Performance of Solar Domestic Hot Water Systems at the National Bureau of Standards—Measurements and Predictions

1983 ◽  
Vol 105 (3) ◽  
pp. 311-321 ◽  
Author(s):  
A. H. Fanney ◽  
S. A. Klein
Keyword(s):  
Heat Exchanger ◽  
Water System ◽  
Water Systems ◽  
Hot Water ◽  
Time Interval ◽  
National Bureau ◽  
Domestic Hot Water ◽  
Direct System ◽  
System A ◽  
One Year

The thermal performance of six solar domestic hot water systems and a conventional hot water system have been carefully monitored by the National Bureau of Standards in Gaithersburg, Maryland. The system configurations include an evacuated-tube air system with a crossflow heat exchanger and two storage tanks, a single-tank direct system, a double-tank direct system, a single-tank indirect system with a wrap-around heat exchanger, a double-tank indirect system with a coil-in-tank heat exchanger, and a thermosyphon system. Results are presented for a one-year time interval commencing January 1980. This paper includes a detailed description of the hot-water systems, experimental test results, and comparisons with computer predictions using the f-chart method [1].

Comparison between Energy Performance of Building and Investments to the Renewable Energy Sources

2014 ◽  
Vol 1020 ◽  
pp. 518-523
Author(s):  
Martin Kovac ◽  
Katarina Knizova
Keyword(s):  
Renewable Energy Sources ◽  
Water System ◽  
Energy Performance ◽  
Water Systems ◽  
Hot Water ◽  
Operating Costs ◽  
Energy Sources ◽  
Domestic Hot Water ◽  
Know How ◽  
The Subject

The subject of the paper is to calculate the energy performance of building in proposed variants. The differences in the variants are in the using of conventional and renewable sources for heating and domestic hot water system. Target of the second part of paper is to know, how much money we need to invest into the proposed variants for heating and domestic hot water systems and how much money will by the user paying for operating costs. The conclusion of the paper describes the payback periods of proposed variants.

Characterization of a Thermosyphon Heat Exchanger for Solar Domestic Hot Water Systems

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
Cynthia A. Cruickshank ◽  
Stephen J. Harrison
Keyword(s):  
Heat Exchanger ◽  
Test Procedure ◽  
Water Systems ◽  
Climatic Conditions ◽  
Hot Water ◽  
Test Method ◽  
Domestic Hot Water ◽  
Operational Conditions ◽  
Flow And Heat Transfer

This paper presents a simplified test method that was developed to allow preconfigured solar domestic hot water systems that use natural convection/thermosyphon heat exchangers to be characterized. The results of this test method produce performance coefficients for simple empirical expressions that describe the fluid flow and heat transfer in the heat-exchange loop. These empirically derived coefficients can be used as an input to a general simulation routine that allows overall system performance to be determined for various loads and climatic conditions. To illustrate the test procedure, results are presented for a typical heat exchanger under a range of operational conditions.

Low return temperature from domestic hot-water system based on instantaneous heat exchanger with chemical-based disinfection solution

Energy ◽  
2021 ◽  
Vol 215 ◽  
pp. 119211
Author(s):  
Theofanis Benakopoulos ◽  
Michele Tunzi ◽  
Robbe Salenbien ◽  
Dirk Vanhoudt ◽  
Svend Svendsen
Keyword(s):  
Heat Exchanger ◽  
Water System ◽  
Hot Water ◽  
Domestic Hot Water

Sporadic Legionnaires' disease: the role of domestic electric hot-water tanks

2011 ◽  
Vol 140 (1) ◽  
pp. 172-181 ◽  
Author(s):  
S. F. DUFRESNE ◽  
M. C. LOCAS ◽  
A. DUCHESNE ◽  
C. RESTIERI ◽  
J. ISMAÏL ◽  
...  
Keyword(s):  
Potable Water ◽  
Water System ◽  
Water Systems ◽  
Pulsed Field Gel Electrophoresis ◽  
Hot Water ◽  
Clinical Isolates ◽  
Domestic Hot Water ◽  
Legionnaires Disease ◽  
Water Tanks

SUMMARYSporadic community-acquired legionellosis (SCAL) can be acquired through contaminated aerosols from residential potable water. Electricity-dependent hot-water tanks are widely used in the province of Quebec (Canada) and have been shown to be frequently contaminated withLegionellaspp. We prospectively investigated the homes of culture-proven SCAL patients from Quebec in order to establish the proportion of patients whose domestic potable hot-water system was contaminated with the sameLegionellaisolate that caused their pneumonia. Water samples were collected in each patient's home. Environmental and clinical isolates were compared using pulsed-field gel electrophoresis. Thirty-six patients were enrolled into the study.Legionellawas recovered in 12/36 (33%) homes. The residential and clinical isolates were found to be microbiologically related in 5/36 (14%) patients. Contaminated electricity-heated domestic hot-water systems contribute to the acquisition of SCAL. The proportion is similar to previous reports, but may be underestimated.

A Design Method for Thermosyphon Solar Domestic Hot Water Systems

1987 ◽  
Vol 109 (2) ◽  
pp. 150-155 ◽  
Author(s):  
M. P. Malkin ◽  
S. A. Klein ◽  
J. A. Duffie ◽  
A. B. Copsey
Keyword(s):  
Flow Rate ◽  
Design Method ◽  
Water Systems ◽  
Hot Water ◽  
Average Flow Rate ◽  
Domestic Hot Water ◽  
Average Flow ◽  
Solar Fraction ◽  
Wide Range ◽  
Flow Circuit

A modification to the f-Chart method has been developed to predict monthly and annual performance of thermosyphon solar domestic hot water systems. Stratification in the storage tank is accounted for through use of a modified collector loss coefficient. The varying flow rate throughout the day and year in a thermosyphon system is accounted for through use of a fixed monthly “equivalent average” flow rate. The “equivalent average” flow rate is that which balances the thermosyphon buoyancy driving force with the frictional losses in the flow circuit on a monthly average basis. Comparison between the annual solar fraction predited by the modified design method and TRNSYS simulations for a wide range of thermosyphon systems shows an RMS error of 2.6 percent.

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