Why do water heaters use water? Radiator heating system. Two-pipe heating system

Hello dear Reader!

I want to tell you about what heating systems I had to deal with.

Some he exploited, some he assembled himself, including heating systems for private houses.

I learned a lot about their pros and cons, although, probably, not everything. As a result, for my house I did:

first, own scheme;
secondly, it is quite reliable;
thirdly, allowing modernization.

I suggest not to delve into a detailed study of various heating schemes.

Let's look at them from the point of view of application in a private house.

After all, a private house can be for permanent residence, and temporary, like a dacha, for example.

So to speak, let's narrow our topic and get closer to practice.

About ten years, maybe I was wrong. I started servicing the first heating system 33 years ago, when I was a student at the Ural Polytechnic Institute. I was lucky to get a job in the institute's boiler room as a mechanic on duty. True, at that time I didn’t even think about what kind of system it was? Worked and everything.

The work was sometimes difficult when there was an accident. And if everything is fine - beauty, sit yourself and learn notes. Night on duty, in the morning to study, "to school", as we then said. Back on duty two nights later. And most importantly, they paid 110 - 120 rubles! At that time, young professionals received the same amount. Yes, plus a scholarship of 40 rubles. Gorgeous life! But, let's get closer to the heat.

From the name itself it is clear that heating occurs with heated air. The air is heated by a heat generator, and then it enters the premises through ducts. The cooled air is returned through the return channels for heating. Pretty comfortable system.

The first heat generator in history was a furnace. She heated the air, which diverged through the channels in the order of natural circulation. Such an air heating system was used in the past centuries in advanced city houses.

Now they use a variety of heat generators-boilers: gas, solid fuel, diesel, electric. In addition to natural circulation, forced circulation is also used. It is, of course, more efficient:

Firstly, it warms up the premises much faster;
Secondly, it has a higher efficiency, since heat is removed from the heat generator much more efficiently;
Thirdly, it can be combined with the air conditioning system.

You probably already understood that here it doesn’t “smell” like a private house. Yes, that's right, for a private house this heating scheme is too cumbersome and expensive. Some calculations are worth something, and if you make a mistake, then it will be, as they say, fatal.

But let's not get upset. If you still want to be heated by air, there is a way out. This is a fireplace.

Moreover, in my opinion, not an ordinary firewood-eater fireplace, but a cast-iron fireplace insert shown in the figure above. This is an ideal option for a homely cozy wood-burning heat generator. It is designed specifically for heating air, and not bricks, like a traditional fireplace.

The air enters the space under the fireplace (where the firewood lies for the entourage), flows around its heated body. Then it flows around the red-hot chimney along the fireplace box and exits through the holes in the upper part of the box. By the way, air ducts can be connected to these holes and hot air can be distributed throughout the premises.

Quite a worthy option, only if done with air ducts, then during construction you need to remember to put them in walls and ceilings. Someone also puts a blower, creating forced ventilation. But this, in my opinion, is overkill. By the fireplace, it is nice to hear the crackling of firewood, rather than the noise of a fan.

I think it is worth mentioning more fan heaters and heat guns. These are, so to speak, mobile air heating units. Very useful devices, especially when the main heating system is not working or you need to quickly “warm up” the air in the room. But, in my opinion, they cannot be considered as the main heating option.

So, a fireplace insert, as a source of air heating, is a good, and, moreover, a pleasant solution for a private house.

Water heating at home

In this case, the coolant is water or special liquids, for example, non-freezing. Here, the heat sources are also very different depending on the fuel. But if there is warm air in the air system comes into the room, then into the water air of the room heated by appliances who give him heat stored in water.

And the water stores a lot of heat. There is such a thing: "heat capacity", remember? If in your own words

The heat capacity of water is the amount of heat that must be transferred to water in order for its temperature to rise by one degree.

So this indicator near the water is very good. Look at the table on the right.

It turns out that we get a chic coolant almost for nothing.

