At the beginning of the industrial era, the word boiler meant a fireplace and its exchanger in large kitchen and heating systems, in steam engines and steam locomotives. In its modern sense, it refers to a device (or an industrial installation, depending on its power) for continuously transferring thermal energy to a coolant (most commonly water).
The transferred thermal energy (heat source) can be either the heat released by combustion (coal, oil, gas, wood, waste, etc.), or the heat contained in another fluid (boiler of recovery on combustion gas or chemical process gas, “nuclear” boiler receiving heat from the primary circuit, etc.), or other sources of heat (for example: electric boilers). Boilers are both industrial and domestic systems. Inside the boiler, this coolant can either be heated (it remains in the liquid phase), heated and vaporized, or heated, vaporized and overheated (so with the passage of liquid phase gas phase).
- Examples of Installed Boilers:
- Boiler construction technology:
- Overall constitution of boilers:
- Installation of a condensing boiler
- Installation of an electric boiler:
- Installation of a cogeneration boiler:
- Installation of a mixed boiler:
- Installation of a boiler with a suction cup or forced flow:
- Installation of a low-temperature boiler:
By definition, a boiler is a system for increasing the temperature of a coolant to move thermal energy. There is a wide variety of boilers. Thus, they can be classified according to different criteria:
- Classification by power range: individual boilers (Powerless than 70 kW) and boilers of industrial type (Power greater than 70 kW).
- Classification by application: Domestic use (central heating), communal heating, industrial applications (agro-food, chemistry, paper, cement, etc.) and thermal power plants.
- Classification by heat source:Combustion boilers, boilers for liquid or gaseous fuels (The boilers for liquid and gaseous fuels are very close by construction. In this type of boiler, the element providing combustion is called the burner. The fuels used are mainly: gas natural gas, liquefied petroleum gas, domestic fuel oil, and heavy fuel oil, a liquid or gaseous fuel boiler may have one or more burners.), Solid Fuel Boilers (There are many combustion processes for solid fuel boilers Solid fuel fireplaces can be separated into three main families: grate fireplaces, fluidized bed fireplaces, and pulverized coal fireplaces.) Recovery boilers (Thermal energy is recovered from a hot fluid (gas exhaust gas turbine or process gas in the chemical industry, for example.) These boilers are therefore similar to heat exchangers but have their boiler name to the fact that the heated heat transfer fluid (usually water) is sprayed (unlike heat exchangers). Also included in this category are the steam generators of nuclear power plants that exchange heat between the primary circuit and the secondary circuit), and electric boilers (Electricity is not strictly speaking a fuel, but it is a source of energy that is sometimes converted into heat in electric boilers There are several principles of heating Resistance boilers heat the water using an electrical resistance immersed in water Joule boilers heat the water with the help of electrodes immersed in the water, which is the effect of the water, which allows the water to be heated or sprayed in. The ionic boilers projections at high speed. Km/ s) with the help of an electric field, which causes the heating fluid to heat up The scarcity of electric boilers can be explained by the price of electricity, which is a more expensive energy than Most of the other energies are electric boilers in the field of domestic central heating, in the humidification of rooms equipped with air conditioning (small steam boilers used for humidification), but also in the industry for powers ranging from up to a few tens of MW. Due to the absence of energy losses by the sensible heat of the fumes, the efficiency of electric boilers is often close to 100%).
- Classification by type of heat transfer fluid: A boiler exchanges heat energy via heat transfer fluids which then convey it to the point of use. If the heat transfer fluid uses the specific heat to move this energy the circuit is called monophasic. A pump sets in motion this heated fluid mass, it is the circulator. For high power, two-phase circuits are used. They use the combination of the specific heat and the latent heat of vaporization. They have higher specific energy. The main heat transfer fluids used are:
- Water (its treatment for this purpose is important: hot water is mainly used in heating systems of residential, commercial or industrial premises. In the field of domestic central heating, it is almost the only fluid used or superheated water which is mainly used in district heating. It can also be found in the industry. Current pressure and temperature of use revolve around 20 bar at 180 ° C with a return to 90 ° C).
