Center for the Built Environment

This section provides full details of work performed in support of Task 2.3 (Underfloor Plenum Testing) and Task 2.5 (Underfloor Plenum Model Development). The ultimate goal of these tasks was to develop a model capable of calculating the thermal performance of underfloor air supply plenums, while at the same time suitable for implementation in EnergyPlus. A secondary goal was to conduct fundamental research that provides a sound theoretical and practical understanding of underfloor plenum energy performance in terms of heat transfer entering the plenum and the resulting airflow and temperature distributions. The technical approach used to accomplish this work included the following tasks:

• Full-scale experiments in CBE’s underfloor plenum test facility

• Development of computational fluid dynamics (CFD) model of underfloor plenum

• Validation of CFD plenum model by comparison with full-scale experimental database

• Use of the validated CFD plenum model to conduct simulations of a broader range of plenum design and operational parameters

• Development of simplified underfloor plenum model based on CFD database for implementation into EnergyPlus

• Comparison between EnergyPlus and CFD plenum model predictions

• Simplified heat balance modeling study of heat transfer pathways in UFAD systems