20320140501007 2
Upcoming SlideShare
Loading in...5
×
 

20320140501007 2

on

  • 214 views

 

Statistics

Views

Total Views
214
Views on SlideShare
214
Embed Views
0

Actions

Likes
0
Downloads
0
Comments
0

0 Embeds 0

No embeds

Accessibility

Categories

Upload Details

Uploaded via as Adobe PDF

Usage Rights

© All Rights Reserved

Report content

Flagged as inappropriate Flag as inappropriate
Flag as inappropriate

Select your reason for flagging this presentation as inappropriate.

Cancel
  • Full Name Full Name Comment goes here.
    Are you sure you want to
    Your message goes here
    Processing…
Post Comment
Edit your comment

20320140501007 2 20320140501007 2 Document Transcript

  • International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308 (Print), ISSN INTERNATIONAL JOURNAL OF CIVIL ENGINEERING AND 0976 – 6316(Online) Volume 5, Issue 1, January (2014), © IAEME TECHNOLOGY (IJCIET) ISSN 0976 – 6308 (Print) ISSN 0976 – 6316(Online) Volume 5, Issue 1, January (2014), pp. 66-72 © IAEME: www.iaeme.com/ijciet.asp Journal Impact Factor (2013): 5.3277 (Calculated by GISI) www.jifactor.com IJCIET ©IAEME FEASIBILITY OF USING INSULATED CONCRETE FORMS IN HOT AND HUMID CLIMATE 1 Selvapandian, 2 Professor. K.P. Ramachandran, 3 Dr. Neeraja 1 2 Caledonian College of Engineering, Muscat, Sultanate of Oman Associate Dean (Research), Caledonian College of Engineering, Muscat, Sultanate of Oman 3 Associate Professor, VIT University, Vellore, Tamilnadu, India ABSTRACT Insulated concrete forms are used widely in cold climates to control heat loss from inside to outside from the living areas of the building. Even though, oil is the major source of power generation in Middle East Countries, there is huge potential to use electrical energy more efficiently in buildings by applying thermal insulation. In this paper, an attempt has been made to compare the hygric behavior of a building with ICF construction and a building with normal concrete construction in Muscat, Sultanate of Oman. Hygrothermal performances of the walls were studied on these buildings during the peak summer months of July, August and September 2013. The result indicates that the performances of insulated concrete forms are comparatively better than the normal concrete block walls. Key words: Hot and Humid Climate, ICF, Thermal Performance, Insulation, EPS. 1. INTRODUCTION Oman is a country which has a long span of summer with dry, hot and humid climate. The summer season of Oman records high humidity condition (up to 80% RH and up to 48º C sometimes) and this is not suitable for the living conditions. Maximum energy is used on the operation of air conditioners to maintain the thermal comfort inside the buildings. Electricity generation is by using petroleum oil, which is the major natural resource of Oman. Energy conservation and the use of thermal insulation for walls and ceilings are an emerging practice in Oman. Thermal and hygric behavior of buildings are related to each other. Increased humidity levels helps heat to transmit more into the walls. Application of thermal insulation in buildings apparently reduces the running cost of air conditioners by minimizing the heat gain through the walls. 66
  • International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308 (Print), ISSN 0976 – 6316(Online) Volume 5, Issue 1, January (2014), © IAEME This paper focus on the performance of insulated concrete forms in hot and humid climatic conditions and also, the hygrothermal performance of the walls. Enough study has been done on the performance of insulated concrete forms in low temperature climates and there is a need for a feasibility study on ICF in hot, dry and humid conditions. 