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Carbon Reform, a startup removing carbon emissions from office buildings, last month raised $4.2 million to close out a $5.5 million convertible note round, the company tells Axios.

Why it matters: The company's unconventional tech gives landlords another tool to cut energy consumption and meet local emissions mandates.

The big picture: New York City, Maryland, and other U.S. cities and states have started requiring large buildings to cut emissions or pay costly fees.

Driving the news: Carbon Reform retrofits commercial HVAC systems with air-purification machines that also trap carbon dioxide and convert the emissions into limestone pellets.

The machines recirculate cleaned air, reducing energy consumption by HVAC systems that otherwise need to pull fresh air from the outside.

Carbon Reform meanwhile collects and sells the limestone to companies such as recycled carpet makers and paint-filler manufacturers.

By the numbers: The tech can cut a building's HVAC use by 50%, in turn reducing energy bills by 20%, marketing manager Meaghan McKiernan tells Axios.

"We see payback in less than a year for building-wide deployment," McKiernan says.

The latest: Azolla Ventures, Cisco Foundation, and RockCreek participated in Carbon Reform's convertible note round, which closed in January after a roughly nine-month raise, McKiernan says.

The startup has raised over $9 million since its launch in 2020. It's labeled its latest round a seed-plus raise.

The fine print: RockCreek invested through an impact fund backed by utility Exelon.

How it works: Carbon Reform leases its devices to customers, so far largely to utilities such as Baltimore Gas & Electric, McKiernan tells Axios.

It's installed two of its full-size Carbon Capsule machines. Each can scrub the air for roughly 20,000 square feet of office space.

The company has also deployed five of its smaller Carbon Canister air purification and carbon removal machines.

What's next: "We're focusing on the mid-Atlantic region," McKiernan tells Axios. "A lot of interest from energy utilities and energy consultants. ... Our next hopes are not only large commercial office spaces, but also schools."

Editor's Note: Due to updated information provided by Carbon Reform after publication, this story has been corrected to reflect that the company raised $5.5 million in its convertible note round (not $4.2 million).

Carbon Reform raises $5.5M for indoor carbon removal

Its tech converts office CO2 emissions into limestone.

A photo of a metallic, rectangular Carbon Reform "Carbon Capsule" device, roughly the size of a fridge on its side, in an office, with duct work running to the ceiling.

Each Carbon Capsule device is roughly the size of a fridge laid on its side. Photo: Courtesy of Carbon Reform

Carbon Reform, a startup removing carbon emissions from office buildings, last month raised $4.2 million to close out a $5.5 million convertible note round, the company tells Axios.Why it matters: The company&#x27;s unconventional tech gives landlords another tool to cut energy consumption and meet local emissions mandates.

Carbon Reform raises $5.5M for indoor carbon removal

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