Improving Classroom Acoustics Through a Low-Cost Noise Reduction Design for an HVAC Fan Coil Unit
Disciplines
Acoustics, Dynamics, and Controls
Abstract (300 words maximum)
The Mathematics Building at Kennesaw State University was constructed in 1962 and subsequently renovated to include an updated HVAC system. During this renovation, fan coil units were installed in the corners of each classroom. With little room to reduce noise from their operation, noise levels that exceed the ANSI standard maximum weighted sound level by 15 dBA for education spaces are present in several classrooms. This can create communication and learning challenges for students and faculty. This project proposes a cost-effective solution to reduce classroom noise without requiring a full system replacement.
Our approach involves designing and testing a noise-dampening silencer to reduce the overall A-weighted and Noise Criteria (NC) levels created by the fan coil units, without a significant increase in airflow restriction. For our prototype, plywood will be used in place of sheet metal, allowing us to test the feasibility of our design at low cost. The inside of the box will be lined with a duct liner to absorb and contain noise generated by the fan coil unit. The duct liner selected has a Noise Reduction Coefficient (NRC) of 0.6, meaning it should absorb 60% of the noise between 250 and 2000 Hz. When testing, we will measure the reduction in sound levels within the classroom and compare them to the regular noise levels without the damper to determine effectiveness.
Once results are obtained, we will be able to determine whether the noise-dampening silencer provides an improvement to the classroom acoustics while remaining cost-efficient. If successful, the design could serve as a practical and affordable solution to addressing similar noise issues in other classrooms with similar noise constraints. Ultimately, this project may offer KSU Facilities a viable option for reducing the noise levels and enhancing the learning environment in the Mathematics Building by improving acoustic conditions.
Use of AI Disclaimer
no
Academic department under which the project should be listed
SPCEET – Mechanical Engineering
Primary Investigator (PI) Name
Richard Ruhala
Improving Classroom Acoustics Through a Low-Cost Noise Reduction Design for an HVAC Fan Coil Unit
The Mathematics Building at Kennesaw State University was constructed in 1962 and subsequently renovated to include an updated HVAC system. During this renovation, fan coil units were installed in the corners of each classroom. With little room to reduce noise from their operation, noise levels that exceed the ANSI standard maximum weighted sound level by 15 dBA for education spaces are present in several classrooms. This can create communication and learning challenges for students and faculty. This project proposes a cost-effective solution to reduce classroom noise without requiring a full system replacement.
Our approach involves designing and testing a noise-dampening silencer to reduce the overall A-weighted and Noise Criteria (NC) levels created by the fan coil units, without a significant increase in airflow restriction. For our prototype, plywood will be used in place of sheet metal, allowing us to test the feasibility of our design at low cost. The inside of the box will be lined with a duct liner to absorb and contain noise generated by the fan coil unit. The duct liner selected has a Noise Reduction Coefficient (NRC) of 0.6, meaning it should absorb 60% of the noise between 250 and 2000 Hz. When testing, we will measure the reduction in sound levels within the classroom and compare them to the regular noise levels without the damper to determine effectiveness.
Once results are obtained, we will be able to determine whether the noise-dampening silencer provides an improvement to the classroom acoustics while remaining cost-efficient. If successful, the design could serve as a practical and affordable solution to addressing similar noise issues in other classrooms with similar noise constraints. Ultimately, this project may offer KSU Facilities a viable option for reducing the noise levels and enhancing the learning environment in the Mathematics Building by improving acoustic conditions.