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CLIMA 2010 - PROGRAM BOOK

InvitationDear Participants of Clima 2010 Rehva World Congress,

I would like to “Welcome you to Clima 2010” on behalf of TTMD and Organizing Committee. We have worked with pleasure and excitement to prepare this Congress; starting four and a half years ago.

Now, the day came and we are together with your works and contribution to create “Sustainable Energy Use in Buildings” as the theme of the Congress... I hope you will find the program of this leading international scientific congress very rich, interesting and full of activities; having new information and building new friendships...

The 10th REHVA World Congress has been prepared with the support of our Ambassadors in many countries, with many National and International Associations and also with our sponsers; with our thanks which led to receive high interest and we have received a record level abstracts and participation with papers and posters. We are happy to present this program to give you the chance to value every minute to listen the oral presentations, examine the posters and contribute to the workshops and follow the other activities like Students Competition and the Industrial Forum organized by rehvaclub.

We are grateful for coming from 6 Continents. Having the format to have the venue in a Congress Hotel will enable you to benefit from the Mediterrenean Holiday atmosphare and taste the Turkish Food and enjoy the sea and sand at your free times... Meeting with international friends will be possible for the the exchange of your scientific knowledge and experience as well as discussing the solutions on the new topics.

Our organization team will be ready to make your stay enjoyable and memorible one. Whenever you need, please find one of us; as we will be everywhere...

Wish all the best and fruitful Congress.

Numan SAHIN President of Clima 2010, 10th REHVA World Congress

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CLIMA 2010 - PROGRAM BOOK

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CLIMA 2010 - PROGRAM BOOK

09 MAY 2010 - SUNDAY 16:30-18:00

17:00 R8-TS8-OP03 Comparing Monitoring Results with Energy Performance Calculation: Uncertainty Analysis

Sihem Tasca Guernouti, Myriam Humbert

17:15 R8-TS8-OP04 A Validation of the Quasi-Steady State Building Energy Model by a Dynamic Numerical Analysis Ilaria Ballarini, Alfonso Capozzoli, Vincenzo Corrado

17:30 R8-TS8-OP05 Experimental Analysis and Modeling of the Thermal Performance of Ventilated Roofs Paolo Baggio, Paolo Pancheri, Alessandro Prada, Marco Baratieri, Guido Libardoni

17:45 R8-TS8-OP06 Integrated Energy Simulation for Building and MEP Systems Including Thermal Cascading in Consideration of the Characteristics of Thermal Energy Media Ryota Kuzuki, Makoto Satoh, Shuzo Murakami, Takashi Akimoto, Hisaya Ishino, Kenichi Sasajima, Fumio Nohara, Hiroshi Ninomiya, Yasuhiro Tabata

ROOM 10 WORKSHOP 16 HVAC TEACHERS MEETING Course Directors : Michael Schmidt, Zoltan Magyar

The objective of this workshop is to increase the co-operation between HVAC teachers in the area of common teaching material, student exchange and the contents of the curricula. The workshops offers an opportunity to exchange idea for future needs and development of teaching to serve better the needs of developing HVAC industry.

ROOM 11 WORKSHOP 1 PRESENTATION OF THE GUIDEBOOK FROM REHVA CONCERNING HVAC AIR FILTERS AND FUTURE ACTIONS Course Directors: Ulf Johansson, Jan Gustavsson

The workshop presents the contents of the new REHVA Guidebook on air filters in air handling systems and discusses the need of the future actions in the area of air cleaning and filtering in respect of indoor air quality and energy efficiency of buildings.

09 MAY 2010 - SUNDAY 16:30-18:00 ROOM 7 TECHNICAL SESSION 7 INDOOR ENVIRONMENT-1 Chairpersons: Shin-ichi Tanabe, Edward A Arens

16:30 R7-TS7-OP01 A Study on Measurement of Indoor Environments of an Office Building and Occupant’s Subjective Evaluation Tae Woo Kim, Byeung Hun Son, Won Hwa Hong

16:45 R7-TS7-OP02 Interior Design and Material Emissions Ingrid Senitkova, Tomas Tomcik

17:00 R7-TS7-OP03 Strategy for Good Perceived Air Quality in Sustainable Buildings Henrik N. Knudsen, Pawel Wargocki