- Water vapor: Saturated steam is mainly used in industrial processes. The steam produced by the boiler is then used to heat fluids through exchangers. Specific machines such as paper machines may also need a steam supply. Or superheated steam which is mainly used for turbining, usually for the purpose of driving an alternator to produce electricity. This principle is used in thermal power plants. Some industries have wastes to be disposed of, these wastes used as fuels allow them to produce electrical energy and all or part of the thermal energy needed by the plant. This is called cogeneration.
- Thermal fluids, generally oils, to achieve high temperatures without requiring high pressures. They are used as heat energy for example in the chipboard industry. The use of thermal fluid also allows better precision in temperature control. However, the use of thermal fluid generates many operating constraints for manufacturers. They are increasingly replaced by steam.
- Melted salts. These are very special boilers that have few or no examples of industrial use. Sodium in some nuclear uses.
- Classification by installation:Floor Boilers (Floor boilers are typically used for homes with a basement or garage, and they occupy an important place) and Wall boilers (Wall boilers are suitable for small dwellings such as apartments; they offer less power than boilers on the ground).
- Classification by type of circulation:With natural circulation (The circulation of water in a boiler is very important to avoid the formation of dry areas where the metal is likely to melt deform or oxidize prematurely under the effect of heat. Natural circulation water tube boilers have an upper tank (called a boiler balloon), from which large tubes are placed out of the fire (called “fall pipes” or “downpipes”). These tubes convey by gravity water either in a lower flask or in “collectors.” The furnace tubes are connected to this lower flask or these manifolds. The water goes back to the (upper) balloon through these tubes, thus receiving the heat of the fire. This water then starts to vaporize. Since the density of the steam is lower than that of the liquid water, the pressure difference between the water column of the down-comers and the water and steam column of the firebox tubes is naturally circulating. Water in the circuit. The water runs through this loop several times (balloon, down tubes, fire tubes, return to the balloon) before being discharged from the balloon in the form of saturated steam), with Assisted circulation (Progressively the operating pressure of the boilers rose, in particular to obtain better yields in the thermal power stations. When the pressure in the flask reaches values of the order of 180 bar, the difference in density between the liquid water and the steam becomes insufficient to ensure natural circulation in the evaporative circuit. Then install a pump in the circuit to ensure the proper flow of water), and with Forced circulation (In this category, there are small central heating boilers, industrial boilers or high-pressure power plants. For the former, the circulation of water in the pipes is ensured by means of a pump also called circulator in the case of the central heating. This configuration facilitates the design of boilers: it is not necessary to ensure that the pressure drops allow natural circulation by convection. For industrial boilers and boilers of thermal power plants, technologies of forced circulation boilers, without a balloon, have been developed. Indeed, the increase in operating pressures has come up against the technological barrier of the mechanical resistance of the boiler balloons. In addition, the role of separating the liquid and vapor phases of the balloon no longer makes sense when supercritical pressures are reached. In forced circulation boilers (such as Benson or Sulzer), the water does not circulate repeatedly in a loop before being vaporized, but enters the evaporator tubes of the hearth in liquid form and comes out in the form of saturated steam, d where the names of “mono-tubular” boilers or “once-through” boilers. The circulation of water in the evaporator is ensured by very high-pressure pumps which “push” the water, then the steam successively in the tubes of the economizer, the evaporator, then the super-heaters. All “supercritical” boilers are necessary of this type. But it is also found in subcritical cycles, in competition with the assisted circulation boilers. Their main advantage is then their shorter start-up time, a notable advantage in advanced thermal power plants. On the other hand, the absence of a balloon makes them more demanding as to the quality of the demineralized water to be used).
- Classification by architecture: This classification only applies to industrial and thermal power plant boilers. We cite Two-pass boiler (This is the most common arrangement. The hearth is surmounted by one or two, and a rear vertical flue receives the other convective exchangers. The combustion gases leave the firebox from above and then descend into the rear flue), and Tower boiler (This arrangement is mostly found in Germany, but examples exist in Italy, France, India, China, South Africa, etc. In this boiler architecture, the hearth is surmounted by all the exchangers of the convective zone. It follows a height of up to 100 m. Among the advantages of such a configuration, there will be reduced risk of erosion and fouling in the case of combustion of very ashy coals).
