March 2nd, 2026
In Joule — Cell Press
Waste Heat Is Mostly a Waste of Time
AtmosZero co-founders Addison Stark, Ashwin Salvi, and Todd Bandhauer published a new commentary in Joule making the case against waste heat recovery, and for scalable, factory-built heat pumps instead.
Heat drives roughly three-quarters of industrial emissions. Getting off fossil combustion at the temperatures manufacturing actually runs on is one of the biggest levers available for reducing scope 1 emissions, and one of the hardest to pull at scale.
For decades, engineers have chased two strategies for putting industrial waste heat to work: turning it into electricity, or using a heat pump to raise it to a useful temperature. Neither has scaled the way the industry hoped. In a new technoeconomic analysis, AtmosZero’s founding team lays out why waste heat recovery so often looks better on paper than it performs in the field.
The math rarely works at low temperatures
Using a standard payback framework, the team compared an electric resistive boiler, a productized air-source steam heat pump, and a waste heat-sourced steam heat pump across a range of source temperatures. The air-source heat pump paid back against an electric boiler in about 2.8 years. A heat pump pulling 60°C waste heat, even with a better coefficient of performance, took 3.6 years, stretching to 6.5 years once just five days of installation downtime were factored in. Below 30°C, payback periods routinely ran past a decade.
Why bespoke engineering doesn’t scale
Boilers, solar panels, and lithium-ion batteries all scaled the same way: through mass manufacturing, not bigger one-off projects. Waste heat is the opposite case. Every facility has different sources, temperatures, and duty cycles, which turns each installation into a custom engineering job. Custom doesn’t scale.
The hurdles don’t stop at economics
- Large heat exchangers and new fluid runs are hard to fit on a crowded factory floor
- Waste heat isn’t always available exactly when a process needs steam
- Custom installations can trigger new permitting or environmental review
- Non-standard systems are harder to maintain and staff
- Manufacturers are understandably cautious about retrofits that risk downtime
Reducing scope 1 emissions starts in the boiler room.
The paper’s conclusion lines up with why AtmosZero built Boiler 2.0 the way we did: as a standardized, factory-built, air-source steam heat pump that drops into an existing boiler room instead of asking every facility to become a custom engineering project.
Read the full commentary in Joule
About the authors
Addison Stark, PhD (MIT) is AtmosZero’s co-founder and CEO. He previously worked on energy innovation at the Bipartisan Policy Center and served as a program director at ARPA-E.
Ashwin Salvi, PhD (University of Michigan) is an AtmosZero co-founder. As an ARPA-E fellow, he helped manage more than $75 million in federal R&D programs.
Todd Bandhauer, PhD (Georgia Tech) is AtmosZero’s co-founder and CTO, and a professor of mechanical engineering at Colorado State University. He holds more than 20 patents in advanced thermal systems.