An indirect manufacturer using the "tank in a tank" technology is fundamentally different from its traditional "colleagues". The basis of the difference lies in the design of the device, and as a result, it was possible to achieve much higher efficiency indicators. This "chip" was developed by the ACV brand, which patented it and began to successfully apply it in the production of water heating equipment powered by heating.
Indirect heating water heater with two tanks: design, heating principle, features
Models with double walls are fundamentally different from conventional boilers, which use a coil to transfer heat from the accumulated liquid. They do not have temperature exchangers at all, but they boast faster heating with less loss.
Design
A boiler of this type is a container placed one inside the other, between the walls of which there is a certain distance. This cavity is completely filled with a coolant, which is heated by the heating system and transfers the thermal energy of the internal tank. Thus, the temperature return area is maximized, which leads to a high speed of reaching the desired temperature in the tank.
Important differences from traditional models
Units with coils have a big minus: their lower part has cold zones that are poorly heated by heat exchangers. Because of this, the time to bring the liquid to the desired thermometer mark can be very long with a high capacity of the device. And the hygiene of the equipment is reduced. Double-wall indirects are devoid of these shortcomings.
Temperature exchangers are placed inside the working tank, so they come into contact with water and can become scaled, which reduces their efficiency and service life. In double-walled models, the liquid acts only on the surface of the tank, which is reliably protected from salt deposits and oxidation.
Advantages of double tank boilers
ACV manufactures its tanks from excellent stainless steel, so the following features can be attributed to the advantages of the equipment:
- maintaining the structure of the material even when exposed to high temperatures;
- stability of aggregates before mechanical impact;
- excellent resistance to rust formation;
- incredibly long service life;
The performance of this type of units is significantly superior to conventional models, since with the same volume, boilers with a double tank concept can serve a larger number of consumer taps. This is possible due to the complete absence of unheated areas: newly incoming cold water increases its temperature in record time and can be used for domestic and household needs.
The ACV brand has various water heaters in its assortment: indirect, combined, direct. But it was the two-capacity boilers with heating operation that began to be in the greatest demand among consumers.
Article plan
If you live in a private house, then installing an indirect heating boiler together with a boiler will allow you to kill two birds with one stone - heat the house and provide constant access to hot water. We have selected for you the best models of water heaters that can be found on sale today - choose!
Briefly about the main characteristics
In conventional storage water heaters, the liquid temperature rises due to the operation of heating elements, while in boilers, heating is carried out due to the circulation of a heated coolant in the system. It looks something like this: water is heated in a single- or double-circuit boiler and fed through pipes to a coil or other heat exchanger installed in the tank; at the same time, cold water enters the tank from the main, which is subsequently heated due to heat exchange through the walls of the coil. Instead of a coil, a tank-in-tank design can be provided. In this case, the coolant is supplied to the external tank, and the heated liquid is supplied to the internal one. The presence of temperature and liquid volume sensors inside the tank, as well as automatic relays, ensure the smooth operation of the equipment. Some models are also equipped with additional electric heaters - even with force majeure with a boiler, you can use hot water. Everything seems to be simple, but before buying it is necessary to understand the main technical characteristics of such equipment.
| Selection criterion | Varieties | Note |
|---|---|---|
| Volume of the tank | from 50 to 400 liters and more | In the most popular models for domestic use, tanks with a volume of 80 to 200 liters are used. The volume is selected based on the consumption of hot water and the number of draw points. |
| Power | from 2 to 60 kW and above | Together with the volume of the tank, the power determines the rate of heating of the liquid. The more powerful the equipment and the smaller the capacity, the faster the heating goes. |
| Max water pressure | 6-10 bar (0.6-1 MPa) | The pressure that the boiler can withstand in operating mode. It is advisable to install pressure reducers to prevent damage from water hammer. |
| Mounting method | Wall | Equipment with a small tank volume (up to 100 liters) is often attached to the wall. The larger the volume, the more difficult it is to do this, so capacious water heaters are made in the floor version. |
| Floor | ||
| Combined | ||
| Heat exchanger design | Coil | The heat carrier from the boiler is supplied through a metal coil installed in a tank with heated water. The most common type. |
| coil in coil | The heat exchange area is increased due to the use of two coils with different spiral diameters. | |
| Tank in a tank | There are two steel tanks - one inside the other. The coolant from the boiler is supplied to the larger tank, heated water is supplied to the smaller one. | |
| Heat exchanger material | Stainless steel, brass | The vast majority are made of stainless steel. However, this material may vary in quality. Therefore, you should not save and buy products of an unknown brand. |
| Material and thickness of the thermal insulation layer | Foam rubber, mineral wool, expanded polystyrene, polyurethane foam - from 20 to 60 mm thick | The effectiveness of thermal insulation is determined by the value of thermal conductivity (the less, the better) and the thickness of the insulation layer (the more, the better). To date, a good solution is the use of 50-60 mm polyurethane foam insulation. |
| Maximum productivity in flow mode when heated to ΔT °C, l/min | where ΔT °C = 25, 45, 55 etc. | Determines the efficiency of the heater in flow mode. Depends on its power. |
| Heating time per ΔT °C, min. | where ΔT °C = 25, 45, 55, 60 etc. | Determines the heating rate of the entire volume of water in the tank. Depends on size and power. |
| Options | heating element | Many models can be upgraded with tubular electric heaters that fire when the boiler is turned off. |
| recycling | The tank may be provided with a circuit for water circulation using a pump. This is necessary so that water is supplied to the consumer at a constant temperature. | |
| Solar collectors | The use of solar energy to heat the coolant with the subsequent transfer of heat to water heating. Collectors are installed on the roof. In the CIS, this option is relevant only in the warm season. | |
| Heat pump | Ability to connect a heat pump to minimize the cost of heating cold water. A very rare option. |
We omitted such a parameter as the thread diameter for connecting to pipes, because. this issue, if necessary, is solved by installing adapters.