- Classification by construction:Smoke tube boilers (This is historically the first type of construction. The first models used a vertical circulation, easier to achieve, because of the convection of gases, but subsequently, we realized boilers with a horizontal arrangement , more adapted to the use for the railway or the navigation A boiler with tubes of fumes consists of a large tank of water traversed by tubes in which circulates the fumes The first tube of the flue This type of construction is now used almost exclusively for gaseous and liquid fuels because the furnace shape of the flue gas boilers makes it difficult to extract the ashes. When used with solid fuels, the fireplace is placed outside the boiler itself, in which case the fireplace is a water tube front. This type of construction is generally reserved for powers not exceeding 20 or 30 MW), and boilers with water tubes (In this construction, it is the heat transfer fluid which circulates in tubes, the gases hot circulating outside of these. The advantage of this formula is especially the safety of not having large quantities of water in the boiler itself, which could in case of mechanical failure, lead to an explosive creation of steam. They also have the advantage of having lower inertia. In this type of boiler, the fireplace always has a very large volume. In addition, the fireplace has the possibility to be open in its lower part. It is these two characteristics that make them often used with solid fuels even for powers of a few MW only).
The installation of a boiler is never done lightly. The location, in particular, must be chosen carefully to ensure safety and comfort to the residents of the home. Depending on the type of boiler, the installation could be either on the wall or on the floor. Each model has different advantages. The wall-mounted boiler frees space on the floor and is often more compact and less expensive. On the other hand, these boilers are less robust than those who settle on the ground. The floor boiler is ideal for heating a very large house because its power and capacity are usually greater than a wall model. In return, the boiler floor is bulkier and often more expensive.
To ensure proper operation of the appliance, as well as optimum safety for all inhabitants of the home, it is important to follow certain rules to choose the location to install a boiler:
- Observe a minimum height, which varies depending on the boiler model.
- Install the boiler in a well-ventilated and fairly large room (usually, an area of at least 8 m3 is required)
In addition, the location of a boiler also depends on: the mode of evacuation of the combustion gases (If you opt for a boiler with a suction cup, the boiler can be installed anywhere, without taking into account the possibility of the connection to a flue pipe) and the location of the parts that will be fed by the boiler (The further the boiler is from the kitchen and bathroom, the greater the risk of losing comfort).
Examples of Installed Boilers:
A central heating boiler allows distributing heat in different rooms. The return of heat is done using radiators or a heated floor. The fluid used is usually water. A second circuit can ensure the production of domestic hot water (shower, etc.). The fumes from standard boilers contain water in the vapor state produced during the combustion reaction.
The condensing boilers: a little more expensive, are equipped with an additional exchanger at the level of the flue gas discharge where circulates the heating water before its introduction into the boiler. This makes it possible to condense the water vapor contained in the combustion products and thus to recover the latent energy of condensation, giving the illusion of a “yield” greater than 1 when it is expressed as a lower calorific value (PCI). These boilers are interesting if the temperature of introduction into the boiler is low (about 40 ° C instead of the usual 60 ° C). There are large ones for biomass energy, with possible hydro-accumulation. The life of a well-branded and carefully maintained boiler every year can exceed 35 years. Low-power boilers (individual boilers) have a service life of 15 to 20 years.
Pulsating boilers: which achieve a yield close to 111% PCI and are based on a combustion principle different from conventional boilers.
A steam locomotive boiler heats water up to the over-pressurized steam stage, this steam while expanding pushes pistons to deliver a mechanical force that is used to move the locomotive.
Steam cleaning systems: in vogue in the years 1990-2000 include a non-closed circuit boiler producing water vapor.
An industrial boiler: used to provide an industrial process, heat and/or strength.
A nuclear power plant boiler uses the nuclear reaction to heat a liquid until it turns into steam to drive a turbine coupled to an alternator.
The pellet boiler uses wood pellets (also called pellets) as fuel, which take the form of compact cylinders of wood residues. These pellets are automatically introduced via a “worm” into the firebox. Compaction and low moisture content of the pellets give them a high calorific value and a relatively high yield:
Lower heating value: 4.6 to 5.3 kWh / kg
Humidity level: <10%
Ash content: <0.7%
Boiler construction technology:
Definition of a boiler calculation: Under the term, boiler calculation lies two different meanings:
- The first is the main determination of the elements constituting the boiler: hearth, recuperators, the surface of the exchangers, etc. This determination implies both the need to calculate and also to choose, among a large number of possible solutions, the best adapted to what is expected of the material.
