Three case studies of HVAC system troubleshooting and remediation

Three case studies highlight important considerations in troubleshooting and remediation work on HVAC systems in buildings. Case Study 1 is a historic church with a large organ. Congregants thought the fan coil units under the stained glass windows were too loud. Acoustical diagnostics revealed that the blower for the antiphonal organ was contributing to most of the excessive sound in the space. Case Study 2 is an existing recording studio where a large HVAC unit on the roof was going to be replaced. Acoustical analysis and diagnostic measurements identified both the unit and the duct work as contributing to the high noise levels in the studio. While the client was willing to add silencers and an isolation curb to the unit, they were not willing to address the high velocities and self-generated noise created by the ductwork. Case Study 3 was an operations center for a large hospital that was in an existing shell space in a parking garage where fresh air access for the new air-conditioning system had to be brought into the building from openings in a curtain wall adjacent to a busy street. Mitigation design for the HVAC system included silencers and duct lagging in addition to upgrades to the facade of the building.