Committee reviews HVAC life‑cycle analysis: chilled beams with geothermal would add about $8.2 million upfront

The Dwight School Building Committee heard a detailed presentation on the HVAC life‑cycle cost analysis for the new school project, focusing on a chilled‑beam system paired with a geothermal well field versus the baseline variable‑refrigerant‑flow (VRF) approach. Tekton lead Justin walked the committee through four options, explained a prior discrepancy in slide decks and said the updated 25‑year life‑cycle totals now include area increases and design contingencies.

Justin told the committee that the chilled‑beam option includes geothermal wells and a gross‑square‑footage increase accounted for in the estimate; he gave a subtotal premium and contingency totals. "We're applying our design and estimating contingency of approximately 10% ... for a total additional cost premium of $8,207,223," Justin said. Consultants noted that chilled beams typically have fewer moving parts and longer in‑service lifespans, while VRF systems may require more frequent replacements and face refrigerant‑compatibility risks over multiple decades.

Vice Chair Nicole Olsen and other committee members pressed presenters to clarify maintenance responsibilities and whether building staff could perform routine work or if outside contractors and certification would be necessary. Consultant Frank Dorayas said chilled beams are simple to maintain but water‑to‑water heat pumps and DOAS functional testing could require extended training or contractor support; he recommended verifying certification options with manufacturers once a system is selected.

Discussion also turned to incentives and the project finance picture. Committee members requested a single slide that reconciles the different slide decks and shows the town's net out‑of‑pocket cost after Energize CT, IRA and utility rebates. Tekton and referenced Kolar/Kohler Ronan spreadsheets include rebate scenarios but presenters acknowledged that numbers must be reconciled across versions before the committee finalizes a recommendation.

The committee did not make a final system decision at the meeting. Members said they want a reconciled, single‑slide summary with (a) the premium to choose chilled beams plus geothermal, (b) assumed rebates and timing, and (c) the projected payback or net cost to the town before voting or recommending a notice to proceed.