In European countries, traditional (Convection) boilers have long been abandoned. What is the reason for this approach? Europeans are thorough people and know how to calculate benefits, but if they use condensing boilers, which means there is a benefit here. What can it be expressed in?
Pros and cons of condensing boilers
- The high efficiency of boilers is ensured by combustion gas, which releases a large amount of water vapor and has a very high temperature. The boiler equipment supplies this “ extra warmth» onto the boiler heat exchanger, which provides additional heat removal.
- Unlike a traditional boiler, a condensing boiler has a modulation range of 6 kW, resulting in a reduction in its consumption (20-30% depending on the average winter temperature).
- Thanks to closed chamber combustion is safer and more environmentally friendly.
- Low weight and dimensions of the boiler.
- Low noise and vibration levels.
From these indicators it is clear why practical Europeans choose condensing boilers, although they are somewhat more expensive than usual. In Russia, according to the owners of such boilers, their payback due to gas savings occurs at 2 – 4 year of operation.
Installation of condensing heating boilers
The use of a condensing boiler in the heating system must be included in the design. Since it differs significantly from the usual one in the wiring, pipe diameter and chimney feature.
As a rule, they are used for heating private houses. wall-mounted boilers. Their power is enough to heat a house, and their compact dimensions allow them to be located in any convenient place; there is no need to build a separate boiler room. For example, a boiler with dimensions of only 589x368x364 is able to heat a house with an area of up to 240 m².
Installation of condensing heating boilers is possible for any solid foundation. To do this, either the fasteners that come with the kit are used, or a mounting frame is made. The use of such a frame allows this boiler to fit organically into any interior.
Having secured the boiler to the wall, proceed to connecting communications according to the appropriate diagrams. Carbon monoxide is removed through the chimney; the pipe must be insulated and there should be no flammable surfaces nearby.
It makes more sense to use such a highly efficient boiler with systems that also have high performance. For example, with Kermi radiators, which have the most high level heat transfer and a heating system known as the Tichelman loop.
Installing heating loops has a number of advantages:
Balance of the system. No additional regulators required.
High efficiency due to equal water flow throughout the system.
Uniform heating of radiators.
These effects are achieved due to the fact that the return heating line starts from the first radiator, reaches the final one, and from there it is supplied to the boiler. As a result, all radiators function as one and, regardless of the distance from the boiler, heat up equally.
Includes not only heating equipment, but also a set of specific measures for its installation and assembly. Correct and high-quality installation will certainly affect the operation of the boiler in the future.
Exists a whole series standards and regulations for the installation of gas condensing boilers. First of all, you need to know that installing a condensing boiler requires permission from the gas inspectorate. When connecting the boiler, you must comply with the technical rules for connecting gas and the necessary safety measures.
This prerequisite to prevent boiler damage and possible injury to people.
It’s even better if the installation and installation of the condensing boiler is carried out by qualified specialists.
How to choose a boiler installation location
The best place to install is non-residential premises. If the house does not have such a separate room, then the boiler can be installed in the kitchen. Ideally, the walls of the room where the boiler will be installed should be tiled, but in no case flammable materials. The floor must be covered with a non-flammable coating; it is advisable that there is a sewerage system in the room. Heating boilers condensation units require the presence of an exhaust hood in the room where they are installed.
The wall-hung condensing boiler is fixed to the wall with special hooks using dowels. It is correct if the condensing boiler is located in such a way that its lower part recedes from the wall more than the upper part.
If, on the contrary, it means that the boiler is not secured correctly. The installation of the condensing boiler is done in such a way that there is no tilt, otherwise this may lead to a short circuit.
Therefore, when attaching the boiler to the hooks, you need to carefully check the verticality of the boiler so that it is not tilted forward or sideways.
Chimneys of condensing boilers
There are many options for connecting a chimney to a condensing boiler. The main requirement for condensing boilers is the tightness of the joints of the chimney elements.
In general, the design of the chimneys of condensing boilers is not very different from the design of the chimney of conventional gas boilers.
Features of chimneys for condensing boilers:
- the material from which they are made. The chimney for a condensing boiler must be made of acid-resistant materials, e.g. stainless steel or plastic. This is due to the fact that the condensate that passes through the chimney is a light acid, so the chimney material must be protected from corrosion.
- The chimney for a condensing boiler must be located at such an angle that the resulting condensate flows back into the boiler, but no precipitation gets there. Hit atmospheric precipitation into the boiler can lead to short circuit or boiler breakdown.
Condensate drainage and main mistakes when installing condensing boilers
A condensing boiler provides an operating system in which condensate is formed from water vapor contained in combustion products.
Depending on power and temperature regime, up to 50 liters of low acidity condensate can be formed per day. This allows you to pour it into the household waste siphon and not harm the environment.
However, there are some errors when:
- Lack of condensate drainage or installation of an unsuitable container for this purpose. Experts can also make this mistake due to inexperience. They may either not install a condensate drain at all or install some kind of container, for example, an ordinary bucket, as a drain. This should not be allowed, because it is a grave mistake.
