Inexpensive Performance Monitoring of Solar Domestic Water Heating Systems

1988 ◽  
Vol 110 (3) ◽  
pp. 187-191 ◽  
Author(s):  
A. M. Clausing

Performance monitoring is essential in order to conclusively demonstrate the cost effectiveness of a solar heating system. Unfortunately, this “last step” is an aspect which has received little engineering consideration. The monitoring programs in progress typically use instrumentation which is much too expensive and complex for use by individual operators of domestic water heating systems. Hence, few systems are monitored, and the average owner knows little about the performance characteristics of his system. Even malfunctions go undetected. An inexpensive performance monitoring system is described in this paper. It could probably be mass-produced for under 15 dollars or built by the typical homeowner for under 30 dollars. The monitor indicates the instantaneous solar fraction. Overall system performance can be improved with this monitor, since it enables the user to correlate load with the availability of solar heated water. Methodology, performance parameters, and some performance data are presented.

Author(s):  
A. M. Boies ◽  
K. O. Homan

Solar integral collector storage (ICS) devices are a potentially low cost means of displacing a portion of the energy required for domestic water heating. However, since ICS systems are rarely used as a stand-alone system and are more typically utilized as a preheater for conventional water heaters, it is imperative to analyze the overall water heating system in order to determine the advantage of any improvements in the thermal performance of the ICS component. In particular, this paper analyzes the performance of a solar ICS heater, in divided and undivided storage configurations, in series with a conventional electric resistance water heater (ERWH) for a range of ICS storage volumes, heat exchanger NTU, initial ICS temperature, and ERWH storage volumes. The undivided storage configuration corresponds to the typical UPICS system whereas the divided storage configuration corresponds to a recently proposed concept for improving the thermal performance of the ICS device. The results show that the ICS preheater does provide significant increases in solar fraction when adequately sized. Although comparison of the divided to undivided storage concept, with the same total ICS storage volume, shows only modest gains of 5–10% in solar fraction, the ICS storage volume necessary to attain the same solar fraction is much less for the divided storage concept. The smaller required storage volume would, in turn, enable faster charging times and potentially higher initial temperatures thereby leading to even further improvements in overall system performance.


1983 ◽  
Vol 105 (1) ◽  
pp. 66-72
Author(s):  
P. Bendt

It is generally assumed that a solar heating system should be sized by minimizing its life-cycle cost. This study shows, however, that the uncertainty in future economic trends makes the results of such a procedure questionable. The design conditions for minimum cost are extremely broad and all practical systems have a solar fraction within the limited range of 30 to 90 percent. Thus, by choosing only three collector areas that give systems within this range, one is assured of selecting a nearly optimal system for any realistic economic scenario. Selecting one of these three systems is essentially equivalent to economic optimization, but simpler. Procedures are derived in this paper for determining the sizes of the three systems. The conclusion is that the collector areas should be about 1/8, 1/5, and 1/3 of the building floor area. This rule of thumb eliminates the need to design solar systems individually, allowing the possiblity of mass-produced homes with standardized solar heating systems.


2020 ◽  
Vol 42 ◽  
pp. e48583 ◽  
Author(s):  
Carolina Kratsch Sgarbossa ◽  
Jorim Sousa das Virgens Filho

 Solar thermal systems consist of water heating from the global solar radiation. Increasing atmospheric concentrations of greenhouse gases tend to increase the earth's surface temperature. The main objective of this work was to estimate the solar fraction obtained by means of solar heating systems for dwellings, for eight locations in the State of Paraná, in scenarios of possible climate changes projected until the end of the 21st century. F-Chart method was used to simulate the performance of solar heating systems based on the monthly average of solar radiation data, which determines the annual solar fraction or percentage of the energy demand that is covered by the solar installation. The results showed that with the impact of the climate changes, the decrease in the percentage of energy demand average that is covered by the solar installation was on average 14.3%, for both scenarios. The simulated values showed a slight decrease trend of radiation data and an increase of the solar fraction. All localities presented a characteristic seasonal behavior, with annual values of solar fraction between 82.4 and 129.8%, according to the studied localities. In relation to the monthly solar fraction, the values between November and March presented averages of solar fraction between 104 and 147.2%. But from May to August, the percentage of energy demand served by the solar installation does not reach the totality, with values between 53.6 and 99.9%. The results prove that the State of Parana has favorable climatic conditions for the installation of solar heating systems, even if it is installed for aggregation purposes, in order to reduce the electric power consumption.


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