17:15 R7-TS7-OP04 A Conceptual Approach to Determine Optimal Indoor Air Quality: A Mixture Experiment Method Godfaurd A John, Derek C Clements Croome, Joe Howe

17:30 R7-TS7-OP05 Simultaneous Measurements of CO2, Radon and Thermal Parameters in a Bank Agency Manuel Gameiro da Silva, José Joaquim Costa, Luis Figueiredo Neves, Alcides Castilho Pereira

17:45 R7-TS7-OP06 Urban Climate Impact on Indoor Environment Quality Adrien Dhalluin, Karim Limam

ROOM 8 TECHNICAL SESSION 8 BUILDING SIMULATION-1 Chairpersons: Vincenzo Corrado, Samir Farid Moujaes

16:30 R8-TS8-OP01 Calculating Heating and Cooling Loads in a Room by Developing a Transient Thermal Simulation Approach Coupled with a Zonal Air Model Ali Kazemipour Papkiadeh, Aziz Azimi, Siamak Kazemzadeh Hannani

16:45 R8-TS8-OP02 Integrated 6R1C Energy Simulation Method – Principles, Verifiacation and Application Piotr Narowski, Maciej Mijakowski, Aleksander Panek, Joanna Rucinska, Jerzy Sowa

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12 MAY 2010 - WEDNESDAY

15:15-17:15

ROOM 1 CLOSING CEREMONY -Selected Student Project Ceremony and Presentation -Selected Poster Ceremony and Presentation -Announcement of the Next Congress

