Autonomous heating systems in country houses can operate on different principles. A very popular design for creating private heating systems is liquid coolant equipment.
It consists of a heating boiler, a piping system and heating radiators.
Usually ordinary water is used as a coolant. In order to prevent scale formation, chemical additives are often added to such “technical” water. But such a system requires constant heating - if the water inside the pipeline system freezes, the latter fails. In order to provide the possibility of pauses in work, non-freezing heating fluid is used.
Why is it better to use antifreeze liquid in the heating system rather than water?
Non-freezing liquid (or antifreeze) in the heating system greatly simplifies the work with the equipment. If you use ordinary water as a coolant, then the heating system must be equipped with additional devices, for example, a valve for releasing air from the expansion tank. In addition, in the case of a country house that is not constantly used, water will have to be drained or refilled into the heating system at each visit, otherwise in winter it will simply freeze.
On the one hand, water has a greater heat capacity and, when moving through the pipelines of the heating system, retains heat longer. This is what determines the wider use of water as a coolant in private country houses.
Can antifreeze be used?
Antifreeze or antifreeze liquids are known to almost everyone. They are widely used in car cooling systems in winter. In a car engine, antifreeze transfers excess heat away from the engine, cooling it. Moreover, even in the most severe frosts it does not freeze. It is these properties - the ability to transfer heat even at the lowest temperatures - that led to the use of antifreeze for the construction of heating systems. It is especially important to use such a coolant in a system where part of the pipeline runs through open areas.
A good feature of “anti-freeze” is that it provokes less corrosion on the inner surface of pipeline systems than ordinary water. Another undoubted advantage is the absence of suspended limestone solutions in non-freezing liquids - so you don’t have to worry about possible scale formation.
There are several modifications of antifreeze liquids that can be used in heating systems. The choice of a specific type is made taking into account climatic conditions and the configuration of the heating system of your home.
What is flushing fluid for the heating system and does it need to be flushed?
In addition to the coolant itself, when operating the heating system, you will also have to purchase a liquid intended for flushing the pipeline and heating radiators.
Of course, as a last resort, you can wash the inner surface of the pipes with ordinary tap water, but it is better to do this with the help of special liquids that contain special chemical additives.
An alternative washing option may be to use water with a caustic soda solution added to it. This mixture is poured into the heating system and remains inside it for about an hour. The soda solution comes into contact with the scale on the inner surface of the system and dissolves it. In addition, the baking soda solution will dissolve areas with corrosion.
How to choose a liquid for a heating system?
- First of all, it is necessary to determine the operating parameters of the system. Here two extreme values will be important to you - the maximum coolant temperature when heating in the boiler and the minimum ambient temperature.
- Next, you need to carefully study the technical characteristics of your heating system. Actually, the main attention should be paid to the characteristics of the heat exchanger in the boiler. Some manufacturers may not allow the use of antifreeze fluids.
- And finally, after determining the permissibility of using non-freezing liquid and its possible temperature parameters, proceed directly to choosing the brand of liquid, focusing on its lowest toxicity. Still, the heating system will be located in a living room, and possible liquid leaks should not lead to poisoning.
Using alcohol as a coolant
No matter how blasphemous it may sound to the male ear, it is allowed to use alcohol as a coolant. Alcohol does not freeze and can be used in a wide range of temperatures. Naturally, industrial alcohol is used in this capacity, which is a deadly poison for humans. However, many manufacturers of boilers and heat exchangers are critical of the use of liquids such as bischofite or ethylene glycol as a coolant.
The disadvantage of using pure alcohol as a coolant is its high volatility - about five liters per year will evaporate through microscopic pores in the system.
Which brand of antifreeze should I choose?
An important factor when choosing an antifreeze liquid for a heating system will be the selection of compatibility of the liquid with the material of the pipeline system. Thus, polypropylene, aluminum, steel or cast iron can be used as a material for making pipes in heating systems. Certain brands of antifreeze liquids may behave differently with each material.
Anti-freeze "Warm Home"
In addition, the maximum temperature to which the coolant fluid will be exposed is also very important. This parameter largely depends on the fuel used in the heating system. So liquid fuels, for example diesel fuel, have a much higher combustion temperature than ordinary birch firewood. Accordingly, the coolant fluid in such systems will heat up to a greater extent.
When using antifreeze, it is necessary to take into account its increased fluidity and permeability, caused by a low surface tension coefficient. As a result, antifreeze can literally seep through the smallest pores in the joints. Thus, the use of antifreeze requires a thorough inspection of all connecting nodes in the heating system of your home.
Please note that different brands of antifreeze from different manufacturers may have different chemical compositions. "Antifreeze" is simply a generic name for a type of antifreeze liquid. Accordingly, the behavior of each liquid with an individual chemical composition will also be individual.
