The rather harsh climate of the middle lane forces us to use heating appliances for more than half of the calendar year. Such intense operation requires from the heating equipment not only high performance, but also reliability. The correct functioning of the heating system depends on the quality of its installation and the characteristics of the coolant used. One of the pressing questions of homeowners and design specialists is the choice of a heat carrier for heating a private house: which is better — anti-freeze or water?

It is worth remembering that any coolant has both advantages and disadvantages, that is, an option that is ideal from all sides simply does not exist. When choosing, consider the following criteria:

  • current operating conditions;
  • type of pumping units;
  • type of boiler equipment.

The main problem of thermal equipment in difficult climatic conditions is the freezing of the coolant during the onset of cold weather. For the uninterrupted operation of the installation at any time of the year, you should use a type of coolant that provides high-quality heating of all rooms and has the following properties:

  • indicator of aggressiveness to metals;
  • resistance to low temperatures;
  • no tendency to precipitate;
  • no aggressive effect on seal materials;
  • operational stability.

In the operating temperature ranges, any coolant for the heating system of a country house is able to operate smoothly for a long time, however, going beyond these limits is fraught with serious changes in their physical and qualitative characteristics. If we consider the coolant from the point of view of safety, then it must have such qualities as non-toxicity and a high vapor ignition temperature. An important criterion in the selection process is the cost of the liquid, which is why it should not be too expensive for the owner, and if the price is quite high, then the coolant should retain its properties and volume for as long as possible.

Water as a heat carrier

Of course, water belongs to the category of the cheapest heat carriers. In addition to cheapness, one can confidently declare its environmental safety and widespread availability. If a leak does occur, then it is not difficult to restore the required volume in the installation, you just need to add a few liters of liquid to a special tank. It is worth remembering that water always contains a lot of impurities: chlorine, iron, salts, which accumulate on the walls when they precipitate and form hard-to-remove scale, which affects the degree of heat transfer of pipes, leads to overheating of the equipment and disables it.

In addition, metal elements inevitably enter into an oxidative reaction with the liquid, which leads to corrosive changes.

Water tends to expand significantly when it freezes, so the lack of circulation in the cold season can disable the heating installation for a long time, breaking the pipes. In no case should a system filled with liquid be left unattended during the heating season in order to avoid freezing, just a few days — and expensive wiring can become unusable. The forced heating system is often powered by electricity, so when it is turned off or the pressure in the pipeline drops, the water can simply freeze in the pipes, and this is fraught with serious problems. Unlike antifreeze, water expands when cooled below +4°C and during heating, it must also be taken into account that it must be changed annually.

If you read the operating instructions for the heating boiler, then all manufacturers unanimously argue that distilled water should be the coolant, since it is completely free of all impurities. The main disadvantage of this approach is the cost, comparable to buying a good antifreeze.

Before filling the installation, it is necessary to thoroughly clean the pipes and heating devices with plain water. To improve the quality of heat transfer and extend the life of the boiler, it is recommended to add special additives to distilled water.

Antifreeze liquids as a heat carrier


The use of antifreeze in heating devices is more relevant for severe winters characteristic of the middle climatic zone. It has a much lower freezing point compared to plain water, which will reliably protect the heating installation from damage due to liquid freezing, even if electricity or gas is turned off for a long time. The unique properties of the fluid, as well as additional additives, protect pipes from scale and corrosion. In our climate, antifreeze is unconditionally the best option for refueling heating devices.

What is antifreeze? The main component here is propylene glycol or ethylene glycol, to which a significant amount of water has been added, as well as targeted additives.

The concentration of propylene glycol in the composition of antifreeze determines its frost resistance, the more it is, the lower should be the temperature at which the composition begins to crystallize. To reduce the corrosive effect of the coolant, special inhibitors are used — chemical compounds that slow down the process of the liquid entering into a reaction with metal and other substances. To prevent sludge formation, the composition includes a scale inhibitor, which prevents the formation of foam during circulation and reduces the risk of dissolution and swelling of the seals.

Antifreeze, as a heat carrier for heating, does not freeze within the operating temperature range, but if hardening does occur, it does not expand like water and does not provoke the destruction of the heating installation. Freezing, it becomes gel-like and does not change its volume; returning to a liquid state does not have any consequences for the coolant and equipment.

Today in specialized stores you can find antifreezes with a minimum temperature of -65 or -30 degrees. If necessary, the concentration of the composition can be changed by adding distilled water to it. The chemical composition of the fluid is designed to operate for 10 seasons or 5 years, after this time, all antifreeze in the system must be changed.

See also: Anti-freeze as a heating system for a private house

With the many advantages of antifreeze, do not forget about its shortcomings. If we compare the operating temperature of anti-freeze and water, it turns out that the heat capacity of anti-freeze is more than 15% lower, therefore, it accumulates heat worse and gives it off worse. Therefore, the consumer is forced to buy more powerful thermal equipment and spend more resources to maintain the desired temperature. Due to the increased viscosity of antifreeze, and it is 5 times higher than water, a powerful circulation pump will be required to maintain the required pressure. At the same time, electricity consumption will increase by 10%. Keeping in mind that antifreeze does not expand when freezing, it should be borne in mind that when heated, its thermal expansion is much greater than that of water, therefore, when using it, a larger expansion tank is needed. In addition, when overheated, antifreeze can permanently lose its properties.

Experts recommend determining the type of coolant even before installing the heating system, it is this approach that guarantees the long service life of all devices, spontaneous retraining can be fraught with serious troubles and lengthy repairs.

The chemical composition of anti-freeze is quite aggressive: it reacts with galvanized surfaces, causing irreparable damage to technical elements, at the same time, such a neighborhood changes the composition of the coolant and contributes to the formation of sediment, which can block the entire system. Rubber gaskets are also sensitive to this environment, so they will have to be changed much more often than when using water heating.


The environmental friendliness of antifreeze also creates many questions during use. In the process of moving through the pipes, the anti-freeze may foam, which can provoke difficulties in adjusting and balancing the system. The owner of a house heated with antifreeze should always have a canister of chemical in stock in order to quickly make up for the deficiency in the event of a leak.

Application of antifreeze

Before purchasing a boiler for heating your home, make sure that it allows the use of this type of antifreeze, otherwise you may void the factory warranty. Concentrated formulations may be mixed with distilled water. When installing the wiring, it is not necessary to use fittings and galvanized pipes, and the heating boiler must be designed to maintain a temperature not exceeding +70 degrees. A system based on anti-freeze will require a powerful pump and a volume tank that is more than twice as large as a water tank.

For the uninterrupted movement of antifreeze, pipes of a larger diameter and fairly voluminous radiators will be required. Automatic air vents will not work here — you will need to install Mayevsky manual taps. Only chemically resistant rubber can be used as a sealant.


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