Yes, the water system is somewhat more complicated, but it is also more flexible.

Imagine that heated water can be supplied through pipes anywhere and there it will give off the accumulated heat.

And the pipes can be easily hidden in the walls, or you can not hide them at all, modern ones look very aesthetically pleasing.

How does water give off heat? For this, several types of devices have been created:

Radiators - massive, for example cast iron, sections assembled into batteries.

Hot water flows inside them. They give off thermal energy mainly due to infrared radiation (radiation).

They are usually steel or aluminum, less often copper. The surrounding air, being heated by the convector, begins its natural upward movement. That is, a flow (convection) of air is created, which removes heat from the convector.

Modern aluminum appliances also belong to convectors, although they are called radiators. It should be noted that now almost all thermal devices for water heating are called radiators, although strictly speaking, this is wrong. But let's not be smart.

Air is pumped through them to be heated. They are often used in supply ventilation systems to heat cold air entering from outside.

"Warm walls" - were used in the seventies in panel housing construction. A serpentine from a steel pipe was embedded in the concrete panels, into which water was supplied from the heating system. I remember from childhood the warm walls of panel five-story buildings.

The water system can be successfully used in a private house. If this is a dacha, you can fill in a non-freezing coolant instead of water and not worry about defrosting the system.

Let's take a closer look at the options for heating systems for low-rise buildings.

Scheme of a gravity heating system

Why self-flowing? Because the water in it actually flows by itself. When heated in the boiler, the water rises, and then, gradually cooling in the radiators, flows down and returns to the boiler again. The system is simple, but the prerequisites must be observed:

The pipe should be of a fairly large diameter from 50 mm, and preferably 76 mm or more.
The pipe is laid with a slope to ensure the gravity flow of water.

Sometimes this same pipe heats the room without radiators and convectors due to its large mass and surface. Such pipes are called registers, they can be found at railway stations and bus stations of old small towns. It is now rarely used in private homes - it does not look very aesthetically pleasing. Imagine - there is a thick pipe in the room, and even an inclined one.

A very big advantage of this system is that it does not need a circulation pump, the water circulates itself. If the boiler is wood, coal or gas - no power outages are terrible, complete autonomy and independence. I'm talking about this because I myself have trouble with power outages.

A feature of a gravity-flow system, which is considered a disadvantage, is that it is open, that is, it communicates with air and there is no pressure in it. This means that an open expansion tank is needed and the water gradually evaporates, you need to monitor this. Of course, this is not a very serious drawback. I'm more repulsed by high sloping pipes.

For a private house, a closed heating system, in my opinion, is the best option. It's better to say closed. Closed means not in contact with air. Here are the new elements:

Membrane expansion tank to compensate for the expansion of water when heated;
Circulation pump for pumping water through the system;
Safety group - make-up valve (for adding water to the system in case of leakage), pressure gauge, safety valve (for releasing steam when water boils).

This is a more modern, aesthetic option. Radiators are used here, and more often aluminum convectors, thin metal-plastic or polypropylene pipes. There is no need to add water, think about the slope of the pipes, they can generally be hidden in walls or ceilings.

You can put beautiful aluminum or bimetallic radiators, a heated towel rail. I use two boilers in one system - an electric boiler and a water circuit for a fireplace insert. Like it worked out well.

The minus of the system is that it cannot work without electricity for the circulation pump. Moreover, if the firebox is “under steam” and the electricity is over, it can turn out to be a “boomsik” with the release of steam and a lot of noise. I know for myself. It looks like the pipes are being pounded with a hammer.

Therefore, the pump was connected to an uninterruptible source (like a computer) so that there was time to safely cool the firebox. And the outlet of the safety valve is in the sewer.

Two-pipe heating system

There are two options for connecting radiators to the heating system:

The only plus of a single-pipe system is savings on pipes. But the minus is significant - the radiator closest to the boiler is the hottest, and the farthest is the coldest. And it’s also problematic to turn off some kind of radiator - they are all in the same circuit. If this is not critical, why not use this option? It's a perfectly normal pattern.

