Efficiency Of Solar Water Heater Research Articles

Optical Characteristics of WO<sub>3</sub> Thin Films Prepared Using the Electrodeposition Method

The tungsten oxide (WO3) thin films on the indium tin oxide (ITO) glass in this study were produced by applying the electrodeposition method (ED). This method involves adjusting ED time to control the structure, film thickness, and morphology of WO3thin films. Furthermore, the crystallization of the WO3thin films was controlled by annealing them at 200 °C and 500 °C. The results show that the WO3coated glass with non-annealed and annealed at 200 °C has a high transmittance of visible light and anti-infrared characteristics. However, the WO3coated glass annealed at 500 °C has high infrared transmittance, with the highest infrared transmittance reaching 85% at the 1000 nm wavelength. To improve the heat collecting efficiency of solar water heaters, the high infrared WO3coated glass can be applied to the surface of the heat collecting component.

To investigate the surface properties for increasing efficiency of solar water heater

Energy crisis is becoming a major problem in Pakistan. Renewable energy sources are used to overcome this crisis. This research is about to increase the efficiency of fin type solar water heater by modification of its surface properties. During this research work, solar water heater module is fabricated and the modification of surfaces by using bare surface, external surface coated with high conductivity paint and lead electroplating is studied and the efficiency of solar heater is observed. The temperature profile and the heat transferred is studied and it was found that paint coated surface is more efficient than bare surface, further surface electroplated with lead is more efficient than painted surface for the same ambient conditions. The average increase in the heat absorption for lead plated and paint coated surface was observed 28.57% and 10.79 % respectively.

The Logical Choice of Auxiliary Heat Source for Solar Energy Water Heating System

This article describes the solar hot water system, and establishes the computational model of hot water system. It analyzes the economical efficiency of solar water heaters which equipped with electric water heaters, gas water heaters and air-source heat pump water heaters. The results show that the initial investment of the system which equipped with an electric water heater and a gas water heater is almost, but the operating cost which equipped with a gas water heater system is lower. The operating cost which equipped with an air-source heat pump water heater is the lowest, though the initial investment is the highest. The solar hot water system which equipped with an air-source heat pump water heater has important reference value for going low-carbon economy road in China.

The Thermal Performance of Residential Electric Water Heaters Subjected to Various Off-Peak Schedules

An increasing number of utilities control the supply of power to residential water heaters as one means of reducing peak electrical demand. Water heaters operated in this manner are referred to as off-peak water heaters. Several utilities are also considering the use of solar domestic water heaters as an additional means of limiting power demand during times of greatest electrical usage. The research described within this paper quantifies the variation in thermal efficiency attributable to subjecting residential electrical water heaters to various off-peak and water removal schedules and, thus, forms a basis of comparison to which the thermal efficiency of solar water heaters or other water heating technologies may be compared. Laboratory tests, where the off-peak period and hot water draw schedule were varied, were conducted on two residential storage water heaters. A computer model of an electric water heater was developed and validated. The laboratory tests and the model were used to quantify the effect that various off-peak and hot water draw schedules have on water heater thermal efficiency. Thermal efficiency was found to vary up to seven percent for water heaters which meet the present minimum efficiency standards as specified within the National Appliance Energy Conservation Act. The energy factor, as measured using the Department of Energy Test Procedure for Water Heaters, is shown to be independent of the off-peak schedule because of a “normalizing” that occurs as part of the calculation procedure.

A proposed standard test code for the determination of the efficiency of solar water heaters of the flat collector type

The properties which must be considered in obtaining an objective estimate of the quality of a flat-plate-type solar water heater are listed. Methods are given for calculating the aerial, orientation, and thermal efficiency of the heater and the heat storage coefficient. A test procedure is outlined for making an objective standard determintion of the efficiency of the heater, and a standardized sheet form is given on which the results can be tabulated.