The Altek SD-P-30 solar collector is made of high-quality components, featuring a tank made of stainless steel 3SUS316L. This thermosiphon non-pressure seasonal water heater is composed of separate vacuum tubes. The energy from solar radiation is absorbed by the absorber and converted into heat, which warms the water. Thanks to the efficient selective coating, the performance of the solar collector is enhanced. This system operates with free circulation of the heat transfer fluid. The vacuum tube is structurally made up of two glass bulbs, with the air between them evacuated to reduce heat loss. The main components of the solar collector’s design are the storage tank (which also serves as a heat exchanger) and the panel where the vacuum tubes are located. The key distinction of the SD-P series heliosystem is its unique design – an integrated internal tank (tank within a tank) that acts as a heat exchanger. The system’s tank consists of two containers: an internal tank with a volume of 70L located inside the outer tank, which serves as a storage for hot water under pressure. The main tank, with a volume of 200L, is filled with water that heats the internal tank. All materials undergo anti-corrosion treatment. The Altek tubular solar vacuum collector is equipped with efficient double-layer and impact-resistant vacuum tubes.