Consequences of using antifreeze with ethidene glycol
Very often, manufacturers add ethylene glycol to antifreeze liquids. Remember that ethylene glycol is a harsh and toxic chemical. As a result, when operating heating systems with antifreeze coolant, a number of safety measures must be observed. In any case, when using antifreeze fluids, your home's heating system and hot water system must be physically separated to prevent the fluids they use from mixing. As a last resort, if there is a real possibility of coolant getting into the hot water supply system, it is necessary to use propylene glycol. It is less effective than ethylene glycol, but much less toxic.
Before pouring anti-freeze liquid into the heating system for the first time, do not forget to flush the inner surface of the pipelines.
How is antifreeze made?
The main component of antifreeze liquids is ordinary water. And the efficiency of the heating system largely depends on its quality and cleanliness. The fact is that the smallest impurities of pollution in water are the areas around which it begins to freeze. Well-purified, distilled water does not freeze even at low sub-zero temperatures.
In addition, impurities in water are scale, which forms on the inner walls of pipelines. The cleaner the water used in the production of antifreeze liquid, the less likely it is for scale to form, the less
To reduce the negative effects in the production of anti-freeze, various chemical additives are used. They completely dissolve in water and prevent the onset of corrosion of metal surfaces, playing the role of inhibitors in the chemical reactions that occur.
What additives are added to antifreeze liquid?
Among the chemical additives used in the production of anti-freeze products are the following:
- Inhibitors, that is, substances that inhibit chemical reactions with metal. These include silicates and phosphates.
- Hybrid additives that perform several functions simultaneously. These mixtures are available on an organic and inorganic basis.
- Additives based on carbosilicates. This is a fairly fresh solution in this industry and it has a broad prospect for development.
Advantages and disadvantages of coolant based on antifreeze
The most important advantage of antifreeze-based fluids when used in heating systems is their ability to maintain a fluid state at subzero temperatures. Even at very low temperatures, such a liquid does not become a solid, but forms a slurry-like substance that will not damage the pipelines and equipment of your system. In addition, at low temperatures and partial freezing, antifreeze does not increase in size. After increasing the temperature, it completely restores its properties.
But for such effectiveness at low temperatures, antifreeze has to pay with a reduced heat capacity, which is reduced by up to 15 percent relative to ordinary water. This leads to increased energy consumption for heating fluid in the heating system. Also, when using “anti-freeze” devices, you will have to use more powerful heating radiators, with a larger number of sections. Antifreeze is more viscous than water and will have to be moved through the system by more powerful pumps.
Please note that after filling the heating system with antifreeze liquid, it must be allowed to stand for two to three hours. During this time, the air present in it will be released from the liquid. Only after this can working pressure be created in the system.
To avoid air leaks into the liquid during system operation, it is necessary to install an expansion tank in it. Compared to systems operating on water, the tank must have a larger volume, which is associated with a greater coefficient of expansion from heat for “anti-freeze”. Also, non-freezing liquid may have a tendency to foam, which must also be compensated for by the expansion tank.
When operating a heating system with antifreeze, it is unacceptable to allow it to overheat, which can lead to irreversible consequences and require a complete replacement of the fluid in the system.
Training video on antifreeze liquids for heating systems in private homes
Taking into account the peculiarities of our climatic conditions, in winter the temperature can drop to 20-30, or even 40 degrees Celsius. This means that if the heating does not function and there is water in the system, it will freeze. It would seem, what's wrong with this? The thing is that when it freezes (transitions into the solid phase), water increases in volume by 9%. Therefore, if the liquid freezes in the heating system, there is a high probability that many components will fail: pipes, the boiler itself, taps and other elements.
Antifreeze - as an antifreeze liquid for the heating system
Household antifreeze is a special coolant that is used in various systems, including heating ones. As a result, there are several varieties of such mixtures, which are based on aqueous solutions of different substances: alcohols, salts, propylene glycol, ethylene glycol and others. Special additives are necessarily added to such elements to improve the characteristics of the solutions. And an important property is the low freezing point.Ethylene glycol based antifreezes
In our country, formulations based on an aqueous solution of ethylene glycol are popular. In many ways, this love of consumers for this type of antifreeze is caused by its availability. Indeed, in fact, such a composition is harmful to health, so it is necessary to prevent its contact with the skin, especially in the body. Even the vapors from the mixture are toxic. The lethal dose of ethylene glycol for humans is up to 5 ml per kilogram of body weight. As a rule, such antifreeze is sold in two types, differing in freezing temperature:- -65°С
- -30°С
Composition of antifreeze
Basically, antifreezes include various types of additives necessary to give the solution the necessary qualities. For example:- preventing destruction of system seals;
- dissolution and removal of scale and sediments that accumulate in the system over time;
- corrosion protection of metals that are part of the heating system.
Fill it up and use it?
