scholarly journals Influence of detailing the climate model on the calculation of energy consumption

2020 ◽  
Vol 164 ◽  
pp. 02008
Author(s):  
Elena Malyavina ◽  
Olga Malikova ◽  
Luong Van Pham

The repeatability of outdoor air temperature and enthalpy combinations in a construction area is a necessary initial information for calculating the energy consumption of air conditioning systems. The most convenient form of presenting climatic data in such calculations is the probabilistic-statistical model, which constitutes a Table, the cells of which show the probabilistic repeatability of the outdoor air temperature and relative humidity. The parameter values given on the vertical and horizontal scales, that form the cell boundaries, can be taken with larger or smaller increments. The paper that served as the basis for this article, provides verification of the initial climatic model detailing experimentally under full-scale conditions in the city of Hanoi (Vietnam). The criterion for the appropriate model detailing was the deviation of the energy consumption estimates of the room cooling system, got experimentally and by calculation. Moreover, the calculations were performed not only on two climate probabilistic and statistical models, but also on the data of direct measurements of the outdoor air temperature and relative humidity with an accuracy of 0.1 for temperature and up to 2 % for relative humidity.

2010 ◽  
Vol 17 (3) ◽  
pp. 269-272 ◽  
Author(s):  
S. Nicolay ◽  
G. Mabille ◽  
X. Fettweis ◽  
M. Erpicum

Abstract. Recently, new cycles, associated with periods of 30 and 43 months, respectively, have been observed by the authors in surface air temperature time series, using a wavelet-based methodology. Although many evidences attest the validity of this method applied to climatic data, no systematic study of its efficiency has been carried out. Here, we estimate confidence levels for this approach and show that the observed cycles are significant. Taking these cycles into consideration should prove helpful in increasing the accuracy of the climate model projections of climate change and weather forecast.


2020 ◽  
Vol 12 (14) ◽  
pp. 5848
Author(s):  
Antonio Martinez-Molina ◽  
Miltiadis Alamaniotis

In recent years, the interest in properly conditioning the indoor environment of historic buildings has increased significantly. However, maintaining a suitable environment for building and artwork preservation while keeping comfortable conditions for occupants is a very challenging and multi-layered job that might require a considerable increase in energy consumption. Most historic structures use traditional on/off heating, ventilation, and air conditioning (HVAC) system controllers with predetermined setpoints. However, these controllers neglect the building sensitivity to occupancy and relative humidity changes. Thus, sophisticated controllers are needed to enhance historic building performance to reduce electric energy consumption and increase sustainability while maintaining the building historic values. This study presents an electric cooling air controller based on a fuzzy inference system (FIS) model to, simultaneously, control air temperature and relative humidity, taking into account building occupancy patterns. The FIS numerically expresses variables via predetermined fuzzy sets and their correlation via 27 fuzzy rules. This intelligent model is compared to the typical thermostat on/off baseline control to evaluate conditions of cooling supply during cooling season. The comparative analysis shows a FIS controller enhancing building performance by improving thermal comfort and optimizing indoor environmental conditions for building and artwork preservation, while reducing the HVAC operation time by 5.7%.


Energies ◽  
2020 ◽  
Vol 13 (19) ◽  
pp. 5038
Author(s):  
Goopyo Hong ◽  
Chul Kim ◽  
Jun Hong

In commercial buildings, HVAC systems are becoming a primary driver of energy consumption, which already account for 45% of the total building energy consumption. In the previous literature, researchers have studied several energy conservation measures to reduce HVAC system energy consumption. One of the effective ways is an economizer in air-handling units. Therefore, this study quantified the impact of the outdoor air fraction by economizer control type in cooling system loads based on actual air-handling unit operation data in a hospital. The optimal outdoor air fraction and energy performance for economizer control types were calculated and analyzed. The result showed that economizer controls using optimal outdoor air fraction were up to 45% more efficient in cooling loads than existing HVAC operations in the hospital. The energy savings potential was 6–14% of the differential dry-bulb temperature control, 17–27% of the differential enthalpy control, 8–17% of the differential dry-bulb temperature and high-limit differential enthalpy control, and 16–27% of the differential enthalpy and high-limit differential dry-bulb temperature control compared to the no economizer control. The result of this study will contribute to providing a better understanding of economizer controls in the hospital when the building operates in hot-humid climate regions.