2. LITERATURE REVIEW Studies have been done all over the world on the performance of Insulated concrete forms in buildings in low temperature climates. NAHB Research Centre (2001) conducted a test on three buildings on the comparison of performance of ICF homes with normal framed structures. The study has shown that ICF homes had an energy reduction by more than 20% [1] A Comparative study on ICF building and a wood framed building were done by Petrie Etal (2001) and the result showed that ICF building consumed 7.5% less energy than the conventional wood framed building. Performance analysis of a seven storey multi residential building with ICF construction was done by the ready mix concrete association (2006) in waterloo, Canada. Two ICF wall specimens were monitored in a study by W. Maref, M.M Amstrong and G. Ganapathy (2012). The outcomes showed the reduction of peak heating load of the furnace and thus have implications on the sizing and the cost of the heating equipment [2]. Florian Antretter and Achilles Karagiozis analyzed the interior temperature and relative humidity distributions in mixed humid and cold climates [3]. They compared the internal conditions of the building with the standard levels. Dr. KevanHeathcote compared the thermal performance analysis of three test buildings in Australia. Recording of temperatures inside and outside the test buildings were analyzed in this paper [4]. Different combinations of wall and roof plans and shapes were suggested by Amjad A. Maghrabi (2005). This study was carried out in Makkah, Saudi Arabia [5]. He concluded that, the net heat transfer through the walls increases or decreases as per the effect of plan shapes of roof and different wall areas. Abdullah yildiz and GokhanGurlek (2008) presented a study on environmental analysis of thermal insulation in buildings with different thickness. The result of this paper was increase of thermal insulation decreases the heat loss in the building with increase in the cost of insulation material [6]. 3. METHODOLOGY Two residential buildings of same volume were selected from phase 7, Mabela, Muscat governorate of Sultanate of Oman. One building was constructed with the normal concrete block and the other building was with the insulated concrete block construction. Data loggers (Type-EBI 20-TH) were used for temperature and relative humidity measurement. The data loggers were placed outside the building with shade and inside the building one foot away from the wall and temperature and relative humidity was recorded during the peak summer months of July, August and September 2013. Transmission heat gain and moisture transfer through the wall structures were calculated for analysis for one week during the first week of July. For the cooling demand and energy calculations, CAS Anova software [13] was used. This paper presents the analysis of heat transmission and moisture transfer in the wall systems and the feasibility study on insulated concrete forms in Oman. 3.1 Factors considered for the feasibility study 1. Transmission heat gain through the walls 2. Actual electricity bills of the buildings 3. Thermal conductivity of the wall 4. Cost of the materials 67
  • International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308 (Print), ISSN 0976 – 6316(Online) Volume 5, Issue 1, January (2014), © IAEME 4. DATA ANALYSIS Recorded data of temperature and relative humidity was downloaded from the data loggers. Average maximum temperature and relative humidity of the buildings was taken for the calculations of heat transmission through the walls, and the moisture transfer through the walls. Maximum temperature of 39ºC and RH of 83% was recorded inside the normal construction building during the month of August. Minimum temperature was recorded inside the ICF building during the month of July. Average RH recorded inside the buildings were above 70% during the three months and the ICF building recorded a minimum of 69% RH in the month of September. Actual electricity bills of the buildings and the thermal conductivity of the walls were also considered for the comparative study. Figure 1: Specification of the Walls Figure 2: Data logger output - ICF House Data logger output – Normal House 68
  • International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308 (Print), ISSN 0976 – 6316(Online) Volume 5, Issue 1, January (2014), © IAEME Table 1: Heat gain through the wall structures (Monthly Average) Month Wall structure Heat gain (Watts) June Normal concrete wall ICF wall 2705 ICF wall 1792 Normal Concrete wall 1803 ICF wall August 2240 Normal concrete wall July 2704 1792 2704 2705 2240 1792 Normal concrete wall ICF wall 1792 ICF wall Normal concrete wall 1803 Normal Concrete wall ICF wall Figure 3: Heat gain through the wall structures Outside air VP Table 2 Water vapour pressure levels 2: ressure Inside air AP Water vapour Pressure