Air-conditioning System Design Strategy for Distribution of IAQ and Thermal Comfort in a Terraced Lecture Room

Abstract

Simplified HVAC system design by rule of thumb in medium size terraced lecture room for 150-450 occupants causes energy waste since the inlets are usually arranged at ceiling in checkerboard pattern omitting the increment of air volume above the seat as the level decreases Such condition happens when the budget and design schedule are tight excluding the application of under floor ventilation devices most recommended for terraced spaces for effectively ventilating occupied zone Above all to provide superior indoor air quality (IAQ) for audience a fast and cost reducing way to design HVAC system is needed Therefore this research improved HVAC system design process by inserting examination steps by means of CFD simulation which enables visualizing IAQ and thermal comfort distribution for further analysis In addition CFD simulation process for terraced space has a few alternatives to apply including zoning concept for segmenting occupied zone and non-occupied zone etc In this research visualizing air distribution standard is contained to study greater ventilation strategy To confirm the credibility of the simulation tool a field measurement of the wind velocity was operated Then the IAQ and ADPI were examined referring common HVAC system design standards such as ASHRAE and discovered that the measured case provided inadequate ADPI In order to analyze the air distribution and develop improving strategy through the improved HVAC system design process the inlet type and arrangement are decided in four cases including a conventional case based on mixing ventilation And then the IAQ and thermal comfort of those cases were analyzed by SVEs and ADPI standards Finally the applicability of improved HVAC system design process was discussed The traditional case has rather high ADPI as 76 95 % (80 % recommended) satisfying required thermal comfort but the negative EDT at middle seats exceed 20 % which means cold draft occurs In addition the SVE 6 value is 2 54 which is three times longer than other cases to eliminate unfresh air With the additional examination steps with these air distribution indices it’s efficient to present visualized air distribution analyze performance of cases and make adjustment

Date of Award	2019
Original language	English
Supervisor	Yaw-Shyan Tsay (Supervisor)