Need For Air Conditioning Research Articles

Analysis of the Influence of Envelope Heat Gain on Hygrothermal Comfort in Tropical Housing: The Case of Benin

The current construction of residential buildings in Benin neglects the importance of thermal insulation of their envelopes. Instead, it relies on active systems as a solution to mitigate over-consumption of electrical energy and guarantee a certain level of thermal comfort inside these buildings. It should be noted that Beninese architects are generally unfamiliar with these thermal aspects.
 The main aim of this study is to assess the effects of thermal insulation on walls and roof, determine the optimum thickness of insulating materials, and integrate a controlled mechanical ventilation system to improve thermal comfort in a humid tropical climate. The investigations were carried out on an example of a typical residential building located in Cotonou, Benin, with precise geographical coordinates (latitude 6°38' North, longitude 2°34' East). To analyze the thermal behavior of this building, a series of dynamic thermal simulations were carried out using TRNSYS software, which was used both to model the building structure and to run the various simulations.
 The results of this study revealed that thermal insulation of the walls and roof, using polystyrene, significantly reduced the need for air conditioning. What's more, the integration of a controlled mechanical ventilation system not only ensured indoor air quality, but also helped regulate indoor humidity, reducing it from 67% to 76%.

Improving The Thermal Comfort Of The Structures By Applying The Sustainable Engineering Requirements

Modern thermal comfort theories recommend that a restricted temperature difference be evenly maintained throughout all architectural styles, regions, and people. This strategy treats structure inhabitants for heating purposes, resulting in thermal comfort criteria that necessitate power climate management measures. This frequently results in a high need for air conditioning. Initial investigation and new Technology, HVAC (Heating, Ventilation, and Climate Control) advanced facilities are contesting conventional assumptions of thermal comfort criteria on the basis that they ignore main social and environmental comfort elements. In this paper the researcher took the effect of the modification in the design on the thermal comfort by several engineering solutions for reducing the total main radiant temperature (TMRT(, Potential air temperature (PAT), and the developing of the relative humidity (RH) with the wind speed (WS) Which are playing a significant role on improving the urban heat island (UHI) The research mainly aims to analyze the effect of urban green spaces on the urban heat island as a common strategy for improving the thermal comfort.

Kudus Traditional House as a Potential Tropical Building Design for Climate Action

One of the Sustainable Development Goals is Climate Action, meaning taking immediate actions to combat climate change and its impacts. This study evaluates the potentials of Indonesian traditional houses in helping mitigating climate change in the tropics. As a case study, the author analyses the designs of Kudus traditional house built primarily in the old city of Kudus, the province of Central Java, Indonesia. The study employs qualitative research, making use of primary data from field observations and interviews. Field observations were carried out to identify design elements of the traditional houses, while interviews were undertaken to obtain data and information on how the designs deal with climate problems. The results show that the Kudus traditional houses are designed in such a way that minimizes the need for air conditioning and energy uses given the hot tropical climate. The designs include the following: (1) building masses are built with an open yard in the middle of the masses’ configuration; (2) building masses are extended from north to south direction; (3) optimization of openings, for lighting and ventilation, on the walls and the roof of the building; (4) The use of a sloping roof with a wide eaves. Although the climate has changed, the traditional Kudus house is still comfortable to use for activities. This proves that the traditional Kudus house is still relevant in responding to the local climate.

Passive Night Cooling Potential in Office Buildings in Continental and Mediterranean Climate Zone in Croatia

The envelope is one of the most important driving factors in the energy efficiency of buildings. Typical for office and commercial buildings, curtain wall facades allow solar heat gains to be used during the winter but can lead to difficulties in reducing the cooling load during summer. The cooling load is dominant in most building types in the temperate maritime climate, while in the temperate continental climate, it is dominant mainly in office and commercial buildings. The goal of this research was to determine the potential of night passive cooling in an office building model in the most populated urban areas in Croatia-Zagreb and Split, which are located in two different climate zones. Suitable to the climate on-site, an appropriate building envelope and various types of passive and mechanical ventilation systems were selected for each location and case. Additional factors included and analysed were climate conditions, heat gains, the heat accumulation of the building, night ventilation through openings, unwanted air infiltration, and cooling loads. Through a detailed description of the model, passive cooling potential calculations, and Computer Fluid Dynamics (CFD) simulations, the results showed a potential of up to 43.5% savings in the cooling energy need for the temperate continental climate and 32.2% in the temperate marine climate. It was found from the analysis that night ventilation is expected to cool down the building enough to delay a need for cooling by several hours and improve fresh air requirements, thus saving power for cooling, and effectively reducing the need for air conditioning.