Calculation of the volume of water
Only you can determine exactly the required volume, because. calculations are tied to the conditions of water consumption. Our task is to provide information that will somehow help in the choice or suggest thoughts when making the calculation. For example, we open SNiP 2.04.01-85 and see that the norms set 7.9-10.9 liters of hot water (HW) per hour per person. Following some simple calculations, we get the following table.
These calculations can only be taken into account if the water heated by the boiler is consistently used and one draw-off point is operating at the same time (only one tap is open). In practice, the given values \u200b\u200bmust be multiplied by 3-5. Why is this happening? Because the norms do not take into account the desire to bask in the shower (+20 l. HW) and take a bath (+80 l. HW), wash a mountain of dishes (+20 l. HW), etc. etc. Take into account the peak loads on the boiler - choose the volume that is most suitable for your needs.
- 50-60 liters is enough for 1 person;
- for 2-3 people you need to choose from models of 80-120 liters;
- for a family of 3-5 people, the capacity of a boiler of 120-200 liters is enough
To make it easier for you to choose the right model of equipment, we have identified four product groups depending on the volume of the storage tank: up to 100, 200, 300 and 400 liters. All technical specifications are taken from open sources, and prices are provided for comparison purposes only.
Important! Please note that some water heaters are only suitable for certain models of boilers. In the description, we will focus on this, but we recommend that you clarify all the nuances before buying.
Up to 100 liters
1. Baxi Combi 80 (80 liters) - from 52,500 rubles.
A notorious Italian player specializing in heating and water heating equipment, Baxi has been holding the quality mark for decades. The Baxi Combi 80 small volume boiler model is designed to work in conjunction with the LUNA-3 Comfort series boilers of the same manufacturer. Placement is floor, the water heater can be installed directly under the boiler, saving space. One of the advantages of this system is its compact dimensions. Corrosion protection is provided by the use of stainless steel and a magnesium anode. Polyurethane foam is used as thermal insulation. TENA connection is not provided.
2. Gorenje GBK80ORRNB6 (72.6 liters) - from 24,000 rubles.
When looking for a small model that can provide hot water for one or two people, pay attention to Slovenian equipment. This is a classic compact boiler with two tubular heat exchangers, the performance of which is enough for two points of water intake at once. The device is equipped with an electronic control unit and allows you to change the DHW temperature in the range of 15-75 °C. It has outlets for connecting to the boiler on the right side, two dry heating elements are installed as an additional heater. The model is equipped with several types of protection: against corrosion (magnesium anode), against freezing (effective thermal insulation), against overheating and heating without water. The manufacturer also provides a function to control legionellosis (a lung disease whose pathogens actively multiply in hot water). One of the best combined solutions in terms of price / quality ratio.
* operating parameters in flow mode are not specified by the manufacturer. The power of the heat exchanger itself is not indicated - only for the heating element.
3. Protherm FS B100S (95 liters) - from 36200 rubles.
The Czech boiler is structurally tied to the boilers of the same manufacturer - the Bear. Compact, with a concise but informative control panel, it easily fits into the kitchen interior as built-in appliances. Enamelled stainless steel, magnesium anode and antibacterial coating - all aimed at protection against corrosion and microorganisms. The tubular heat exchanger provides a high rate of heating of the entire volume of liquid: water is heated by 50 degrees in 13 minutes. To keep warm, the product is protected by a polyurethane foam coat.
4. ACV COMFORT 100 (100 liters) - from 48,000 rubles.
A Belgian manufacturer with almost a century of history offers an interesting solution based on a tank-in-tank heat exchanger - model. The boiler consists of two stainless steel containers of different volumes, one of which is inserted into the other. Particular attention should be paid to the internal container: its surface is corrugated, therefore, due to thermal expansion, a change in size takes place, followed by the removal of the formed plaque of hardness salts (scale). The equipment is installed on the floor by default, but with the help of additional fixings it is possible to mount it on the wall. The heat-insulating layer is made of polyurethane foam 30 mm thick. The set of standard functions is small, but an optional control panel can be installed. It is also worth considering the lack of the possibility of recycling and connecting the heating element.
