Physical properties of ethylene glycol C2H4 (OH) 2 - aqueous solution (antifreeze)

Coolant requirements

You need to immediately understand that there is no ideal coolant. Those types of coolants that exist today can perform their functions only in a certain temperature range. If you go beyond this range, then the characteristics of the quality of the coolant can change dramatically.
The heat carrier for heating must have such properties that will allow for a certain unit of time to transfer as much heat as possible. The viscosity of the coolant largely determines what effect it will have on the pumping of the coolant throughout the heating system for a specific time interval. The higher the viscosity of the coolant, the better characteristics it has.

Physical properties of coolants

If this condition is not met, then the choice of materials will become more limited. In addition to the above properties, the coolant must also have lubricating properties. The choice of materials that are used for the construction of various mechanisms and circulation pumps depends on these characteristics.

In addition, the coolant must be safe based on such characteristics as: ignition temperature, release of toxic substances, flash of vapors. Also, the coolant should not be too expensive, studying the reviews, you can understand that even if the system works efficiently, it will not justify itself from a financial point of view.

A video about how the system is filled with coolant and how the coolant is replaced in the heating system can be viewed below.

How antifreeze works

Water at 0 ° C abruptly and abruptly turns into ice, while expanding by 11%. The pipes cannot withstand this load. The heating system has to be dismantled, including the boiler and all radiators. Water is a good solvent, so even a small amount of antifreeze will greatly displace the crystallization point of water, and there is no jump-like transformation into ice.

Water with the addition of antifreeze at negative temperatures slowly thickens, and the expansion of the liquid is insignificant, so the heating system remains intact.

For example, the crystallization of water with 30% antifreeze liquid (propylene glycol) is so slow that there is no need to dilute the coolant to -30 ° C, it is enough to add antifreeze to the design temperature of -12-15 ° C. With a drop in temperature below the calculated one, such a mixture will slowly but surely solidify, and only at -30 ° C can it freeze completely.

Why choose Teply Dom brand antifreeze

For heating, "Warm House" can protect the heating from destruction, which is ensured by the thermophysical characteristics of the composition, even if the system encounters an emergency stop problem. The pipes will not collapse, because the composition turns into a jelly-like state at lower temperatures.

If you use heat transfer fluids with a high content of ethylene glycol, then this can cause carbon deposits on the surface of the heating elements or in the area of ​​the burner. Among other things, you may encounter the problem of the formation of resinous sediments, as well as overheating of heating elements.

In order to obtain an aqueous solution with the required operating temperature, it is necessary to dilute the liquid for "Warm House" batteries with distilled water or water taken from the water supply system.

Features of using water as a heat carrier

Water is a unique and the only liquid in nature that expands both when heated and cooled. Its high density, equal to 917 kg / m3, varies greatly with temperature. This property can do a "disservice" to the owner of the house - if it expands during freezing, the liquid can easily damage the heating system.

Water has a maximum heat capacity (1 kcal / (kg * deg)). This means that when a kilogram of this liquid is heated to a temperature of 90 degrees, and then it is cooled in a heating radiator to 70, as much as 20 kcal of thermal energy will enter this very radiator.

Water as a heat carrier

Water is perhaps the most accessible and cheapest type of heat carrier, besides, it is distinguished by a high level of safety and is unlikely (under any conditions) to pose a serious threat to the health of the owner of the house and his family. And in the event of a leaking working fluid from the heating system, the deficiency can be easily replenished by pouring ordinary tap water.

Interestingly, water is not just a combination of two hydrogen molecules with one oxygen molecule. In fact, it also contains other elements - these are metals, chlorine impurities and various salts. Unfortunately, because of this, water can cause various deposits to appear inside the heating system and even lead to failure over time.