- The second is the actual calculation, when it is a question of determining the behavior of a set defined in its dimensions and its main parameters of operation, for different gaits or modified input data concerning the fuel, the excess of air, flow rates, temperatures, etc.
Starting data of a boiler calculation: There are four categories of data needed to determine a boiler that requires custom design to meet particular conditions: operating conditions, water, and vapor characteristics, characteristics of fuels and their optimum combustion conditions, as well as those of the environment, and finally expected performance and normal or extreme conditions of use of the equipment.
Cast iron boilers: The different elements of a cast iron boiler are obtained by molding from a model. Cast iron boilers are found in the range of small and medium powers (powers below 2000th / h). These are usually hot water boilers.
Steel boilers: Steel boilers are obtained by welding from sheets and tubes. It is then possible to realize the most diverse firms. These boilers are used for all power ranges. This type of construction is essential for high-pressure equipment containing water (over 110 ° C) or steam (over 0.50 bar).
Overall constitution of boilers:
The boilers consist of various exchange surfaces called heating surfaces and tanks. The heating surfaces comprise several parts:
- The main part where heating occurs (hot water and superheated water) or vaporization.
- Auxiliary parts (not always available in small boilers) in which various heat exchanges take place such as:
- The combustion air heater
- The feed water heater (economizer)
- Steam super-heater
- And possibly, the steam super-heater.
The focus of a boiler: The hearth is called inside when it is placed inside one of the cylindrical bodies of the boiler, the water being around the hearth. The hearth is called outside when flames and fumes develop outside the cylindrical body or bodies constituting the boiler. The whole is enclosed in a refractory masonry enclosure equipped with baffles forcing the gases of combustion to sweep the outer surface of the body before going to the chimney.
The grids: In coal-fired boilers, the grids on which the coal burns, and which are characterized by their surface in m, are of fixed or moving types. Fixed grids consist of simple cast iron bars juxtaposed and resting on bedsteads; these bars leave between them the space necessary for the passage of the combustion air. Mechanical grids are of various types. The most commonly used ones affect the shape of a kind of metal slatted carpet passing over rollers with a horizontal axis.
Water tubes: Connecting these and some parts of the body of the boiler, these tubes, permanently filled with water, are arranged in the passage of the hot gases at the top of the hearth. These tubes can be vertical, horizontal or inclined. In some types of boilers, water tubes are a very important unit. These tubular bundles, which contain most of the water in the boiler, provide the heating surface. As for the number of bundle tubes, it is considerable and of the order of several thousand in large boilers (multi-tubular boilers).
Air heater: Located after the economizer (in the flue gas path), the air heater is a device that uses flue gas heat to heat the air before sending it into the fireplace. In addition to the thermal recovery thus carried out, hot air is sometimes necessary for the combustion chamber for the ignition of certain fuels or for drying during the grinding of the pulverized coal. The air heater can be either of the surface types, in both variants with parallel plates and manifolds. Either regeneration type where a thin sheet assembly is heated by the fumes, then, by the effect of the rotation of the assembly, is brought into contact with the air to which it gives up its heat.
Installation of a condensing boiler
The gas condensing boiler is undoubtedly the most efficient boiler on the market. Depending on the model, the savings on your heating consumption can reach up to 20%. Its installation also allows benefiting from a tax credit of 30%. The condensing gas boiler can be installed simply in place of your old boiler, on the floor or on a wall. The model chosen according to your needs and the available space is accompanied if necessary by a hot water tank. The gas network or an individual gas tank supply the boiler. A condensing gas boiler does not pose any particular installation problem, but it is essential that the installation is carried out by a qualified Gas Professional.
A central heating circuit, the first condition of the installation of a gas condensing boiler: This central heating circuit is a conventional network of pipes between the boiler and transmitters that distribute the heat. These are hot water radiators, high or low temperature, or a heated floor. The installation is compatible with all types of radiators. The operation of the network is optimal when one is in the presence of emitters operating at an average temperature of less than 65 °. The efficiency increases when the return water temperature is low. If your circuit has radiators that work with water heated between 75 ° and 90 °, so-called high temperature, the system is less efficient.