Up to 200 liters
5. Baxi Premier plus 150 (150 liters) - from 50,600 rubles.
It is possible to ensure the full operation of two hot water points with the help of. In a series of these heaters, a tubular coil-in-coil heat exchanger is used. Due to its low weight, the device can be hung on a wall or placed on the floor. The parts of the structure that come into contact with water are made of DUPLEX stainless steel, the minimization of heat losses is achieved by the use of polyurethane foam. The model is equipped with a thermostat and can be used in conjunction with any type of boilers. Optionally, it is possible to connect a tubular electric heater. The manufacturer has provided for the connection of the recirculation circuit. According to reviews, this is one of the best solutions in terms of price and quality for a family of four.
6. BOSCH WSTB 160 (160 liters) - from 28,000 rubles.
If a gas boiler is installed in your house, then you should think about buying a water heater. Although there is no possibility of connecting a heating element here, there is a recirculation system. The model is adapted to the harsh conditions of use in the CIS, i.e. suitable for hard water. To protect steel from corrosion, the material is coated with a special composition of glass-ceramic. There is a recirculation line so you can always count on getting water at a constant temperature. To minimize heat losses, a fur coat of 50 mm polyurethane foam is provided, the lining is made of PVC, soft. Frontal connection, it is possible to connect a temperature sensor. The entire volume is heated to ΔT=45°C in 37 minutes.
7. Protherm FE 200 BM (184 liters) - from 41650 rubles.
Many manufacturers offer storage heaters that are only suitable for their boiler models. If you installed a Proterm boiler, then to meet the needs of a large family in hot water supply, you should think about installing it. This is an indirect floor standing boiler made of stainless steel, enameled for corrosion protection. The installed titanium anode serves the same purpose. To prevent bacteria from multiplying on the walls of the container, they are covered with a layer of antibacterial substance. Productivity is high - with a delta of 25 degrees, you can get more than 30 liters of water per minute. Without the possibility of connecting the recirculation line and heating element.
8. Gorenje GV 200 (188.9 liters) - from 25,800 rubles.
Floor water heater of indirect type Combustion GV 200 - simplicity of the device, reliability of a design and laconic design. The product is an enameled steel tank with a tubular heat exchanger inside. Installed on the floor under the boiler. An overpressure relief valve is used as protection against overheating. The device is protected from corrosion by enamel and magnesium anode. It takes up to 24 minutes to heat the entire volume of water in the tank from 15 to 75 degrees. A 40 mm thick thermal insulation layer is responsible for maintaining the temperature of the hot water supply.
* the possibility of working in flow mode is not announced by the manufacturer
Up to 300 liters
9. ACV COMFORT 240 (240 l.) - from 65,000 rubles.
Another representative of indirect water heaters that use a tank-in-tank heat exchanger. The model is able to provide hot water to three points of water intake. The product is protected from corrosion due to the use of stainless steel and a special approach to the formation of the walls of the inner tank. Here it is corrugated, which has a positive effect on its work even with very hard water. At the same time, the equipment is characterized by the same features as for products of the same series: a minimum of functions, a thermal insulation layer of 30 mm, the inability to connect a tubular electric heater and a recirculation circuit.
10. Protherm FS B300S (295 liters) - from 63,000 rubles.
This accumulator is intended for use with Proterm Grizzly or Bizon boilers. - a capacious tank with a tubular heat exchanger. There are two flanges in the tank: for installing a heating element and servicing the boiler. Enamelled surfaces that come into contact with water, as well as the presence of a titanium anode, protect equipment from corrosion. Not to mention the presence of an antibacterial coating. A layer of polyurethane insulation is responsible for reducing heat loss. The device is characterized by high performance in flow mode, it is possible to connect a recirculation line. The possibilities of this heater will be appreciated by the owners of large private houses with more than three bathrooms.
11. Baxi Premier plus 300 (300 liters) - from 70,000 rubles.
Often the main criterion for choosing a boiler is not only its volume, but also the heating rate. In this case, it is relevant to consider models with a coil-in-coil heat exchanger. - exactly what is needed! Firstly, it is compatible with any boilers. Secondly, high-quality stainless steel, perfectly protected from corrosion, is used for its production. Thirdly, with a fairly compact size and low weight, the equipment has a universal placement and is equipped with an accurate thermostat. The model allows you to supplement the system with a recirculation circuit. Connecting a heating element for 2.7 kW is optional.
