In our fairly severe climate, heating systems that ensure the heating of the premises by circulating liquid coolant in a closed system are considerable popularly. Moreover, traditionally, water for heating systems is used in its quality, since it is widely accessible and is characterized by good quality characteristics. But at the same time, numerous antifreezes are often used as a coolant for the liquid heating system, which are positively distinguished by their lower freezing temperature. Because of this, their properties can not be worried that pipes and radiators in a house with disconnected heating are burst when cold.
Requirements for the coolant
How to choose antifreeze
It should be distinguished by low viscosity to create less resistance when pumping through pipes and radiators;
transmit maximum heat along the entire contour over the least time without significant losses;
The coolant itself or its pairs must comply with the standards for toxicity and ignition temperature;
should not cause corrosion of materials of all components of the system.
In fact, none of the substances used in the role of the coolant can fully satisfy all these requirements. In fact, each of them is optimal only in specific operating conditions.
Water and antifreeze
Water as a coolant in the pipes of heating systems is favorably different due to its high heat capacity. In addition, water does not pose at all a threat to human health, so in the case of leakage there is no reason for concern for the safety of residents. After eliminating the leaks, it is only necessary to make up for the formed lack of water in the system of the system. In addition, at the cost she does not have rivals at all.
However, you should not pour simple water into the water heating system, immediately from the crane or from the well. It always contains a lot of oxygen and salts of minerals. And they are able to cause the formation of scale and corrosion of the materials of all components of the system, which is why its effectiveness worsens over time, and as a result it will require its renewal. Therefore, preliminary water needs to be softened.
Softening can be carried out thermal or chemically. In the first case, the water is boiled, as a result of which dissolved minerals fall into the precipitate. But more persistent compounds of calcium and magnesium still remain in water, so they resort to the use of chemical reagents.
To remove an excess of oxygen, you can also boil water or use chemical reagents that help remove oxygen in it.
Ideally, it is recommended to fill in distilled water, but it will have to buy it. Therefore, many collect rain water, which is noticeably softer than water supply or artesian.
A house, in the liquid heating system of which water is used, cannot be left unattended in winter. With a decrease in room temperature to minus values, frozen water is able to literally break pipes and heating radiators. This is considered the most obvious disadvantage of water selection as a coolant.
It is possible to get rid of this problem if instead of water to pour antifreeze into the heating system. These chemical compositions, also called «non -freezes» in everyday life, remain fluidity even at high negative ambient temperatures. Of course, with a significant decrease in temperature, the viscosity of antifreeze decreases, they pass into a gel -like state. Nevertheless, they practically do not increase in volume, which excludes the risk of deformation, rupture of pipes and heating radiators. Many of these compositions are capable of performing their function up to a temperature of — 65 degrees Celsius. It is recommended to completely update such a coolant every 3 — 5 years.
But antifreeze as a coolant has its own disadvantages. First of all, it is worth noting:
high viscosity in comparison with simple water, due to which there is a need for the installation of circulation pumps in the heating system;
The heat capacity of the antifreeze is noticeably inferior to a similar indicator of water;
Some components of antifreeze (for example, ethylene glycol) have toxicity, which makes higher requirements for the tightness of the entire contour.
The choice in favor of one or another coolant is determined by the operating conditions, the climatic area of the object of the object. Moreover, it is important to solve this issue at the stage of designing the heating system, since the systems under water and antifreeze are significantly different. If the air temperature is rarely reduced to a zero mark, then the best solution can be considered water, previously cleansed of impurities and excess oxygen. For more severe climatic zones, it makes sense to make a choice in favor of antifreeze. Especially if it is assumed that the house will not be used for a permanent residence for a long time.