It would seem that if there is a problem - the risk of water freezing in the heating system - there is no need to hesitate, you need to fill in antifreeze. Indeed, in our conditions, power outages for a long time are commonplace, and without warning. This means that in winter serious problems can arise in private homes. But there is another difficulty. Many manufacturers of heating boilers categorically do not recommend the use of antifreeze in systems in which their devices are involved. A reasonable question arises: why?Reasons why boiler manufacturers refuse to use antifreeze
The manufacturer Proterm (Slovakia) declares that it is not responsible for the consequences caused by the use of antifreeze. Cast iron boilers manufactured by the company are not designed to interact with non-freezing liquids. Vaillant (Germany) is even more categorical, declaring that non-freezing liquids cannot be used in wall-mounted boilers! As for other manufacturers, everything is more confusing here. Some of them inform about the use of special paronite gaskets in the design of boilers, which are suitable for many types of antifreeze. However, the other side of the coin is not advertised: difficulties with seals are not the only problem when using antifreeze.What problems exist when using antifreeze fluid in heating systems?
Problem #1
Since water and antifreeze have different physical characteristics, when designing a heating system, it is necessary to take into account whether one or another liquid will be used. Basic calculations are made, of course, for water. If you plan to use antifreeze, you will need to change some system parameters:- boiler power;
- increase the pressure of the circulation pump by 60%;
- increase the volume of the expansion tank by 50%;
- increase the thermal power of radiators by 50%.
Problem #2
Antifreezes based on ethylene glycol have one feature - they “do not like” system overheating. For example, if at any point in the system the temperature exceeds the critical temperature for a given brand of mixture, ethylene glycol and additives will decompose, resulting in the formation of solid precipitates and acids. When precipitation falls on the heating components of the boiler, carbon deposits appear, which reduces heat transfer, stimulates the appearance of new precipitation, and increases the likelihood of overheating.
The acids formed during the decomposition of ethylene glycol react with the metals of the system, as a result of which the development of corrosion processes is possible. Decomposition of additives can cause a decrease in the protective characteristics of the composition in relation to seals, which can cause leakage at the joints. If the system is zinc coated, the use of antifreeze is not permitted. When overheated, increased foaming occurs, which means that airing of the system is guaranteed. Therefore, in order to eliminate all these phenomena, it is necessary to strictly control the heating process. Since boiler manufacturers do not know the physical properties of the coolants used (except water), they exclude their use.
Problems #3
Antifreezes have increased fluidity. Consequently, an increase in the number of connecting points and elements entails an increase in the likelihood of leaks. Moreover, this problem mainly appears when the system has cooled down, when the heating is turned off. When cooled, the volume of metal compounds decreases, microchannels appear, through which the composition oozes. It is therefore important that all system connections are accessible. Given the toxicity of antifreeze, they cannot be used to heat water in hot water systems. Otherwise, the mixture may get into hot water distribution points, which will pose a danger to residents.
Which coolant to choose?
Nowadays, antifreezes based on environmentally friendly food-grade propylene glycol are gaining popularity, although they are more expensive. This composition is not harmful to humans and can be used in dual-circuit systems. Their hydraulic and thermal characteristics are comparable to those of ethylene glycol mixtures. It is noteworthy that many boiler manufacturers have approved the use of such a coolant. It is also worth saying that both types of antifreeze under different brands are already manufactured in Russia.Is there an alternative to antifreeze?
- Creation of a heating system with electrically independent boilers.
- Use of backup power sources: batteries and electric generators.
Results: water or antifreeze?
First you need to determine how high the probability of a long (more than 24 hours) power outage in a country house is. If such phenomena are unlikely, then you definitely need to fill the heating system with water, supplementing it with a battery uninterruptible power supply. If power outages are not only likely, but also occur regularly, it is recommended to use antifreeze. However, this decision must be correlated with the characteristics of the system elements. Also, before using the mixture, it is recommended to first check whether it precipitates when mixed with water.If this happens, then you should use distilled liquid. As already noted, the use of antifreeze in galvanized systems is prohibited. Also, the composition should not be diluted by more than 50 percent, which reduces the anti-corrosion characteristics of the mixture. You also need to remember about the aging of antifreeze, so it will have to be changed after some time. Typically the period is about five years. Therefore we can draw a conclusion. It is impossible to unequivocally answer the question of whether it is worth pouring antifreeze into the heating system of a house; it is the best coolant. You will have to compare your conditions with those described above, based on which you will make a decision. Finally, we can only note that since the active use of antifreeze in heating, not a single serious accident has been reported. Therefore, statistics suggest that in practice everything may not be so scary.
There is no limit to perfection - this hackneyed expression applies not only to the world of high fashion or luxury cars. It is also quite suitable for more prosaic areas of our lives, for example, for arranging our own home. And in particular to the creation of a heating system. Sometimes, in order to make it absolutely functional and reliable, homeowners introduce innovations, sometimes quite risky. Moreover, this applies not only to innovative technologies and developments, but also to very familiar things. Tell me, which heating system is most common today? Of course, water heating - everything seems clear and simple. But in fact, they are also constantly experimenting with it, for example, changing the heating fluid.