The two-pipe scheme is more flexible:

All radiators are almost equal. Water is supplied to each at the same temperature;
You can set your own temperature on each radiator by regulating the flow of water through it;
You can painlessly shut off the water supply to any radiator, for example, when it's hot or you need to flush the radiator;
More convenient for increasing the number of radiators.

Thus, in my opinion, a two-pipe scheme is more preferable.

For the sake of justice, it must be said that in the two-pipe version, the last radiator is somewhat “offended”, it gets less heat. The reason is that on it the pressure difference between supply and return is almost zero and the water flow is minimal.

So what choice did I make?

I installed an air-to-water heating system in my house. The fireplace is responsible for the air. The closed two-pipe water circuit includes an electric boiler, a fireplace insert water circuit and 40 aluminum radiator sections (6 radiators). 64 square meters of the first floor are heated in excess in any frost.

That's all for today. In the following articles I will bring to your attention a gas heating system, underfloor heating, infrared heating. Comment, ask questions. Thanks, see you!

When installing the system, it is very important to decide which water heating radiators are best used. Consider the characteristic features of each type.

Cast iron radiators

Cast iron batteries are the most traditional type of battery and have been in use for decades.

Today, cast iron water heating radiators are often produced in a modern aesthetic design with flat facades. These are inexpensive, strong and durable batteries that can last 50 years or more.

The disadvantage of cast iron radiators is not the highest level of heat transfer. The large thermal inertia causes the batteries to heat up for a long time after the system is started. They also have a significant internal volume, which makes them inefficient when used in individual heating systems. In addition, cast iron radiators are heavy and quite bulky.

They are not designed for high working pressure. The brittleness of cast iron makes radiators weakly resistant to water hammer.

Ogint cast iron radiators are an excellent example of how, with the help of modern developments, technologies can be improved, the quality and effectiveness of which have been proven over the years.

Cast iron radiators from Ogint have an attractive modern design and durability. Cast iron batteries have all the necessary certificates of conformity, and their reliability is confirmed by a 2-year warranty from the manufacturer.

Catalog of Ogint cast iron radiators:

Steel radiators

This is another traditional type of battery. In this category, two types of water heating radiators can be produced - panel and tubular. In the Russian market, panel ones are the most common. They consist of two stamped steel sheets welded together. The complex relief of the sheets forms channels inside the radiator through which the coolant moves.

Steel radiators are characterized by good heat dissipation, aesthetic design and a wide variety of dimensions. Their light weight makes them easy to mount on various surfaces. However, steel radiators do not withstand high operating pressure and are extremely sensitive to water hammer, so their use is only allowed in individual heating systems.

Aluminum radiators

This type of heater is also intended only for individual systems, since it cannot withstand high pressure, can become clogged with dirty coolant and corrode if the water has a pH level above 8.

These radiators have maximum heat output due to the high thermal conductivity of aluminum. They also have minimal thermal inertia and heat up almost immediately after starting the system. Their design allows for intense convection and radiant heat transfer, which significantly improves heating efficiency.

Due to the small internal volume, they have a high efficiency, and the operation of boiler equipment is carried out in a gentle mode. In addition, this allows efficient use of temperature controllers.

Aluminum is a very light metal, which explains the low weight of the batteries. Due to this, aluminum water heating radiators are quickly and easily mounted without any serious requirements for the strength of the base.

Ogint aluminum radiators undergo multi-stage quality control according to the OGINT Protect system in full compliance with the ISO 9002 standard, and a 5-year warranty is provided.

Catalog of Ogint aluminum radiators:

Bimetal radiators

Another modern type are bimetallic water heating radiators. They are made up of two metals.

The coolant moves through durable steel pipes, which are placed in an aluminum case with fins. This design allows you to maximize the benefits of aluminum radiators in centralized heating systems.