Analisa Kebutuhan Beban Pendingin Untuk Aula Kampus III UM Sumatera Barat

The comfort factor of a room is determined according to the location, characteristics and activities in the room. In order for the room to feel comfortable, a tool is needed to cool the room. The hall of Campus III UM West Sumatra as a place for academic activities measuring 28.3 m long, 8.3 m wide, 3.2 m high with a capacity of 130 people, requires air conditioning according to the needs of the room. This study aims to determine the need for air conditioning cooling load for the hall space. The research carried out literature review and observation, calculating temperature, temperature, hall size, and others. The result of the research is that the cooling load is 25.44 kW, so 3 units of split PK type AC are needed

Sustainable solutions for reducing air-conditioning costs and tailpipe emissions from heavy-duty transportation across Europe

Heavy-duty trucks emit >25% of the CO2 of the European road transport sector despite representing ≈2.5% of its fleet. Escalating temperatures associated to global warming will increase the use of air-conditioning (AC) in heavy-duty trucks, further raising their fuel consumption and emissions. Thus, sustainable solutions are needed to reduce the thermal loads affecting the truck cabins, to minimize the need for AC and decrease the sector’s costs and environmental footprint. We assessed the economic and environmental impact of AC use in the European heavy-duty transportation fleet, for realistic environmental conditions throughout the year, across the different European regions. Potential reductions were estimated for various changes in the optical properties of the cabin external paints and glazing elements (windshield and side-windows). The use of high-reflectivity paints in the cabin external surfaces and low-transmissivity glazing can reduce fuel costs by ≈€195 million/year across Europe (i.e., ≈0.1% of the total fuel costs of the European heavy-duty fleet), and decrease CO2 emissions by 1% of the reduction target set for 2025. These potential reductions highlight the importance of engaging with transportation stakeholders (e.g., workers unions, vehicle manufacturers, policymakers, and regulating bodies), to raise awareness about the potential benefits for the European transportation sector and the environment, and to promote the necessary adaptation in the transportation fleets.

Technical effectiveness of cement-based mortar for high-reflective building envelope through building energy simulations: preliminary results

In areas with high levels of solar radiation, decreasing the amount of solar energy absorbed by the building envelope is useful to reduce the need of air conditioning and "heat island" effects. Most high-reflective products, however, suffer from low durability. The COOL-IT project is developing an innovative high-reflective cement based mortar for precast products to be used as outer layer in buildings for both vertical and horizontal surfaces, or for road pavement. The mix design is aimed at increasing the durability of this cement-based component while retaining high reflectance to solar radiation. This paper presents the preliminary results of the project, based on the simulation of the energy demand of a residential building, intended as a support to optimize the proposed mixes. The model is analysed in three different locations in Italy, for one year of operation. This allows evaluating the trade-off of the energy demand between the winter increase and the summer reduction.

A survey on need for air conditioning, and the residential thermal environment of adults with cerebral palsy

A survey on need for air conditioning, and the residential thermal environment of adults with cerebral palsy

A cooler paint

Cooling Technology Passive radiative cooling relies on materials that emit infrared radiation through an atmospheric window of low energy absorption, thereby using outer space as a cold sink. Li et al. found a paint-like material that allowed for daytime, subambient daytime cooling. Calcium carbonate particles with a wide size distribution were mixed with acrylic and the resulting paint was field tested to demonstrate the cooling capabilities. Passively providing cooling may help mitigate the need for air conditioning and easy application is a key incentive for adopting the technology. Cell Rep. Phys. Sci. 1 , 100221 (2020).