Ordinary water: this is what is filled in most heating pipes for public use, and it is what private homeowners most often use when heating their homes. But this state of affairs has recently begun to change. More and more people prefer alternative coolants, although it is believed that this will entail large financial costs. Antifreeze liquid for heating systems is very expensive! Is it really? To do this, it is worth taking a comprehensive look at the negative and positive aspects of using water as a coolant, as well as a non-freezing liquid.
Attention! Antifreeze heating fluid from different manufacturers may have different component compositions. Thus, on the market you can find “anti-freeze” products based on the following substances: glycerin, propylene glycol, saline solution and bischofite brine.
Benefits of water
Water is a cheap and accessible coolant. Most heating boilers, fittings and other heating elements are designed specifically for water circulation. In addition, in the event of a leak in the heating system, there will be a spill of ordinary water, which is environmentally safe for human health.
Traditionally, water plays the role of coolant in heating systems.
Disadvantages of water
- If frosts come suddenly and the heating system is not running, then this is fraught with rupture of pipes, and sometimes the heating boiler. In this case, the damage will be colossal.
- The constant use of water in the heating pipeline over time leads to the formation of scale, which in turn leads to excessive energy consumption by 25-30%. As a result, home heating costs increase significantly.
- When using water instead of a special heating fluid, scale forms in the pipes over time, which accumulates and leads to excessive energy consumption of up to 30%. This significantly increases the cost of heating a home, given the considerable cost of fuel.
- If we talk about metal pipelines, then the water coolant will sooner or later provoke the manifestation of corrosive processes.
Benefits of antifreeze
- The “anti-freeze” does not need to be drained from the heating system - the functional characteristics of the equipment, components and pipelines will be completely preserved even at extremely low outdoor temperatures.
- Thanks to special additives, this coolant does not foam, does not cause corrosion and scale on the internal shells of heating elements, and does not cause swelling or dissolution of seals.
“Anti-freeze” as an alternative to water coolant
Disadvantages of antifreeze
- Non-freezing heating fluid made on the basis of propylene glycol releases harmful fumes into the air when leaking.
- This coolant is characterized by increased aggressiveness towards pipes, fittings, taps, etc.
- The viscosity of antifreeze is approximately 20% higher than that of water. This entails additional hydraulic loads on the pumps. For this reason, when choosing a circulation pump, it is worth choosing models with a power reserve.
Important! To reduce the load and increase heat transfer, the antifreeze liquid can be diluted with distilled water. Ordinary water contains a high percentage of calcium salts, which provoke the appearance of deposits on the inner walls of pipes, pumps and heat exchangers.
Which antifreeze should you prefer?
The market offer for these specific products is extensive and varied. But there are also obvious “favorites”. The heating fluid “Warm Home” is very popular among consumers. These are Russian-made products. It has been used for heating for many years now and, as they say, it has stood the test of time. Antifreeze does not lose its high performance characteristics for 5 years or 10 heating seasons, as indicated in the manufacturer’s recommendations for use. And this, you see, is the best proof of quality.
"Warm House" - a popular non-freezing liquid for heating
Since the demand for heating antifreeze is constantly increasing, Russian manufacturers are expanding the range of antifreeze products made from environmentally friendly raw materials - food-grade propylene glycol.
Very important! It is unacceptable to pour car antifreeze into the heating system. Its formulation contains additives, the use of which is unacceptable in residential premises.
Why is the question posed this way? Everything is very simple - you can easily familiarize yourself with the specific positive qualities of any brand of antifreeze. Such information is actively distributed by manufacturers. For our part, we want to present those features of this technical fluid that they are trying to keep silent about:
- Antifreeze cannot be used in double-circuit boilers - it is possible to mix coolant from the heating circuit into the water supply circuit. As is known, non-freezing liquid is poisonous due to its physical and chemical properties.
- It also cannot be used in open systems - evaporation of the coolant is possible.
- It is unacceptable to use antifreeze in a system with a galvanized pipeline - it is fraught with chemical changes and loss of its original properties.
- The heat capacity of non-freezing liquid is lower than that of water, which means that radiator batteries of higher power will be required.
- The viscosity of antifreeze is also higher - more powerful circulation pumps are needed.
The container for antifreeze must be of sufficient volume and correctly calculated according to the project
Of course, in this case, as in many others, the final choice remains with the consumer. It is impossible to say unequivocally what is good and what is bad about water or non-freezing liquid. It all depends on the specific heating parameters, but before making a final decision regarding the choice of the type of coolant, it is better to consult with a specialist.