- The condensate drain is taken to the street, which, of course, minus temperature will cause icing and freezing of the tube. This will block the boiler and may cause it to break.
- Installation of boilers on walls with flammable coating.
- The use of a gas meter that does not correspond to the boiler power.
- No gas filters.
- Non-compliance correct angle boiler slope.
A condensing boiler requires the presence of all of the above points, and also ensures compliance with all technical rules and installation and installation standards.
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Condensing gas boilers: operating principle, types and advantages
Thanks to their high-tech design, condensing boilers make the heating system much more convenient, comfortable, and economical. If in conventional devices combustion products give off only part of the thermal energy, then in in this case this is done to the maximum. The company "Luch Tepla" presents in large assortment boilers of all types.
Design
In their structure, condensing boilers are indistinguishable from typical heating devices. Available in several options:
- wall-mounted (more traditional, focused on individual heating systems of private residential buildings);
- floor ( increased power, intended for use in office and industrial premises).
Their design includes a non-standard heat exchanger made on the basis of acid-resistant materials. Usually made of stainless steel or silumin. It looks like a pipe with a complex cross-section and spiral ribs. All this increases the heat exchange area and makes the gas boiler more efficient.
In addition, the condensation device is equipped with a fan located in front of the burner. It “sucks” gas from the gas pipeline, mixes it with air and directs it directly to the burner. The boiler also has an electronically controlled pump, which allows you to optimize heating power, reduce noise from the coolant flowing through the system and save on electricity.
Types of Condensing Gas Boilers :
There are several types of condensing boilers:
- single-circuit;
- double-circuit;
- heating;
- water heating.
Moreover, their power can vary from 20 kW to 100 kW, which is quite enough for household boilers. For office and industrial premises they are produced with greater power and in a floor-standing version.
Operating principle of condensing gas boilers :
In standard boilers, the escaping hot gases are simply released into the atmosphere through the chimney duct, losing a significant proportion of unused heat. It is discharged outside along with waste products in the form of water vapor formed during fuel combustion. It is in the pair that additional thermal energy, which condensing boilers store and then transfer to the heating system.
As the steam cools, it condenses, that is, it becomes a liquid, and releases a certain amount of heat. This process takes place in a special heat exchanger with an expanded area. It is he who “takes” heat for transfer to the heating system. This approach was known before. But they began to use it relatively recently due to the advent of corrosion-resistant alloys, which form the basis for the production of condensing boilers.
Features of operation of CONDENSING gas boilers:
The efficiency of such gas devices largely depends on the characteristics heating system. The lower the water temperature, the more complete the process of condensation of water vapor occurs. Consequently, the higher the amount of latent heat that is returned to the system.
In this way, the condensation mode is maintained throughout the entire heating period. That's why the most important condition for the operation of a condensing boiler is the average coolant temperature. For example, at the entrance to the boiler it should be less than 60 degrees (ideally up to 57 degrees). This will give better condensation and increase the efficiency of the heating device.
But even if you combine a condensing boiler with old system, it will still bring tangible savings, since it will be more efficient than previous equipment. This is due to the fact that in our climate zone the coldest days in total occupy a little more than 10 percent of the duration of the entire heating period. On other days, optimal condensation is possible.
Advantages
Among the basic advantages of this type of boiler is high efficiency. In this case, it is equal to 108-109 percent, when compared with other boilers. Another advantage is their increased efficiency. It is approximately 15-20 percent more than that of standard heating devices.
From the design instructions for condensing boilers Buderus (Germany).
Compliant SNiP 41-01-2003 clause 6.4.1 PIPELINES
: "...Polymer pipes, used in heating systems together With metal pipes(including in external heat supply systems) or with devices and equipment that have restrictions on the content of dissolved oxygen in the coolant, must have an oxygen permeability of no more than 0.1 g/(m3
∙day)..."
VITODENS Gas condensing boilers
Design instructions
Bosch Condens 3000W
- Possibility of direct connection to the underfloor heating system
Other model
BoschCondens 5000 W Maxx
Possibility of direct connection to the underfloor heating system
Without required minimum flow circulating water
High quality components such as plasma polymerized aluminum heat exchanger and reliable design make the Condens 5000 W Maxx not only extremely reliable, but also extremely durable. Thanks to innovative Flow Plus technology there is no minimum value of water pressure through the heat exchanger . For this reason, complete hydraulic system not required.
About the anti-diffusion layer (oxygen barrier):
"... This result confirms once again the fallacy of the widespread statement: “Pipes of small diameters do not necessarily need to be reinforced or protected from the ingress of oxygen into the coolant, since the flow of oxygen through the wall of such pipes can be neglected.” Proponents of this point of view urge not to reinforce with aluminum and not to cover with an AVOH layer (anti-diffusion layer for PEX pipes). and small diameter PPR pipes. However, it is precisely these pipes that stand, for example, in front of steel panel radiators (steel wall thickness is 1.2 mm). Therefore, to reinforce small and large pipes with aluminum large diameter necessary for heating systems. Moreover, for small-diameter pipes this rule is more important than for large-diameter pipes, where calculation and reference to a specific application scheme is necessary.
