Solar collectors with open loop system

Open collector

— open loop systems are called collectors that work without additional pressure in the water circulation system. Usually, such a device is equipped with a tank in the upper part, into which a supply of water is poured; after that, the water by gravity flows to the points of water intake. At first glance, open systems are not very convenient: they need to be placed high (and the pressure will depend on the height difference between the collector and the water intake points), while it is necessary to think over the way to fill the tank (bring a hose with a pump to it), and the purpose of such devices is limited domestic hot water supply and heated pools. On the other hand, such collectors are extremely simple, inexpensive, do not require a connection to the mains and can work even in the absence of electricity (as long as there is water in the tank).

Another design option is devices without a tank, powered by a circulation pump. However, they are less common, mainly among models for heating pools (see "Suitable for").