Distilled water

As a working fluid for the heating system, it is advised to use rainwater or its analogue - melt water, because even these fluids have fewer impurities and additives than water from a tap or from a well.

disadvantages

The main disadvantages of water as a heat carrier:

• high corrosive activity;
• scale formation;
• the possibility of destruction of the heating system in just a couple of days if the liquid accidentally freezes;
• fluid change should be done annually.

In the photo - the consequences of freezing water in the battery

The water scale can be slightly reduced. This process is called mitigation. The easiest option is to simply boil water in a metal container without closing the lid. Some connections that have no place in the heating system will settle to the bottom, carbon dioxide will be released. Unfortunately, only some substances can be removed by boiling - for example, unstable calcium or magnesium bicarbonates.

There is also a chemical method for improving the composition of water, which turns soluble salts in a liquid into insoluble. It is carried out using slaked lime, sodium orthophosphate or soda ash. All of these additives are capable of causing precipitation that can be removed by simply filtering the water.

Also, antifreeze, unlike water, is more "scrupulous" in relation to the rules of use - the possibility of its use significantly depends on their observance.

1. The pumps required to circulate the coolant must be very powerful, otherwise it will be difficult for the antifreeze to move through the pipes. In some cases, it may be necessary to install an external blower.
2. Pipes with a large diameter should be used and the radiators should also be large.
3. Air removal devices should not be automatic.
4. The gaskets and seals used in the system can only be made of dense and resistant to chemical compounds rubber or made of teflon and paronite.
5. When the boiler is turned on, the heating temperature should be increased gradually. In this case, the temperature of the coolant should not exceed 70 degrees.

The power of the heating boiler should be increased gradually after starting.

Antifreeze should never be used in the following cases:

• if the heating system in the house is an open type system;
• if the heating system is galvanized;
• if the heating boiler is capable of heating the antifreeze to more than 70 degrees;
• if oil paint was used as a sealant for the joints in the system, linen winding;
• if ion boilers are used.

Water is the cheapest, most affordable and environmentally friendly heat carrier; an accidental leak from the heating system will not create problems for the health of households. And in the event of such a leak, it is very easy to restore the original volume of water in the heating system - you just need to add the required number of liters into the open expansion tank of the heating system.

Disadvantages:

• water forms scale and reduces heat transfer, as a result of which - energy consumption increases;
• water inevitably leads to corrosion of the heating circuit;
• in the event of a power outage or a drop in gas pressure, at a negative temperature outside, water, having the properties of expanding when freezing, will simply disable the heating system of your house by breaking the heating pipes;
• it is impossible to leave the house unattended in winter, even under unforeseen circumstances, in order to avoid freezing of water (two or three days and an expensive replacement of heating pipes is provided);
• the water must be changed at least once a year, as opposed to the 5-year service life of antifreeze.

Read more: Do-it-yourself window tinting in the apartment Video - Trowel

Water is the only natural liquid that expands both when heated and cooled. Water in its chemical composition has many different impurities of iron, chlorine, salts, and therefore, when heated, salting out occurs on the walls of pipes, on the surfaces of heat exchangers, heating elements, which is the reason for the deterioration of heat transfer and the heating elements may fail due to overheating.

The simplest way to soften water is well known to everyone - thermal (boiling), using a metal container without a lid. In the process of heat treatment, part of the salts will be deposited at the bottom of the container, and carbon dioxide will be removed from the water volume. The disadvantage of the thermal method is that in this way only unstable magnesium and calcium bicarbonates can be removed from the water, and their stable compounds will remain.

The chemical or reagent method is more effective, it allows you to transfer the salts contained in water to an insoluble state. For its implementation, slaked lime, soda ash or sodium orthophosphate are used, but in this case it is necessary to know the exact dosage of the reagents. In all operating instructions, manufacturer's recommendations and manuals for installers, it is unanimously stated that heating structures are designed to use a standard coolant in them - distilled water, there are no impurities in it at all, but there are drawbacks - you will have to spend money on the purchase.

