Gradient’s Heat Pumps Get New Smarts to Enable Old-Building Retrofits

Old buildings have a problem. Many structures built decades ago—when massive boilers were cutting-edge technology—struggle to maintain comfortable temperatures. They’re often too hot or too cold, but seldom just right. For building owners in cities like New York, the solution has traditionally meant expensive, time-consuming HVAC overhauls. But a climate tech startup called Gradient is changing that equation with intelligent window heat pumps and newly launched software that transforms how multifamily buildings manage heating and cooling.

The Challenge of Aging Building Stock

Across the United States, thousands of buildings are reaching a critical juncture. Steam boilers that have served for generations are nearing the end of their operational lives, particularly in older urban centers like New York City. Traditional HVAC retrofits to replace these systems can cost millions of dollars and require extensive construction—tearing out walls, rewiring electrical systems, and disrupting tenants for weeks or months.[1]

This reality has created what Gradient’s chief technology officer Vince Romanin calls an “ignored sector.”[1] Multifamily residential buildings, colleges, universities, and public housing complexes have largely been overlooked by traditional HVAC companies, despite representing a massive market opportunity for climate solutions. The buildings themselves are often fine structurally; they just need better climate control systems that don’t require invasive renovations.

Window Heat Pumps: A Different Approach

Gradient’s solution centers on horseshoe-shaped window heat pumps that look superficially similar to traditional window air conditioners but function fundamentally differently.[1] Rather than blocking views and only providing cooling, these units can both heat and cool year-round. More importantly, they install in under 30 minutes without requiring ductwork, rewiring, or significant tenant disruption.[6]

The technology addresses a critical pain point in building electrification. Many older buildings have aging electrical infrastructure that cannot support the full 12-amp loads required by traditional minisplit heat pump systems. Gradient’s 120V window units sidestep this problem entirely, allowing building owners to electrify without costly electrical upgrades.[1]

The company has already demonstrated the viability of this approach through pilot programs with major institutions. Gradient has worked with the New York City Housing Authority to install its heat pumps in public housing and conducted pilots in affordable-housing complexes. The startup is also engaging with colleges and universities, many of which operate dormitories that weren’t designed with modern climate challenges in mind.[1]

Nexus: Software That Scales Intelligence

The real breakthrough came recently with the launch of Nexus, Gradient’s new intelligent energy-control software platform.[2] While the window heat pumps themselves represent an innovative hardware solution, Nexus transforms how building managers operate fleets of these units across entire properties.

Nexus links every window unit in a multifamily building into a coordinated, software-defined system.[2] Rather than treating each unit as an independent device, building managers gain unprecedented visibility and control through a single dashboard that consolidates temperature trends, runtime data, alarms, and energy usage across every unit.[2]

The platform introduces several key capabilities designed specifically for multifamily operators:

Comfort guardrails allow building managers to set heating and cooling boundaries that align with operating budgets while tenants retain individual control within those limits.[2] This addresses a fundamental challenge in older buildings: when multiple units share a single electric meter, residents have little incentive to moderate their heating or air conditioning use. In one real-world example, a building manager set the heating limit at 78°F, and energy consumption dropped by 25% the next day.[1]

Zone-level control enables managers to adjust modes and temperatures across entire floors or buildings from a single interface, rather than checking devices one by one.[2] Power-aware operations dynamically manage total power draw across units—critical for older buildings attempting to electrify without major electrical upgrades.[2]

Proven Results and Real-World Impact

The platform isn’t theoretical. During beta testing, Gradient customers achieved a 25% reduction in energy consumption by deploying Nexus and remotely optimizing setpoints across their buildings.[2] The platform is currently deployed across 200+ residence units in Boston, Detroit, and Washington, D.C.[2]

These results matter enormously for building owners facing difficult choices. A 25% energy reduction translates directly to lower operating costs and reduced carbon emissions. For affordable housing providers and public housing authorities, these savings can be reinvested in maintenance, improvements, or keeping rents stable.

Grid Benefits and Future Capabilities

Beyond individual buildings, Nexus positions Gradient’s heat pumps to support broader grid stability. As demand response becomes increasingly important—particularly during peak summer cooling periods when grids face strain—Gradient is developing capabilities to dial back heat pump output during peak demand while maintaining occupant comfort.[1]

By using building information and sensor feedback, the company can predict which units can reduce air conditioning demand, such as those on shady sides of buildings.[1] This demand response capability helps the grid serve more heat pumps without requiring costly infrastructure upgrades—addressing a fundamental concern about electrification’s feasibility.

Conclusion

Gradient’s combination of innovative window heat pump hardware and intelligent Nexus software represents a pragmatic approach to building decarbonization. Rather than requiring expensive, disruptive renovations, the company is proving that aging buildings can be retrofitted quickly, affordably, and effectively. As thousands of buildings face aging boiler replacement decisions, Gradient’s technology offers a path forward that benefits building owners, tenants, and the grid itself.

Original source: TechCrunch – Gradient’s heat pumps get new smarts to enable old-building retrofits