2014 ◽  
Vol 18 (3) ◽  
pp. 925-934 ◽  
Author(s):  
Meghana Charde ◽  
Sourabh Bhati ◽  
Ayushman Kheterpal ◽  
Rajiv Gupta

Energy efficient building technologies can reduce energy consumption in buildings. In present paper effect of designed static sunshade, brick cavity wall with brick projections and their combined effect on indoor air temperature has been analyzed by constructing three test rooms each of habitable dimensions (3.0 m ? 4.0 m ? 3.0 m) and studying hourly temperatures on typical days for one month in summer and winter each. The three rooms have also been simulated using a software and the results have been compared with the experimental results. Designed static sunshade increased indoor air temperature in winter while proposed brick cavity wall with brick projections lowered it in summer. Combined effect of building elements lowered indoor air temperature in summer and increased it in winter as compared to outdoor air temperature. It is thus useful for energy conservation in buildings in composite climate.


Energies ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 522
Author(s):  
Su Liu ◽  
Jae-Weon Jeong

This study investigated the annual energy saving potential and system performance of two different evaporative cooling-based liquid desiccant and evaporative cooling-assisted air conditioning systems. One system used an indirect and direct evaporative cooler with a two-stage package to match the target supply air point. The other was equipped with a single-stage, packaged dew-point evaporative cooler that used a portion of the process air, which had been dehumidified in advance. Systems installed with the two evaporative coolers were compared to determine which one was more energy efficient and which one could provide better thermal comfort for building occupants in a given climate zone, using detailed simulation data. The detailed energy consumption data of these two systems were estimated using an engineering equation solver with each component model. The results showed that the liquid desiccant and dew-point evaporative-cooler-assisted 100% outdoor air system (LDEOAS) resulted in approximately 34% more annual primary energy consumption than that of the liquid desiccant and the indirect and direct evaporative-cooler-assisted 100% outdoor air system (LDIDECOAS). However, the LDEOAS could provide drier and cooler supply air, compared with the LDIDECOAS. In conclusion, LDIDECOAS has a higher energy saving potential than LDEOAS, with an acceptable level of thermal comfort.


2019 ◽  
Vol 111 ◽  
pp. 06045
Author(s):  
Mizuki Niimura ◽  
U Yanagi

Subterranean temperature at a depth of 10 m is almost equal to the average outdoor air temperature of the same area. Therefore, if a building cooling trench is used as an outdoor air duct, outdoor air can be cooled in summer and warmed in winter. This energy-saving technique is often used in Japan. However, since the relative humidity in a cooling trench is high, microbe numbers tend to increase in summer. The present study sought to characterize the microbiome status in the cooling trench of such an office building in Japan. Specifically, we performed a metagenomic analysis in which we analyzed DNA directly upon collection from the environment, without intervening cultivation. The results showed the presence of bacteria of the genera Pseudomonas, Lactobacillus, Nesterenkonia, Staphylococcus, Deinococcus, Acinetobacter, Enhydorobacter, and Corynebacterium. Bacteria of the genera Nesterenkonia, Deinococcus, Enhydorobacter, and Corynebacterium predominated on the surface of the trench. Notably, bacteria of the genus Nesterenkonia constituted >50% of the organisms on the surface of the downstream end of the cooling trench. Principal coordinate analysis was used to compare bacterial inhabitants of outdoor air, indoor air from 2nd- and 3rdfloor offices, and the region downstream of the cooling trench. The results suggested that the microbiome of air in this cooling trench influenced indoor air within the building.