Before pouring distilled water into the heating system, it is necessary to thoroughly rinse the heating devices with plain water. It is desirable that special additives be added to the distilled water to help "extend the life" of the heating system. Please note that at temperatures below 0 ° C, it will freeze, expand and cause irreparable damage to the heating system, therefore it is more practical and correct to use antifreeze.

Do not forget that it should not be car antifreeze, transformer oil or ethyl alcohol, but antifreeze specially designed for heating systems. Moreover, we must not forget that antifreeze must be fireproof and not contain additives that interact with the metal of the equipment and are not approved for use in residential premises.

• Before purchasing a heating boiler, make sure that the manufacturer allows it to work in the heating system with this antifreeze, otherwise the factory warranty for the boiler will not be valid.
• Highly concentrated antifreeze is often diluted with water.To obtain antifreeze with a freezing point of -30 ° C, one part of distilled water should be added to two parts of antifreeze. To achieve a freezing point of -20 ° C, antifreeze is mixed in half with water. We must not forget that the first available water should not be used to dilute the antifreeze - it must be soft.
• When constructing the heating circuit, do not use galvanized pipes and fittings.
• The heating boiler should not heat the coolant to temperatures exceeding 70 ° C (this is the limiting heating temperature of any antifreeze, it cannot be heated above due to the high temperature expansion inherent in coolants of this group).
• Equip the system with a more powerful circulation pump than would be needed for hot water heating.
• Install a larger expansion tank, the volume of which is at least twice the volume required for the water coolant.
• In the heating system, use pipes of a deliberately larger diameter and volumetric radiators.
• Do not install automatic air vents - only manual ones (for example, Mayevsky taps).
• Seal detachable joints with gaskets made of chemically resistant rubber, paronite or Teflon only. You can use linen roll along with an ethylene glycol resistant sealant (in the case of using an antifreeze based on ethylene glycol).
• Use only gaskets made of chemically resistant materials in all detachable joints. When buying cast iron radiators, it is necessary to disassemble them into sections and replace the existing rubber gaskets with paronite or Teflon ones.
• Before each complete pouring of antifreeze into the system, it is imperative to rinse it with water (the boiler too) - manufacturers of anti-freeze devices recommend completely replacing them in the heating system every 2-3 years;
• you should not set a cold boiler immediately to a high heating temperature of the antifreeze coolant, you need to raise the temperature gradually, giving the coolant time to warm up (non-freezing systems have a lower heat capacity than water).
• In winter, when you turn off a double-circuit boiler in a system with antifreeze for a long time, do not forget to drain the water from the hot water supply circuit, because it can freeze and damage the circuit pipes.

If the temperature in the heating circuit during the cold season does not drop below 5 ° C, then the optimal coolant for such a system is water, from which the salt compounds are removed to the maximum. If there is a possibility of the temperature falling to minus values, then in this case only antifreeze is needed.

• permissible extremely low temperature;
• the composition of the additives and their purpose;
• what interactions with elements of the heating system (made of ferrous and non-ferrous metals, cast iron, plastic, rubber, etc.) can occur when using it;
• the duration of the period of use in the system without replacement;
• safety for human health and the environment (after all, it will have to be merged somewhere).

How to dilute antifreeze?

How to dilute antifreeze concentrate? If the product is certified and released to the market, the packaging will display detailed instructions for proper mixing with distilled water. You need to focus on the climatic zone in which you are at the moment. If you live in regions where the temperature can easily drop below -20 Celsius in winter, it makes sense to achieve a concentration that will withstand 40-degree frosts.

Related article: Estimating engine resource on Hyundai Elantra

There are a number of standard values ​​and recommendations:

• in order for antifreeze to withstand a temperature drop down to -25 degrees, it is required to mix in a 2 to 3 ratio. 2 measuring cups of substrate and 3 cups of distillate. Remember that the boiling point is reduced to 130 degrees Celsius;
• to achieve an indicator of -45 degrees, it is necessary to mix equal proportions, i.e. 1 to 1.

