Thermal solutions

Solar Water Heating

Principles of Natural Draft Circulation System

Thermosyphonic solar water heaters make use of two natural phenomena for their operations: Black objects absorb heat, and hot water rises. It is a simple system and the only moving part is water. The black chrome selective surface is designed to absorb and retain the solar energy. When the sun heats the absorber surface the heat is transferred to the water in the collector. The hot water rises in the collector tank where it displaces colder water which descends to the bottom of the collector. As the sun continually heats the water, this circular path continues

The case for the environment


Electric water heating is the biggest contributor to household greenhouse gas emissions, accounting for around 25% of the average homes carbon footprint. With a solar water heater which uses the sun's natural energy you could save up to 70-80% of your water heating energy consumption, reducing greenhouse gas emissions by 3 - 3.5 tonnes every year, which is the equivalent of taking a 4 cylinder car off the road.

System description

  • Special enameled water storage jacket tank with capacities of 150, 200 or 300 liter
  • One high efficiency closed cycle collector with 150 or 200 liters systems
  • Two high efficiency closed cycle collector with 300 liters systems
  • 76.1% optical efficiency
  • Gross surface 2,01 square meters​ per collector
  • Type of covering: tempered glass, with a low iron content
  • Type of absorber: aluminum plate with highly selective Almond Mirotherm treatment
  • Type of insulation: rock wool
  • Systems are equipped with back-up electrical elements
  • Systems come with corrosion fighting heating water-glycol mixture
  • Systems include corrosion fighting magnesium anode
  • Aluminum mounting frames that can be installed on flat or pitched roof

Features of natural circulation systems

  • No moving parts

  • ​Easy to install

  • Easy to maintain

  • Include back-up electric elements to ensure hot water under any weather circumstance 

  • For improved performance, several natural circulation systems can be integrated using the Tichelmann connection


Technical data

  Unit 150 Liters 200 Liters 300 Liters
collectors number 1 1 2
Surface Area of Collectors sqm 2.01 2.5 4.02
Suitable For persons 1-2 3-4 5-6
Height m 1.75 1.75 1.75
Width m 1.15 1.15 2.3
Depth m 0.87 0.87 0.87