Up to 400 liters
12. Drazice OKC 400 NTRR / 1 MPa (380 liters) - from 68,000 rubles.
The Czech boiler is equipped with two tubular heat exchangers, one of which is designed to be connected to a solar collector, and the second to the boiler. This allows you to save a lot on heating water on sunny days, especially in summer. If necessary, for example, a malfunction of the boiler equipment, two auxiliary electric heating elements can be mounted. The enameled tank, as well as the presence of a magnesium anode, provide long-term protection of the tank from corrosion. 50 mm rigid polyurethane foam is used as a heat-insulating layer. There is a recirculation pipe.
Information on the rate of water heating in flow mode is not provided by the manufacturer. This is due to the presence of two independent heat exchangers with different temperature conditions.
13. Bosch SK 400-3 ZB (388 l.) - from 59,500 rubles.
There are not many indirect water heaters of the capacity we are interested in in the Bosch assortment, but among them there is a special model - Bosch SK 400-3 ZB. This is an enameled tank with a stainless steel coil. Corrosion protection is represented by a magnesium anode, which has already become a natural phenomenon in such equipment. The device is quite simple: a built-in thermometer and a flange for easy maintenance. At the same time, it is possible to connect a hot water recirculation line, as well as synchronize with the boiler if the latter has an NTC sensor connector (thermal sensor). Those. you can fine-tune the operation of water heating equipment. Separately, it must be said about thermal insulation. Here it is not polyurethane foam, but made of rigid foam, which, with equal thickness, gives a lower heat-shielding effect.
14. BAXI UBVT 400 SC (395 l.) - from 58100 rubles.
If the prevailing part of the boilers is designed to work in tandem with the boiler, then the model is an exception to the rule. It is adapted for connection to a solar collector, so its purchase will be appropriate in two cases: in places with year-round sunny weather or for seasonal use. Additionally, for heating, it is possible to install electric heaters. The container itself is made of steel coated with titanium enamel - it turned out to be a corrosion-resistant and durable coating. The latter is also facilitated by the presence of a magnesium anode. The kit includes a thermometer for temperature control, there are sockets for connecting sensors. The design provides a flange for monitoring the condition of the coil, as well as a built-in pipe for recirculation.
15. Hajdu STA 400 C (400 liters) - from 64,100 rubles.
The model from the notorious Hungarian manufacturer is interesting in that with one heat exchanger, fine-tuning of the equipment is possible. So, in the cold season, such an indirect heating boiler can be configured to work in tandem with the boiler, while in the summer it can be connected to a solar collector. In the latter case, if necessary, the heating element is additionally connected. The tank and heat exchanger are protected from corrosion by a layer of hot enamel and a magnesium anode. To minimize heat loss, the container is covered on the outside with a layer of polyurethane foam protected by a plastic casing. A branch pipe is provided for connecting a DHW recirculation system.
In the next video, this boiler is presented in section.
Editor's Choice
For ease of comparison, we will enter the main characteristics in the table and decide on the most successful models. To make it clearer, we choose a boiler for 1-2 people, 2-4 people, 4-6 people. (marked in the table below in bold from top to bottom, respectively). Because far from all manufacturers adhere to uniform standards when drawing up technical documentation, for example, not all indicate the value of performance in the flow mode, then we introduce the characteristic N. It shows the ratio of a unit of power per 1 liter. water. Those. we simply took and divided the capacities indicated by the manufacturer by the useful volume of drives. The larger this value, the faster the heating takes place.
| Model name | Useful volume, l | power, kWt | N, kW/l | Accommodation | heat exchanger | heating element | rec-tion | price, rub. |
|---|---|---|---|---|---|---|---|---|
| 80 | 31 | 0,3875 | outdoor | coil | — | — | 52500 | |
| 72,6 | 2 | 0,027548 | wall | coil | + | — | 24000 | |
| 95 | 26,1 | 0,274737 | outdoor | coil | — | — | 36200 | |
| 100 | 23 | 0,23 | floor/wall | tank in a tank | — | — | 48000 | |
| 150 | 30 | 0,2 | floor/wall | serpentine in serpentine | + | + | 50600 | |
| 160 | 20,8 | 0,13 | wall | coil | — | + | 28000 | |
| 184 | 43,2 | 0,234783 | outdoor | coil | — | — | 41650 | |
| 188,9 | 17,6 | 0,093171 | outdoor | coil | — | — | 25800 | |
| 240 | 53 | 0,220833 | floor/wall | tank in a tank | — | — | 65000 | |
| Gorenje KGV 300-2/BG | 280 | 69,6 | 0,248571 | outdoor | coil | + | + | 83700 |
| 295 | 46 | 0,155932 | outdoor | coil | + | + | 63000 | |
| 300 | 30 | 0,1 | floor/wall | serpentine in serpentine | + | + | 70000 | |
| 380 | 57 | 0,15 | outdoor | coil | + | + | 68000 | |
| 388 | 60 | 0,154639 | outdoor | coil | — | + | 59500 |
Updated: 16.09.2018 15:03:29
Judge: David Lieberman
*Overview of the best in the opinion of the editors of the site. About selection criteria. This material is subjective, is not an advertisement and does not serve as a guide to the purchase. Before buying, you need to consult with a specialist.