More detailed values ​​will be shown in this table.

Pay key attention to the boiling point of the finished liquid.... Here the regularity “the more water, the lower the boiling point” is in full force. Should antifreeze be diluted to critical values? Act according to the conditions in which the vehicle is used. Do not be greedy and overdo it with the "solvent", otherwise the key product will completely lose its useful properties.

What's the difference between green and red antifreeze?

Pure 100% antifreeze is not used as a heat carrier - always in a diluted state: from 20 to 35% antifreeze and 80-65% water, respectively. In heating, only 2 types of antifreeze based on dihydric alcohols are used: ethylene glycol and propylene glycol. Manufacturers produce both a concentrated composition and already diluted for pouring into the heating system. Ethylene glycol is a concentrated red solution and ethylene glycol is a green solution. I will describe their differences below.

Read next: Putty sander

Why dilute antifreeze concentrate

To understand the need to dilute the antifreeze concentrate before pouring it into the coolant tank, you need to understand its chemical composition and the functions that it must perform. As you know, the main task of antifreeze in the system is to maintain the operating temperature of the engine at about 90-110 degrees Celsius. If the temperature is higher, the engine will overheat.

Based on this, we can conclude that antifreeze must be in a liquid state at any time of the year in order to "run" through the cooling system and reduce the temperature of the engine elements. Both ordinary water and concentrated antifreeze cannot cope with this task. The fact is that the antifreeze concentrate is ethylene glycol, that is, dihydric alcohol. It is able to keep a high boiling threshold at about 200 degrees, but its cooling threshold is not suitable for the conditions of the Russian winter. Already at minus 13 degrees, pure ethylene glycol will freeze, which is unacceptable for the liquid poured into the cooling system.

Ethylene glycol mixes well with water and alcohols, after which it acquires new properties. By diluting the antifreeze concentrate, you can lower the temperature at which it freezes to the required values, down to minus 70 degrees Celsius. Of course, when antifreeze is diluted with water, the threshold of its heat resistance decreases, that is, the liquid boils at lower temperatures than when it is in a concentrated form.

How to fill in the system correctly?

Crimson solution. A toxic substance used in the auto industry, the production of motor oils, plastic and cellophane. It has an extremely low pour point of -70 ° C. It is mainly used in heating and anti-icing systems of industrial facilities, football fields. It is not recommended to use ethylene glycol in suburban heating systems due to its toxicity.

Green solution, food additive E1520, used in the cosmetics industry. The pour point is -50 ° C. 3 times more viscous and 2 times more expensive than ethylene glycol. It is widely used in buildings where there is a risk of system defrosting, but environmental performance is required. In our country, propylene glycol for the heating system is produced from imported raw materials, therefore, it is much more expensive than ethylene glycol.

I got a lot of questions about "glycerin". A glycerin-based coolant in the heating system is unacceptable, even in a diluted state.

First, the monstrous kinematic viscosity at negative temperatures (at 0 ° C –9000 m2 / s x 106 - glycerin, 67 m2 / s x 106 - ethylene glycol) - and hence the monstrous pressure loss.It will be difficult to push the glycerin-based coolant through the pipes.

Secondly, the adhesion of organic particles of glycerin to the surface of the boiler heat exchanger, its overheating and complete exit from standing. Dilution of glycerin with alcohols only leads to the formation of explosive compounds.

Any other non-freezing liquids, for example, antifreeze in the heating system, are unacceptable, because do not contain the required amount of anti-corrosion additives. The cost of antifreeze for heating is determined by the quality of these very additives, thanks to which some antifreezes last 5 years and others 10. Over the years, antifreeze in the heating system oxidizes to form acetic acid, which leads to the destruction of brass connections on radiators, so it is important to change the coolant on time.

For household needs, i.e. for heating systems of private houses, antifreezes are produced based on ethylene glycol (monoethylene glycol) and propylene glycol, most of which are offered in Russia - made on the basis of ethylene glycol. This is a toxic substance that is extremely dangerous for humans and its contact with the skin or even more so in the human body is absolutely undesirable.