Review on Energy and Fire Performance of Water Wall Systems as a Green Building Façade

Glass façades are widely utilized in green buildings. Ensuring fire safety while reducing the energy need without compromising occupants’ comfort is a challenge in the modern-day green buildings with glass façades. One way of achieving both aspects is to construct a water wall system as a building façade. A water wall system has a water layer between two glass panes and can be considered as a glass façade system. The focus of this review, which builds on the published studies, is how water wall systems can help ensure fire safety and reduce energy demand in green buildings. The water layer within two glass panes of the water wall system store the solar radiation heat throughout the daytime, reducing the amount of heat transferred through the building facade. The reduced heat transfer effects lessen the need for air conditioning to sustain the thermal comfort of the building occupants. The stored energy is released during the nighttime. The transparency of the water wall system also allows daylight to enter the building, thus reducing artificial lighting needs. Furthermore, the water layer acts as a fire safety mechanism in case of a fire. However, the water wall systems are not much utilized in the modern-day green buildings due to their unpopularity and the unavailability of design guidelines. On the basis of the findings of the literature review, stakeholders and the public are encouraged to adopt water wall systems in green building projects as an energy-efficient strategy and a fire safety mechanism.

Energy-saving window systems: types, development, comparisons and perspectives

The tendency to use natural resources is decreasing; energy conservation and ecosystems are taking the first positions. Therefore, the use of glass finishing of buildings has become a starting point in the search for new technologies to save energy use, reduce the need for air conditioning and additional lighting. The developed smart glass is an advanced type of glass that can change transparency depending on different conditions, or convert sunlight into electricity that can be used for human needs. The work examines the appearance of the first types of smart windows, and further development of smart windows using various films, chemical and organic compounds. The prospect of using smart glass to improve natural lighting in various fields and the future possibilities of related technologies by comparing several types of smart glass. The main types of smart windows are presented: photochromic window, thermochromic window, electrochromic window, liquid crystal windows, windows based on suspended particles, window using a "thermal mirror". On the basis of the given characteristics of various technologies of smart glass, its advantages and disadvantages, as well as the associated difficulties, which should be resolved in the future, are revealed. The existing classification of smart windows by the type of use of films in them and their advantages and disadvantages of using. The main newest technologies of absorption of sunlight by the surface of the window and the conversion of light into electricity, the problem of achieving transparency by glass, and the tendency of solving this issue are described. On specific examples, the areas of application of glass with controlled transparency are considered, and the economic indicators obtained when it is used in buildings. The technology of using solar panels in the form of blinds and their influence on providing the building with energy is considered. improvement of some of its optical properties, contributed to a decrease in its cost, which leads to an increase in the availability of this material.

Impact of CH2018 Climate Change Scenarios for Switzerland on today’s Swiss building stock

The energy demand of buildings heavily depends on outdoor temperature. Current climate change projections suggest an increase in annual mean temperatures of up to 5.4°C for Switzerland until the end of the century. In this study, an existing bottom-up building stock model is coupled with the latest spatio-temporal climate change projections. This allows for simulating the heat demand for each Swiss building for three different climate change scenarios and three periods. It is found that while space heat demand can decrease up to 33% by the end of the century, the need for air conditioning can arise. Furthermore, the impact of climate change differs between regions in Switzerland.

Envelop Insulation for Energy Efficient Smart Buildings in India

The building sector is amongst the largest energy consuming sector across the world. Within the building sector, about 75 percent of the total energy is consumed by the residential buildings. The energy sector is directly and indirectly associated with greenhouse gas emissions, since majority of energy sector is dependent on fossil fuels, which are primary source of emanation. Building energy requirements are comprised of need for lighting, air conditioning and other home appliances operations. Air conditioning requirement is derived from the climatic condition in which a building exists. The building components such as walls, roof and windows are exposed to solar radiation and outside air temperature. Heat is conducted from exterior environment into the interior of the building envelop through these channels, wherein majority (approx. 60%) is conducted by walls and roof. Envelop insulation is considered as an efficient retrofitting measure to reduce heat gain from walls and roof, thereby need of air conditioning to remove that heat. In this work, envelop insulation has been designed for the Indian residential buildings existing in the three climate zones of India, i.e. warm-humid, hot-dry and composite climate zones. Electricity saving potential in an insulated envelop and associated life cycle cost saving analysis is carried out considering the application of four commercial insulation materials namely, expanded polystyrene, fiberglass, polyurethane foam and extruded polystyrene. It was concluded that at the design temperature 25˚C, annual electricity saving potential in retrofitted wall per unit area varies from 9 kWh to 16 kWh, whereas in case of roof it varies from 18 kWh to 28 kWh per unit area per year. Fiberglass is observed as the most cost effective insulation material, considering life cycle performance of the insulation material for all the climate zones.

