King county libraries upgrade air systems for COVID safety for employees and patrons

Entrance to the exterior mechanical cage. Following the original mechanical design for the building, the condensing units are outside and the air handlers are located in the mechanical room above the main entrance to the building. Large refrigerant lines, controls lines, and electrical run in between the two space underground and along the building.

By Cynthia Flash

Even during the COVID-19 shutdown, King County Library System (KCLS) libraries in Shoreline, Kenmore, Richmond Beach and Lake Forest Park have remained integral parts of many people’s lives as students and adults stuck at home continue to borrow books, music and movies.

Although KCLS libraries are closed to in-building use, employees continue to fill orders for patrons to pick up curbside. That means the buildings must be made as safe as possible for employees – and they must be prepared for when the public comes back in.

Condensing unit #1 for the library transfers conditioned refrigerant to the air handler in the mechanical room.

KCLS has upgraded the filters in their HVAC systems to a version that traps smaller air particles and droplets. In addition, the interior air is being replaced much more frequently throughout the day with fresh outside air. Each night the air in the buildings is also recirculated with outdoor air, said KCLS Facilities Management Director Greg Smith.

 
Even when buildings are unoccupied, Smith is able to monitor many of the library system’s buildings remotely to adjust the HVAC systems and keep track of discrepancies in the buildings if something is going wrong, or if the building is using too much energy.

“This has allowed us to be able to safely occupy our buildings. With filtration, flushing buildings and monitoring our buildings for proper temperature, we’ve been able to keep staff in the buildings,” he said.

HVAC contractor MacDonald-Miller worked with KCLS to make sure its libraries are safe for employees and patrons during the COVID-19 pandemic. 

“Every evening we’re flushing buildings for eight hours with outside air and during the day we’re doing it as much as the system will allow us with outside air and being able to maintain temperature,” Smith said. “We could not replace the indoor air without the integrated control system that MacDonald-Miller helped us put together.” 

 

Air handler #1 for the library regulates temperature and air flow for the building. This is one of the new main units at Shoreline, manufactured by Trane.

MacDonald-Miller President Gus Simonds said that when bringing workers and eventually patrons back inside, the key consideration is safety. 

“The Centers for Disease Control has declared that COVID-19 is an airborne virus, meaning that those tasked with building safety must work even harder to protect people from this airborne illness when at work. They truly are the heroes of safely bringing people inside when they follow the research and guidelines from the CDC, the state, and the American Society of Heating, Refrigerating and Air-Conditioning Engineers,” Simonds said.

“As KCLS understands, HVAC systems can reduce the airborne concentration of COVID-19 inside, which reduces the virus load that individuals are exposed to as they work or conduct their business inside. By using best practices to bring in as much fresh air as possible, we can create just as safe an environment indoors as outdoors, as long as people continue to social distance and wear masks.”

 

This picture shows the shroud that was constructed to protect and hide the multiple refrigerant lines, controls lines and electrical that runs in-between the exterior mechanical cage and the mechanical room.

KCLS looks forward to opening its buildings to patrons when it is safe to do so. Along with upgrades to the HVAC systems, KCLS is installing plexiglass dividers to further protect everyone inside and will require social distancing, masks and other health protocols. 

“In addition to monitoring occupancy numbers and scheduling limited hours, we’ll close for a mid-day cleaning and air recirculation as well,” Smith said.