Technical constraints: extraction of products from combustion, evacuation of condensates: Air intakes are not required in the room where the condensing gas boiler is installed. Indeed, the smoke evacuation is sealed, that is to say, that the air supply is done directly outside through the flue. The boiler, which burns gas, condenses the vapors of water contained in the fumes. This, cooling makes liquid its water vapor component. An exhaust duct for water from condensation is required. The duct must resist corrosion because this water is acidic. It is usually PVC, if this pipe is cast iron or cement, a condensate neutralizer must be installed.
Implementation conditions: If your new energy-efficient gas boiler replaces an existing boiler, it is recommended to debug the heating circuit. The condensing gas boiler must be installed and put into service in compliance with the gas standard developed by the certification and control bodies. That is why the intervention of a professional proves unavoidable. The latter must once the installation is completed, provide you with a gas conformity certificate (CC2 or CC4). He is also in a position to apply the technical requirements of the manufacturer and to maintain the boiler and the heating circuit.
Installation of an electric boiler:
Electric boilers have the advantage of being particularly simple to install, which is why many private individuals get involved in this project during the renovation or construction of their home.
Steps to install an electric boiler: To put a boiler functioning with the electricity does not involve a big obstacle, otherwise the elements inherent to the implementation of a building site, whatever it is. It is essential to choose the location of the device to facilitate its accessibility and promote its longevity (prefer clean and dry places). In general, the equipment is quite compact, and it is quite possible to put it yourself without encountering major problems. Just connect it directly to the hydraulic and electrical installation of the housing to then use it and regulate the heat throughout the home. A thermostat can be supplied with the device, to benefit from a sophisticated and easy-to-use control system. The last step is to check the correct operation of the installation by starting the boiler.
What to know before installing electric boilers: Equipment of this type may be wall mounted, that is to say, it must be installed directly on the wall. In this case, be careful to install solid fasteners that can withstand the weight of the full boiler without any problem. This way, you will avoid the big glitches caused by the fall of the device. It is essential to check the tightness of the pipes as well as the non-obstruction of each element, to allow the general functioning of this system. Also, make sure that each component is properly insulated to prevent heat loss during heating production. Finally, there are safety standards established by the state that must be respected, so be sure to follow the instructions provided with your installation kit.
The advantage of installing electric heating: The electric boiler is acclaimed by individuals for its ease of installation and use. Among the advantages of this system, there is notably the absence of storage tank (tank type or other) which thus greatly facilitates the installation of the device. In addition, the energy used does not generate CO2 emissions and is, therefore, less risky than for other types of heating. Finally, thermostats and other regulation tools make it possible to control energy expenditure in a very precise way, and thus to minimize the financial losses related to the energy consumption of housing.
Installation of a cogeneration boiler:
By producing heat and electricity from the same energy source, the cogeneration boiler is an effective solution for heating a home and reducing its dependence on electricity suppliers.
The operation of micro-cogeneration: The principle of cogeneration is the simultaneous production and from single energy of electricity and heat. It is used on an industrial scale or for collective residential buildings but also for individuals in single-family homes where it is more a question of micro-cogeneration. In this case, the micro-cogeneration boiler produces both electricity and hot water for heating or sanitary purposes. It can run on gas, oil or wood. It is in most cases a condensing boiler to which is added a Stirling engine producing electricity by rotating an alternator. The heat created by this process is recovered for heating and hot water. A second family exists with fuel cells. Electricity and heat are produced by a reaction between hydrogen and oxygen. Rarely, these models have not yet reached a reasonable cost to be marketed on a large scale.
Advantages and disadvantages of the micro-cogeneration boiler: The very good efficiency of the micro-cogeneration gas boilers make them an excellent heating system to save money. Their performance can exceed that of a conventional gas condensing boiler, already very powerful. The second advantage is, of course, the production of electricity that leads to self-consumption and independence vis-à-vis electricity suppliers. The major disadvantage of this boiler is its price, still very high. While a gas condensing boiler costs between € 3,000 and € 6,000, count between € 10,000 and € 20,000 for a micro-CHP boiler. A budget that can slow down, despite the eligibility of this equipment to the tax credit.