Hybrid Nonlinear MPC of a Solar Cooling Plant

Solar energy for cooling systems has been widely used to fulfill the growing air conditioning demand. The advantage of this approach is based on the fact that the need of air conditioning is usually well correlated to solar radiation. These kinds of plants can work in different operation modes resulting on a hybrid system. The control approaches designed for this kind of plant have usually a twofold goal: (a) regulating the outlet temperature of the solar collector field and (b) choosing the operation mode. Since the operation mode is defined by a set of valve positions (discrete variables), the overall control problem is a nonlinear optimization problem which involves discrete and continuous variables. This problems are difficult to solve within the normal sampling times for control purposes (around 20–30 s). In this paper, a two layer control strategy is proposed. The first layer is a nonlinear model predictive controller for regulating the outlet temperature of the solar field. The second layer is a fuzzy algorithm which selects the adequate operation mode for the plant taken into account the operation conditions. The control strategy is tested on a model of the plant showing a proper performance.

Indoor comfort and adaptation in low-income and middle-income residential buildings in a Nigerian city during a dry season

This paper investigates occupants' comfort, adaptation and their responses during the dry season in low-income to middle-income residential buildings in Abuja, Nigeria. The study aims to provide empirical data on occupants' comfort through evaluating 171 households in four different locations in Abuja. The study considered a combination of different research methods for data collection. Post-occupancy surveys were used to evaluate the buildings and residents' adaptation within the thermal environment. Thermal comfort surveys were also carried out in eight low-income residential households to assess occupants' perception of the thermal environment. Based on the short duration of the physical measurements, building simulation was also used to examine thermal comfort of occupants for an extended period. The Post Occupancy Evaluation (POE) results revealed over 70% of the occupants were dissatisfied with their thermal environment. The comfort surveys reported similar results with over 65% of the responses revealed being ‘uncomfortably warm’. The results showed an overall mean temperature of all the measured case studies to be 31.7 °C and the average temperature (predicted) of 30.7 °C. The neutral temperatures were in a range of 28°C–30.4 °C compared to the preferred temperature range of 27.5°C–29.4 °C. The prevalence of thermal discomfort highlights the need to explore the possibilities of reducing internal temperatures, particularly by passive means (fabric, shading, insulation etc.) given the need to avoid or reduce the need for air conditioning to make the buildings energy-efficient for low to middle income groups.

Особенности устройства различных вариантов кровельных покрытий с системами озеленения

Выявление новых тенденций развития в городском про­странстве с учётом формирования архитектурно-средовой концепции города и изменения потребностей жителей города является актуальной проблемой современного градо­строительства. Озеленение городских пространств, предпо­лагающее использование систем озеленения на стеновых и кровельных покрытиях зданий, является важным и полезным элементом градоформирующего потенциала жилищного ком­плекса в формировании городского пространства.
 Устройство кровельных и фасадных покрытий с система­ми озеленения полезно для окружающей среды, потому что такие покрытия «оздоравливают» здания, снижая выбросы, затраты на отопление и охлаждение, фильтруют осадки, а также улучшают качество воздуха, улавливая загрязнения.
 «Зелёные» крыши предлагают решение этих проблем, по­тому что они поглощают дождевую воду и снижают уровень вредных испарений в воздухе, улучшая процесс внутреннего охлаждения зданий и уменьшая потребность в кондициони­ровании воздуха. Преобразование общественных пространств позволяет формировать новый многоуровневый каркас с «зелёными» зонами. Устройство кровельных покрытий с системами озеленения имеет отличительные особенности, которые следует учитывать в процессе производства работ. Проведён анализ технологических процессов устройства экс­плуатируемых кровельных покрытий с системами озеленения и поиск оптимальных конструктивно-технологических решений. В исследовании использовался метод сравнительного анализа различных вариантов устройства кровельных покрытий с систе­мами озеленения. Приведены различные типы «зелёных» крыш в зависимости от нагрузки на покрытие здания: экстенсивный и интенсивный тип озеленения. В исследовании приводится анализ различных вариантов устройства кровельных покрытий с системами озеленения на основе сравнения показателей трудоёмкости работ при их устройстве.