Among the wide variety of water heaters, buyers show particular interest in indirect heating boilers. Outwardly, these models do not differ from conventional storage devices. Most often, manufacturers stop at a rectangular or cylindrical body shape. Indirect boilers have their pros and cons. Experts recommend paying attention to several technical parameters.
How to choose an indirect heating boiler
- Power heater is selected taking into account the volume of the tank and the desired rate of water heating. When studying the documents for the boiler, it is necessary to take into account the useful power of the device.
- capacity water heating tank depends on the number of users. To take a shower in the country for a couple of avid gardeners and gardeners, a 100-liter drive is enough. If the family is large, there are small children, then more capacious boilers (200-300 liters) should be preferred. But at the same time, the power of the heat exchanger should be greater so that the heating of the water does not drag on for a long time.
- Heating rate also depends on the area of the heat exchanger. To find the optimal combination, you can start from the following ratio. The heating rate of water with a volume of 120 liters with a coil area of 1 sq. m will be about 30 minutes.
- Reliability and durability boiler is largely determined by the quality of the tank. A stainless steel tank will last the longest, but the price of such models is high. Manufacturers cover tanks made of ordinary steel with enamel or glass-ceramic. Additionally, magnesium anodes help resist corrosion, they also protect the internal cavity from scale formation.
- Maintain temperature water in a given interval helps thermal insulation. Budget boilers have a foam layer, more modern products are equipped with polyurethane foam insulation.
- Functionality. Various options help to minimize human intervention in the operation of the boiler. These are overheat protection, safety valve, thermostats and thermometers.
- Number of water intake points. With the help of a boiler, you can conduct hot water in several rooms. To do this, you need to choose a water heater with several points of water intake.
What is better indirect heating boiler or gas boiler
|
Boiler type |
Advantages |
Flaws |
|
high power Fast water heating Easy setup and adjustment Multiple water points |
Inconvenience of ignition Gas costs High price |
|
|
Indirect |
Effective thermal insulation Can be connected to different power sources High performance No additional costs |
Performance depends on the temperature of the coolant Large dimensions and weight Attachment to the source of energy |
Rating of the best indirect heating boilers
| Nomination | place | Name of product | price |
| The best indirect heating boilers with a volume of 100 l | 1 | 62 100 ₽ | |
| 2 | 26 900 ₽ | ||
| 3 | 18 361 ₽ | ||
| The best indirect heating boilers with a volume of 150 l | 1 | 39 451 ₽ | |
| 2 | 42 040 ₽ | ||
| 3 | 21 700 ₽ | ||
| The best indirect heating boilers with a volume of 200 l | 1 | 49 250 ₽ | |
| 2 | 56 580 ₽ | ||
| 3 | 24 600 ₽ | ||
| The best indirect heating boilers with a volume of 300 l | 1 | 114 000 ₽ | |
| 2 | 60 362 ₽ | ||
| 3 | 36 400 ₽ |
The best indirect heating boilers with a volume of 100 l
Indirect boilers with a small tank (100 l) are in demand among single residents or families consisting of 2 people. Devices of this type are installed in apartments or cottages. The experts selected several models.
The most modern indirect heating boiler in design is the Belgian development ACV Smart 100. The water heater is a heat exchanger that uses two stainless steel tanks. The tank-in-tank system is different in that the coolant heats the contents of a small tank over the entire area. This approach allows for the same time to heat twice as much water as in the traditional way using a coil. The maximum temperature is limited to 90ºС.
Experts gave the first place in the rating of the model for high-quality thermal insulation. The manufacturer used polyurethane foam 50 mm thick, which is famous for its low thermal conductivity. Experts also speak flatteringly about the wavy surface of the tank, due to which self-cleaning of scale occurs.
Advantages
- modern design;
- effective thermal insulation;
- self-cleaning from scale;
- fast heating of water;
Flaws
- high price.
The indirect heating boiler Electrolux CWH 100.1 Elitec allows you to heat water up to 100ºС. In this component, it outperforms its competitors. The capacity of this small water heater is 390 l/h. Both the heat exchanger and the steel tank are covered with a double layer of glass enamel. To extend the life of the boiler, a large magnesium anode is installed inside. The manufacturer also took care of the thermal insulation, the water remains hot for a long time due to the use of a 75 mm thick insulation. Additionally, you can install a heating element, which is important in the summer.
Although the device is somewhat inferior to the winner in innovation and efficiency, it is affordable, and the warranty period is 10 years.
Advantages
- high performance;
- reliable protective coating;
- effective thermal insulation;
- several points of water intake;
Flaws
- small heat exchanger area;
- heavy weight (55 kg).