The installation: The installation of such a boiler is very similar to that of a conventional boiler with a connection to the central heating network (water radiators or underfloor heating). However, you must add a connection to the electricity network and your electricity meter to record the quantity of electricity produced, if any, the part sold.
Alternatives to cogeneration: If you do not have such a budget, you can always opt for a condensing boiler, preferably natural gas if you have a gas connection. It is the least expensive model and the easiest to install and maintain. Hybrid boilers are also an interesting solution to take advantage of the efficiency of a condensing boiler while limiting its consumption of natural gas. Coupling the boiler with an air to water heat pump maximizes the free heat recovery in the outdoor air while limiting the phases during which the efficiency of the heat pump is low. In fact, when it is too cold, the condensing gas boiler takes over and works with better performance than the heat pump.
Installation of a mixed boiler:
A mixed boiler, also called a hybrid boiler, is a type of installation that uses two energy sources, unlike a conventional boiler that is powered by a single fuel. Natural gas, oil, wood, solar … different energy resources can be used to operate a mixed boiler.
Operation of a mixed boiler: To operate, a conventional boiler uses a single source of energy. The fuel (natural gas, oil, coal, wood, LPG …) feeds the burner which heats the coolant which will then circulate in the heating system. This makes it possible to heat the rooms thanks to the radiators, and to supply the toilets (shower, bathtub …) in hot water. In the case of a mixed boiler, the operation is identical, but the intelligent control of the device determines which energy resource to use at a specific time. Day and night, the operation adapts to the needs for optimal performance. Thus, when the first fuel is exhausted, the second takes over, ensuring the thermal comfort of the dwelling at all times. Equipped with two separate fireplaces, the mixed boiler also produces domestic hot water and feeds the heating system.
The advantages and disadvantages of the mixed boiler: The mixed boiler offers many advantages. By combining two types of energy, it is first possible to save money on energy bills. Then, this type of system offers the possibility of choosing the most powerful device, according to the energy consumption of the housing. In addition, both systems can work together or alternately. For example, in summer and in a sunny area, a solar / gas or solar/wood boiler, among others, can be powered only by solar energy.
The efficiency of the combination boiler is one of the main advantages of this heating device. Offering a yield of around 95%, this boiler not only consumes less energy but also enjoys great thermal comfort. It should be noted that the hybrid boiler cannot be installed in an apartment, because of its size. The maintenance and upkeep of the two combined systems are more expensive than a typical installation. We must negotiate a maintenance contract at the best price to not spend too much. In the case of a mixed model combining a gas boiler with another system, it will also be necessary to purge the radiators. Finally, when the dwelling does not have a central heating system, the cost of the work can weigh on the budget. But once these are realized, the savings are immediate and are visible for years.
The cost of a mixed boiler: At installation, the cost of the mixed boiler is much higher than that of a conventional condensing gas boiler. This is due to the price of the boiler itself and the components it needs to operate. The most affordable mixed boilers are around 6000 €. The most successful models cost about 15 000 €. These prices may include the installation of the boiler and its various components, such as the hot water tank, heat pump, solar panels, radiators and all that is needed to operate the installation. However, it is necessary to add the cost of the maintenance of the mixed boiler, compulsory every year.
Installation of a boiler with a suction cup or forced flow:
The technology of this heater, whether it uses wood, gas or fuel has changed significantly in recent years. This evolution offers the households concerned improved efficiency, increased security and greater simplicity. The suction cup boiler is the perfect example of simplicity in both installation and maintenance.
What is a suction boiler: The suction cup boiler is not a special type of boilers. It can operate on gas, fuel or wood and be of the conventional type, low temperature or condensation. This designation reveals that the boiler concerned is equipped with a special flue gas evacuation and air supply system. Usually, these functions are provided via a chimney and an air intake. In a suction boiler also called “forced flow,” a dual-channel duct combines the intake of fresh air necessary for combustion and evacuation of fumes outside the boiler room. The suction pipe can be installed on the front (horizontal suction cup) or on the roof (vertical suction cup).
