Performance evaluation of an integrated Personalized VentilationePersonalized Exhaust system in conjunction with two background ventilation systems Yang Junjing a , Chandra Sekhar a, * , David Cheong a , Benny Raphael b a Department of Building, School of Design and Environment, National University of Singapore, Singapore b Civil Engg. Department, IIT Madras, Chennai, India article info Article history: Received 22 November 2013 Received in revised form 25 March 2014 Accepted 22 April 2014 Available online 2 May 2014 Keywords: Personalized Ventilation Personalized Exhaust Inhaled air quality Personal exposure effectiveness Tracer gas abstract The inhaled air quality in the breathing zone is strongly influenced by flow interactions around occu- pants. Personalized Ventilation (PV) aims to supply conditioned outdoor air directly to the occupants’ breathing zone and thus improves the inhaled air quality. In this research, a Personalized Exhaust (PE) system is developed, which has two local exhaust devices installed with the chair, just above the shoulder level. Such a system placed in front of a PV system will introduce more PV air into the breathing zone of a seated person as well as exhausting part of the exhaled air from the free convective flow. This study investigates how the performance of a PV system will be affected after being integrated with the PE system. Experiments were conducted in an environmental chamber in Mixing Ventilation or Displace- ment Ventilation mode for the background air-conditioning system. A breathing thermal manikin was placed in the PE integrated chair in front of the PV air terminal device (ATD) to simulate a seated person in an office environment. The manikin was moved longitudinally away from the PV ATD as well as in an arc to 12 different locations. The performance of the PVePE system at the 12 different locations was tested with regard to its ability in pulling the PV air towards a seated person moving within a small area in front of the workstation. Findings imply that the use of the combined PVePE system for a seated person could provide more outdoor air than a PV system alone. Ó 2014 Elsevier Ltd. All rights reserved. 1. Introduction People consume around 1 kg food and 2 kg water, but breathe around 10 kg air in a day and therefore, the inhaled air quality is so important that it affects the work performance and occupant health [1,2]. For indoor environment, various ventilation strategies and devices have been developed during the past decades to provide more conditioned outdoor air to an occupant. One of them is Personalized Ventilation (PV), which aims to provide clean air close to the occupants and to the breathing zone so as to improve the inhaled air quality [3]. Many research studies have addressed the application of Personalized Ventilation (PV) in different indoor environments to provide better inhaled air quality and thermal comfort compared with total volume ventilation [4e10]. However, the amount of PV air that can be delivered into the breathing zone is influenced by a few parameters: the type of PV air terminal device (ATD), PV air flow rate and the microenvironment of flow interac- tion of free convective flow around the human body, air flow created by the background ventilation, the exhalation flow and the PV air flow. Many PV ATDs have been developed and evaluated but most of them were fixed and have little flexibility to move [4,11,12,9,13,14]. When the seated person moves around within a small range in front of the desk, he is likely to move out of the range of the PV air core and so the PV ATD may fail to supply the fresh air to the breathing zone. One of the strategies to bring more PV air in the inhaled air within a wider range is to create a microenviron- ment which can let the PV air penetrate further into the breathing zone. In this study, this is achieved with the development of a new concept of combining the PV system with a Personalized Exhaust (PE) system. PE, also called local exhaust ventilation in the industry, is a type of ventilation which extracts the air locally. It is not a new concept and has been studied as a ventilation type for the control of the transmission of infectious air [15e18]. However, the study of the combination of PV and PE is very limited. Bolashikov et al. * Corresponding author. Department of Building, School of Design and Environ- ment, National University of Singapore, 4 Architecture Drive, Singapore 117566, Singapore. Tel.: þ65 65163479; fax: þ65 67755502. E-mail address: bdgscs@nus.edu.sg (C. Sekhar). Contents lists available at ScienceDirect Building and Environment journal homepage: www.elsevier.com/locate/buildenv http://dx.doi.org/10.1016/j.buildenv.2014.04.015 0360-1323/Ó 2014 Elsevier Ltd. All rights reserved. Building and Environment 78 (2014) 103e110