Heating systems, depending on access to energy conductors, can be conditionally divided into two types:
- Open (popularly called gravity). The most primitive in design and operation. But the number of its shortcomings completely negates its advantages: it is expensive to buy material, large-sized boron, difficult to assemble, low efficiency, thick-walled pipes with a large diameter are used, and because of these materials it is very difficult to hide the entire system behind decorative panels. This open heating system is most often found in Soviet houses.
- Closed. All parts of the structure are tightly interconnected and with the help of a low-power pump, the circulation of the coolant is accelerated.
The working process of an open system is based on the laws of thermodynamics, according to which the heated liquid flows upwards, creating some vacuum at the inlet to the boiler and increased pressure at the outlet. Thus, self-circulation passes through the pipes of this design, where water moves fromhigh pressure to lower. With circulation and temperature changes, the water expands, as a result, in order to avoid breakage, the system is equipped with an additional tank, which is called the "expansion tank of the open heating system." It is not airtight; heated water in the form of steam escapes through it into the atmosphere.
Open heating system justifies itself using only water and no other energy conductors, as it is a cheap resource. Another disadvantage is the constant evaporation of the liquid, which must be periodically renewed so that the entire structure does not become airy.
Open heating systems have a huge disadvantage, which is slow circulation, because of which heating must be carried out very slowly in order to avoid breakdown. Not to mention the slowness, immediately there is a problem with draining water in the winter season when the pipes are idle, so that frozen water does not damage them.
To achieve a sufficient level of water circulation rate, the placement of the boiler of this system should be carried out as low as possible, and the expansion tank, on the contrary, in the highest place. The tank, in turn, needs to be insulated. An open heating system does not need a pump. When installing this design, you need to abuse turns and connecting parts as little as possible.
Openthe heating system requires pipes of various diameters. This feature is a characteristic feature of this design. The diameter of the larger pipe, which is installed at the outlet of the boiler, with a heating area of 50 to 100 m² is approximately 40 mm. Accordingly, an increase in area forces a proportional increase in diameter and financial costs.
Among other things, it is necessary to take into account the slope of horizontally laid pipes, which is approximately 0.005-0.01% in the direction from the highest point to the heating radiators and then to the boiler.
