Analysis of solar domestic hot water heaters

Determination of design space and optimization of solar water heating systems

“…Application of F charts (Barley and Winn, 1978;Buckles and Klein, 1980;Zeid and Hawas, 1983) assumes a fixed collector loss and an average daily solar irradiation. Applicability of /-F chart method (Braun et al, 1983;Colle and Vidal, 2004) is restricted due to the complexity involved in the calculation of utilizability.…”

Retrofitting Domestic Hot Water Heaters for Solar Water Heating Systems in Single-Family Houses in a Cold Climate: A Theoretical Analysis

“…The charging is also stopped if the temperature at the top of the tank, T top , reaches 100 °C.  Radiation processor-type 109-TMY2 used to compute the radiation and weather data for Lund, Sweden (latitude 55°44'N, longitude 13°12'E);  Domestic hot water load profile-type 14 used to generate the daily load profile ( Figure 1);  Energy balance check-type 28 with energy balance check based on Buckles and Klein [17] for every simulation time-step, t, of six min.…”

“…The annual solar fraction takes into account the energy to produce the domestic hot water required by the load including losses and necessary energy to run pumps as well as the saved energy by the collectors. It was calculated based on Equation (2) [17]. …”

“…In 2009, Hobbi and Siddiqui [18] used TRNSYS to theoretically optimize the design of a forced circulation hot water system for cold climates. As in other studies, the annual solar fraction was used as design parameter to be optimized [11,15,[17][18][19][20][21][22][23][24]. Of specific interest is the fact that there is a lack of studies investigating the retrofitting of existing water heaters in single-family houses for solar hot water application in cold regions.…”

“…Wongsuwan and Kumar [15] concluded that TRNSYS software [16] predicts accurately the performance of forced circulation systems. Buckles and Klein [17] used TRNSYS software to theoretically investigate different system configurations, and concluded that heat exchangers, with the same capacity, have similar performance whether placed inside or outside the storage. In 2009, Hobbi and Siddiqui [18] used TRNSYS to theoretically optimize the design of a forced circulation hot water system for cold climates.…”