All-season solar collectors

Year-round use

— this category includes solar collectors that can be used throughout the year — including in winter, at sub-zero air temperatures. The only condition for the effective operation of such a device is the presence of sunlight.

The main distinguishing feature of such models is a high degree of thermal insulation, designed not only to reduce heat loss but to protect the coolant circulating inside from freezing. In most of these devices, thermal insulation is provided by vacuum (note that these can be not only vacuum but also improved flat collectors — see "Type" for more details). In addition, the principle of indirect heating is often used in year-round” collectors: antifreeze with a freezing point well below zero plays the role of a heat carrier, and the heated water receives heat through the heat exchanger wall. However, modern technologies make it possible to make frost-resistant devices with direct heating.

The convenience of collectors of this type is obvious. However, they are not cheap. Therefore, it is worth purchasing a model with the ability to be used all year round only if such an opportunity is critical; it hardly makes sense to install a year-round collector, for example, in a country house where no one visits in winter.