At the most affordable price, the Gorenje GV 100 boiler is sold on the domestic market. The quality of the heater is quite high. The role of a heat source is played by a tubular carrier, which allows you to connect the boiler to various heating mains (even to central heating). Water can be heated up to 85ºС, the manufacturer has provided several points of water intake. The model has all the main options, it is a thermometer, indication of switching on and heating, overheating protection, safety and check valve. The heat exchanger is made of stainless steel, and the steel container is covered with enamel. Magnesium anode provides additional anti-corrosion protection to the tank. Users do not complain about the quality of workmanship, but the search for spare parts and mounting elements becomes a serious problem.
Advantages
- versatility of connection;
- low price;
- rich functional content;
Flaws
- lack of spare parts and components.
What is better indirect heating boiler or double-circuit boiler
|
HEATER TYPE |
ADVANTAGES |
LIMITATIONS |
|
INDIRECT HEATING BOILER |
HIGH VOLUME HIGH-QUALITY HEAT INSULATION MINIMUM SCALING |
HIGH PRICE LARGE OVERALL DIMENSIONS |
|
DOUBLE-CIRCUIT BOILER |
AFFORDABLE PRICE HIGH RELIABILITY EASY OPERATION |
LOW PERFORMANCE PRODUCES A LOT OF SCALE |
The best indirect heating boilers with a volume of 150 l
Boilers with a storage tank of 150 liters can provide hot water to residents of apartments or houses in the amount of 2-3 people. They are affordable and compact in size. Here are some successful water heaters.
Boiler indirect heating Vaillant uniSTOR VIH R 150/6 B has a stylish appearance. It can be installed in any premises, the manufacturer has provided for vertical mounting with top trim. The device allows you to heat water up to 85ºС, and the inlet pressure can reach 10 atm. A powerful heat exchanger (25.5 kW) quickly heats up the contents of the tank, and effective thermal insulation keeps the water hot for a long time. The tank is made of ordinary steel, which is covered with a layer of enamel. The magnetic anode becomes an additional way to protect the tank from corrosion.
Advantages
- stylish design;
- magnetic anode;
- fast heating;
- high water temperature;
Flaws
- heavy weight (79 kg).
One of the most popular indirect heating boilers is the Italian model Baxi Premier Plus 150. Experts in different countries recognize the excellent quality of the product. The storage tank is made of stainless steel, which is highly resistant to corrosion. The efficient polyurethane foam insulation helps keep heat loss to a minimum. A tubular coil will cope with fast and uniform heating of water.
The high strength and reliability of the boiler is perfectly combined with lightness (31 kg), so the user can choose between wall or floor mounting.
Advantages
- high efficiency;
- effective thermal insulation;
- lightness and compactness;
- quality assembly;
Flaws
- high price;
- incomprehensible installation instructions.
The Hajdu AQ IND150SC floor heater attracts the attention of potential buyers with an affordable price. The model is capable of serving several points with hot water. The manufacturer provided for the possibility of installing an electric heater with a power of 2 or 3 kW. The inner surface of the tank is covered with glass enamel, which permanently protects the steel from corrosion. The heat exchanger is made of ordinary steel with protective enamel. Thermal insulation made of polyurethane foam in combination with a polymer paint layer on the outer surface allows the water to remain hot for a long time.
Advantages
- affordable price;
- reliable thermal insulation;
- good equipment;
Flaws
- coil leaks are noted;
- service difficulties.
The best indirect heating boilers with a volume of 200 l
Full-fledged families of 3-4 people need a lot of hot water, especially in the summer. Boilers of indirect heating with a volume of 200 liters are capable of ensuring uninterrupted supply. Experts have chosen the following models.
Users call the Viessmann Vitocell-V 100 CVA-200 boiler a reliable heating device. Its work is stable, the unit is easy to operate, the service life is more than ten years. Powerful heat exchanger (36 kW) with an area of 1 sq. m quickly heats water up to 95ºС. The steel tank is protected by an enamel coating, and a magnesium anode is additionally installed, which is powered by a third-party energy source. The manufacturer effectively isolated the tank from the outside world with the help of eco-friendly insulation.
The boiler deservedly becomes the winner of the rating for the optimal combination of price and quality. Users are satisfied with the reliability and uniform heating of water.
Advantages
- fast heating of water;
- long service life;
- high heating temperature;
- reliable protection against corrosion;
Flaws
- not detected.
To speed up the process of heating water with a volume of 200 liters to a temperature of 90ºС, the Ariston BC2S CD2 200 boiler was equipped with two heat exchangers. Thanks to this constructive solution, it was possible to bring the heat exchanger area to 1.8 square meters. m. The heater can be connected to gas boilers and solar collectors. The manufacturer has applied complex protection, the inner surface of the steel tank is covered with a layer of fine enamel. The magnesium anode helps fight corrosion. The layer of polyurethane foam allows to reduce heat loss. The thermostat prevents overheating of water, the device has a safety drain valve. In the absence of water in the tank, protection against turning on the heating is provided.
Experts put the boiler in the second position in the rating for its large weight (111 kg).