17:15-18:00 FAREWELL COFFEE

INDEX

A. Fahim Ahmed A Medhat 98, 60

Abak Kazım 99

Abdenacer Kaabi 74

Abuhafeetha Maha 32

Acul Hasan 90

Adamovsky Daniel 55

Adnot Jérôme 96

Afjei Thomas 37, 90

Afshari Alireza 62, 93, 33

Ağra Özden 57

Ahached Mohamed 62

Ahmadi G. 54

Ahmed Zebun Nasreen 40

Ahn Taekyung 78

Airaksinen Miimu 11, 100

Akbalık Bayram 30

Akimoto Takashi 62, 75, 100, 15, 64

Akio Onishi 11

Akoua Jean Jacques 73, 12

Akpinar Irem 52

Aksel Haluk 57

Al Emar Wid A 83

Al Mutawa Nawaf K 77

Al Rashidi Khaled E 77

Ala Juusela Mia 70

Alain Rousset 27

Alajmi Ali F 83

Alameddine Zeinab 71

Albert Maik 37

Albieri Michele 57

Ålenius Lars 46

Alexandre Jose Luis C 50, 97, 23, 96

Ali Toudert Fazia 38

Alina Girip 26, 60

Allard Francis 37, 73, 12, 23, 34

Almeida Susana Marta 45

Almesri Issa F. 65

Alsbjer Markus 83

Alucci Marcia Peinado 66

Alvarez Servando 10, 49

Álvarez Domínguez Servando 73

Ampenberger Andreas 46

Andersen Per Arnold 67

Andre Philippe 10, 10, 29, 29, 29, 10

Andújar Rabindranath 38

Angelotti Adriana 38, 72, 77

Anica Ilie 60, 43

Antonescu Nicolae 58, 58

Aradag Selin 43

Arens Edward 44

Ari Seckin 37

Ariaudo Federica 79

Ariya Parisa A 32

Armstrong Peter 19

Arsan Zeynep Durmus 84, 39

Arslan Gökhan 12

Arumägi Endrik 61

Asada Hideo 65

Asadi Ehsan 55

Asano Natsuki 75

Asdrubali Francesco 66

Ashjaee Dr.mehdi 89

Asikainen Vesa 54, 46

Åström Johan 88

Ataer Ercan Ö. 85

Atılgan İbrahim 44, 66

Atmaca Merve 12

Awbi Hazim B. 65

Axell Monica 25, 83, 95

Aydar Emir 70

Azami Ahadollah 98

Azimi Aziz 14

Babiak Jan 9, 39

Baccoli Roberto 30

Bacigalupo Emilio Giuliano 53

Bağbancı Bilal Muhammed 61

Bağbancı Özlem Köprülü 61

Baggio Paolo 90, 15, 39

Baghvand Aysan 98

Bahloul Ali 86, 55

Baker Derek K. 40

Bakhar Ravi 51

Bakirci Kadir 29

Baldassa Paolo 49

Baldinelli Giorgio 66

Baldini Luca 88, 52

Bales Chris 37

Ballarini Ilaria 15

Balta Mustafa Tolga 30

Baltaretu Florin 99

Balvers Jaap 53

Baranowski Andrzej 50, 61

Baratieri Marco 24, 15, 27, 42

Barbosa Juliana Cortez 78

Barna Lajos 96

Başaran Tahsin 28

Başkaya Şenol 44, 66

Basso Luigi 57

Basta Jiri 36

Başyazici Ibrahim Utku 85

Baumann Mihaly 20

Bayer Ozgur 37, 43

Bayraktar Meltem 84

Bayraktar Seyfettin 42

Bayulu Funda 37

Beauregard Sandy 11

Becchio Cristina 23

Beck Wouter 84

Beghein Claudine 23

Beghi Alessandro 57

Bekker Bernard 86

Belarbi Rafik 46

Bellone Tamara 79

Benedetti Cristina 27, 42

Benjamin Boillot 24

Benoît Andlauer 39

Bergsøe Niels Christian 93, 33, 62

Berkland Stephanie 11

Bernard Collignan 33

Bernard Flament 39

Bernier Michel 61

Bertagnolio Stephane 10, 10, 29, 29, 29, 87

Bhattacharya Kishore 28

Bianchi Ana Maria 99

Bianchi Mikael 37

Bienert Sven 20

Biesbroeck Katrien 71

Bilge Mustafa 85

Bilgili Mehmet 52

Bingöl Ekin 26

Bistran Ioan 55

Biwole Pascal Henry 64

Blaszczok Monika 52, 65

Blom Inge 91

Bozic Nejc 76

Boazu Rodica 20

Boelman Elisa 21

Boerstra Atze 53, 76

Bogataj Uroš 76

Bogdan Anna 65, 63, 66

Bogdan Caracaleanu 60

Boian Ioan 77

Bolashikov Zhecho 54

Borderon Julien 50

Borhansadigh Alireza 98

Borodinecs Anatolijs 20, 86

Bossaer Alain 31

Bouaziz Nahla 62

Bouchaala Mourad 42

Bourrelle Julien S 51

Boxem Gert 70, 20, 94

Bozdağ Şaziye 99

Bozonnet Emmanuel 34

Brahmanis Arturs 44

Brand Marek 54

Brata Silviana 55

Breesch Hilde 71

Brito Augusto 59

Brohus Henrik 50

Bronsema Benjamin 10

Broström Tor 61

Brunk Marten F 60

Budiaková Mária 13

Bulinska Anna 43