If the freezing point of antifreeze is -30 ° C, then the concentration of ethylene glycol in such a solution is approximately 44%. At a freezing point of -65 ° C, the concentration reaches 65%, (the remaining 4% are inhibitor additives). This product, considered optimal in terms of thermal performance, never delaminates, does not freeze down to a temperature of -65 ...

-70 ° С, and ethylene glycol practically does not evaporate from it. But in order to perform its main function (heat transfer), antifreeze must not only have satisfactory thermal conductivity, but also not boil in the operating temperature range, not foam, be chemically stable (not form deposits on the surface of the system) and not destroy structural materials.

Various additives help him to solve these problems: metal corrosion inhibitors, antifoam agents, etc., which make up about 4% of the solution weight. The use of ethylene glycol-based antifreeze is undesirable in two-circuit heating systems, when there is a possibility of mixing the coolant from the heating circuit into the water supply circuit, as well as in open heating systems (with an open expansion tank), where the coolant may evaporate.

Formulations based on the first type are more common and cheaper than those based on expensive propylene glycol, but they are very toxic. Working with antifreeze containing ethylene glycol requires mandatory protection of the skin, respiratory system and eyes. Ethylene glycol, which is part of antifreeze, when it enters the human body becomes a "poison" (belongs to the third group of danger), a lethal dose for an adult can be a one-time "intake" of only 100 ml of this substance.

That is why antifreeze on this basis is recommended for use exclusively (!) In closed heating systems (with a closed expansion tank). Another disadvantage of such compositions is that ethylene glycol-based antifreezes are especially sensitive to overheating - with any, even short-term temperature rise above the limit set by the manufacturer for a given brand of non-freezing, its thermal decomposition occurs, insoluble precipitate and acids are formed.

Sediment, if it gets on the surfaces of the heating elements, forms a sludge that worsens heat exchange at the local level and causes overheating with re-formation of sludge, etc. The acids formed as a result of the decomposition of ethylene glycol react chemically with the structural metals of the heating system, causing multiple foci of corrosion.

As a result of the decomposition of the additives, the protective properties of the coolant, previously provided by it for the material of the seals of detachable joints, are sharply reduced, and with high fluidity, this will immediately cause a leak. In addition, overheating increases the foam formation of the antifreeze, which, in turn, adds air to the heating system.

Less dangerous to human life and health. It is important to remember that in the composition of such antifreeze there must be special additives, taking into account the fact that seals in the heating system can be made of various metals, which can be destroyed as a result of the use of an unsuitable component for them.

Non-freezers with propylene glycol are allowed to be used in double-circuit boilers, because their accidental penetration into drinking water, as well as leaks in the places of detachable joints, will not harm people. Propylene glycol coolants, in addition to the general same positive characteristics as ethylene glycol ones, inside the heating system have a lubricating effect, reduce hydrodynamic resistance and facilitate the operation of the secondary circuit pumps.

In some conditions, there is a need to use a heat transfer fluid with a fairly low freezing threshold. Such substances are called antifreezes. Antifreeze based on ethylene glycol accounts for approximately 25% of all heat transfer fluids.

Special additives are introduced into the composition of antifreeze based on ethylene glycol - inhibitors, which slow down the rate of undesirable chemical processes under the influence of ethylene glycol.

The freezing temperature can reach -60 ° C.

