Air Distribution and Microenvironment Evaluation of a Desktop Task Conditioning System

Abstract

Task conditioning aims to provide each occupant with personalized clean air direct to the breathing zone. The microenvironment of a typical office workplace, consisting of two desktop task conditioning systems (a Horizontal Desk Grill (HDG) and Vertical Desk Grill (VDG)) were studied by numerical simulation. Numerical simulation by k- 3-D turbulent flow was separately conducted to study the influence of supply velocity on the microenvironment of these two desktop task conditioning systems. Three task conditioning velocities were studied. Temperature and velocity distribution, Draught Rating (DR) and Predicted Percentage of Dissatisfied (PPD) of the room and workstation were applied to study the performance of task air conditioning. Results show that the performances of HDG and VDG are almost the same. Results also show that task conditioning can provide excellent working environment when supply velocity is well designed. The supply velocity of task conditioning can be set between 0.8-1.0 m/s. However, task conditioning may cause draught, and engineers should seriously consider this problem. The results can provide important references for design and optimization of the task conditioning system.