difference ICF Normal ICF Normal ICF Normal 4090 4261 3374 3715 716 546 4295 4729 3603 4830 692 101 4255 4995 2017 1989 2238 3006 Vapour pressure of the air is determined by the ability of the building fabric and contents to absorb or desorb water vapour. This will reduce or increase the vapour pressure depending on whether the building is cooling or heating [7]. Individual “T” test was conducted in SPSS for the temperatures inside the Insulated concrete form house and the normal concrete structure house. T critical is greater than the calculated T statistics. From this, it is evident that the performance of the ICF wall structure is better than the normal concrete wall structure. Actual electricity bills of both the buildings were considered for the analysis of energy consumed. 69
  • International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308 (Print), ISSN 0976 – 6316(Online) Volume 5, Issue 1, January (2014), © IAEME Below table shows the difference in units consumed by the buildings per meter square area. There is a significant difference between the ICF wall and the normal concrete wall in transmitting heat through the walls. Heat transmission through the walls during the month of august is in minimum difference as the atmospheric temperature started falling because of the unusual rain in Muscat. Actual electrical bills of the buildings from MEDC (Muscat Electricity Distribution Company) were considered for the comparison of the electrical energy consumption per one meter square area. ICF buildings consume 20% to 40% of less energy than the normal concrete building. Table 3 Actual Electricity Bill Month Building Total Kwh Consumed July Normal building 4883 35 ICF Building 4542 27.5 Normal building 4164 30 ICF Building 3042 18.4 Normal building 4137 29.3 ICF Building 2891 17.5 21% 38% 40% July August ICF Building Normal building ICF Building Normal building 40 30 20 10 0 ICF Building Units/m² September Normal building August Units/m² Reduction in units in ICF Building September Figure 4: Electrical energy consumption 4.1 Thermal Conductivity Thermal conductivity of the two wall structures were measured with a thermal conductivity meter [Model No: KD2 Pro]. Thermal conductivity of ICF wall is in the desirable range within 0.74as mentioned in the thermal insulation regulations of Gulf cooperation council countries (GCC) [8]. Table 4: Thermal Conductivity Wall Type Thermal conductivity (W/m²) Normal concrete wall structure 1.814 ICF wall Structure 0.4 70
  • International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308 (Print), ISSN 0976 – 6316(Online) Volume 5, Issue 1, January (2014), © IAEME Table 5: Cost Comparison Type of Structure Cost/m² of gross wall area Normal concrete structure 3.5 Omani Riyals ICF wall Structure 6.5Omani Riyals Insulated concrete block structure 5.8Omani Riyals Cost of ICF construction is higher than the normal concrete block and the double cavity EPS insulated concrete block, but ICF construction has the advantage of simple and easy method of construction, since it has the conventional materials like reinforcement, concrete and EPS insulation with monolithic construction. Number of labor hours required for constructing a building with ICF is comparatively less with other types of traditional type of construction. An ICF building in Yemen was constructed within three months in the year 2010. 5. RESULTS AND DISCUSSION In this study, the feasibility of using of ICF system in Oman was analyzed. Transmission heat gain calculation through the walls structures during the peak summer months of July, August, and September shows that, ICF walls transmits 17% less than normal concrete walls structure. Annual energy demand for cooling is 36% less in ICF houses than traditional concrete buildings. From actual electricity bills of the two buildings it is evident that, ICF houses consume 20% to 40% less energy than the traditional building. On an average, money spent for electricity in the ICF house is 36% less than the normal construction. Economic Analysis on thermal insulation shows that, it is feasible to have a reduced operating cost of air conditioners [10]. Initial cost of ICF can be compensated with the less running cost because of its excellent thermal behavior. Insulated concrete forms are suitable to use in countries with dry, hot, and humid climate. Due to the massive concrete core, the buildings constructed with insulating concrete forms have the same durability and stability as conventional buildings [11].Even though, since Oman has a long coastal area, structural rigidity of the ICF wall systems needs to be studied, because of the salt crystallization and coastal climatic conditions. 