Immediately recognizing the opportunity to reposition the National Historic Registered 1910 office building as a premiere property, the Portland-based real estate investment firm, Unico, acquired the Galleria building in 2018. Guided by their commitment to energy efficiency, innovation, and tenant well-being, Unico conducted a major retrofit of the downtown Portland building to achieve Energy Trust of Oregon’s Path to Net Zero status and LEED Platinum certification.

By combining proven building renewal technologies and approaches—including a very high efficiency dedicated outside air system (DOAS) with high efficiency particulate air (HEPA) filtration—they knew they could revitalize the building and offer tenants the very best in indoor comfort, efficiency, air quality, and wildfire resiliency.

Conversion summary

Equipped with active, passive, and outdoor air quality (OAQ) modes, the Galleria’s new HVAC system is able to adjust automatically to enhance efficiency and comfort—even during the most extreme weather events. With wildfires increasing in frequency throughout the Western U.S., this feature is all the more crucial to ensure the health, safety, and comfort of the Galleria’s occupants.

The project team installed HEPA filters upstream of the HRV units to work in tandem with the system’s OAQ mode, which engages temporary booster fans when outdoor sensors indicate poor air quality. Third-party measurement at the Galleria building confirmed that these mitigation strategies successfully reduced hazardous PM2.5 particulates by 85% in the indoor spaces, while only adding an energy use intensity (EUI) of 0.06 kBTU/sq. ft./year to annual energy bills. The Galleria building’s occupants can now rest easy knowing that their indoor air will remain clean, safe, and comfortable, regardless of what’s happening outside.

Upon system installation, the Northwest Energy Efficiency Alliance funded a living laboratory retro-commissioning study of the very high efficiency DOAS. With 15-minute interval data provided by a wide range of sensors, including those tracking energy use, electrical demand, indoor air quality, and outdoor weather, the analysis team compiled and investigated a wealth of system performance and occupant comfort information.

In addition to contributing to the very high efficiency DOAS’s well-documented ability to deliver clean indoor air, comfort, and efficient operations, the study confirmed that combining the system’s enhanced controls with HEPA filtration can provide significant protection from even the most extreme outside weather events.

In addition to reducing overall building EUI by 62% and reducing harmful outside air particles by 85%, the new HVAC system provides a variety of benefits to employees, clients, owners, and operators, including:

• Enhanced indoor air quality due to filtered 100% outside air coming into the space, with less recirculation between rooms than the pre-conversion system
• Increased occupant comfort through improved temperature stability and the ability to create zones with unique temperature controls
• Reduced energy bills
• Energy Trust of Oregon Path to Net Zero status
• LEED Platinum certification

Photo credit: SERA Architects