To use ethylene glycol, the following factors must be taken into account:

1. Viscosity. Ethylene glycol is not used in its pure form; it is mixed with water. Depending on the concentration, the viscosity of the substance also changes. With an increase in viscosity, the speed of movement of the coolant through the pipes also decreases. Because of this, it is necessary to increase the pump performance, which leads to an increase in the cost of generating heat.
2. Thermal expansion. The coefficient of thermal expansion of this substance is on average 50% higher than that of water. Therefore, during heating, in order to prevent pressure build-up in the heating devices, it is necessary to install an expansion tank. The same tank should also serve to feed the coolant when the temperature drops.
3. Chemical properties. By its properties, ethylene glycol is aggressive towards some types of materials. For example, when using it, it is necessary to abandon rubber seals. You will need to replace them with paronite. Also, the use of galvanized pipes is not possible. Ethylene glycol dissolves zinc. When deciding to use ethylene glycol as a coolant, it is necessary to carefully study the passports of all installed heating devices for the possibility of its use.
4. Filling the system. Filling the system with a water-glycol mixture is possible only with a make-up pump. Taking into account the increased viscosity of the mixture, it is necessary to correctly select the pump parameters. Also, it is necessary to select the material for the tank, from which the pump will fill the heating circuit with a solution. When choosing a pump, it is imperative to take into account the parameters of the liquid that it will pump.
5. Toxicity Due to its high toxicity, ethylene glycol has not found widespread use. For humans, a lethal dose can be 50–500 mg. It is strictly forbidden to use ethylene glycol in open systems. Materials contaminated with ethylene glycol must be replaced.

Read more: Rating of solid fuel heating boilers for a private house

Positive sides:

1. Defrosting the system is almost impossible.
2. Good heat capacity.
3. Low likelihood of lime scale formation.
4. Quite an attractive price.

The negative side is toxicity! This is what prevents ethylene glycol from gradually displacing water from the leading position.Ethylene glycol is deadly.

The most reliable, safe and modern heat carrier is a propylene glycol-based product. It began to be used in the world since the 60s of the last century. In leading European countries, this antifreeze has been used as the main coolant for 20 years. In our country, propylene glycol accounts for only 5%.

When using propylene glycol, the following factors must be taken into account:

1. Viscosity. Taking into account the increased viscosity compared to water, when designing a heating system, it is necessary to select a circulation pump with increased performance. This will ensure the normal rate of heat transfer from the boiler to the heating radiators.
2. Chemical properties. In terms of its chemical properties, this antifreeze is close to ethylene glycol. Before starting to use it, you need to make sure that it is possible to use this coolant on the selected equipment. Otherwise, the boiler and the heating system as a whole can be damaged. The use of rubber seals, as well as tow, is also not possible.
3. Filling the system. In order to fill the heating circuit with propylene glycol, a recharge pump must be used. At the lowest point of the heating system, it is necessary to provide a place for connecting a booster pump. The system must be filled slowly. In this case, all air valves must be open. This filling method will help to avoid blocking the system with air.

Ethylene glycol solution - antifreeze liquid for refrigeration (cooling) and heating systems

To improve the thermophysical properties of an aqueous solution of ethylene glycol (coolant, antifreeze, antifreeze liquid), the additive package used includes about a dozen substances designed to reduce the corrosive and oxidizing properties of the solution, its foaming, prevent the formation of scale and remove existing scale, as well as to stabilize the thermophysical characteristics coolant (The quality characteristics of ethylene glycol solutions must meet the requirements GOST 28084-89 "Non-freezing cooling liquids"
and technical specifications developed on its basis). Most concentrated heat transfer fluids are a solution consisting of 60% -65% ethylene glycol, 30% -35% water and 3% -4% active additives.

Such percentage ratios of ethylene glycol, water and inhibitors make it possible to obtain the best thermophysical characteristics of an aqueous solution as an effective heat carrier with a maximum minus temperature of the onset of crystallization of -70 ° C.

Aqueous solutions of ethylene glycol with a lower freezing point are produced using a lower concentration of ethylene glycol and the mass fraction of additives (inhibitors) remains practically unchanged. The dependence of the freezing point on the concentration of ethylene glycol is shown below, in table 1.