It is almost impossible to survive in winter without heating in our country, so a lot of time, effort and money are devoted to its installation. The most common type of heating in our country is water (liquid) heating. Its component is the coolant. How to choose a coolant for a heating system and how to pump it in is in the article.
What is a coolant and what should it be like?
The coolant in a liquid heating system is the substance through which heat is transferred from the boiler to the radiators. Our systems use water or special antifreeze liquids as a coolant. When choosing, you must be guided by several criteria:
Taking into account these requirements, the most suitable liquid for the heating system is water. It is safe, harmless, has a high heat capacity, and its service life is unlimited. But in those heating systems where there is a high probability of downtime in winter, water can do a poor job. If it freezes, it will burst pipes and/or radiators. That’s why antifreeze is used in such systems. At subzero temperatures they lose fluidity, but the equipment does not tear. So choosing a coolant for a heating system from this point of view is easy: if the system is always under supervision and in working order, you can use water. If the house is temporary residence (dacha) or can be left unattended for a long time (business trips, winter vacation), if frequent and/or long-term power outages are possible in the region, it is better to pour antifreeze into the system.
Features of using water as a coolant
From the point of view of heat transfer efficiency, water is an ideal coolant. It has a very high heat capacity and fluidity, which allows it to deliver heat to the radiators in the required volume. What kind of water should I fill? If so, you can fill the water directly from the tap.
Yes, tap water is not ideal in composition; it contains salts and a certain amount of mechanical impurities. And yes, they will settle on the elements of the heating system. But this will happen once: in a closed system, the coolant circulates for years, and replenishment with a small amount is very rarely required. Therefore, some amount of sediment will not cause any tangible harm.
If the heating is of an open type, the requirements for the quality of water as a coolant are much higher. Here, gradual evaporation of water occurs, which is periodically replenished by adding water. Thus, it turns out that the concentration of salts in the liquid increases all the time. This means that sediment also accumulates on the elements. That is why purified or distilled water is poured into open-type heating systems (with an open expansion tank in the attic).
In this case, it is better to use distillate, but getting it in the required volume can be problematic and expensive. Then you can fill in purified water that has been passed through filters. The most critical is the presence of large amounts of iron and hardness salts. Mechanical impurities are also useless, but they are the easiest thing to deal with - several mesh filters with cells of different sizes will help catch most of them.
In order not to buy purified water or distillate, you can prepare it yourself. First, pour and let sit until most of the iron settles. Carefully pour the settled water into a large container and boil (do not cover with a lid). This removes hardness salts (potassium and magnesium). In principle, such water is already well prepared and can be poured into the system. And then top up with either distilled water or purified drinking water. This is no longer as expensive as the initial fill.
Antifreeze for heating
In addition to water, special non-freezing liquids - antifreeze - are poured into heating systems. Usually these are aqueous solutions of polyhydric alcohols. Not so long ago, glycerin-based antifreeze appeared on our market. So now there are three types of non-freezing liquids for heating systems.
Types of non-freezing liquids and their properties
Antifreezes are based on two substances: ethylene glycol and propylene glycol. The first is cheaper, freezes at lower temperatures, but is very toxic. You can get poisoned not only by drinking, but even by simply getting your hands wet or inhaling fumes. The second non-freezing coolant for the heating system is based on propylene glycol. It is more expensive, but safe. Sometimes it is even used as a dietary supplement. Its disadvantage (besides the price) is that it loses fluidity at higher temperatures than propylene glycol.
Despite their high toxicity, ethylene glycol coolants are more often purchased. This is most likely due to the price - propylene glycol is twice as expensive. But ethylene glycol antifreeze in its pure form is also chemically active, can foam, and has increased fluidity. Foam and activity are combated with additives, and increased fluidity is not corrected in any way. Paired with toxicity, it is a dangerous combination. If there is the slightest possibility somewhere, this antifreeze will leak. And since its vapors are poisonous, this will not lead to anything good. Therefore, if possible, use propylene glycol.
| Name | Substance | Weight | Operating temperature range | Beginning of crystallization | Thermal decomposition temperature | Life time | Possibility of dilution with water | Price |
|---|---|---|---|---|---|---|---|---|
| Dixis (Dixis) 65 | monoethylene glycol | 10 kg | -65°С ~ +95°С | -66°С | + 111°C | 10 years | Yes | 850 rub. |
| Warm House - Eco | propylene glycol | 10 kg | -30°С to +106°С | -30°C | +170°С | 5 years | Yes | 1050 rub. |
| Dixis TOP (Dixis TOP) -30 | propylene glycol | 10 kg | -30°С to +100°С | - 31°C | +106°С | 3 years | Yes | 960 rub. |
| ANTIFROST based on glycerin | glycerol | 10 kg | -30°С to +105°С | 4 years | No | 700 rub | ||
| PRIMOCLIMA ANTIFROST based on propylene glycol | propylene glycol | 10 kg | -30°С to +106°С | -30°C | +120°С | 5 years | Yes | 762 RUR |
| TERMAGENT 30 | ethylene glycol | 10 kg | -20°С to +90°С | -30°C | +170°С | 10 years | No | 650 rub. |
| Teplokom (glycerin) | glycerol | 10 kg | – 30°С to +105°С | 8 years | No | 780 rub. |
Another important drawback is that ethylene glycol reacts very poorly to overheating, and overheating occurs at a fairly low temperature. Already at +70°C, a large amount of sediment is formed, which settles on the elements of the heating system. Deposits reduce heat transfer, which again leads to overheating. In this regard, such antifreezes are not used in systems with solid fuel boilers.
