Occupied. Active. Uninterrupted. GreenerU delivers high-impact energy retrofit in R1 research lab

At a mission-critical medical facility in New England, massive energy waste was a massive problem. 

The building’s two 20,000-cfm air handling units operated with 100% outside air. Relief air from offices and corridors was vented straight into a mechanical room. Lab exhaust—about 30,000 cubic feet per minute (cfm)—was discharged through high-plume rooftop fans with zero heat recovery.

This wasn’t just an energy project. It was a surgical energy retrofit in a building that couldn’t slow down.

That meant thousands of therms of tempered air, paid for with campus steam and chilled water, were being discarded every hour. There was no recovery system in place, no pathway for reuse, and no clear plan—until a passing comment from an HVAC controls technician, who noted that there was a considerable volume of conditioned air being unnecessarily and constantly exhausted into the mechanical room, sparked a deeper look.

So GreenerU performed an investigation. Conducting interviews, using comments and feedback from building users, looking at the data, and reviewing existing equipment, our engineering team designed and implemented a new system.

Energy retrofit included return air, heat recovery, and unmatched execution

GreenerU designed and executed two major energy conservation measures:

1. Return air integration. GreenerU converted the 100% outdoor air units to mixed-air operation by adding mechanical ductwork, dampers, and sensors, and reprogramming the control sequences to safely recirculate up to 10,000 cfm of tempered return air. Economizer mode was preserved and outside air minimums were fully maintained.
2. Glycol heat recovery system. A new run-around loop connects rooftop exhaust and basement AHUs, transferring thermal energy from the exhaust stream back into the supply. The system includes new piping risers (routed discreetly through closets), pumps with VFDs, modulating coils, and DDC controls—all integrated into existing infrastructure without disrupting lab operations.

Savings without disruption

With a project cost of approximately $1.1 million, this energy retrofit saved 4,700 MMBtu annually across steam and chilled water systems—a cost savings of more than $700,000 each year.

What’s more, this project was a live energy retrofit in a five-story research facility with zero margin for disruption. GreenerU coordinated shutdowns with surgical precision, preserved lab uptime, and routed vertical piping through non-lab spaces, minimizing visual and functional impact on occupants.

No labs were shut down. No experiments were delayed. No complaints were filed. The system came online during the 2021 heating season, and performance was immediate: consistent 15°F+ heat recovery differentials, even before peak winter demand.

GreenerU’s approach: occupied retrofits done right

This project exemplifies how GreenerU approaches complex, technical retrofits in lab settings. We start with curiosity, often spotting overlooked inefficiencies through field insight, not just data. We bring precision to both engineering and execution, integrating seamlessly with active systems. And we prioritize relationships over transactions, ensuring our work builds trust and opens doors to future collaboration.

In critical environments, energy retrofits are not just about saving energy. They’re about doing them quietly, intelligently, and with complete respect for the institution’s mission.

For energy retrofits performed with surgical precision, minimal to no disruption, and maximal energy and cost savings, contact us right now.

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