to introduce new products geared toward energy storage. That includes existing radiator covers, heat pumps that work in above-freezing weather and thermal batteries that can automatically take in electricity at night and power the the heat pump during the day.WEBSITE kel.vin

Marshall Cox was working toward his doctorate in electrical engineering at Columbia University when his houseguest complained about the temperature of his student apartment.

The guest was Cox's twin brother, a ballet dancer who had accepted a part on Broadway and asked to crash. The year was 2012. At night, he was discovering the stifling indoor climate produced by steam systems in the vast majority of New York City residential units.

"He complained nonstop about the heating," said Cox, now the founder of Kelvin, a Brooklyn Navy Yard-based company that installs hybrid electrification HVAC systems for legacy buildings.

Having an engineer for a brother has its perks, and Cox fashioned a radiator cover out of bubble wrap to keep some of the heat out of the room and help his brother sleep. The rustic prototype eventually became a product called Cozy, a smart thermostatic radiator enclosure that works as a physical barrier to trap heat before it enters a room. An internet-connected infrared thermometer and custom software provide feedback to the building's boiler about when to turn on and off.More than a decade later, Cox is staring down a basement boiler-sized opportunity. New York City's buildings are sprinting to install affordable, quick-turnaround updates that will cut emissions in compliance with Local Law 97, which goes into effect in January. At the same time the federal government has made the radiator enclosure eligible for an Inflation Reduction Act tax credit, drastically reducing the cost of installation.

Cox said he feels that the proximity of the emissions deadline has required building managers and co-op boards to recognize that there are ways to reduce reliance on natural gas without incurring enormous expense. "A few years ago, it was electrify or nothing," Cox said of the atmosphere in the green-building movement.

But that mindset led to stasis, he said, since electrifying an entire building costs tens of millions of dollars, and residents have nowhere to live in the meantime. Co-op boards have a fiduciary duty to improve a building's bottom line, so they were unable to move forward on big environmental investments that would make the building more efficient in the long run. "People may say they care about it, and they do, but there's little wiggle room," he said.

Now, he said, the math is easier. A New York City steam-heated building could outfit its radiators with Kelvin's enclosures for about $10 per unit per month without paying a cent in capital expenditures up front. Since Kelvin modifies each enclosure to custom fit each radiator, installation partners don't need specialized HVAC certification to put them in. Afterwards, building-wide heating expenses drop 25% or more, according to a 2018 report by the New York State Energy Research and Development Authority. The company said installations can lower costs and energy use by as much as 45%. For most buildings, that alone would bring emissions below Local Law 97's 2024 and 2030 benchmarks, Cox said.

When an enclosure prevents heat from entering one apartment, which is already at a comfortable temperature, it heads to a colder apartment. The boiler does not have to kick on again, which brings about the savings.

"The people in the building who were really hot are really happy," said Chris McGinnis, who is on the board at the co-op at 2 Charlton St., a 175-unit building that installed the Cozy in 2021. Kelvin said there are 4,000 units in the northeastern U.S. that have a Cozy. Other customers include universities and city agencies.

At first, buildings had to pay up front. Cox later added rebates and creative financing, but he said the IRA tax credit eligibility has changed the business, drumming up demand from less well-capitalized landlords or co-op boards uninterested in levying assessments.

Cox's company was called Radiator Labs until recently, but on May 18 it announced it had raised $30 million in a Series A round and was rebranding as Kelvin. The money will go to meeting demand for the regulation-fueled growth ahead, especially by hiring engineers, operations staff and sales team members. The new name reflects an expansion from just radiators to a suite of smart products, including heat pumps and individual thermal batteries, which Cox said could help legacy buildings turn to electricity for 80% of their heating and cooling needs.

"I haven't been as excited about a company in a long time," said Christian Hernandez, partner and co-founder of 2150, a climate-focused venture capital firm with headquarters in Europe, which led the fundraising round. "Who’d have thought I’d be so passionate about radiator covers?"

The Partnership Fund for New York City also joined the round as an investor.