During the operation of various life support systems, engines, devices in the cold season, a situation arises when the negative ambient temperature negatively affects the physical properties of the fluids that are inside them. For example, these are coolants that serve to prevent overheating of the mechanisms themselves or a variety of coolants.
Therefore, the so-called antifreeze fluids are used. Antifreeze is a liquid substance that retains all its properties, regardless of the temperature difference. Antifreezes are used in construction, in the manufacture of automobiles, in heating and ventilation systems of private houses or industrial buildings.
Heat carriers and their types
Almost all antifreezes include water and special additives. The basis of any coolant can be:
- Propylene glycol - if you compare it with other types of antifreeze, then this substance does not cause any harm to human health, not only through direct contact, but even by inhalation of its vapor. The main advantage of this type of antifreeze is its safety. That is why it is actively used in dual-circuit heat supply systems, since even if the substance gets into the circuit with hot water, nothing bad will happen. In addition, propylene glycol is used as an agent in the confectionery industry, as well as being a food additive. Propylene glycol is usually green. Due to the availability of different colors of antifreeze on sale, there is confusion as to whether it is possible to mix antifreeze of different colors or not. It all depends on the purpose and operating conditions. Like other antifreezes, the freezing point of propylene glycol is around -35 C.
- Ethylene glycol is a very popular type of antifreeze, mainly due to its low market value, and in addition, it is available in two types: with freezing temperatures of -30 ° C and -65 ° C. Its main drawback is the increased danger to human health. Therefore, this brand of antifreeze has a red color, so that in case of leakage it is noticeable and its consequences can be quickly eliminated.
- Triethylene glycol is the less commonly used antifreeze, mainly in those systems where there are high temperatures. Triethylene glycol is considered a special antifreeze.
Therefore, when choosing which brand of antifreeze you need, it is better to resolve this issue even before the construction of the house begins.
Properties of antifreezes and their characteristics
Antifreezes differ:
- Density.
- Freezing point.
- Viscosity.
- Acid-base balance (pH).
- Color.
- Heat capacity.
Each individual brand of antifreeze has its own individual characteristics inherent only to it. Antifreezes in their composition have various additives that are necessary to improve their quality.
Properties of antifreezes that are important during their operation
They are as follows:
- Operation over time. Without replacing the coolant, antifreeze systems can be safely operated for a long time. This also ensures an increase in the service life of the entire heating or ventilation system as a whole.
- Antifreezes are resistant to corrosion. Due to the presence of special additives in the antifreeze composition, no rust is formed inside the heating systems. This helps to increase the heating efficiency of the room, and at the same time significantly reduces energy costs.
- Resistance to cavitation. In ordinary water, if the pressure in the system decreases, the appearance of bubbles inevitably occurs. In the case of antifreezes, this is not observed. Thus, they also save the system from water shocks and vibrations.
In the manufacture of antifreeze additives are required. The non-use of these components in propylene glycol or ethylene glycol would be unreasonable from an economic point of view.
Nuances when buying antifreeze
All antifreezes sold on the construction market have a different price, depending on the brand, manufacturer, and the distinctive performance properties of the substance itself. Ignorant people often buy automobile antifreezes for their heating systems (transformer oil, antifreeze and others). This is categorically unacceptable, since they include substances harmful to humans and animals. In addition, they are highly inflammable.
The optimal solution in choosing a coolant for heating is ethylene glycol. That is, that brand of antifreeze that is produced on its basis.
Tips & Tricks
One of the most common questions asked by customers in stores is: “ Can I mix antifreeze in different colors? ” Sometimes this is acceptable, but only after a serious check of substances for compatibility. Most often, mixing different colors of antifreeze leads to a decrease in the operational properties of the coolant and the formation of plaque from rust on the pipe walls.
It is best to dilute antifreeze with distilled water. It does not contain salts of such chemical elements as calcium and magnesium, therefore it is usually softer than the required value. Normal water, when used in conjunction with antifreeze, is likely to also lead to the formation of precipitation. The permissible hardness of the water used to dilute antifreeze is 5 mEq.
When carrying out any work with heating systems, it is necessary to monitor such an indicator as the density of antifreeze. The table, as a rule, is located on the back of the tank, with its help you can determine the performance of this brand of coolant.
Ethylene glycol-based antifreezes are less thermally conductive than water (by 15-20%).
Without fear of reducing the effectiveness of the heating system, antifreeze can be used for 5 years. Then you should completely drain the old and pour clean, new coolant.
What is the density of antifreeze measured?
Density is indicated in grams per cm cubic. Check the freezing temperature and the amount of ethylene glycol will help the density of antifreeze. The density table contains many indicators, it is easy to use.
To check the density of antifreeze, you can use a hydrometer. This is a device for measuring the density of antifreeze. It has two scales - for measuring density and freezing temperature.
Refractometer Density Check
You can check the density of antifreeze and a refractometer. Testing is quick, just a drop of coolant is enough.
The measurement procedure is as follows:
- Pipette antifreeze onto the prism of the device.
- Sharpen the eyepiece.
- Read indications from the scale along the index line.
You can also use the folk method - put a little substance in a plastic bottle, clog it and put it in the freezer of the refrigerator. Stir in an hour. If the solution has not crystallized, then this antifreeze can be used at a temperature of -24 ° C (average freezer temperature).
Density of antifreeze depending on temperature changes significantly, and when used at temperatures below -65 ° C, it still begins to decompose. As a result, the operation of the heating system is disrupted, and the coolant itself will fail.