Laboratory testing of a displacement ventilation diffuser for underfloor air distribution systems

We performed 19 full scale laboratory experiments in which we varied the number of diffusers and the internal loads over a range of values typically found in office spaces. We quantified the amount of thermal stratification by measuring the dimensionless temperature at ankle height and found a degree of stratification that is typical of DV systems - higher than is typical in UFAD systems. We developed a model based on these results that can be used to simulate these systems in whole building energy simulation tools, such as EnergyPlus, and simplified UFAD design tools.