For various climatic operating modes and operating conditions of heating systems, a series of high-quality aqueous solutions of ethylene glycol

with the required crystallization temperature and stable thermophysical characteristics:

Ethylene glycol aqueous solution - heat carrier and antifreeze liquid for heating and cooling systems (package of anti-corrosion, antifoam, anti-scale and stabilizing additives)

Properties, characteristics and application features

In autonomous heating and industrial air conditioning systems as coolant

an aqueous solution of ethylene glycol with additives for various purposes is widely used. The density of pure ethylene glycol is 1.112 g / cm3 at 20 ° C, the freezing point is –13 ° C. Aqueous solutions with an ethylene glycol concentration of 30% to 70% have a lower freezing point. The maximum freezing temperature of –70 ° C is reached at an ethylene glycol concentration of 70%. Upon freezing, the ethylene glycol solution passes into an amorphous state, forming a viscous mass with an increase in volume within slightly larger limits than an increase in the volume of water during its freezing.

Concentrated solutions with 95% ethylene glycol content are also produced, they are diluted with water before filling into the system. The percentage of ethylene glycol is recommended to be selected based on the minimum temperature at which the coolant will be operated. Ready concentrated heat transfer fluids with the required freezing point are diluted with water before filling the system. For dilution, it is advisable to use distilled water, in its absence - tap water with a hardness of up to 6 units. But it must be borne in mind that the use of untreated water is undesirable due to possible incompatibility with the additive package.

Dilution of concentrated ethylene glycol by more than 50% leads to a noticeable deterioration in the consumer properties of the heat carrier.

Obtaining a high-quality aqueous solution of ethylene glycol with the required crystallization temperature and stable thermophysical characteristics is possible only under industrial conditions. The operating instructions for the equipment of most heating and industrial air conditioning systems make high demands on the thermophysical properties of solutions, and therefore it is recommended to use only ready-made aqueous solutions designed for the appropriate crystallization (freezing) temperature. Therefore the company CHIMTERMO produces a whole series of high quality
aqueous solutions of ethylene glycol
.

The consumer should take into account that due to a number of significant differences in the thermophysical properties of water and heat transfer fluids based on ethylene glycol, when using the latter, a number of technical features arise that require special attention.

The viscosity of an ethylene glycol solution is 1.5-2.5 times higher than that of water, respectively, and the hydrodynamic resistance to the movement of a liquid (aqueous solution) in pipes will be higher, which will require a more powerful circulation pump (approximately 8% in capacity and 50% in pressure).

Aqueous ethylene glycol solution has a higher coefficient of thermal expansion than water, therefore it is necessary to use a large expansion tank.

Heat carrier

based on distilled aqueous solution
ethylene glycol
toxic and poisonous to the human body (belongs to the third class of hazard of moderately hazardous substances) and is recommended for use only in closed heating systems (with a closed expansion tank).

The heat capacity of an ethylene glycol solution is about 15% less than that of water, which worsens the heat exchange conditions and requires the installation of more powerful radiators.

It is undesirable to bring an aqueous solution of ethylene glycol to a boil, as this will lead to an irreversible change in the chemical composition and properties of the aqueous solution.

What kind of coolant to buy?

There are a large number of different brands of heat transfer fluids on the market. All of them are approximately the same in their properties and technical characteristics.In most cases, the different costs are due to marketing and advertising costs. Those. the more popular the brand, the more expensive the product. There are, of course, certain nuances and patented formulations, but as a rule they do not justify the high cost of the product and are exclusively marketing "chips", ie. they do not make some kind of revolution in the heat carrier market and absolutely certainly are not worth overpaying for them.

In turn, we can recommend you the "ThermoStream" heat carrier from a domestic manufacturer - the best price-quality ratio. Nothing superfluous and affordable price.

Which coolant to choose for heating?

For a heating system, the differences between ethylene glycol and propylene glycol are insignificant, but different freezing temperatures (-70 and -50 ° C) affect the percentage of the substance. To ensure the same crystallization temperature (-25 ° C), almost 2 times less ethylene glycol is required than propylene glycol, but the relationship is not linear.