Author(s):  
L.V. Malytska ◽  
V. O Balabukh

In Ukraine, as in the world, substantial climatic changes have happened throughout past decades. It is a fact that they are manifested in changing of parameters of the thermal regime, regimes of wind and humidity. It is expected that they will be observed also in future that will lead to aggravation of negative effects and risks due to climate change. That determines the relevance of the problem of forecasting such changes in future both globally and regionally. After all, knowledge of climate’s behavior in future is very important in the development of strategies, program and measures to adapt to climate change. The article is devoted to assessing spatio-temporal distribution main climatic indicators (air temperature, wind speed and relative humidity) in Ukraine, their variability and the probable values to the middle of the 21st century (2021-2050). Projection of changes in meteorological conditions was made for A1B scenario of SRES family using data of the regional climate model REMO and data from the hydrometeorological observation network of Ukraine (175 stations). Estimated data obtained from the European FP-6 ENSEMBLES project with a resolution of 25 km. For spatial distribution (mapping) we used open-source Geographic Information System QGIS, type of geographic coordinate system for project is WGS84. In the middle of the XXI century, if A1B scenario is released, it is expected a significant changes of climatic parameters regarding the 1981-2010 climatic norm: air temperature is rise by 1,5 °C, average wind speed is decrease by 5-8%, relative humidity in winter probably drop by 2%, but in summer it rises by 1,5%. The unidirectionality of the changes is characteristic only of air temperature, for wind speed and relative humidity the changes are in different directions. The intensity of changes is also not uniform across the country for all climatic parameters, has its regional and seasonal features. Statistical likelihood for most of highlighted changes for all climatic parameters is 66 % and more, the air temperature change is virtually certain (p-level <0.001).


Author(s):  
Shubham S Kulkarni ◽  

As we know that nowadays due to the hot and humid weather and the increasing temperature the high amount of energy consumption is used for the heating & cooling purpose in residential as well as in commercial building for air conditioning systems. To overcome this problem and to reduce the energy consumption as well as good thermal comfort to people in the indoor environment, use the radiant heating & cooling system is a better way. This concept is used to cool or heat the room and absorbs the indoor sensible heat by thermal radiation. The system removes heat by using less energy and more energy-efficient. This system uses water as a medium to cool or heat the room space. There are three types discussed in these papers for cooling & heating. In this paper, we did an overall study regarding radiant heating and cooling systems. It reduces the energy lost due to the duct leakage. It also has a lower life cycle cost compared to conventional. In this paper, we have reviewed how to reduce energy consumption and give thermal comfortable air-condition through radiant cooling and chilled ceiling panel system.


Insects ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 860
Author(s):  
Jürgen Junk ◽  
Michael Eickermann ◽  
Milan Milenovic ◽  
Pompeo Suma ◽  
Carmelo Rapisarda

The red gum lerp psyllid, Glycaspis brimblecombei Moore (Hemiptera: Aphalaridae), is an invasive pest of Eucalyptus trees worldwide, responsible for serious damage, including the death of plants. Knowledge about the incidence of climatic factors on the insect development are essential to define useful strategies for controlling this pest. To this aim, G. brimblecombei has been sampled by two different methods from April 2012 to February 2013 in eastern Sicily on Eucalyptus camaldulensis in nine different sites, where the main climatic data (air temperature, relative humidity, and precipitation) have been also registered. The Glycaspis brimblecombei population showed a similar trend in all nine sites, positively correlated only with air temperature, but a negative correlation has emerged with precipitation and relative humidity. The results show the need for a deeper understanding of the role played by other abiotic (such as different concentrations of CO2) and biotic (e.g., the antagonistic action of natural enemies, competition with other pests, etc.) factors. The greater sensitivity, even at low densities of psyllid, of sampling methods based on the random collection of a fixed number of leaves compared to methods based on the collection of infested leaves in a fixed time interval has been also outlined.


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