EFFECT OF IRAQI INSULATION POSITION IN WALLS AND ROOFS ON COOLING LOAD IN IRAQI BUILDINGs USING TFM

Transfer function method is used to study the effect of local insulation position in walls and roofs on cooling load in Iraqi building. room 4*4*3m with east window on21stJuly located in Baghdad and made of local metals in walls and roofs is used as case study. Many types of walls and roofs (with insulation and without it) are used in different directions to study how the magnitude and the distribution of cooling load an changed. The results show that using local insulation (clay) in walls and roof reduces the cooling load by (23%)and the peak loads reduced (10%), also the study shows that the insulation (any insulation) used in eastern and western wall is more efficient in reducing the cooling load than the southern and northern walls . The results also show that when using the same amount of insulation in walls and roof at the same time the cooling load distribution changes more than when using this amount of insulation in each one. The study shows that when using north and south window and using efficient (not local)insulation the cooling load is reduced by (32%). This result shows the local insulation is good and active in reducing cooling load. صلختسملا ةقيرط تمدختسا ) CTF ( لمح ىلع حوطسلاو ناردجلا يف ةيقارعلا لزاوعلا عقوم ريثأت ةساردل ةيقارعلا ةينبلاا يف ديربتلا . اهداعبا ةفرغ ) 4*4*3 m ( موي يف يقرش كابش ىلع يوتحت ٢١ يفزومت يقيبطت لاثمك تمدختسا حوطسلاو ناردجلل ةيلحم ءانب داوم مدختست دادغب ةساردلل . عاونا ةدع تمدختسا ناردجلاو حوطسلا نم ) هنودب وا لزاعلا مادختسا عم ( ديربتلا لمح ةميق ريغت ةيفيك ةساردل تاهاجتا ةدعل هلكشو . يقارعلا لزاعلا مادختسا نا ترهظا جئاتنلا ) نيطلا ( ةبسنب ديربتلا لمح للق حوطسلاو ناردجلا يف ٢٣ % مب ضفخنا ىصقلاا ديربتلا لمحو رادق ١٠ % لزاعلا نا ةساردلا تنيب امك ) لزاع يا ( يف مدختسي يبونجلا رادجلا ىلع مدختسا ول اميف ديربتلا لمح ضيفخت يف رثكا ريثأت وذ نوكي يبرغلاو يقرشلا رادجلا يلامشلاو . سفن يف فقسلاو ناردجلا نيب اهعيزوتو لزاوعلا نم ةيمكلا سفن مادختسا نا جئاتنلا تنيب امك يغت تقولا فوقسلا وا ناردجلا يف ةيمكلا سفن تمدختسا ول اميف رثكا ديربتلا لمح عيزوت نم ر . تنيبو لزاع عضو عم يبونجو يلامش كابش ىلع يوتحت ةفرغ مادختسأب اضيا ةسسارلا ) ءوفك ( لمح ضفخنا Received on ٢٠٠٦ / ١ / ١١ Accepted on 8/7/2007 * University of Technology Mechanical Department رادقمب ديربتلا ٣٢ % نوكل يرارحلا لمحلا ضيفخت يف رثؤمو ديج يقارعلا لزاعلا نا انل نيبي اذهو جئاتنلا ةبراقتم . NOMENCLATURE A Area, m Ai Area of the ith surface, m 2 C Specific heat, W/kg.C F View factor Fs-g View factor from the surface to the ground Fs-sky View factor from the surface to the sky g Gravity acceleration, m/s Gt Total solar irradiation incident on the surface, W/m hc Convection coefficient, W/(m-K) i,j,k Unit vectors k Thermal conductivity, W/m. C N Number of surfaces in the room q Heat flux, W/m q" condition, out, j,θ Conduction heat flux, W/m 2 q" convection, out, j,θ Convection heat flux, W/m 2 q" radiation, out, j,θ Thermal radiation heat flux, W/m 2 q" solar, out, j,θ Absorbed solar heat flux W/m 2 θ n, infltratio q& Heat gain due to infiltration, W θ system, q& Heat gain due to the mechanical system, W θ conv, internal, q& Convective portion of internal heat gains due to people, lights. or equipment, W t Local temperature at point in the slab, C tg Ground temperature, K tos,j,θ The surface temperature, K tsky Effective sky temperature, K U Overall heat transfer coefficient, W/m.K V Wind speed m/s X Exterior CTF coefficient W/m.K Xn Exterior CTF coefficient, W/(m-K) Y Cross CTF coefficient W/m.K Yn Cross CTF coefficient, W/(m-K) Z Interior CTF coefficient W/m.K Zn Interior CTF coefficient, W/(m-K) α Thermal diffusivity, k/ρ. C ε Surface long wavelength emissivity σ Stefan-Boltzmann constant = 5.67 x 10-8 W/(m2-K4) Φn Flux coefficient, dimensionless ε Surface long wave emissivity θ Time, s ρ Density, kg/m Φ Flux coefficient, dimensionless б Stefan Boltizman constant 5.6×10 -8 W/m.K. Subscript s-g ground in Inside os Outside surface n Number out Outdoor