Propylene glycol, on the contrary, is chemically almost neutral. It reacts less than other coolants with other substances; overheating occurs at higher temperatures and does not lead to the same consequences.
Propylene glycol coolant is safe, but costs more and freezes at higher temperatures
At the end of the last century, antifreeze for heating systems based on glycerin was developed. It is a cross between ethylene and propylene coolants. It is safe for humans, but does not have a very good effect on gaskets, and also reacts poorly to overheating. In terms of price and temperature characteristics, it is approximately in the same range as propylene coolants (see table).
Features of systems with antifreeze as a coolant
When designing a heating system, the coolant must initially be taken into account. This is due to the lower heat capacity of non-freezing liquids, as well as their other properties. If all the equipment was designed for water, and antifreeze is poured into it, the following problems may arise:
As you understand, the best coolant for a heating system is water. It has better characteristics and is several times cheaper. If the heating is in danger of defrosting, you have to fill in antifreeze, but not for automobiles, but special ones for heating. In this case, if you have enough funds, it is better to use propylene glycol. Ethylene antifreezes are a last resort. They are suitable in closed systems, in which special gaskets and automated boilers are installed that will prevent overheating.
To make it easier for customers to navigate, dyes are added to coolants. Ethylene ones are red or pink, propylene ones are green, glycerin ones are blue. After some time, the color may become less intense or disappear completely. This occurs due to thermal destruction of dyes, but does not affect the properties of the antifreeze itself.
How to pump coolant
Problems usually arise only with closed systems, since open ones are filled through an expansion tank. The coolant for the heating system is simply poured into it. It spreads throughout the system under the influence of gravity. It is important that all air vents are open when filling the system.
There are several ways to charge a closed heating system with coolant. There is a way to fill without the use of technology - by gravity, there is with or a special one with which they do it.
Fill by gravity
Although this method of pumping coolant for a heating system does not require equipment, it takes a lot of time. You have to squeeze out the air for a long time and also gain the required pressure for a long time. By the way, we pump it up with a car pump. So you will still need equipment.
Finding the highest point. Usually this is one of the gas vents (we remove it). When filling, open the valve to drain the coolant (lowest point). When water runs through it, the system is full.
With this method, you can connect a hose from the water supply, you can pour prepared water into a barrel, raise it above the entry point and then pour it into the system. Antifreeze is also added, but when working with ethylene glycol you will need a respirator, protective rubber gloves and clothing. If the substance gets on fabric or other material, it also becomes toxic and must be destroyed.
When the system is full (water runs out of the drain tap), take a rubber hose about 1.5 meters long and attach it to the entrance to the system. We select the entrance so that the pressure gauge is visible. At this point we install a check valve and a ball valve. To the free end of the hose we attach an easily removable adapter for connecting a car pump. Having removed the adapter, pour coolant into the hose (keep it raised up). After filling the hose, use an adapter to connect the pump, open the ball valve and pump liquid into the system. You need to make sure that air is not pumped in. When almost all the water contained in the hose has been pumped in, the tap is closed and the operation is repeated. On small systems, to get 1.5 Bar, you will have to repeat it 5-7 times, with larger ones you will have to tinker longer.
Fill using a submersible pump
To create working pressure, the coolant for the heating system can be pumped with a low-power submersible pump like Malysh. We connect it to the lowest point (not the system drain point). We connect the pump through a ball valve and a check valve, and install a ball valve at the drain point of the system.
We pour the coolant into the container, lower the pump, and turn it on. During operation, we constantly add coolant - the pump should not drive air.
We monitor the pressure gauge during this process. As soon as its needle moves from the zero mark, the system is full. Until this point, manual air vents on radiators can be opened and air will escape through them. As soon as the system is full, they must be closed.
Next, we begin to increase the pressure - we continue to pump the coolant for the heating system with the pump. When it reaches the required level, we stop the pump and close the ball valve. We open all the air vents (on the radiators too). The air comes out, the pressure drops. We turn on the pump again, pump up a little coolant until the pressure reaches the design value. We release the air again. We repeat this until air stops coming out of their air vents.
