Simulation of natural gas saving through foam lightweight concrete utilization in residential buildings

Heat loss through walls in houses is remarkable and it shares about 25% of total loss. Utilizing Foam Lightweight Concrete [FLC] block in walls may lead to reduction in both gas consumption and greenhouse gas emissions. This is due to heat insulation property of the block and consequently less energy consumption. The main objective of this research was to investigate how FLC block can save natural gas usage within building envelop. A typical residential building was simulated for pressed brick, terra-cotta block, 3D panel, and FLC block by utilizing Behsazan software. Afterwards, building gas consumption and relevant carbon dioxide emissions were compared for abovementioned wall materials, while the building area was constant and its height was variable. Results showed that annual gas reduction attributed to utilizing FLC block walls with different heights varies from 25.7% to 30.6% and from 18.5% to 23.3% in comparison with pressed brick and terra-cotta block walls, respectively. This reduction for 3D panel walls was about 4.6%. Moreover, CO[2] emission reduction depending on the number of floors for FLC block walls with pressed brick, terra-cotta block, and 3D panel walls were equal to 20.8 to 24, 15 to 18.3, and 3.4 to 3.8 kg CO[2]/m[2], respectively

Estimating temporal and seasonal variation of ventilation coefficients

The main objective of a research program, whose output is presented here, has been to estimate "Ventilation Coefficients", a critical parameter in determining air pollution concentration near the surface ground which signifies the ability for natural ventilation of an air shed in an urban or rural area. Relevant measured data from the city of Tehran has been used to calibrate and further demonstrate the validity of the mathematical model developed. Since most polluted mega cities require significant air pollution modeling activities, capable of providing relatively reliable outputs, calculating such highly important parameter is by far the most important outcome of this research. The Ventilation Coefficients have been estimated assuming normal adiabatic lapse rates and utilizing ten-year daily atmospheric radio-sound data. Mean Maximum Mixing Depth, Wind Speed at Mean Maximum Mixing Depth, and the Ventilation Coefficients have been computed and as a result it has been noted that despite the fact than Mean Maximum Mixing Depth peacks in June and Wind Speed Coefficient to remain at its peack almost constant over April-June time span. It may also be observed for an urban area such as Tehran, the Ventilation Coefficient stands maximum in spring at 22329.17 m[2]/s and minimum in fall at 22329.17 m[2]/s

Air quality deterioration in Tehran due to motorcycles

Since there is a rise of motorcycles population as well as other motor vehicles, it seems that air Pollution deterioration should be studied as one of its environmental impacts. The main objective of this study was to develop a number of scenarios in order to determine the amount of Tehran's air pollution attributable to motorcycles and select the best and the most probable case to be recommended for implementation. The first step was to collect data such as the number of active motorcycles, daily traffic volume, average traveling speed and actual emission factors. For this purpose, a detailed questionnaire was designed to be completed by field surveys and measurements. The collected data were compared with traffic volume data, manufacturing statistics and the latest production capacity forecast in this field. Finally, with this data and emission factors for each type of motorcycle, an emissions inventory model was chosen to provide annual emissions from motorcycles in Tehran in different scenarios. The results showed that in 2002, there has been about 450'000 active motorcycles [4-stroke 58%, 2-stroke 28%, and moped 14%] with average speed of 40 km/h and average mileage of 110 km/d. Five scenarios were developed. The best scenario was "Changing all motorcycles to 4-strokes under EU-97 standard" which would result in reduction of NMVOC by 75%, CO by 35% and PM10 by 88%