Reducing energy consumption and to ensure thermal comfort are two important considerations in designing an air conditioning system. The control strategy proposed is fuzzy logic controller (FLC).This paper describes the development of an algorithm for air condition control system based on fuzzy logic (FL) to provide the conditions necessary for comfort living inside a building.Simulation of the controlling air conditioning system, on which the strategy is adopted, was carried out based on MATLAB This system consists of two sensors for feedback control: one to monitor temperature and another one to monitor humidity. The controller i.e. FLC was developed to control the compressor motor speed and fan speed in order to maintain the room temperature at or close to the setpoint temperature.
The present study was concerned with the analysis, simulation of the air flow pat-terns and thermal comfort levels in the University of Anbar at conferences hall (Ibn Al Haitham hall). The study was performed in a hot - dry season. The pur-pose of the present work was to investigate the level of thermal comfort and the influence of the air flow on the flow patterns at the conferences hall. It has been assumed that the total number of occupying audiences in the hall was approxi-mately 100 persons. The present work simulated and analyzed four hypothetical cases, namely: in the first case, the hall was assumed as an empty place, whereas the other three cases were performed by redistribution for the three units of air conditioning, the hall was assumed as a filled place with persons in September 2019. The study was accomplished using simulation techniques, a CFD code (FLUENT 6.2) v.17, which is commercially available. The CFD modelling tech-niques were applied to solve the continuity, momentum and the energy conserva-tion equations in addition to the Turbulence k-є (RNG) model equations for a tur-bulence closure model. Thermal comfort was assessed by finding the values of predicted mean vote (PMV), predicted percentage of dissatisfied (PPD), and ASHRAE standard-55. In conclusion, the second case was the superior in compar-ison to these other cases. It was noted that the PMV value was 0.17, whereas the PPD value was 6.79 at the breathing level.
The White Cement Kiln Dust (WCKD) is a byproduct material, formed in cement factory during the operation of cement production. In highway construction, the WCKD can be used in different ways such as stabilizing the subgrade of highway embankment and as mineral filler in Hot Mix Asphalt (HMA); the latter usage will give clean and healthy environment in addition to more economy. In Iraq, there are two common types of fillers, Portland cement and lime stone powder. In this research, WCKD taken from Fallujah cement plant used as mineral filler in addition to two common types. Various percentages , such as 100%WCKD, 50%WCKD + 50%Cement(C) ,100%C , 50%WCKD+50%Limestone (L), and 100% L, were used to prepare asphaltic concrete mixes. In general, five tests were used to evaluate the performance of these mixes. Standard Marshall Test procedure was applied under three different conditions, two of them at two temperatures at 60 OC and 70 OC and in the third one it was used to test samples immersed in water, at room temperature(24 OC), for four days. Indirect Tensile Strength Test (ITST) was used to evaluate conditioning and un-conditioning samples. All test results, when compared with controlled asphalt concrete sample (Sample contained 100% limestone as filler), were acceptable and within the AASHTO and Iraqi Standard Specifications of Roads & Bridges 2003. Stability values, at standard condition test, of samples containing 100% WCKD, 50%WCKD+50%C, and 50%WCKD+50%L are 11.9kN, 13.2kN, and 14.0kN respectively, while for controlled sample was 9.0kN. The Marshall stiffness values showed similar trends, for samples having 100% WCKD, 50%WCKD+50%C, and 50%WCKD+50%L giving 3.22kN/mm, 3.38kN/mm, 3.5kN/mm respectively but for controlled sample was 2.43 kN/mm. Same trends of results gained in ITST .The results showed the beneficial using of WCKD as filler that will conserve the environment and encourage the HMA producers to use this inexpensive material in their works.
This paper describes a numerical method for calculating the temperature distribution and latent heat storage (LHS) in the treated wall (TW) and non-treated wall (NTW). The developed method was assumed that the outer cement layer (Iraqi wall) enveloping the external wall of building and houses are contains paraffin wax as a phase change material (PCM). (25%) is the volume percentage of paraffin wax is mixed with cement which forming a treated layer. A comparison results between the (TW) and (NTW) has been done. The paper presents a simple calculation of case study for air-conditioning in two walls type of residential building. The outer solar air temperatures as function of day time are considered for a hot day in summer (July) for Baghdad city. The aim of this paper was to obtain physical validation of the numerical results produced from using developed FORTRAN program. This validation was obtained through a comparison of numerical solution of two different wall compositions exposed to the same external and internal load conditions. The calculations on transient heat transmissions across different walls were conducted. It was found that when using the (TW) with (PCM) produces lower surface and heat flux towards the cooling space with respect to (NTW).
The present research is devoted to solve the problem of high energy consumption by air conditioners in summer. In order to eliminate domestic electricity for cooling purposes and rely directly on solar energy isolated from the grid connection and increases the performance of the solar panel by using front water spray cooling system for the panel, and by using Adruino as controller to control the cooling system. The experimental system setup arranged in Iraq at Al-taje site during the summer season at a room. The proposed system consists of an array of photovoltaic, battery used to store power, PWM charge controller, and DC air cooler, Adruino. During the examination of the system, The enhancement of the solar panel has a positive effect on long-term batteries and improves the battery life by which the charge and discharge when combined with a direct photovoltaic air conditioning system without refrigeration. Excess power generated from the PV panels is storage in the batteries, which make the system is the most familiar with Iraq's summer conditions
This study focuses on improving the thermal comfort in Mosques in Iraq. Omar bin Abdul Aziz Mosque in Baghdad is taken as a case study. In general, the weather in Baghdad is hot- dry climate during the summer. the study was conducted at the time of noon prayer on Friday where the maximum number of people can be obtained inside the Mosque about 500 worshipers and severe environmental conditions. Numerical methods (CFD) are used for the simulation utilizing the package of ANSYS (FLUENT V. 18). As the results depending on the number of elements, 4 millions elements are used for dividing the physical domain. Thermal comfort was assessed by finding the values of the predicted mean vote (PMV), predicted percentage of dissatisfied (PPD), and ASHRAE standard-55. The adaptive redistribution of the air conditioning device strategy at five cases is used to obtain the best thermal comfort. Moreover, changing the angle of air intake of space by changing the angle inclination of the access blade at three different angles of 0o, 7.5o and 15o degree, and studying its effect on the thermal comfort in breathing level. The four case is the best in terms of thermal comfort when the angle of intake air at 0o.when the PMV was 0.35 and PPD is 7.5, which is lower than the original state. The improving percentage of PPD is 10 % and PMV 14 %.
The reducing of heat gain through the outer walls of the buildings in summer will contribute in reducing the air conditioning costs. This is one of the best features of design requirements nowadays. To achieve this, the phase change materials (PCM) can be used as an embedded material in the walls to reduce heat transfer. The paraffin wax is one of the common materials used as a PCM in the building walls. The paraffin wax is used in this study with (20%) volume percentage in the external layer of the treated wall. In the present work, the treated wall (with embedded wax in the wall) and non-treated walls have been experimentally investigated. Two Iraqi wall models were employed to run the experiments, whereby these models were exposed to an external heat source using (1000 W) projector for each model. The temperatures were recorded at different locations in the walls during the charging and discharging periods. The results showed that the temperature of the internal surface for the treated wall was lower than that of the non-treated wall at the end of the discharging period (6 hr) where the temperature difference between the treated and non-treated walls was reached (1.6℃).