Steelcase Wall Systems at Southeastern Freight Lines HQ, Columbia SC

Location: Columbia, South Carolina
Office System Manufacturer: Steelcase
Owner: Southeastern Freight Lines

Acoustic Testing of Steelcase Wall Partition Systems in Columbia, South Carolina

Steelcase is an international manufacturer of high-quality furniture and partitioning systems for offices, hospitals, classrooms, and residential interiors. The company contracted HGC to visit the headquarters of Southeastern Freight Lines in Columbia SC in order to conduct sound transmission testing of several office partition systems installed at that facility. The testing was requested by Steelcase to better understand and to enable future improvements to in-situ airborne sound insulation provided by these various wall systems, taking into account real-world performance effects of flanking paths, gaps, door seals, etc.

ASTM E336 “Standard Test Method for Measurement of Airborne Sound Attenuation between Rooms in Buildings”

Acoustic performance was evaluated using ASTM field testing standards to measure how well the installed Steelcase wall systems and doors block sound under actual workplace conditions. While ASTM E90 measure a partition’s ideal Sound Transmission Class (STC), under laboratory conditions, actual on-site testing should take into account flanking paths, gaps and other factors that reduce acoustic performance. Therefore, testing at the Southeastern Freight Lines headquarters followed ASTM E336 “Standard Test Method for Measurement of Airborne Sound Attenuation between Rooms in Buildings”, E-336 testing yields various ratings including the Apparent Sound Transmission Class (ASTC) rating and related metrics. An ASTC rating includes contributions from flanking paths (i.e., transmission via other structures or airborne paths) and thus will be somewhat lower than the lab-tested STC value.

Under standard E-336, for an ASTC rating to be reported, the test rooms must conform to specific volumetric requirements. For measurement of sound transmission between large spaces , as was the case with the testing performed at Southeastern Freight Lines, Noise Isolation Class (NIC) was reported on. NIC is a single integer rating similar to ASTC, though it does not account for the room effect (reverberation) of the receiver room.

ASTM E2964 & Door Transmission Class (DTC) Ratings

To better understand the role of doors in overall acoustic performance, separate ASTM E2964 “Standard Test Method for Measurement of the Normalized Insertion Loss of Doors” tests were conducted to determine Door Transmission Class (DTC) ratings. Tests were conducted at three private offices after hours with one set of doors, and then repeated the following evening with another set of doors. Together, all these tests provided a clear picture of how the wall and door systems perform acoustically under typical office conditions. An acoustic camera was also deployed in several cases to help highlight potential weaknesses in the installation. The results of the tests were summarized and presented in a report to Steelcase for evaluation and consideration

Acoustical consulting services delivered included:

• ASTM 336 Standard Test Method for Measurement of Airborne Sound Attenuation between Rooms in Buildings

• ASTM E2964 Standard Test Method for Measurement of the Normalized Insertion Loss of Door

• Door Transmission Class (DTC) Rating Testing and Analysis

• Apparent Sound Transmission Class (ASTC) Rating Testing and Analysis

• Noise Isolation Class (NIC) Rating Testing and Analysis