Bulut Murat 37

Chen Yixing 75, 75

Chiara Sbicego 79

Chikamoto Tomoyuki 75, 100

Chiriac Florea 37, 43

Chludzinska Marta 66

Cho Ga Young 91

Cho Jinkyun 19, 63

Cho Woosuk 63

Choi Jin Tae 74

Chopra Nikhil 53

Chow Tin Tai 13, 96

Christian Bruss 99

Christian Ghiaus 40, 40

Chung Minhee 12

Ciampi Mario 72

Cibej Marko 76

Claesson Johan 21

Clements Croome Derek C 14

Clita Iulian 11, 55

Cocchi Alessandro 58

Cocora Octavia 90

Çolak Levent 90

Colda Iolanda 41, 64, 76, 33, 44

Coll Sergi 38

Comakli Kemal 29

Conrad Ernest 52

Corgnati Stefano P. 42, 79

Corrado Vincenzo 59, 15

Cortés Inés Olmedo 73

Coskun Can 34

Costa Andrea 90

Costa Gaia 26, 38

Costa Jose J. 55, 14

Crutescu Marin 40

Crutescu Ruxandra 40

Culakova Monika 39

Cullin James 61

D Alessandro Daniela 89

D Orazio Annunziata 89

Dai Tongyong 83

Dalal Hari Sankar 31

Dam Peter van 78

Busato Filippo 85, 30

Busnardo Elena 57

Buswell Richard 43

Butala Vincenc 24, 66

Byun Sooyoung 12

Caillet Julien 96

Cakir Ugur 29

Çakır Gökçe 44

Çakmanus Ibrahim 39

Caldare Ioan 49

Calí Davide 60

Çalışkan Sinan 44, 66

Çallı Ümit 90

Calota Razvan 84

Camargo Renata 72

Cambray James T 94

Canha Nuno 45

Cano Cristina 73

Cansevdi Bekir 90

Cantin Richard 50

Cao Bin 77

Cao Guangyu 76, 76, 100

Cao Zhixuan 13, 87

Capozzoli Alfonso 15

Cappelletti Francesca 59, 90, 39

Cappon Francesco 30

Caputo Paola 26, 38

Caram Rosana 72, 91

Carew Paul 86

Carlini Ubaldo 30

Casabó Jordi 38

Cauret Odile 61

Causone Francesco 42, 77

Cecchinato Luca 57

Celik Burcu Cigdem 84

Cha Dong An 74

Chan Apple 96

Chan Hoy Yen 96

Chan Kwoktai 83

Chandrasen Kshitij 34

Chao Christopher 75

Chen Qingyan 72, 72, 75

Dama Alessandro 72

Dang Thong Q 75

Daniels Ole 64

Daşgan Yıldız 99

David Benjamin 49

David Mathieu 79

Davis Adreans 28

De Araújo Victor Almeida 78

De Carli Michele 59, 30, 77, 44, 79

De Carvalho Ricardo Luis Teles 33

De Giuli Valeria 59

De Meester Bram 31

De Paepe Michel 9, 95

De Ridder Fjo 61

De Rossi Luigi 57

De Santoli Livio 20

De Schepper Paul 41

Decorme Regis 70

Deecke Holmer 9

Delahaye Claire 91

Demetriou Dustin 19

Demircioğlu Olgu 57

Demiriz Mete 30

Deng Jie 74

Derome Dominique 99

Dervishi Sokol 67

Desmedt Johan 19, 28, 61

Desmyter Jan 32

Dhalluin Adrien 14

Diakaki Christina 38

Dias Maria João 86

Dicaire Dan 12

Dikici Derya 61, 99

Dimitriu Sorin 40, 99

Dincer Ibrahim 30, 34

Djamel Alkama 40, 66

Djuric Natasa 50

Dobosi Ioan Silviu 55, 55, 79

Doğrul Ali 42

Doi Kota 63

Dolezilkova Hana 9

Dolmans Dick 84

Dombi Veronica Elvira 77

Dominique Marchio 39

Dong Bing 89

Dönmez Aydın Hacı 42

Doosam Song 22

Doppelbauer Eva Maria 44

Dorgan Chad B 72

Döring Bernd 24

Dornelles Kelen Almeida 91

Dovjak Mateja 11, 65

Doya Maxime 34

Dragos Hera 26, 60

Druette Lionel 88

Drughean Liviu Geo 72

Du Hu 10

Dubrow David 40

Duer Karsten 31, 46, 67

Duijm Frans 62

Dulc Matej 40

Dumitrescu Rodica 37, 43

Durisova Emilia 23

Duyvis Martina 74

Dyck Alf 76

Eayni Malekabodi Ali 34

Edge Jerry S. 10

Eggers Inga 32

Egido Manzano Moisés 86

Eğrican N. 70

Ekberg Lars 93

Ekberg Lars E. 62

Ekmekçi İsmail 70

El Mankibi Mohamed 28

Elena Palomo Del Barrio 34

Elsadi Hafia 84

Emmi Giuseppe 79

Enache Dumitru Stefan 49

Enai Masamichi 72, 72

Engel Peter Van Den 22

Entius Jordy 69

Eordoghne Miklos Maria 31

Eralp Cahit 26

Calculating heating and cooling loads in a room by developing a transient thermal simulation approach coupled with a zonal air model

