An evaluation of energy savings potential on hot water production for a student residence

2021 ◽  
Author(s):  
Russel Mhundwa ◽  
Michael Simon
2012 ◽  
Vol 16 (3) ◽  
pp. 131
Author(s):  
Didik Ariwibowo

Didik Ariwibowo, in this paper explain that energy audit activities conducted through several phases, namely: the initial audit, detailed audit, analysis of energy savings opportunities, and the proposed energy savings. Total energy consumed consists of electrical energy, fuel, and materials in this case is water. Electrical energy consumption data obtained from payment of electricity accounts for a year while consumption of fuel and water obtained from the payment of material procurement. From the calculation data, IKE hotels accounted for 420.867 kWh/m2.tahun, while the IKE standards for the hotel is 300 kWh/m2.tahun. Thus, IKE hotel included categorized wasteful in energy usage. The largest energy consumption on electric energy consumption. Largest electric energy consumption is on the air conditioning (AC-air conditioning) that is equal to 71.3%, and lighting and electrical equipment at 27.28%, and hot water supply system by 4.44%. Electrical energy consumption in AC looks very big. Ministry of Energy and Mineral Resources of the statutes, the profile of energy use by air conditioning at the hotel by 48.5%. With these considerations in the AC target for audit detail as the next phase of activity. The results of a detailed audit analysis to find an air conditioning system energy savings opportunities in pumping systems. Recommendations on these savings is the integration of automation on the pumping system and fan coil units (FCU). The principle of energy conservation in the pumping system is by installing variable speed drives (VSD) pump drive motor to adjust speed according to load on the FCU. Load variations FCU provide input on the VSD pumps to match. Adaptation is predicted pump can save electricity consumption up to 65.7%. Keywords: energy audit, IKE, AC


2006 ◽  
Vol 129 (2) ◽  
pp. 226-234
Author(s):  
Robert Hendron ◽  
Mark Eastment ◽  
Ed Hancock ◽  
Greg Barker ◽  
Paul Reeves

Building America (BA) partner McStain Neighborhoods built the Discovery House in Loveland, CO, with an extensive package of energy-efficient features, including a high-performance envelope, efficient mechanical systems, a solar water heater integrated with the space-heating system, a heat-recovery ventilator (HRV), and ENERGY STAR appliances. The National Renewable Energy Laboratory (NREL) and Building Science Consortium conducted short-term field-testing and building energy simulations to evaluate the performance of the house. These evaluations are utilized by BA to improve future prototype designs and to identify critical research needs. The Discovery House building envelope and ducts were very tight under normal operating conditions. The HRV provided fresh air at a rate of about 35L∕s(75cfm), consistent with the recommendations of ASHRAE Standard 62.2. The solar hot water system is expected to meet the bulk of the domestic hot water (DHW) load (>83%), but only about 12% of the space-heating load. DOE-2.2 simulations predict whole-house source energy savings of 54% compared to the BA Benchmark (Hendron, R., 2005 NREL Report No. 37529, NREL, Golden, CO). The largest contributors to energy savings beyond McStain’s standard practice are the solar water heater, HRV, improved air distribution, high-efficiency boiler, and compact fluorescent lighting package.


2012 ◽  
Vol 30 ◽  
pp. 101-105 ◽  
Author(s):  
Andreas Genkinger ◽  
Ralf Dott ◽  
Thomas Afjei

Author(s):  
Robert Hendron ◽  
Mark Eastment ◽  
Ed Hancock ◽  
Greg Barker ◽  
Paul Reeves

Building America (BA) partner McStain Neighborhoods built the Discovery House in Loveland, Colorado, with an extensive package of energy-efficient features, including a high-performance envelope, efficient mechanical systems, a solar water heater integrated with the space-heating system, a heat-recovery ventilator (HRV), and ENERGY STAR™ appliances. The National Renewable Energy Laboratory (NREL) and Building Science Consortium (BSC) conducted short-term field-testing and building energy simulations to evaluate the performance of the house. These evaluations are utilized by BA to improve future prototype designs and to identify critical research needs. The Discovery House building envelope and ducts were very tight under normal operating conditions. The HRV provided fresh air at a rate of about 75 cfm (35 l/s), consistent with the recommendations of ASHRAE Standard 62.2. The solar hot water system is expected to meet the bulk of the domestic hot water (DHW) load (>83%), but only about 12% of the space-heating load. DOE-2.2 simulations predict whole-house source energy savings of 54% compared to the BA Benchmark [1]. The largest contributors to energy savings beyond McStain’s standard practice are the solar water heater, HRV, improved air distribution, high-efficiency boiler, and compact fluorescent lighting package.


