A Simple—Low Cost Solar Water Heater for Thailand

Abstract

The objective of this paper was to develop an appropriate domestic hot water system to satisfy Thai users, which require the following main requirements: low cost; not over 1,000-2,000 Baht/m², warm water and a simple and flexible design so that it can be built by user himself.

This objective is accomplished by using commercial PVC pipes (1(1/2)“). The water capacity was limited to 35 liters. Water is withdrawn at different times of the day. Experiments were performed during March—June 2000. CPAC monier board was installed at the backside acting, therefore, as absorber and storage for sun energy. The collectors were tested in two orientations: west wall and tilt south faced surfaces. With covered mounted roof collector, temperature as high as 72 ^oC was obtained whereas with the wall configuration, the temperature was about 65 ^oC to avoide damage to PVC pipes caused by temperature above 60 ^oC, air was permitted to circulate between the cover and the pipes.

Finally, plastic covered CPAC-PVC pipe collector with appropriate openings at the top and bottom for air circulation seems to be very interesting. Due to the low—cost, simplicity of design and wide availability of materials used throughout the country, application of the design concept developed here seems to be very promising.

Keywords : Domestic Hot Water / Low Cost I PVC Pipes I CPAC Monier Board