Batteries of this type are characterized by maximum strength and are able to withstand significant operating pressure, and also resist water hammer well. At the same time, the aluminum housing provides high heat dissipation.

Bimetal are beautiful and reliable radiators that have a small internal volume and minimal thermal inertia, which allows the use of devices for manual or automatic adjustment of each battery.

All our radiators have all the necessary certificates and meet high quality requirements. They are perfectly adapted to Russian conditions, providing efficient heating and a long service life.

Turning to our company, you order excellent radiators from the direct manufacturer. This means that the price of supplies will be as profitable as possible. Take this opportunity and contact us through the contact form on the website or by phone.

A radiator heating system is the most common version of a building heating device. The principle of operation is the flow of heated liquid (usually water) from the boiler through pipes to radiators, which transfer heat to the room. Such heating can be of different types depending on certain parameters.

Classification by type of radiators

Radiators used in heating systems may differ from each other in design and material of manufacture.

Sectional

Such batteries consist of the same sections. The radiator is assembled in accordance with the required dimensions and power.

They can be made of cast iron, aluminum or aluminum and steel (bimetal).

Tubular

Closed system

Its main difference is the presence of a closed tank, resembling a capsule in shape. It is divided into two parts by a membrane partition: in one half there is water, and in the other - nitrogen under pressure. Principle of operation: the liquid is heated to the desired temperature, moves to the expansion tank and equalizes the pressure. The water moves back with a pump.

Such a system is capable of heating large areas, it is able to provide heat to a building of any number of storeys. Therefore, it has been widely used in private and industrial scales.

Has a number of advantages:

Thanks to the tank, the liquid does not evaporate, there is no need to monitor the water level.
The equipment is not subject to corrosive deposits and oxidation.
Due to the adjustment, the pressure at the outlet and inlet is the same, so the pipes are not subjected to water hammer.
Long service life.
High efficiency due to fast heating and good heat dissipation.

As a heat carrier, most centralized and autonomous heating systems hot water is used for residential and non-residential premises.

This type of battery filling effective and time tested. Therefore, water heating radiators are the most popular in the thematic market.

Varieties of water heating radiators

When choosing, the buyer pays attention to the appearance of the product. However, the priority is material, structure and type of battery mounting.

These indicators affect favorable performance. It is important that the appliance is suitable for the heated area.

Water radiators come in several types.

Panel with adjustment by cranes

One-piece batteries that are ready to mount and use - no additional mounts or heatsink kits needed. Often made from become. Panel-type radiators are widely used in heating networks with an independent circuit. Interacts with the automatic temperature control system.

Advantages of panel radiators:

At leakage change the entire device at once, and not a single element.
Low resistance to corrosion. If the operating conditions are not observed (presence of air, annual water discharges, unregulated pH), the panel radiator will quickly fail.
Should not be allowed water hammer. To do this, a pressure reducer is installed at the inlet.
A strong blow disables the device and it will have to be change.

Sectional

The design consists of interconnected sections. Manufactured under pressure by casting, connected by threaded elements or spot welding. The material is usually cast iron or steel. Type feature - large thermal inertia. Sectional batteries made of steel are more expensive than cast iron because of the production technology. Used in central heating systems.

Advantages of sectional radiators:

Ease of use- if one section is damaged, it is enough to replace only it. No need for replacement the entire device. You can also add additional sections.
The term of use is on average 30 years.

Over time, the system accumulates sediment- due to the slow movement of the coolant. Therefore, radiators are washed periodically.
Can't change quickly heating temperature due to high heat capacity.
Availability connections between sections increases the unreliability of the system.

Tubular

By design, these are welded tubular devices. Issued with the calculation pressure of 10-15 atmospheres. Made from steel. It is preferable to install in buildings with an independent heating system, since central heating sometimes provokes pressure drops, which leads to depressurization of the joints.

Important! Battery efficiency depends on the number of handsets Optimum — 6.