We use a pump for crimping
The system is filled in the same way as in the case described above. In this case, a special pump is used. It is usually manual, with a container into which the coolant for the heating system is poured. From this container, liquid is pumped through a hose into the system. You can rent it from companies that sell water pipes. In principle, it makes sense to buy it - if you use antifreeze, you will have to change it periodically, that is, you will need to fill the system again.
This is a manual pump for pressure testing, with which you can pump coolant for the heating system
When the system is filled, the lever moves more or less easily, but when the pressure rises, it becomes more difficult to work. There is a pressure gauge both on the pump and in the system. You can follow where it is more convenient. Next, the sequence is the same as described above: pump up to the required pressure, deflate the air, repeat again. Do this until there is no air left in the system. After that, we also start the circulation system for about five minutes (or the entire system, if the pump is in the boiler), and bleed the air. We also repeat several times.
Double-circuit boiler equipment, solar systems and heat pumps appeared, and plastic pipes, taps and connections began to be used as materials. Installation of the system has become simpler, more convenient and more accessible for “non-professionals”; it is easier to configure and repair. The usual solution has been the use of “warm floors” based on circulation pipelines.
All these innovations led to the development of another technical solution: the use of non-freezing fluids - coolants in individual heating systems of private houses.
The use of coolants raises many questions, speculations and disputes. Some stereotypes have already formed a practice of application, which sometimes looks comical. Therefore, in this article, specialists from the Heat Transfer Fluids department will answer the most common questions.
1. To use or not to use antifreeze liquid as a coolant?
There is no GOST or standard that requires the mandatory use of a coolant or prohibits its use. Sometimes there are designs for industrial systems that require the use of “water-glycol solutions,” and if you turn to heating equipment manufacturers, they also do not have a single general solution - some prohibit them altogether, while others allow the use of certain brands of coolants. Which decision is correct?
The answer to this question can be obtained by taking into account a combination of many factors: this is the equipment model, the type of structure, the mode of its use, the material and insulation of the walls, the type of system, and the region of location. But the most important factor is the degree of security of the system in unforeseen, emergency cases.
eddiki
I made my own heating system for the first time in my life using metal-plastic, there are no leaks in the fittings. The argument in favor of antifreeze was given by the specialist who started my boiler - antifreeze has its drawbacks, but the main thing is to preserve the system in any force majeure. According to him, last winter a lot of COs died on the water for various reasons. I have propylene glycol, -20, the system works, and I sleep peacefully when I’m not at the dacha.
It's no secret that the main task of the coolant is to protect the system from defrosting and damage in case of unforeseen situations. And there are quite a lot of situations when a house can be left without heating for a long time:
- long-term departure of the whole family, when there is no one to heat the house;
- seasonal use of a summer house or house;
- Finally, no one is immune from gas pipeline accidents or long-term power outages, which have become common in winter after freezing rains that cut power lines.
In such conditions, the use of non-freezing liquid is an absolutely justified solution.
2. Which one to choose, how do they differ?
Serg3515
A lot has been written and rewritten on this topic, but I have never seen a clear answer (and preferably from a user with experience). In this regard, if I may ask some questions. So, after all, what to fill in? (what kind of non-freezing liquid). Electric boiler, two-pipe system, metal-plastic pipes.
For an uninitiated person, understanding the abundance of offers and the price range can be very difficult.
The key factor in choosing a coolant is its basis, i.e. basic chemical raw materials. The following are traditionally used as a basis:
- ethylene glycol is a toxic dihydric alcohol;
- propylene glycol is a non-toxic substance acceptable for use in the food industry.
The second selection criterion is the additives used in the coolant. There are organic additives (carboxylate) and inorganic. Additives affect the service life and quality of the coolant. Coolant with organic additives has a longer service life and, during operation, more reliably protects the system from corrosion.
The third indicator is how heating equipment manufacturers treat this product; in other words, whether a particular coolant is acceptable for use in the system where this type of equipment is used.
- from equipment manufacturers. This coolant provides the widest range of indicators: environmental friendliness and safety, service life, physical and chemical properties, and versatility of use, from kindergarten to food production.
- Coolant based on ethylene glycol with organic additives and approvals from equipment manufacturers. Such a coolant already has limitations in its use. You can determine its purpose: industrial facilities and systems that are reliably isolated from human activity.
- Coolant based on propylene glycol with conventional inorganic additives. Although such a product has a shorter service life, it is harmless enough to be around people and animals.
- Coolant based on ethylene glycol with inorganic additives. Poisonous, short service life. Its use is often driven by the need to save money. If the system is well isolated from contact with human life, such a solution is quite logical.
P.S. Glycerin based coolant. Glycerin is the simplest trihydric alcohol, which is a viscous transparent liquid, also used as a food additive. The product has high density, kinematic and dynamic viscosity. Equipment manufacturers provide indicators several times lower than those present in glycerin-based coolant. The product has no operational or physical advantages, although it is quite easy to produce, which is why it is inexpensive. European manufacturers of chemical compounds have a very negative attitude towards the use of glycerin as a base for antifreeze liquids.
