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One of the most useful and simplified approaches in assessing building energy estimates is the degree days method. The heating and cooling requirements can be easily compared for different locations as well as system trends. In this paper, the cooling degree day values for the capitals of the Gulf Cooperation Council (GCC) are presented. Degree day values at different base temperatures are also produced for these locations. These values are useful for engineers and policy makers for evaluating energy demands and their cost for these countries. A typical two-story residential building is considered here and its yearly cooling load is evaluated. The total cooling energy is compared based on the energy cost of the respective GCC countries. The results presented in this investigation illustrated that the cooling load, based on the cooling degree days (CDDs) at a 23 °C base temperature, agrees well with the detailed hourly cooling load simulated by eQuest software. Additionally, the highest CDDs value of 2589 was observed in the city of Doha and the lowest value of 2037 was seen in Riyadh city. The lowest cooling cost of USD 492 corresponds to Muscat, while the highest value of USD 1672 belong to Abu Dubai, partially due to a higher tariff of 0.081 USD/kWh.

Wood-plastic composites (WPCs) are becoming one of the most attractive materials in building envelopes. In addition to WPCs' architectural and design attraction, they can enhance the thermal performance of buildings by acting as insulation materials. The thermal performance of building materials requires new experimental methods that can simulate true indoor/outdoor temperatures. In this study, a simple quasi-steady heating film (QSHF) method is devised to measure the thermal conductivity of WPC samples utilizing blocks of standard materials with known thermal conductivity. QSHF device uses a 10cm×10cm×0.5mm silicon heating film controlled by a temperature regulator and several transparent acrylic square blocks of the same size with 10mm thickness as the standard materials along with various specially designed WPC samples for Kuwait. The WPC samples' top surface is considered the cold side of the system, which is open to indoor temperatures of 22 to 23 oC. The bottom layer is maintained at fixed temperatures ranging from 25 to 55 oC to simulate the outdoor temperatures of a hot subtropical desert environment like Kuwait. The thermal conductivity of several WPCs type namely FB16, FB18W, CD, and TD were obtained as 0.0912, 0.1174, 0.3453, and 0.3078 W/m.K, respectively. Experimental results for DP45-1 were not consistent at different temperatures. hence Multiphysics CFD simulation was conducted for DP45 which shows strong 2D effects. A typical building sample was also modelled in TRNSYS to compare cooling loads with and without WPC. Also, the limitations and advantages of using QSHF method are discussed.

This research attempts to develop a systematic method to address climate changes by studying temperature-humidity patterns as the two major meteorological parameters and to moderate these effects using a commercially available window film on interior windows of an office building with double-glazing. A three-floor educational building at Australian College of Kuwait (ACK) was equipped with temperature, humidity and illuminance sensors for two similar size offices, one with 3 M Neutral 20 window films. Total readings of 50,000 entries from each sensor was recorded every 3 min by a home-designed microprocessor-based logging system for three months of June, July, and August 2019. In parallel, the ACK building was simulated in EnergyPlus and DesignBuilder software and calibrated with the experimental measurements. Histograms and a probability density function (PDF) of temperature and humidity are built by a representative rational function as a model of main climate parameters variations. By examining min-mean-max values of data, it is observed that the office with window films has increased indoor humidity and, in most instances, reduced temperature by 2–5 °C compared to double-glazed bare windows which can significantly reduce cooling loads in extreme hot-arid climates. Simulation results are presented on the energy saved and the reduced CO2 footprints by applying the solar window films in the ACK building.

Industrial lubricants are widely introduced to the mechanical systems to reduce the wear and energy losses. With the increasing demand for environmental protection, developing eco-friendly lubricants becomes more crucial. Due to their abundance, biodegradability, non-toxicity, high thermal stability and low cost, cellulose nanocrystals (CNCs) may be an appropriate choice for formulating green lubricants. In this study, using different microstructural and tribological characterization methods, we systematically investigated the effect of ultrasonic treatment on lubrication performance of CNC aqueous suspensions. It was observed that within sonication energy of 4-50 kJ/g

This study examines the performance of solar window films installed on double-glazed windows of typical offices in actual working conditions in a hot and dry climate. Passive thin films stuck interiorly on double-glazed windows were used to affect various solaroptical impacts including energy saving, UV reduction, and increased thermal comfort. Real-time measurements of environmental parameters, including temperature, humidity, and luminous, were performed continuously in 5-minute intervals over three summer months of June, July, and August 2019 in Kuwait and data were stored automatically through a WiFi system. Arduino-type microprocessors and various temperature, humidity, Lux, and UV sensors were assembled and programmed to transfer and store data in real-time. Temporal and spectral analyses were conducted to compare the effects of the window films on these environmental parameters. It is evident that windows film has good potential to decrease interior temperature and its variability, to save energy and reduce CO 2 footprints, to save water by preserving interior humidity to level of human comfort, to restrict the solar UV rays to minimum level, and to reduce visual impacts of high solar luminous in hot-dry climates. The benefits and drawbacks of the selected windows film are discussed.

This work examines the solar performance of double-glazed windows in four offices in ACK buildings with and without solar window film in actual working conditions. Window films are passive thin films stick to the interior or exterior of windows to effect various solar-optical impacts including energy saving, UV reduction, and increased thermal comfort. For this study, the 3M Neutral 20 and 70 are selected which are made of multilayer nanofilms of 220 SAN25/THV 95-nm thick reflective layers. Real-time measurements of temperature, humidity, and luminous were conducted in 5 min intervals over the months of June, July, and August 2019 and data stored through WiFi system in iClouds. Arduino-type microprocessors and various temperature-humidity, and LUX sensors were assembled and programmed to transfer and store data in real time. Exploring and analyzing the data collected for four offices with and without window films in summer of Kuwait, it is evident that window film has good potential to save water by preserving interior humidity to the level of human comfort, decrease interior temperature to save energy and reduce CO2 footprints, to restrict the solar UV rays to minimum level, and to reduce visual impacts of high solar luminous. The benefits and drawbacks of the selected window films are discussed here for the weather condition of Kuwait.

In the oil and gas industry, application of nanoparticles is becoming a more common practice. There are a number of researches on lubricating effects of nanoparticles in different applications; therefore, some fundamental studies are eminent on mechanisms and functions of skin friction reduction of nanoparticles in pipe flows. In addition, studies on coagulation and agglomeration of nanoparticle precipitation on the pipe surfaces are of practical interest. In this research, development of a miniature Reynolds apparatus is sought to study different flow regimes from laminar to turbulent. The first goal is to measure rheological properties of Newtonian and non-Newtonian nanofluids at laminar flows. The miniature Reynolds apparatus should continuously circulate 1 L or lower amounts of nanofluid and measure pressure drop and flow rates for at least three Reynolds numbers. This paper summarizes the design procedure and provides CFD simulations for the designed system. Analysis of the measured data will provide useful information on skin friction reduction and precipitation of nanoparticles on pipe surfaces.

Flow instabilities in a compression system at low flow rates set the flow limit of the stable operating range. Experiments to investigate the feasibility of controlling the stall in the radial diffuser of a low speed centrifugal compressor were carried out. The technique was very simple and involved using rough surfaces (i.e., sand papers) attached to the diffuser shroud. The results showed that the flow instability in the diffuser (stall) was delayed to a lower flow coefficient (the mass flow rate could be reduced to 70% of its value with the smooth surface) when the rough surfaces were positioned on the diffuser shroud.Copyright © 2006 by ASME