For example, with D = 2x10-11 m2/s (oxygen permeability of polypropylene) and ∆сО2 MAX = 270 g/m3 (approximate oxygen content in the atmosphere)
Q/V=1.9٠10-8/DN2 (g/s٠m3) or 1.6٠10-3/DN2 (g/day٠m3)
for DN20mm, we get 4 g/m3 of oxygen per day - in other words, the formation of 30 g of rust is possible. One meter of pipe DN20 PN20 (SDR=6) contains 2.2x10-4 m3; accordingly, through this linear meter pipes into the coolant will pass a maximum of 8.8x10-4 g/day. oxygen.
For example, if the heating system is made of polypropylene pipe PN20 (unreinforced or fiberglass reinforced), the volume of the heating system is 100 l, there is a wall-mounted boiler with an aluminum-copper heat exchanger and a heating temperature of 80 C ° and steel panel radiators, and the pipe capacity is 50 l, then per day for a typical set of pipes of different diameters with SDR=6 about 0.1 g of oxygen will pass into the coolant; in terms of per year this amounts to 37 g of oxygen, or 250 g of rust obtained in steel panel radiators(which will very likely leak after a year or two of use).
The scope of this article does not include an exact quantitative analysis of oxygen permeability, however, the given example allows us to resolve the frequently asked question: “How much oxygen does the plastic pipe? Is it a lot or a little? I think we have given a very specific answer. In conclusion, we note that many informative works have been written on this topic, but the conclusions of readers or companies supplying similar products to the market do not always correspond to the analysis carried out in these articles..."
Conventionally, the installation diagram (we are considering the Victrix 50 boiler as an example) can be divided into several connection stages:
- safety kit;
- storage boiler;
- solar collector;
- hydraulic separator.
Let's look at each stage in detail.
Safety kit
When connecting a boiler with a power of more than 35 kW, European legislation requires paying closer attention to safety issues. Therefore, a special safety kit is provided, which includes a safety thermostat, a maximum water pressure switch (4 bar), a pressure gauge and a system filling valve (sleeve for connecting the thermal cylinder of the gas shut-off valve).
There are also fittings for connecting expansion tank and a sleeve for an immersion alcohol thermometer. The pressure switch and overheating thermostat have manual unlocking and are connected in series to the boiler power circuit (Fig. 2). Operation limit safety devices adjustable to 3 bar and 105 °C, respectively. This kit allows you to produce a compact, fast and reliable installation safety devices and also guarantees reliable protection from emergency situations under any circumstances.
Storage boiler
Since the boilers are single-circuit, it is proposed to use a storage type boiler to meet the needs for hot water. Several standard sizes of boilers are offered, with a capacity from 80 to 200 liters. Boilers have a rectangular body white. The material used to make the boiler body and coil is food grade stainless steel. high quality. To reduce heat loss, the boiler is enclosed in highly efficient polyurethane foam insulation.
The boilers are equipped with spiral heat exchangers with a large heat exchange surface, which are connected in a counterflow circuit (Fig. 3). This allows you to quickly heat the accumulated water supply. To ensure large volume cooking hot water, you can use two 200 liter boilers, in which the coolant and sanitary water circuits are connected in parallel. To connect the boiler to the boiler, you must use a special kit, which consists of adapters and three way valve. As in all others mounted boilers, operation in hot water supply mode is based on the principle of strict DHW priority.
Connecting solar collectors
A special feature of 200-liter boilers is the ability to work with solar collectors. In Fig. Figure 4 shows an example of connecting solar collectors to a heat supply system based on a condensing boiler. High-quality solar collectors and a home heating system coordinated with them make it possible to consider the economic use of solar energy as necessary condition building an effective system.
At our latitudes, the total radiation (reflected and direct) in optimal conditions(cloudless clear sky, mid-day) is a maximum of 1000 W/m2. Solar collectors, depending on their type, allow the use of up to 75% of the total radiation. It remains only to note that from our point of view the combination of condensing boiler + solar collector(heat pump) - the most promising direction further development autonomous heat supply systems.
Hydraulic separator
Since the boiler is designed to carry a significant heat load, this requires the presence of separate heating system circuits with zone control. Therefore, the issue of independent control of circuits becomes relevant. There is a possibility of a change in the amount of coolant circulating through the boiler, which adversely affects its hydraulic mode.
A natural solution in this situation is the use of a hydraulic separator (hydraulic arrow). At the same time, a transition is made to pipes of larger diameter, which makes it possible to connect the “hydraulic arrow” directly to the supply and return distribution manifolds. For one boiler, a compact solution for this unit is proposed, in the form of a rectangular pipe (Fig. 5).
This unit is located directly under the boiler, which makes it possible to significantly reduce the dimensions of the installation. Since the collector is installed horizontally, to remove sludge from the heating system, it is necessary to install a sediment filter on the return line, in front of the collector.