3. How to find out the required quantity?
A common but simple question. After completing the installation of the system, it is necessary to carry out commissioning work. The regulations provide for the need for a control check - water pressure testing of the system. After pressure testing, the water obtained from the system will indicate the exact amount of coolant required for the system.
4. Should I dilute with water or not?
The origin of this issue is due to the fact that equipment manufacturers set the same requirements, worrying about the safest and most efficient operation possible. Buyers stick to their line, driven by the need to save money. And coolant manufacturers maneuver between the requirements of manufacturers, buyers and sales practices. As always, the truth is somewhere in the middle.
Manufacturers of antifreeze liquids mainly offer “-65C” or “-30C” coolants to the market. Firstly, this is due to established demand, and secondly, such a coolant is guaranteed not to be frozen at the time of sale.
Equipment manufacturers have their own truth. Thus, the density of non-freezing liquid marked “-25C”, mainly recommended by equipment manufacturers for reasons of optimal fluidity, is 1.03 g/cm3, and that of liquid “-30C” is 1.04 g/cm3.
On the other hand, diluting the coolant from “-30C” to “-25C” - and this value is 3-4% - will not bring tangible savings to the buyer, but will increase the risk of losing other necessary properties. But in the case when the buyer plans to use concentrated coolant “-65C” and dilute it, the savings can already be up to 20%.
5. How do coolants interact with aluminum and steel radiators, polypropylene taps and pipes?
If we are not dealing with “garage production”, and the manufacturer complies with the requirements and test methods in accordance with GOST 28084, there is nothing to worry about, because to neutralize the aggressive factors of non-freezing liquids, they contain additives. If organic (carboxylate) additives are used in the coolant, this is an additional plus. The main thing is the level of trust in the manufacturer, because the consumer will not be able to independently check the indicators at home, and in a laboratory, these tests are quite expensive.
6. What is the service life, how do you know: when to replace?
The question is quite common.
Andreic
Experts, clarify the situation: today contractors said that antifreeze has a validity period of 5-7 years. Then it loses its properties, begins to precipitate, and generally does not flow through the heating system as it should. True or not?
For coolants that contain organic (carboxylate) additives, the service life is 10 seasons (10 years), for coolants with “ordinary” silicate additives, this period is about 5 years (heating seasons). In order to control quality, every year, after the end of the heating season, you can carry out a simple procedure - pour a small amount of coolant into a transparent glass container. The resulting sample is visually inspected for the presence of mechanical and other impurities, color, and transparency. If the coolant contains mechanical impurities (crumbs, grains of scale), it can be drained, filtered, flushed the system and refilled. If there are traces of chemical changes (flakes, clots), you need to contact a specialist.
7. In what systems can antifreeze liquid be used?
There are a number of restrictions on the use of antifreeze:
- Antifreeze liquid, regardless of its chemical composition, can only be used in a closed circuit. This means that there is constant pressure in the system, circulation is constantly forced, due to the pump.
- Coolants are not used with electrolysis-type electric boilers. Electrolysis type is when the coolant is used as an electrical conductor. The electrical conductivity of coolants is low, and this will lead to high energy costs.
- Antifreeze liquids must not be used in contact with galvanized surfaces (pipes).
8. How to determine the required temperature, or is -30C too much or too little?
Application practice shows that the temperature in a room that has not been heated for a long time and the ambient temperature are always different. The room will always be warmer - by 10 degrees or more. Even if it’s minus 40 outside the window, and the room is frozen to minus 30, the coolant will not turn into ice and, accordingly, will not burst pipes and radiators. In order for antifreeze labeled -30C to freeze and damage the heating system, the temperature (in the house) must be below -50C, which in reality is quite difficult to imagine.
Rash98
For three seasons I have been using propylene glycol as antifreeze in a natural circulation system. Everything works perfectly. The batteries heat up after just 10 minutes. I use propylene glycol not concentrated, but diluted to the freezing point of minus 30 degrees. S. Flooded once three years ago.
On the other hand, non-freezing liquids with temperatures of minus 10, 15 and even 20C should not be used for a number of reasons:
- Even in the central regions of Russia in winter the temperature drops below these values. In such conditions, it is unlikely that anyone will want to buy a product that has turned into “snow porridge”, despite the fact that after thawing it will completely return to its properties.
Indeed, more fluid than water. And fluidity increases with increasing temperature. They do not contain chemical compounds that, by forming calcium deposits, can clog microgaps. Even if the microgaps become clogged with something, coolant additives will “clean” the clogged formations and restore the leak. Therefore, more attention must be paid to the assembly of joints in a system where it is planned to use antifreeze. And, as mentioned earlier, before starting it is necessary to carry out commissioning work, including pressure testing of the system.