Advantages
- two heat exchangers;
- high performance;
- the presence of protective options;
- durable anti-corrosion coating;
Flaws
- great weight.
The Hajdu AQ IND200SC indirect heating boiler was liked by specialists for its affordable price and stylish design. The model is able to heat water up to 65ºС at a maximum water pressure of 6 atm. Experts note good power (32 kW) and a large heat exchanger area (1.06 sq. M). To protect the inner surface of the tank, a glass-ceramic coating is applied, and the coil is made of an enameled pipe. The magnesium anode helps fight corrosion. The manufacturer has provided the possibility of installing an electric heater with a power of 2 or 3 kW.
Another boiler with a progressive "tank in tank" system becomes the winner in our ranking. This is the ACV Smart Multi-Energy 300 model, which is a floor standing version of the water heater. The device is designed to provide hot water to cottages, offices and production shops. A well-designed design allows you to connect the boiler to the heating systems of residential and industrial facilities. The thermal power is 32 kW, however, the storage device is economical. This is due to excellent thermal insulation, for 8 hours the water temperature drops by only 3ºС.
Experts highly appreciated the use of stainless steel for the manufacture of tanks and components, which makes the boiler exceptionally reliable and durable. In addition, it is also the lightest (99 kg).
Advantages
- high power;
- reliability and durability;
- several points of water intake;
- quality manufacturing;
Flaws
- high price.
The high power of the Buderus Logalux SU300 indirect heating boiler is provided by a smooth-tube heat exchanger. It is able to quickly heat water up to 95ºС. The manufacturer chose to make the storage tank out of ordinary steel, thermal glaze was used in combination with a magnesium anode to protect against corrosion. Thermal insulation made of thick polyurethane foam (50 mm), which does not contain dangerous fluorine and chlorine hydrocarbons, helps to keep the high temperature of the water.
The model is located on the second position not only because of the steel tank, the large weight (145 kg) also made a negative contribution. It is not surprising that the installation of the tank is provided only on the floor, and adjustable supports help to quickly level the boiler. Users like the model for the optimal combination of price and quality.
Advantages
- quality assembly;
- effective thermal insulation;
- powerful heat exchanger;
Flaws
- great weight.
The Hajdu STA300C indirect heating boiler has several advantages that helped it climb to the third step in the rating. Firstly, the model is sold in the domestic market at an affordable price. Secondly, you can connect the heater to different energy sources, from a gas boiler to a solar collector. The manufacturer uses the classic scheme to protect the steel tank from corrosion (glass-ceramic + magnesium anode). Heating efficiency is achieved by a powerful heat exchanger (45 kW) with a recirculation pipe. Possibility of installation of additional TEN is provided.
The boiler is not perfect in build quality, which has prevented it from climbing higher in the rankings. Users note a number of minor flaws that have to be eliminated on their own.
Advantages
- connects to different energy sources;
- affordable price;
- installation of an additional heating element is allowed;
Flaws
- build quality sucks.
Attention! This rating is subjective, is not an advertisement and does not serve as a purchase guide. Before buying, you need to consult with a specialist.
This question is often asked by owners of private houses. Many rightly believe that if they already have an installed heating system that allows them to supply the house not only with heating, but also with hot water for household needs, then why spend money and install an indirect heating boiler? At first glance, the boiler device really looks like a waste of money. But it's not.
The indirect heating boiler has a very low heat loss coefficient.
What is an indirect heating boiler and why is it needed?
An indirect heating boiler is a water heater that allows you to provide uninterrupted supply of hot water to all households at the same time.
In addition, its design does not imply the presence of its own heat source. External heat sources are used as a heat carrier for an indirect heating boiler. They can be a heating boiler, central heating, etc.
So, why do we need an indirect water heating boiler? Let's take as an example a situation where the hostess decided to wash the dishes, and the host in the meantime decided to take a shower. In this case, both will face either a shortage of hot water, or a sharp drop in water temperature, which is also unpleasant. The device of this water heater will avoid such situations, since it will be able to compensate for the shortage of hot water.
How does an indirect heating boiler work
Externally, an indirect heating boiler looks like a large tank that has a cylindrical shape. And the design of the boiler itself consists of the following parts:
- boiler body;
- insulation;
- tank made of stainless steel;
- thermometer;
- heat exchanger;
- magnesium anode.
Due to the presence of a layer of insulation between the tank and the body of the boiler itself, the heat loss coefficient is 3-4ºС per day. The thermometer allows you to control the set temperature of the water in the tank. The heat exchanger is a spiral steel or brass tube, which is located inside the boiler itself. Very often this tube has a complex shape and is located closer to the bottom of the boiler. Manufacturers claim that it is thanks to this fact that uniform heating of water in the entire tank can be achieved. The magnesium anode is designed to protect the tank from galvanic corrosion. Almost all electrochemical reactions will affect the magnesium anode without affecting other parts of the water heater. Over time, this part of the water heater will have to be replaced, as it is subject to constant wear and tear.
