Case Studies of HVAC Noise Control with Challenging Design Constraints

Acoustical design in existing buildings and buildings under construction always involves challenging design constraints. Case studies are presented including HVAC noise control for an office space fit-out below existing rooftop units and HVAC noise control for a constructed office space with fan-powered terminal units. The goal for each project was to manage noisy equipment to meet strict room noise goals in the same space or adjacent spaces. The design constraints included existing HVAC systems that could not be moved or replaced and spatial constraints due to other existing building systems. Other challenges included impacts to the HVAC system, limitations on manufacturer-provided equipment noise emissions data, poor quality measurement data, managing client expectations, and coordination with general contractors. The acoustical design solutions included HVAC noise control measures and sound isolation design to limit noise transmission. A mixture of modeling and measurement results are presented, which show successes and limitations of the acoustical design.