Ali Kazemipour1, Aziz Azimi2, Siamak Kazemzadeh Hannani1 1Sharif University of Technology, Tehran, Iran 2Chamran University, Ahvaz, Iran Corresponding email: aazimi@asme.org SUMMARY Implementation of simple and effective models is essential to many applications such as building performance diagnosis and optimal control. Simple models are based on many ad-hoc assumptions and may not always reflect the physical behaviors. On the other hand, detailed physical models are time consuming and often not cost-effective. In this study, a heat balance method coupled with an air zonal model was utilized to make up a simple and fast but powerful method to simulate thermal behavior of buildings. Equations for transient heat transfer of walls are solved and radiation between walls, radiation through the window and storage of energy in the room are taken into consideration. For conservation equations for air, the very simple bulk (single node) model is replaced by a zonal model and thus air circulation and also temperature distribution in the room is predicted. The model showed compatible results with the experimental data and also the commercial software Carrier HAP. Keywords: Air Zonal Model, Building Thermal Modeling, Air Conditioning, Hourly Heating (Cooling) Load INTRODUCTION In all parts of the world, reasonable consumption of energy is important. Statistics indicate that the share of energy consumption in residential and commercial buildings is very high. As an example, almost 50 percent of the total energy produced is consumed in buildings in developed countries [1]. In Iran, according to the statistics obtained from the Iranian Fuel Conservation Company (IFCO), 39 percent of the energy produced, is consumed in buildings [2]. Therefore predicting thermal behavior of a building, mainly heating or cooling load behavior, is necessary for the optimization of its energy consumption. While simple calculations for building heating and cooling loads have a history of about a century, the first simulation models were produced in the 1960s [3]. Now, models for the thermal analysis of a building have a wide diversity, ranging from very simple models, such as manual HVAC calculations to full physical models such as computational fluid dynamics (CFD).

Among the methods to model the building heating and cooling loads, we can name Transfer Function Method (TFM) [3] that was introduced in 1967 by Mitalas and Stephenson [4] and Heat Balance Method (HTM) [3] that is a dynamic method for load calculation and was presented in 1990s by Pederson et al [5, 6]. In fact, the Transfer Function Method model lies in simplicity between very simple models which ignore the effects mass (steady state models) and complex and complete ones like Heat Balance Method. TFM is employed by some commercial software such as Carrier HAP [ 4, 7, 8]. TFM or simpler models are not useful for transient modeling. For instance, predicting the next-24-hour load in a building is essential for the optimal control of HVAC systems that use thermal or cool storage technology and this prediction cannot be performed by use of simple models. To completely model the thermal behavior, one also needs to know about the velocity and temperature field in the building as a tool to use with the HTM. The question that arises is whether we can solve the governing equations (Momentum, energy and mass conservation equations) completely for the inside air to find the velocity and temperature field? The answer is almost negative. Because the building thermal simulation, is generally performed for several days and in transient mode, it would take a long time to obtain a complete solution of conservation equations. Therefore, we may need to use simpler models instead. The simplest way is to use a single node for a whole room. The most physical and most exact method is CFD which is not always practical. In between, there exist other models that are not as complex as CFD but are somehow accurate. Nodal model and zonal model are two of them [9]. In the nodal model which is rather a simple one, the whole room is divided into a network of nodes that are connected to each other by one-dimensional air flow paths. However, in the zonal approach, a (Cartesian) network of control volumes control is used. This model is very similar to the CFD model. In Figure 1, a schematic of the solution networks for the 4 models described is shown. In this study, we have used the Heat Balance Method. The method is dynamic and transient and solves of the heat balance equation for walls and the room. A zonal model is used for calculating the temperature and velocity field in the room. As explained later, it solves all (but simplified versions) of conservations equations for the room air.

Figure 1 - Comparison between different models for calculating the temperature and velocity field in a room.

MODELING In the study, equations for transient heat transfer of walls are solved and radiation between walls, radiation through the window and storage of energy in the room are taken into consideration. As explained before, to solve the conservation equations for air, a zonal model and thus air circulation and also temperature distribution in the room is predicted. 2.1. Heat Conduction Heat transfer within the walls, ceiling and floor is transient heat conduction. According to the dimensions and geometries of the walls, heat conduction can be regarded as one-dimensional. Boundary condition of walls on both sides is a combination of heat convection and flux. Convection boundary condition is due to removal (or addition) of heat from (to) the boundary because of convective heat transfer with the atmosphere. Flux boundary condition is due to radiative heat transfer mechanism. Knowing all of the above, the conduction heat transfer equation can be easily solved. We used the Finite Volume approach to solve it. 2.2. Radiation Between Walls If the surfaces of all walls are opaque and gray and also the radiation is uniform in all directions, radiation exchange between them will be the solution of the equation (1) [10]:

1 1 1 1 1 2 1 1 1 1

2 2 1 2 2 2 2 2 2 2

1 2

1 ...

