Improvement in demand-controlled ventilation simulation on multi-purposed facilities under an occupant based ventilation standard Jae-Weon Jeong a, * , Anseop Choi a , Sang-Tae No b a Department of Architectural Engineering, Sejong University, 98 Gunja-Dong, Gwangjin-Gu, Seoul 143-747, Republic of Korea b Department of Architectural Engineering, Chungju National University, 72 Daehak-Ro, Chungju-Si, Chungbuk 380-702, Republic of Korea article info Article history: Received 30 December 2008 Received in revised form 3 September 2009 Accepted 19 September 2009 Available online 26 September 2009 Keywords: Demand-controlled ventilation Indoor air quality Dedicated outdoor air system CO 2 RFID abstract The objective of this paper was to find an effective way of improving demand-controlled ventilation (DCV) simulation performed under an occupant based ventilation standard established in many countries. Two attractive DCV approaches, CO 2 –DCV and RFID–DCV, were applied to DCV simulations for a theoretical public assembly space served by a ded- icated outdoor air system (DOAS) with an enthalpy recovery device. A numerical model for predicting the real-time occupant number, required ventilation amount, CO 2 and formalde- hyde (HCHO) concentrations under given conditions was developed using a commercial equation solver program. The current ventilation standard used in Korea was applied as a case of occupant based ventilation standards. It was found that the current standard might cause unstable DCV simulation results, especially under CO 2 –DCV. This is because the ventilation rate (per person) indicated in the standard is the sum of the outdoor air required to remove or dilute air contaminants generated by both occupants and the build- ings themselves, and not a pure function of occupant numbers. Finally, it makes DCV con- trol unstable when ventilation flow is regulated only by the number of occupants. In order to solve this problem, the current occupant based ventilation standard was modified as a form of ASHRAE Standard 62.1-2007 showing good applicability to various DCV approaches. It was found that this modification enhances applicability of the current ven- tilation standard to CO 2 –DCV significantly and can maintain acceptable HCHO concentra- tions during the entire time of operation. Fan energy reduction can also be expected from DCV operations. Ó 2009 Elsevier B.V. All rights reserved. 1. Introduction In order to enhance the indoor air quality in multipurpose facilities, the existing ventilation standard has been revised in South Korea [1]. The new ventilation standard defines minimum ventilation rates per person for various facilities in which several undesirable air quality problems caused by insufficient ventilation have been continuously reported over the past decade [2–6]. In early 2000, after it became a well-known fact that formaldehyde (HCHO) and Volatile Organic Compounds (VOCs) emitted from conventional building materials are major sources of various indoor air quality problems and physical symptoms [7–10], the Korea Institute of Construction Technology (KICT) investigated the indoor air quality of many different types of multipurpose facilities, and proposed minimum required ventilation rates for each facility which can maintain in- door HCHO concentration under the limit of 100–120 lg/m 3 recommended by the World Health Organization (WHO) [11]. 1569-190X/$ - see front matter Ó 2009 Elsevier B.V. All rights reserved. doi:10.1016/j.simpat.2009.09.009 * Corresponding author. Tel.: +82 2 3408 4037; fax: +82 2 3408 4331. E-mail address: jjwarc@sejong.ac.kr (J.-W. Jeong). Simulation Modelling Practice and Theory 18 (2010) 51–62 Contents lists available at ScienceDirect Simulation Modelling Practice and Theory journal homepage: www.elsevier.com/locate/simpat