Almost all new models of modern boilers have an alternative heat source. Such devices are also called combined. In the summer, when the heating season is over, boilers use either electricity or gas to heat water. There are also models on the market that are able to heat water due to sunlight.
The principle of operation of the device
The indirect heating boiler is not complicated, and the principle of its operation will be clear to anyone. A spiral-shaped tube, hollow inside, passes inside a large tank, most often it is called a coil. The coolant circulates continuously in the tube. Constant circulation is provided by a pump specially installed for this purpose, which, in turn, is equipped with an automatic control system. As soon as the water temperature reaches the set parameter, the pump turns off. Since the source of the heat carrier is a working heating system, at the time of heating the water in the boiler, a slight decrease in the temperature of the heating elements is possible. However, the water in the tank heats up quite quickly, so you can only notice a decrease in temperature for a short time with the help of a thermometer.
After the water in the tank reaches the desired temperature, it will remain so for a long time. Modern insulating materials help to significantly reduce heat loss in the tank. As thermal insulation for boilers, polystyrene foam or polyurethane foam is perfect.
Each boiler has two inlet and outlet pipes, and they perform different tasks. The inlet pipe is connected to the heating boiler, where the coolant enters the coil through it, thereby heating the water in the tank. And the outlet pipe delivers already heated water directly to the place of its supply.
Before you decide to buy a boiler, be sure to check the power of your heating system. After all, if you purchase a boiler with a large volume, there is a possibility that the heating system in your home simply will not cope with the task. Or heating will occur very slowly, and during this period the temperature of the heating devices will drop sharply, which will have an extremely negative effect on the comfort of people living in the house. You will also need to choose in advance which type of boiler you want to purchase: floor or wall. If you have a wall-mounted water heating system, then it is best to purchase a wall-mounted boiler. And vice versa. Experts advise purchasing a heating system and an indirect heating boiler from the same manufacturer. In this case, installation and installation will be easy and fast. And the results of their work will be effective and productive.
Advantages and disadvantages of the system
The main and main advantages of indirect heating boilers, in contrast to flow-type heaters, are:
- The ability to heat water in large quantities.
- Compensation for the emerging shortage of hot water during the peak load period. For example, when the hostess decided to wash the dishes and the host decided to take a shower. Thanks to the boiler, several people in the house can use hot water at once without causing discomfort to other users.
- The cost of water heated by an indirect heating boiler is extremely low. After all, no additional energy was spent for its production. An indirect heat source fully satisfied the need for heating water. In winter, the use of a boiler becomes extremely important due to the high savings in energy spent on heating and heating.
- Compared to a flow type water heater, the use of an indirect heating boiler makes it possible to supply hot water in several directions at once.
- Possibility to use alternative heat sources (gas, electricity, sunlight, etc.).
The disadvantages of indirect heating boilers include the following:
- High cost of equipment. Given the fact that in order to install an indirect heating boiler, it is necessary to first install a heating boiler, the installation of the first one places a heavy financial burden on the owners of a private house.
- In order to heat water in a container weighing 100 liters, it will take several hours. For this period of time, the heating temperature in all residential premises will be reduced.
- The whole structure takes up quite a lot of space. Usually, a heating boiler and an indirect heating boiler are installed in close proximity to each other. And since the dimensions of the equipment are rather big, sometimes a whole small room in the economic zone is allocated for them.
How to choose the right boiler?
The main criterion that you should be guided by when choosing a boiler is its capacity. In order to understand what should be the optimal mass of your water heater, you can use the average figures, and then multiply them by the number of people living in the house and round the resulting figure up.
So, statistics say that a person spends hot water per day on:
- washing - 6-16 l;
- washing dishes - 20-25 l;
- shower - 60-85 l;
- taking a bath - 160-180 liters.
For example, it will take about 40 minutes to heat water to the desired temperature in a 20-liter indirect heating boiler, and about 6 hours for a 200-liter boiler.
After you have decided on the required volume of the boiler, be sure to specify what material the coil is made of. In inexpensive boilers, the coil is made of steel and welded to the tank. And in models of a higher price category, the coil is removable and made of brass. Of course, a removable coil is more practical, since over time you can easily remove it and clean it from the scale that has accumulated in it.
Also, inexpensive models have a layer of glass-ceramic or enamel as a protective coating. However, such a coating is not entirely reliable, because constant temperature changes will occur inside the tank, which will eventually lead to microcracks and will no longer save the metal from corrosion. Therefore, when buying a boiler, choose a tank that is made of stainless steel, such a boiler will cost you more, but it will also last much longer.
The next thing you will need to pay attention to is the insulation material. In some models, foam rubber is used as a heater; this material is extremely unreliable and impractical. Polyurethane is best suited for these purposes. It is with such a heater that heat loss from the tank is practically excluded, which means that excess energy is not wasted to heat the water again.