1 ...

... ... ... ... ... ...

... 1

n

n

n n n n n n n n n

F F F J E

F F F J E

F F F J E

, (1)

Where, E is emission (energy emitted from your body as a result of its temperature), J is radiosity (sum of the emission and reflected fraction of radiation received or irradiation), and Fijs are shape coefficients between walls i and j. After solving this system of equations and by denoting irradiation (the total received radiation from all objects around) by G, we can find the net energy output from the surface i as:

i i iq J G , (2)

3.2. Room Thermal Equilibrium Room air temperature is changed due to heat exchange with the walls and inside equipment via convection and also the produced or extracted heat. Absorbed radiation or emission is negligible. The governing equation is as follows if we use the bulk (single node) model:

, ,air

air p air i s i air fur fur air geni

dTm c h T T h T T Q

dt , (3)

Where Ts,i and Tfur are respectively the temperature of surface i (walls, windows, roof, …) and temperature of accessories, internal walls and other components in the room and Qgen, is the heat production term. The term containing equipments’ temperature, is due to heat transfer via

convection; this equipments get warm due to absorption of incoming radiation and give back their energy via heat convection to the air. An equipment’s temperature changes because of heat exchange with the air. The equipments may have temperature gradients inside, but because the lack of information and increasing in complexity of the model, the gradient is neglected and an average temperature is used for the whole equipments. Heat balance for the equipments is as follows:

, ,fur

fur p fur fur fur air Rad in

dTm c h T T q

dt , (4)

In which, QRad,in is the net radiation of heat into the equipments. 2.4. Zonal model The formulation in the previous section, was based on simple bulk model (single node) for room air. As mentioned earlier, the bulk model uses only a single node in the room. Thus no air flow exists, and temperature gradient is neglected. In this model, as any energy is input from any point of the room, the whole room temperature will change. The zonal model used, assumes that the flow mass flow is produced only by the effect of pressure difference. This assumption may be true for the low velocity flow inside a room. So we assume the mass flow from region j to region i that have a common vertical border (Fig. 2 a), to be as [11, 12]:

1

22ij j i ij d ij ijm m C A P , (5)

In which,Pij=Pj-Pi and, ij=sign(Pij) . The density used depends on the flow direction; is the density of the volume from which the fluid flows to another. I.e., if the flow is from region j to region i ( ij=1), then and vice versa. Similarly, the mass flow between two volumes having a common vertical border (Fig. 2 b) is:

1

212

2

1

2

ij j i ij d ij ij i i j j

ij ij i i j j

m m C A P gh gh

sign P gh gh

, (6)

Used coefficient CD is a discharge coefficient which must be determined before we can perform calculations. However, this coefficient can be variable, but the in our zonal model, we pick a fixed value. Research results indicate that for the case of flow due to free convection, a value of about 0.3-0.6 produces acceptable results [11, 12]. Mass and energy conservation equations for node i can be written as follows:

0ijj

m , (7)

,, 0 , 0 :

0ij ij

j iij p j ij p i n k i wall n i

j m j m j n wallsij

T Tm c T m c T k h A T T

x

, (8)

a)

b)

Figure 2 - Flow between two zones with different pressures; a) zones with a common vertical border (a) zones with a common horizontal border These relations are obtained using two assumptions (other the assumption of pressure-driven flow) for the zonal model. These assumptions are: • Thermal dissipation terms in the energy equation are neglected. • Due to very low speeds, air can be considered incompressible. 3. RESULTS 3.1. Validation of Zonal Model Results We first choose to validate the results of the zonal model. For this purpose, we compared our result with experimental results and also with the results of Boukhris et al [12]. The test case was a parallelepiped cell formed by two single volumes connected by a doorway and was called Minibat. The experimental were fulfilled by Boukhris et al. The shape and dimensions of the cell is presented in Fig. 3.

