In open air applications, airflow dispersed through a vent or an open pipe mixes in an expanding effectiveness. When similar configurations are used within the space confines of a raised access floor, the flow pattern from the diffusers are bounded on two sides, resulting in significantly longer throw and reduced airflow mixing.
This CFD analysis provided by the Center for the Built Environment (CBE) at the University of California Berkeley, reveals the expected dynamic airflow patterns within the plenum. In this model, diffuser location can clearly effect dispersion temperature.
Full-scale thermal performance tests, by the CBE have investigated the impact of distributing cool supply air into an underfloor plenum using DuctSox.
For the test configurations studied, the results indicated that compared to an open plenum design, the use of DuctSox reduced thermal decay (temperature gain) in the perimeter zone. Overall, the temperature distribution within the plenum was more uniform with DuctSox. Adding DuctSox required some increased fan power, but this is still under investigation. Due to the promising results, CBE expects to conduct additional experiments on other DuctSox configurations.
Comments on research provided by Fred Bauman, PE, Center for the Built Environment, University of California, Berkeley.
This photo reveals the uniform low velocity dispersion pattern that provides a uniform airflow pattern providing consistent temperatures.