Proceedings of 2010 IEEE Student Conference on Research and Development (SCOReD 2010), 13 - 14 Dec 2010, Putrajaya, Malaysia Modeling of Heat and Moisture Transfer in Building Using RLF Method Raad Z. Hamad, Khairul Salleh Mohamed Sahari, Farrukh Nagi University of Tenaga Nasional Department of Mechanical Engineering Km7 Jalan Kajang-Puchong, 43009 Kajang, Malaysia Email: raadahmood@yahoo.com Abstract-This study is concerned with effectiveness of building internal temperature and relative humidity by ventilation and iniltration low rate. Building model is inevitable to study the feasibility of building ventilation, and how to affect on indoor air quality. The empirical method which used in building model is a residential load factor (RLF). RLF formed to calculate cooling/heating load depend upon indoor/outdoor temperature. The transparency, functionality of indoor/outdoor temperatures and simplicity of RLF make it suitable for use in this model. Furthermore the parameters of model can be calculated room by room and that's proper for variable air volume (VAV). Today a VAV system is universally accepted as means of achieving energy eicient and comfortable building environment. The model what we get veriied with different method, by manual or sotware program calculation. Kywords-Building model; HV A C; RLF; Enery control; Nonlinear control 1. INTRODUCTION The pioneerng simulation work of Stephenson and Mitalas [1] on the response factor method signiicantly advanced the modeling of transient heat transfer through the opaque fabric and the heat transfer between intenal surfaces and the room air. The heat balance approaches were introduced in the 1970s [2] to enable a more rigorous treatment of building loads. Rather than utilizing weighting factors to characterize the thermal response of the room air to solar insolation, intenal gains, and heat transfer through the fabric, this methodology solves heat balances for the room air and at the surfaces of fabric components. The building model simulation system has been in a constant state of evolution and renewal since its irst prototype was developed over two decades ago [3). Numerical discretization and simultaneous solution techniques were developed as a higher-resolution altenative to the response factor methods [3]. Essentially, this approach extends the concept of the heat balance methodology to all relevant building and plant components. More complex and rigorous methods for modeling HVAC systems were introduced in the 1980s. Transient models and more undamental approaches were developed [4] as altenatives to the traditional approach which perfomed mass and energy balances on pre-conigured templates of common HVAC systems. he delivery of training and the production of leaning materials [5] are also receiving increasing attention. Additionally, many validation exercises have been conducted [6] and test procedures developed [7] to assess, improve, and demonstrate the integrity of simulation tools. 978-1-4244-8648-9/10/$26.00 ©201 0 IEEE 287 Haider A. F. Mohamed University of Nottingham Malaysia Campus Department of Electrical & Electronic Engineering Jalan Broga, 43500 Semenyih, Selangor Darul Ehsan, Malaysia E-mail: haider.abbas@nottingham.edu.my In addition to these undamental methodological developments, more rigorous, accurate, and highly resolved methods have been continue to be developed for many of the signiicant heat transfer paths. The empirical of themal building simulation techniques were developed as a higher resolution altenative to the response heat balance methods [8). The empirical methods like RLF method was derived rom residential heat balance (RHB), [9, 10] they build RLF method by applying several thousand residential heat balnce (B) cooling load results, and using these result to create RLF by Statistical regression technique to fmd values for the load factors. The procedure method of (RLF) is presented by ASRAE [II). There are many reasons to adopt this method to build model like more itness to applied on computer process, calculate cooling and heating load depending on inside and outside temperatre and cooling and heating load can be calculated room by room and that's proper for variable air volume (VAV) system. Where there re two types of scheme for multiple zone system are available, a constant air volume (CAV) and variable air volume (VAV) which is recently become vey popular. This is because of the signiicant energy savings as compred to the other (CAV) multiple zone central system. Furthermore the (VAV) can condition part of building which is occupied only. II. MODELING ApPROACH The proposed model was structured in four groups which represented four building domain: conditioned space, opaque surfaces structure, transparent fenestration surfaces and slab loors as shown in igure (1). The irst group, conditioned space sub-model, is related to the thermal capacitance of indoor air space and building uniture, where air space and uniture are considered at same temperature. The second group, opaque surfaces structure sub-model, is related to the radiation exchanges between envelope and its neighborhood and to the heat and mass transfers through the opaque surfaces structure material. Where the opaque surfaces structure are comprise of walls, doors, roofs and ceilings. The thrd group, transparent fenestration surfaces sub-model, is related to the direct and indirect radiation exchanges between transparent envelope and its neighborhood and to the heat transfers trough the transparent fenestration surfaces material. Where the transparent fenestration surfaces are comprise of windows, skylights and glazed doors. The fourth group, slab loors sub model, is related to the heat transfers through the slab loor layers due to heat release and store in it.