Casing Radiated Treatment on Air Terminal Units Based on ASHRAE-130 Test Procedures

Air Terminal Units used in Rooftop VAV air conditioning systems can have a negative impact on the acoustical environment in the built space. The primary sound transmission path for air terminal units such as Variable Air Volume (VAV) and Fan Powered models (FPVAV) affecting noise sensitive spaces below is the radiated path. This paper will present data from testing of removable acoustical wraps in a certified reverberation chamber per the ASHRAE-130 test methodology for AHRI-800 certification of a Fan Powered VAV unit. Four different acoustical jacket configurations were tested along with an induction air silencer. Testing for custom fabricated jackets was compared to a field applied solution site cut from roll good materials. Additional testing documented the performance impact of partial treatments which excluded jackets on electrical boxes/control cabinets. Lastly, performance of acoustical jackets for air terminal units without the unit fan or primary airflow was evaluated using a calibrated pink noise sound source generated from a speaker mounted in the ATU cabinet. Inlet and discharge ductwork to and from the unit inside the test chamber was acoustically lagged to address flanking noise.