How does a suction boiler work: A suction device associates two concentric tubes, one ensuring the supply of the boiler by the air sucked to the outside and the other an optimal evacuation of fumes thanks to a fan. This system induces a forced draft that draws air out. By eliminating the need for an air intake inside the housing, the suction cup avoids any risk of penetration of fumes in the latter following a call for air. A sucker boiler is, therefore, a totally waterproof device particularly safe.
What are the advantages of a suction boiler: In addition to its enhanced safety, according to the studies of ADEME (the French Environment and Energy Management Agency), a suction boiler offers 4 to 5% more efficient than a boiler with conventional ducts. In addition, unlike the chimney flue which ensures the evacuation of fumes from the latter, the suction system does not require regular sweeping. This type of boiler is perfect for equipping a dwelling that does not have a chimney flue or when it needs to be used with expensive stainless steel casing. Note that in a condominium, the installation of a suction system requires the agreement of the latter because it changes the external appearance of the building and requires drilling a potentially buoyant wall. In addition, the forced nature of the air intake and flue gas flow allows them to travel further. When this is required by the configuration of the premises, this makes it possible to install the boiler in a room remote from the suction device.
How to install a suction cup boiler: The installation of a suction cup boiler must comply with the requirements of the decree of 27 April 2009. The latter imposes a minimum distance of 0.40 m between the flue gas discharge axis and any opening bay, from 0, 60 m with a ventilation opening and the presence of mechanical protection for any suction cup located less than 1.80 m from the ground. This installation must be done by a certified professional who delivers a certificate of conformity at the end. A suction boiler offers an ideal technical solution for many homes. The suction technology multiplies the possibilities of installation of the boiler at home and thus allows to position it in the place which seems to you the most appropriate. It is not the suction device that defines the price of the boiler but the technology and energy that it uses. However, avoiding expensive stainless steel casing and annual cleaning while giving the boiler better performance, the suction device generates significant savings. A very flexible solution to consider for the realization or renovation of your heating system.
Installation of a low-temperature boiler:
The low-temperature boiler offers a good price/return ratio, but it is doomed to disappear in the coming years, to the benefit of the condensing boiler, more efficient and equipped with a smoke evacuation system less harmful to the environment. The appearance of boilers at low temperatures marked a technological advance: thanks to a large exchanger system, they offer the same performance as a conventional boiler for much lower consumption. The low-temperature boiler delivers water at 60 ° C in the heating circuit while this temperature reached 90 ° C with a traditional boiler, offering a reduced energy consumption of up to 15%.
The condensing boiler: a boiler at very low temperature: Thanks to a two-stage heat exchanger with a baffle, the condensing boilers recover the calories produced during the condensation of the flue gas to preheat the water of the central heating circuit. They optimize the combustion of gas or fuel oil to reduce energy consumption. Like boilers at low temperatures, they can be connected to a hot water tank. Their performance is estimated up to 110% of the PCI. Condensing boilers are considered as boilers at very low temperatures: the flue gas temperature is below 55 ° C.
Install and maintain a low-temperature boiler: For maximum efficiency, the low-temperature boiler, such as the condensing boiler, must be connected to suitable heat emitters, which can operate at a moderate temperature. Coupling them with a heated floor is particularly sensible. The installation of a boiler at low or very low temperature must imperatively be carried out by a professional. It can be easily performed when the dwelling is already equipped with a central heating system. The maintenance of the boilers is governed by strict rules, in order to guarantee the best performances and the safety of the installation. An annual visit by a professional is mandatory. It can be the subject of a maintenance contract. Chimney sweeping is usually done during this mandatory visit.
The decline of low-temperature boilers without condensation: In 2015, the European Eco-design Directive began a transition to the least polluting and most efficient heating modes, proposing a gradual disappearance of equipment with a yield of less than 86%. A derogation was allowed for type B1 devices in collective housing, under certain conditions, because in this type of building, it was not possible to install condensing boilers. In September 2018, due to a new requirement for the emission rate of nitrogen oxides (NOx) from the combustion of gas, appliances emitting more than 56 m / kWh NOx will be banned for sale. This concerns low-temperature boilers type B1. Gas condensing boilers will soon be the new standard for equipping any type of home, both in new construction and renovation.