Propylene glycol for heating systems is made from petroleum products, has excellent performance and can be used as a working fluid. This substance, when freezing from the liquid phase, passes into a gel state, which helps protect pipelines from corrosion and ruptures.
Features of the water system
In our country, the most common water heating system, in which energy is transferred from the source to the heating devices through a liquid coolant, which is usually water. It is worth noting that it best copes with the heat transfer function. However, it is characterized by the only drawback - during freezing, this coolant expands, crushing radiators from the inside and rendering the cast iron and steel systems unusable. Ice plugs that form in pipelines during local freezing are less dangerous, but they can cause a lot of problems and lead to local overheating or even boiling of the coolant.
This moment explains the high interest of owners of autonomous heating systems and heat engineering in antifreezes, which can replace water that is affordable and safe for human health and life. It is far from a secret that even in the most reliable system, malfunctions and leaks are not ruled out.
Among these fluids, propylene glycol-based antifreeze for heating systems should be distinguished.
Propylene glycol
This coolant is a colorless viscous liquid, which is characterized by a sweetish taste and a corresponding smell. And most importantly, it is safe for human health. Propylene glycol is widely used in various sectors of the economy, including the cosmetics and food industries.
Propylene glycol for heating systems has all the properties of an ideal heat carrier: it boils at a temperature of 187 ° C, and crystallizes at -60 ° C.
Another advantage of propylene glycol is its low corrosivity, which reduces the bar for steel quality requirements for heating systems and, accordingly, reduces their cost.
Propylene glycol is excellent for systems that include structural elements made of rubber, polymeric materials, aluminum, copper, cast iron and steel. In addition, when using this substance, scale and precipitation do not form on the inner surface of the heating system, which ensures high heat transfer and increases the operational life.
The properties
Propylene glycol has the following properties:
- good hygroscopicity;
- at any percentage, propylene glycol is completely soluble in water;
- this substance is non-toxic;
- excellent bactericidal and sterilizing properties;
- low volatility;
- system protection against corrosion and freezing.
In addition, propylene glycol for heating systems can withstand high temperatures.
Specifications
Propylene glycol has the following:
- transparent (colorless);
- boiling point at atmospheric pressure from 188.2 ° C;
- at a temperature of 20 ° C, the density of a 70% solution of 1.044 g / cm 3 ;
- the beginning of crystallization of a 70% solution at a temperature of -67 ° C;
- operating temperature ranges from -40 ° C to +108 ° C.
Advantages
The first advantage of antifreeze, due to which it received such a name, should be called the property not to freeze at high subzero temperatures, which the coolant under consideration possesses. Propylene glycol for the heating system forms an amorphous structure, which is what distinguishes it from water. This substance does not increase in volume, respectively, the destruction of the heating system as a result of this does not threaten.
disadvantages
Unlike water, propylene glycol for heating systems has a lower heat capacity. This means that it accumulates less heat and, therefore, gives less of it. As a result, consumers will need more powerful heaters.
The viscosity of antifreeze is 4 to 5 times higher than that of water. For this reason, the intensity of propylene glycol circulation in the system will be less. When choosing coolants for propylene glycol-based heating systems , these factors must be taken into account.
Application
Before pouring anti-freezing fluid into the heating system, a hydraulic test must be performed.
The right choice of antifreeze deserves special attention, it is important to choose the one that will fully comply with the heating system. For these purposes, an analysis of its elements is carried out, as well as the materials of which it consists. After that, antifreeze is selected, which will not contain additives dangerous for the materials of the system.
For heating systems, the most popular is non-freezing fluid with carboxylate additives. As a rule, it has been used for at least 5 years. It is also worth noting that the propylene glycol coolant for the heating system without effective additives is especially dangerous for copper heat exchangers and can lead to their unsuitability after a year of operation.
In the process of use, the coolant is contaminated, therefore its quality requires constant monitoring, which is desirable to produce in laboratory conditions.
The propylene glycol antifreeze for heating systems must be replaced only after a hydraulic test of the system and washing it with an alkaline solution.
Efficient use
For the effective use of this anti-freezing fluid, it should be poured into the circuit of the heating system after carefully sealing all components and conducting hydraulic tests. It is recommended that the system itself be supplemented with a circulation pump.
By changing the percentage of propylene glycol solution for heating systems, you can get a liquid with a freezing temperature from -1 ° C to -65 ° C.
The life of propylene glycol without additives is on average 5 years, then in the ventilation, cooling or heating system, it is necessary to either flush using an alkaline solution or completely replace the liquid. With prolonged or frequent exposure to low temperatures (for example, the heating system was not used for a long time in the winter), it is preferable to change the solution every 3 years.
Flushing
The heating system needs periodic flushing. For these purposes, various liquids are used. Washing at home is usually done with water.
To get a good result, the system must be filled with caustic soda for about an hour , which perfectly fights corrosion and scale.
Another important point is to know what the freezing temperature of antifreeze is needed. Only when this condition is met, you can choose the most optimal fluid for heating systems. Propylene glycol has several advantages over ordinary water. And the main is the ability to not freeze at low temperatures.
After pouring antifreeze into the heating system, you don’t have to worry about the “defrosting” of heating devices in a country house. You do not have to go there constantly to check the status of the system.
Various additives give non-freezing liquid the best qualities. As a result, the heating system will last longer. Additives can protect metal surfaces from corrosion, while preventing the destruction of the sealing elements.
How to choose antifreeze
Today, the construction market offers a wide range of coolants, the basis of which is propylene glycol for heating systems (reviews about them are mostly positive). All of them have different costs, which directly depends on the brand, country of manufacture, as well as the operational characteristics of the solution itself.
Some consumers, without special knowledge, use automotive antifreezes (transformer oil, antifreeze, etc.) in their heating systems. However, this is unacceptable, since such solutions contain unsafe for human health and flammable substances. The most optimal and universal in operation is considered a non-freezing liquid based on propylene glycol. When choosing a coolant for the heating system, you should pay attention to the following points:
- Shelf life. Antifreeze can be stored in its original packaging for a long time (even if the shelf life is unlimited, it must in any case be specified by the manufacturer).
- Terms of Use. Non-freezing fluid can be universal, and can be suitable only for a certain type of equipment.
- Packing material. Non-freezing liquids are usually sold in plastic cans. In a galvanized container, this substance loses its operational properties.
- Certificate of quality. Non-freezing fluid must be manufactured in accordance with technological rules and regulations, tested in laboratory conditions and approved for sale.
- The presence of refined products.
It is very important to use antifreeze strictly for its intended purpose. Neglecting the rules for choosing a non-freezing fluid will lead to negative consequences - emergency situations, water hammer, rupture of pipelines, etc.