Scio Township Hall HVAC Replacement
Client
Scio Township Government
Year
2025-2026
Location
Scio Township, MI
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Inclination Engineering helped Scio Township replace an aging, inefficient HVAC system with a fully electric geothermal heat pump solution aligned with the township’s climate action goals. After studying the existing rooftop units and comparing replacement options, the team identified geothermal as the strongest balance of efficiency, comfort, ventilation performance, and long-term value, especially after federal incentives narrowed the cost gap with conventional systems. The final design combined cost-conscious and performance-focused strategies, including polypropylene distribution piping, hydraulic separation, integration of the server room cooling load, energy recovery ventilation, and provisions for future geothermal expansion. Together, these measures delivered a resilient, efficient, and expandable HVAC system without fuel-fired equipment.
$440K
IN FEDERAL REBATES
Direct pay. Available to owners whether or not they owe taxes. (Estimated; application in process)
$1.1M
FINAL COST
$520,000 below guaranteed maximum price from three design innovations
2 Loops
GEOTHERMAL SYSTEM
Joined by a hydraulic separator instead of a heat exchanger, saving energy and costs. Bore field pumps can slow or stop while building pumps run.
2035
NEXT-PHASE READY
Eight 400-foot bores in 2026, with four more already capped, ready for further electrification when gas rooftop units require replacement in 2035.
From Study to Construction
The older portion of Scio Township Hall was conditioned by three rooftop units installed during a 1999 renovation. After the units exceeded their expected useful life, the township needed a replacement plan that supported its sustainability goals. In 2022, Inclination Engineering studied the building systems and found that the existing equipment operated inefficiently and struggled to maintain comfortable temperatures and adequate ventilation. The resulting replacement options emphasized fully electrified heating.
Later in 2022, the Inflation Reduction Act created generous federal incentives for ground-source geothermal heat pumps and extended eligibility to non-tax-paying entities such as township governments. Inclination Engineering reevaluated the replacement options and found that a ground-source heat pump system offered the best efficiency and comfort performance. With the federal rebates applied, the geothermal system was expected to have nearly the same construction cost as the alternatives.
In 2025, Inclination Engineering partnered with mechanical contractor Boone & Darr to win a design-build contract for the township hall HVAC replacement.
Two of the previous rooftop units were removed and their curbs were capped.
An energy recovery ventilator for the meeting hall was installed over the third unit's capped curb.
Design Features
The project incorporated several innovative design features to reduce construction costs while improving efficiency and performance.
Polypropylene piping was selected for the indoor geothermal water lines to reduce material and labor costs while improving corrosion resistance. To increase system efficiency, a hydraulic separator decouples the indoor distribution piping from the underground geothermal wells. The two loops share the same water-glycol fluid but can operate at different flow rates, allowing the geothermal pump to slow down or turn off during favorable conditions.
The geothermal bore field includes eight 400-foot-deep bores drilled beneath a grass and dirt area next to the parking lot. After construction, the area was replanted and a sidewalk was added to improve the entrance to the neighboring township park.
During a second round of bore field modeling, Inclination Engineering determined that connecting the township hall server room to the geothermal system would improve the heating-to-cooling balance and reduce the total bore field size. Although the server room was served by a mini-split with at least five years of expected useful life remaining, replacing it with a geothermal heat pump provided better overall value. The server room heat pump includes a waterside economizer that can provide cooling without operating the compressor when loop temperatures are low.
To improve office ventilation without adding gas-fired equipment, Inclination Engineering incorporated energy recovery ventilators. These units use energy exchange cores to recover heat and moisture from exhaust air, prewarming and humidifying incoming outdoor air. This approach significantly reduces heating demand, keeps ventilation air within the heat pumps’ acceptable operating range, and provides reliable, consistent ventilation.
Hydraulic separator (black) connects indoor and outdoor geothermal water loops.
Geothermal bores were installed below a grassy area behind the parking lot.
Geothermal piping in trench
Planning for Future Expansion
The Utility Department Wing, added in 2017, is served by rooftop units that are not expected to require replacement until 2032 to 2037. Although that work was outside the project scope, the design was planned to support future conversion to geothermal. An extra pipe header was installed on the mechanical room manifold and extended underground into the parking lot, where capped piping can be used to add future bores to the geothermal loop. Installing the headers during this project will reduce future trenching and pavement cutting, and the variable-speed bore field pumps were selected to serve both the current system and the projected flows of an expanded field.