Effects of Cooling Tower Performance to Water Cooled Chiller Energy Use: a Case Study toward Energy Conservation of Office Building

Author(s):  
I. Nyoman Suamir ◽  
I. Nengah Ardita ◽  
I. Made Rasta
Author(s):  
N.Sujith Prasanna ◽  
Dr.J.Nagesh Kumar

Energy cost is significant in many of the manufacturing activities. The efficiency of energy use is quiet low as there are substantial visible and hidden losses. Visible losses can be easily identified and corrective action can be taken. However hidden and indirect losses form a sizeable portion of the losses. Identifying these losses is not easy and requires an integrated approach which includes thorough study of process, operations and their interactions with energy use. Industries across sectors have implemented lean management principles which target various wastes occurring in the plant. This paper discusses case studies which highlight the exploitation of lean tools as a means for unearthing hidden energy saving potential that often go unnoticed. In addition to the energy savings which results in improved profits and competitiveness, the approach also aids the industry to pursue a path of sustainable manufacturing.


Energies ◽  
2020 ◽  
Vol 13 (21) ◽  
pp. 5541
Author(s):  
Andrea Ferrantelli ◽  
Helena Kuivjõgi ◽  
Jarek Kurnitski ◽  
Martin Thalfeldt

Large office buildings are responsible for a substantial portion of energy consumption in urban districts. However, thorough assessments regarding the Nordic countries are still lacking. In this paper we analyse the largest dataset to date for a Nordic office building, by considering a case study located in Stockholm, Sweden, that is occupied by nearly a thousand employees. Distinguishing the lighting and occupants’ appliances energy use from heating and cooling, we can estimate the impact of occupancy without any schedule data. A standard frequentist analysis is compared with Bayesian inference, and the according regression formulas are listed in tables that are easy to implement into building performance simulations (BPS). Monthly as well as seasonal correlations are addressed, showing the critical importance of occupancy. A simple method, grounded on the power drain measurements aimed at generating boundary conditions for the BPS, is also introduced; it shows how, for this type of data and number of occupants, no more complexities are needed in order to obtain reliable predictions. For an average year, we overestimate the measured cumulative consumption by only 4.7%. The model can be easily generalised to a variety of datasets.


Solar Energy ◽  
2006 ◽  
Author(s):  
Abderrezek Khlifi ◽  
Moncef Krarti

This paper describes a daylighting control strategy suitable to operate the electrical lighting fixtures in order to maintain a desired illuminance level for one or several specific working locations. The control is based on genetic algorithm to minimize energy use of electrical lighting systems. The algorithm has been developped using experimental data obtained for an office space in Boulder, Colorado. The GA-based control can be coupled with any switching settings to operate the electrical lighting systems such as on-off, stepped, and dimming. The analysis indicated that the GA-based control can save up to 70% of total electrical lighting energy use for the case study of the office building in Boulder, Colorado.


2012 ◽  
Vol 7 (1) ◽  
Author(s):  
Yanjin Liu ◽  
Giraldo Eugenio

Cultured bacteria addition is one of the technologies used for odor control and FOG (fat, oil, and grease) removal in wastewater collection systems. This study investigated the efficiency of bacterial addition on wastewater odor control by conducting a set of full scale trials in a 60,000 cubic meter per day system for a period of two years. The objectives of this study were: (i) to identify factors that could impact wastewater treatment plant (WWTP) operations due to the effect of bacterial addition in the collection system, (ii) to estimate/understand the level of those impacts, and (iii) to present some interesting findings from the completed case study. The plant operation data before and during the bacterial addition were reviewed. The application of the cultured bacteria presented in the study was found to have significant impacts on the operation of the WWTP in terms of influent biological oxygen demand (BOD) and total suspended solids (TSS) loading, primary settling, sludge production, energy use, dissolved sulfides concentration, and methane production.


Buildings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 230
Author(s):  
Hossein Omrany ◽  
Veronica Soebarto ◽  
Jian Zuo ◽  
Ruidong Chang

This paper aims to propose a comprehensive framework for a clear description of system boundary conditions in life cycle energy assessment (LCEA) analysis in order to promote the incorporation of embodied energy impacts into building energy-efficiency regulations (BEERs). The proposed framework was developed based on an extensive review of 66 studies representing 243 case studies in over 15 countries. The framework consists of six distinctive dimensions, i.e., temporal, physical, methodological, hypothetical, spatial, and functional. These dimensions encapsulate 15 components collectively. The proposed framework possesses two key characteristics; first, its application facilitates defining the conditions of a system boundary within a transparent context. This consequently leads to increasing reliability of obtained LCEA results for decision-making purposes since any particular conditions (e.g., truncation or assumption) considered in establishing the boundaries of a system under study can be revealed. Second, the use of a framework can also provide a meaningful basis for cross comparing cases within a global context. This characteristic can further result in identifying best practices for the design of buildings with low life cycle energy use performance. Furthermore, this paper applies the proposed framework to analyse the LCEA performance of a case study in Adelaide, Australia. Thereafter, the framework is utilised to cross compare the achieved LCEA results with a case study retrieved from literature in order to demonstrate the framework’s capacity for cross comparison. The results indicate the capability of the framework for maintaining transparency in establishing a system boundary in an LCEA analysis, as well as a standardised basis for cross comparing cases. This study also offers recommendations for policy makers in the building sector to incorporate embodied energy into BEERs.


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