Mitigating urban heat island effect and carbon dioxide emissions through different mobility concepts: Comparison of conventional vehicles with electric vehicles, hydrogen vehicles and public transportation

Research has shown, that the replacement of conventional vehicles (CVs) by electric vehicles (EVs) can reduce urban heat island intensity (UHII). This leads not only to a more comfortable climate during summer but also to a reduction of carbon dioxide emissions from the vehicles themselves and to a reduction in the need for air conditioning (AC) and associated emissions. The current study examines to what extent a range of different mobility concepts, can lead to a reduction in urban heat island intensity and carbon dioxide emissions in the city of Beijing, China. For this purpose, the impact that electric vehicles fuelled with the average energy mix, hydrogen vehicles (HyVs) fuelled with hydrogen from electrolysis from the regular energy mix, HyVs fuelled with hydrogen produced through wind power, energy efficient CVs, EVs fuelled with wind power and energy efficient metro light railway (metro) travel have on summer heat island intensity (SHII) and CO2-emissions is analysed. The lowest SHII mitigation effect was found for a replacement of CVs with fuel efficient diesel cars while hydrogen cars that are fuelled with hydrogen generated from the average electricity mix even leads to higher SHII and higher CO2 emissions. The largest SHII mitigation effect was found for a scenario where conventional vehicles are replaced with energy efficient metro travel. The CO2 saving potential is highest for EVs which are powered with electricity generated from wind turbines, closely followed by HyVs that are fuelled with hydrogen generated from electrolysis of water using wind electricity.The paper helps policymakers and consumers to make the right choices when it comes to environmentally friendly mobility options.

Painting on the cool

Optical Metamaterials Passive radiative cooling materials emit heat. They can reduce the need for air conditioning by providing daytime cooling but are often challenging to apply to rooftops and other building surfaces. Mandal et al. fabricated porous poly(vinylidene fluoride-co-hexafluoropropene) to create an excellent radiative cooling material. Better yet, the polymer is easy to paint or spray onto a wide range of surfaces, has good durability, and can even be dyed. This makes it a promising candidate for widespread use as a high-performance passive radiative cooling material. Science , this issue p. [315][1] [1]: /lookup/doi/10.1126/science.aat9513

Hierarchically porous polymer coatings for highly efficient passive daytime radiative cooling.

Passive daytime radiative cooling (PDRC) involves spontaneously cooling a surface by reflecting sunlight and radiating heat to the cold outer space. Current PDRC designs are promising alternatives to electrical cooling but are either inefficient or have limited applicability. We present a simple, inexpensive, and scalable phase inversion-based method for fabricating hierarchically porous poly(vinylidene fluoride-co-hexafluoropropene) [P(VdF-HFP)HP] coatings with excellent PDRC capability. High, substrate-independent hemispherical solar reflectances (0.96 ± 0.03) and long-wave infrared emittances (0.97 ± 0.02) allow for subambient temperature drops of ~6°C and cooling powers of ~96 watts per square meter (W m-2) under solar intensities of 890 and 750 W m-2, respectively. The performance equals or surpasses those of state-of-the-art PDRC designs, and the technique offers a paint-like simplicity.

Rancang Bangun Pendingin Portable Dengan Menggunakan Konsumsi Daya Rendah

The need for air conditioning is currently increasing its use, especially with the global warming that occurs in every region. But there are still many that take into account the use of electrical power electrical energy required for this air conditioner. Therefore, in this study we will design a cooling device using peltier thermoelectric elements with low power electric power USAge by using 8 peltier elements to be combined in series-parallel to achieve more efficient power. Based on the result of series-parallel combination has been obtained 27,87 electric power. In this research tool more effective for long distance in this case that is 2 meter.