Advantages of tubular radiators:

Small steel thickness (maximum 1 mm).
low heat transfer.
High price through a complex manufacturing process.

lamellar

The battery system consists of U-tube through which water moves. Heat transfer plates are strung on the tube. A common material is steel.

They are used in residential and public buildings, industrial facilities.

Advantages of plate radiators:

Unattractive appearance.
The probability that the ribs on the battery will become clogged dust and adversely affect the heating temperature.

Battery selection by material

It is the material that plays a primary role in the efficiency of heat transfer. After all, each material has its own heat transfer level.

There are the following materials:

Cast iron

Used for over 100 years, recognized as durable and reliable. Suitable for the central heating system of multi-storey buildings. Power of one section - 90-160 W.

Appearance is not very presentable. Cast iron radiators are bulky and heavy. For better heat dissipation, batteries are advised to be painted in a dark color.

Cast iron withstand water hammer, pressure drops, low quality of the coolant.
Doesn't rust or break corrosion.
Affordable price compared to other materials.
Life time - over 40-45 years old.

Low heat dissipation.
High inertia, which does not allow the use of cast iron in modern thermoregulation systems.
Absence heat savings- due to the high thermal inertia and the inability to use thermostatic regulators.
The need to constantly repaint battery to maintain an aesthetic appearance.
Maintenance difficulties due to large mass.
The inner walls of cast-iron channels in batteries rough, which eventually leads to the formation of plaque, and as a result, a drop in heat transfer.

Aluminum

The material has a minimum thermal inertia (i.e., it reacts to temperature changes in the coolant in a short period of time), which allows it to be used in combination with a thermostat. Aluminum has good heat dissipation without the need for bulky batteries. Thermal power - 190 W per section.

Aluminum is a light, malleable and soft material, so stylish heating batteries are made from it. Often produce sections white colors to match any interior.

Photo 1. Aluminum water heating radiator Eco 500/800 mm, weight 6.18 kg, manufacturer - Lammin, Finland.

Good Ratio cost and quality.
Method of heating aluminum material - convection, in which dust does not accumulate between the sections.
Resistant to corrosion so aluminum batteries do not need to be repainted.
Allows save heat, as it works in combination with a thermostat.
Ideal for heating in private houses.
High operating pressure - up to 17 atm.

Low quality coolant degrades aluminium.
Can't stand water hammer.
Not suitable for apartment buildings.

Steel

Heating structures made of steel are preferably used in rooms with autonomous heating due to the technical features of the material. Produce panel and tubular batteries.

Second type more resistant to sudden pressure drops in the network.

Such designs are quite presentable and concise. Heat power for one section - 450-5600 W.

If properly maintained, the radiator will last at least 20 years old.
Steel has good heat dissipation.
economy- due to the small volume of coolant in the device and its high thermal conductivity.

Requires constancy in the pressure of the coolant due to open steel seams.
Water as a heat carrier should be exclusively purified.
Doesn't tolerate water hammer.

Bimetallic

They combined the high thermal performance of aluminum and the durability of steel. Outwardly, they are similar to monolithic aluminum convectors, but they are much stronger than brittle aluminum. Sometimes bimetallic convectors are made in the form of separate sections - from 4 to 14 pieces. Thermal power one section - 200 watts.

Photo 2. Bimetallic water radiator model Base 350, power 1632 W, manufacturer - "Rifar", Russia.

The internal components of the device are welded from seamless steel pipes, which prevents corrosion and allows you to withstand high atmospheric pressure. They also install convection fins to achieve maximum heat transfer.

Easy and fast installation.
Aesthetics.
Reliability and durability designs.
High heat transfer.
Working atmospheric pressure — up to 50 atm.

Bimetal convector - the most expensive type.
High hydraulic resistance- more energy is required to pump the coolant.
Small passage area.

Important! Some manufacturers go for tricks - instead of a steel monolithic contour, steel is used only in vertical channels radiator, so the buyer will need special care.