For example, when the concentration of ethylene glycol in water becomes more than 50%, its characteristics begin to decline. This is due to the ineffective work of anti-corrosion additives, which do not come into contact with water well.

Which antifreeze is best for heating a house

The main criterion for choosing antifreeze is safety!

Propylene glycol is used in the food industry. The substance is not toxic. It is used as antifreeze in heating systems of cottages, country houses and premises with constant presence of people.

If the building does not require environmental safety, for example, warehouses, garages and production halls, you can safely use ethylene glycol. In all other cases, propylene glycol.

Recipe for the preparation of a 100 l solution from a concentrated heat carrier

"Warm House" is a liquid that can be used to prepare a ready-made solution that is poured into the heating system. The proportions of the ingredients will affect the temperature at which they begin to freeze or crystallize. Thus, if 77 liters of coolant are added to 23 liters of water, the temperature of the onset of freezing will remain at around -40 ° С.

By adding 65 liters of coolant to 35 liters of water, you will achieve that you create a solution that will freeze at a temperature of -30 ° C.

Forty liters of water and 60 liters of coolant will produce a solution that will begin to crystallize at 25 ° C below zero. If the thermometer in your house does not drop below -20 ° C, then 54 liters of coolant will be enough for 46 liters of water.

Liquid "Warm House" can be diluted with water from a well or well, but it should be borne in mind that in this case, you may encounter an increased content of metals and salts. In order to avoid problems during the operation of the heating system, a small volume of the coolant should be previously mixed with water. Use a transparent container for this. As a result, you should get a clear solution so that you can make sure that there is no sediment. This mixing can be done before filling the system, especially for natural circulation systems.

The described coolant is characterized by high stability of thermophysical properties, therefore, it will be able to ensure continuous operation of the system for 5 years. After this period, the coolant will be a low-freezing liquid, but it can already be considered a solution that has exhausted the resource of additives, due to which you may encounter an increase in scale and corrosion. Therefore, the coolant is drained and disposed of. Before filling a new batch, the system is flushed with water or a special liquid.

Calculation of the amount of coolant

Estimated

It is necessary to add up the amount of coolant in the boiler, radiators and pipelines.Data on the amount of coolant in the boiler and batteries can be taken from passports.

The volume of liquid inside the pipe can be calculated using the formula:

• V = S (sectional area of ​​the pipe) x L (length of the pipe).

To simplify calculations, there is a volume table.

Radiator water volume:

• aluminum radiator - 1 section - 0.450 liters;
• bimetallic radiator - 1 section - 0.250 liters;
• old cast iron battery - 1 section - 1,700 liters;

The volume of water in 1 running meter of the pipe:

• ø15 (G ½ ") - 0.177 liters;
• ø20 (G ¾ ") - 0.310 liters;
• ø25 (G 1.0 ″) - 0.490 liters;
• ø32 (G 1¼ ") - 0.800 liters;

Experienced

To determine the volume empirically, it is necessary to completely fill the heating circuit with water. Then it is necessary to carefully drain the water, measuring the volume with a measuring container.

When filling with water, it is necessary to slightly open the tap installed in the section of the water treatment system. In this case, the air valves must be open. In this way, airing of the system can be avoided.

The water from the heating circuit is drained through the drain valve into the sewerage system or the make-up tank. The system must be filled with propylene glycol using a booster pump.

As with water, the filling must be done at a low speed. Considering the cost of propylene glycol, systems need to be drained only into the make-up tank.

It is necessary to fill the systems with ethylene glycol with all precautions. Under no circumstances should antifreeze be spilled or spilled on the body. Technically, the procedure for both draining and filling is identical to the procedures using propylene glycol.

https://www.youtube.com/watch?v=lKKW_NrnUug

The frequency of water replacement in the heating circuit is usually one thermal season. For antifreeze, the frequency set by the manufacturer is 5 years.