We offer solar water heaters. features better performance in winter and cloudy days.No scale formation will occur by using salt & hard water.Compressed puf insulated storage tank to retain the hot water for more than 48 hrs.Inner tank made of sus 316l grade surgical steel used in marine applications.Suitable for bore well water and hard water usage.All fasteners are made of sus 304 food grade for rust free.Auxiliary tank is fitted instead of air vent, withstands high pressure of cold water.Pressure also minimize mixing of hot & cold water.Isi maked 1.5 back-up heater with thermostat (optional).Completed 6 years of service with satisfied customers globally.Replacement warranty. Free service & minimum product life span of 25-30 yrs. technical specifications type of collector : etcspecifications :47 x 1800 mmnumber of tubes : 12, 15, 18, 24, 28, 35frame angle : 27 degreesinner tank materials : food grade stainless steelinsulation : imported high quality pu materialstank volume : 100 l -300 louter tank : powder coated stainless steelnumber of persons to use : 3- 10 persons. comparison between conventional flat plate collector and evacuated tube collectorflat plate collector evacuated tube collector evacuated tube collectorhardness of water affect the efficiency due to scale formation in the long run. hardness does not affect the heating system as no metal tubes is used.Cleaning is not possible. periodical cleaning is possible.Replacement of individual collector tube is not possible. replacement of individual collector tube is very easy.Absorption area per day is 65% only very high absorption area of 94% due to circular tubes.