Figure 3. The shape and dimensions of the test cell In the case that was studied by Boukhris, the cell was equipped with a cold south face. Table 1 gives the values of average inside surface temperatures measured. Table 1. Values of average inside temperature (°C)

North South East West Ceiling Floor

17.93 11.7 17.20 17.32 17.1 16.71

A comparison of Boukhris’s results, experimental data and those from present work is given in Fig. 4 (a and b) for the air temperature on cold and warm sides of the partition. As seen, good agreement is achived. Deviation between calculated and measured temperatures was within 0.5 °C in the cold room, and less than 0.6 °C in the warm room.

a) b) Figure 4. Comparison of vertical distribution of air temperature on, a) the warm side and b) the cold side, of the Minibat cell. 3.2. Hourly Heating and Cooling Load Prediction For the 24-hour analysis, two sample rooms were selected in Tehran, Iran and the heating and cooling loads during the day were calculated and compared with Carrier HAP results. The results were for a quasi-transient situation. That is, the outdoor condition (for example outside temperature) has the same hourly profile for multiple days. So the hourly load profiles will be the same for all days. We did not simulate the conditions with a sudden change in outdoor conditions. For our study, two different days, one in July and the other in winter January were selected. Model input data, i.e. climate data, including temperature and solar radiation flux, was extracted from Carrier HAP software. The selected rooms, were quite simple and all the four walls and the ceiling were exposed to unconditioned (outside) space. In the first room, no windows existed and in the second one, a window was located on the south wall. The room area was 16 square meters. The plans of the rooms are shown in Fig. 5. The materials used for the ceiling, walls and windows are as shown in Table 2.

a) b)

Figure 5. Plans of the rooms, a) with window and b) without window.

Table 2. The materials used for the room.

Enclosure Layers Thickness (mm)

Specific Heat (J/kg K)

Density (kg/m3)

Conductivity (W/m K)

Absorptivity

North & South Walls

3 15 100 100

1090 840 920

801 609 2002

0.161 0.381 1.332

0.9

East & West Walls

3 15 150 100

1090 840 920

801 609 2002

0.161 0.381 1.332

0.9

Ceiling 3 25 10 100

920 1470 920

32 1121 2002

0.0208 0.1627 1.332

0.9

Windows 1 (Single glazing)

6 2000 2000 1 0.081 (Reflectance= 0.078)

Figures 6 and 7 show the results for hourly loads during a day for the two rooms. The results show that there is a very good agreement between our results and those of the Carrier HAP. As can be seen, maximum percentage of difference in heating loads is less than 2 and in cooling loads is about 10. Thus, so developed model for computing heat and cooling has passed validation test and is reliable.

a) b) Figure 6. Comparison of carrier and present work for hourly load for the room without window, a) in July and b) in January.

a) b) Figure 7. Comparison of carrier and present work for hourly load for the room with window, a) in July and b) in January.

4. DISCUSSION In this study, we studied the thermal modeling of a room; a model developed for numerical analysis of heating and cooling loads in a room. The thermal model developed included the complete and transient one-dimensional solution of heat conduction in the walls and windows, radiation heat exchange between walls, radiation through windows and a zonal model for room air. Zonal models was employed in order to find a relatively precise temperature field in the room on one hand and to reduce the complexities associated with the CFD model on the other hand. The presented new model provides good results, so that the hourly loads showed good agreement with the results of Carrier HAP software. It means that it can be used as a substitute. But the advantage over these quasi steady modeling is that the new model can predict the loads in a fully transient situation rather than a repeating 24-hour outdoor situations. As a future work, experimental data should be collected in order to validate the transient results obtained from the model. REFERENCES 1. Novoselac, A., Combined airflow and energy simulation program for building mechanical system design. 2005, The Pennsylvania State University.

2. Iranian Fuel Conservation Company (IFCO), http://www.ifco.ir/building/building_index.asp

3. Nikoofard, S., Calculating energy consumption of different heating equipments for the efficient design of energy consuming eqipments, M.Sc. Thesis, Sharif University of Technology, 2007.

4. Stephenson, D.G. and G.P. Mitalas, Cooling load calculations by thermal response factor method. ASHRAE Transactions, 1967. 73(1): p. 508-515.

5. Pedersen, C.O., D.E. Fisher, and R.J. Liesen, A heat balance based cooling load calculation procedure. ASHRAE Transactions, 1997. 103(2): p. 459-468.

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