6. CONCLUSION • • • • • • From this study it is clear that, the use of insulated concrete forms in hot and humid climates is feasible Thermal and moisture behavior of ICF is good and the chance of condensation in wall structures is not possible Energy consumption towards the thermal comfort in the buildings is less with ICF buildings Thermal conductivity of ICF walls is less as per the standard prescribed by Gulf Cooperation countries [12] ICF system offers better and uniform insulation, more airtight envelope, and faster construction. However, it costs more than other construction systems [11]. At present, nine residential buildings were constructed and one commercial cum residential complex is under construction in Muscat 71
  • International Journal of Civil Engineering and Technology (IJCIET), ISSN 0976 – 6308 (Print), ISSN 0976 – 6316(Online) Volume 5, Issue 1, January (2014), © IAEME ACKNOWLEDGEMENT The author would like to extend sincere thanks to Caledonian College of Engineering, Muscat and Innovation Building LLC (Member of Ali & Abdul Karim Group and W.J Towell Group) Ghala, Muscat, for the opportunity provided to conduct this study. REFERENCES [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] NABH Research Centre (National Association of home builders, USA), (2001), “Costs and benefits of insulating concrete forms for residential construction”, Policy development and research, US Department of housing and urban Development W. Maref, M. M. Armstrong, H. Saber, M. Rousseau, G. Ganapathy, M. Nicholls and M.C. Swinton, (2012), “Field Energy Performance of an Insulating Concrete Form (ICF) Wall”, National Research Council, Canada Florian Antretter, Andreas Holim, Achilles Karagiozis, Samuel glass, (2010), “Interior Temperature and relative humidity distributions in mixed humid and cold climates as building simulation boundary conditions”, Buildings XI conference, ASHRAE Dr. KevanHeathcote, (2007), “Comparative analysis of thermal performance of three test buildings”, Earth building research forum, University of Technology, Sydney Amjed A. Maghrabi, (2005), “Comparative study of thermal insulation alternatives for buildings, walls and roofs in Makkah, Saudi Arabia”, Journal of Science and Engineering, Umm Al Aura University Abdullah Yildiz, GolahanGurlek, Mehmet Erkek, (2008), “Economic and environmental analysis of thermal insulation thickness in buildings”, Journal of thermal science and technology, Turkey BS 5250:2002, “Code of practice for control of condensation in buildings” M.M. Abo Elazm, A. M. Elharidi, (2010), “A case study of the effect of insulation materials on HVAC energy consumption”, World renewable energy congress “Green building regulations and specifications”, Public Authority of electricity and water, UAE Eball H. Ahmad, (2002), “Cost analysis and thickness optimization of thermal insulation materials used in residential buildings in Saudi Arabia”, Sixth Saudi engineering conference, Kind Fahad University of Petroleum and Minerals, Dhahran Dr. Mohammad S. Al-Homoud, (2004), “Performance characteristics and practical applications of common building thermal insulation materials”, Journal of building & environment, Elsevier “Green building regulations and specifications”, Public Authority of Electricity and Water, UAE “CAS Anova”, www.nesa1.uni-siegen.de Sameer Ul Bashir, Younis Majid and Ubair Muzzaffer Rather, “Effect of Rapidite on Strength of Concrete in Warm Climates”, International Journal of Civil Engineering & Technology (IJCIET), Volume 4, Issue 6, 2013, pp. 126 - 133, ISSN Print: 0976 – 6308, ISSN Online: 0976 – 6316. P.C.Madhuraj and J.Sudhakumar, “Assessment of Transient Hygroscopic Behaviour for Design of Passive Solar Building Envelope for Hot-Humid Regions”, International Journal of Civil Engineering & Technology (IJCIET), Volume 1, Issue 1, 2010, pp. 46 - 54, ISSN Print: 0976 – 6308, ISSN Online: 0976 – 6316. 72