2020 ◽  
Vol 12 (0) ◽  
pp. 1-6
Author(s):  
Giedrius Šiupšinskas ◽  
Martynas Blinstrubis

This article examines the possibilities of using waste heat in a building for the production of medical products. During the production, 6 compressors operate continuously, and the generated excess heat is removed through coolers or partially used in building heating, ventilation and domestic hot water production systems. The aim of this article is to model and evaluate the possibilities of using waste heat after performing the analysis of heat flow demand of all the engineering systems. The pinch method is used to achieve this goal. Heat flows and heat exchanger network are modelled using PinCH 3.0 software. The performed assessment shows that with the help of pinch analysis, in the analysed object it is possible to recover and use more than 20% of waste heat as compared to the initial design variant.


Author(s):  
І. Puhoviy ◽  
М. Makhrov

Problems. Windows in the summer let through a large amount of solar energy into the room, which causes an additional cost of cooling the air by conditioning. It is known that the limit of comfort is the temperature of 26 oC. To reduce the temperature, use air conditioners, which are required 0,3...0,5 kW of electrical power for 10 m2 of housing. The study deals with the capture of solar energy by water and its use for domestic water purposes (DHW). The goal of the research. Experimental verification of patented developments and calculations of hot water quantity obtained per day, energy savings and economic indicators. Methods of implementation. Experiments were conducted on the south window of the room, with water pumping by a pump and periodic measurement of air and water temperatures at the outlet of the system by mercury thermometer. The calculations were performed using the methods developed by the authors. The studies were conducted within three days of November. The temperature inside ranged a room from 19 to 23 °C. The system was operated in circulating mode on a water battery tank located below the absorber. Isolation of the absorber from the side of the room was made of a transparent food film. Research results. Water temperature reached 45 °C per 1,5-2 hours. Water consumption is enhanced by the thermosiphon effect when water moves from the bottom up. On a clear day of spring and autumn, you can heat for 50-70 % more water than the average for the average day of months of the warm season. For preparing DHW with 1 m2 of absorber, it is possible to get 45-50 kW∙h of heat for each month from March to September, taking into account cloudiness. The savings from the use of hot water and from reducing the consumption of electricity in the air conditioner are calculated. Conclusions. The payback period of the system, taking into account the cost of the heat for DHW and electricity savings for an electric air conditioner, is approximately 4-5 years. The cost of the system is close to the cost of a home air conditioner, for a premise with a single window oriented south. To the energy-saving factor, an additional advantage is the environmental friendliness of the system compared to the air conditioner.


2019 ◽  
Vol 111 ◽  
pp. 01066
Author(s):  
F. J. Aguilar ◽  
D. Crespí ◽  
P. V. Quiles

This article presents an experimental and modelling work which uses a compact domestic hot water heat pump (DHW-HP) that is simultaneously powered from photovoltaic panels (PV) and from the grid. Results from more than 240 days of experimental works have been used in order to develop and to validate the computer model of the system. The program, implemented in MATLAB, is computationally ‘light’ enough to allow mid-term simulations yet also detailed enough to accurately and coherently portray stratification within thermal storage tanks. Finally, as an example of the model capabilities, it has been used to simulate a domestic hot water tapping cycle from the European Standard EN 16147.


Author(s):  
Michele Totaro ◽  
Anna Laura Costa ◽  
Lorenzo Frendo ◽  
Sara Profeti ◽  
Beatrice Casini ◽  
...  

Despite an increase of literature data on Legionella spp. presence in private water systems, epidemiological reports assert a continuing high incidence of Legionnaires’ disease infection in Italy. In this study, we report a survey on Legionella spp. colonization in 58 buildings with solar thermal systems for hot water production (TB). In all buildings, Legionella spp. presence was enumerated in hot and cold water samples. Microbiological potability standards of cold water were also evaluated. Legionella spp. was detected in 40% of the buildings. Moreover, we detected correlations between the count of Legionella spp. and the presence of the optimal temperature for the microorganism growth (less than 40 °C). Our results showed that cold water was free from microbiological hazards, but Legionella spp., was detected when the mean cold water temperature was 19.1 ± 2.2 °C. This may considered close to the suboptimal value for the Legionella growth (more then 20 °C). In conclusion, we observed the presence of a Legionnaires’ disease risk and the need of some strategies aimed to reduce it, such as the application of training programs for all the workers involved in water systems maintenance.


2020 ◽  
Vol 19 ◽  
pp. 100573 ◽  
Author(s):  
George Dogkas ◽  
John Konstantaras ◽  
Maria K. Koukou ◽  
Michail Gr. Vrachopoulos ◽  
Christos Pagkalos ◽  
...  

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