Sitka Public Library

Sitka, Alaska

Deep Green Retrofit & High-Efficiency Mechanical Systems

The 2016 renovation and expansion of the Sitka Public Library transformed a 1967-era building into a high-performance, carbon-neutral facility, eliminating fossil fuel reliance while keeping electrical consumption nearly unchanged. The 4,800 SF expansion increased the heated floor area by 63%, yet through aggressive energy reduction strategies, the building’s Energy Use Intensity (EUI) dropped from 99 to 32 kBTU/SF/yr—just one-third of the national average for libraries.

The project prioritized load reduction and energy-efficient HVAC design to minimize heating demand and optimize system performance:

• Heating & Cooling: A variable refrigerant flow (VRF) heat pump system provides precise zonal control, coupled with hydronic heat exchangers and radiant floor heating in large open spaces. Smaller rooms utilize air-side wall cassettes for localized comfort.
• Ventilation: A Dedicated Outdoor Air System (DOAS) with ECM fans and an 80% effective heat recovery core recycles heat from exhaust air, significantly reducing heating loads while maintaining excellent indoor air quality.
• Water Heating: A high-efficiency heat pump water heater serves the building’s domestic hot water needs, paired with low-flow fixtures to minimize hot water demand.
• Cooling & Air Quality: Natural ventilation via operable windows enhances occupant comfort, leveraging Sitka’s mild summers for passive cooling and improved indoor air quality.

Despite more than doubling the conditioned space, the electrical load only increased by 32%, demonstrating the effectiveness of the deep energy retrofit. The building now operates entirely on hydropower, eliminating all carbon emissions while cutting utility costs by nearly 50%, with estimated annual savings of $9,500.

Learn more about this project here:

• Powering an Alaska Village, ASHRAE High Performing Buildings Magazine, Summer 2018