Table of Contents
Hot-water supply and heating – without what there cannot be no house if, of course, its owners do not expect to come here accidentally and only to warm season. At construction of the house intended for full-time residence it is impossible to bypass similar questions. And the problem of right choice of the boiler optimum for this area will be one of the most important. Boilers can be separated on marks, construction features, efficiency and other parts. But the main distinction consists in what fuel is used for operation of the equipment.
The boiler can be:
- liquid-fuel or universal.
The choice needs to be made depending on local specific conditions. Each look has pluses and minuses which we also will consider.
The optimal variant if the site adjoins to the main gas pipeline as it is impossible to find cheaper fuel. Not accidentally 3/4 boilers, gas.
There is set of models and great number of producers of gas boilers. More simply to understand this variety, all offers should be separated into two groups: floor and wall. It divisions can seem too conditional. Really there is big difference between the design which is hanging on wall or standing on floor? In fact this difference is rather essential as at floor and wall boilers the complete set and the device significantly differ. Let’s begin with consideration of options floor.
Floor gas boilers
The boiler wall can be called thing rather conservative and traditional, for many decades it seriously did not change. The heat exchanger of such devices usually is steel or pig-iron. It is unlikely it is possible to receive definite answer to what question from them better. The pig-iron heat exchanger, on the one hand, is exposed to corrosion less, walls of its heat exchanger are thicker, and, so longer life cycle. But same becomes also the reason of shortcomings. Cast iron – metal brittle that leads to risk of education in transportation time of microcracks. Besides, if hardness of water is increased, because of properties of cast iron and features of pig-iron heat exchangers, over time there can be their destruction to which lead local overheating. If the heat exchanger is made of steel, that is big danger of damage when transporting. Also misuse can lead to what steel heat exchangers will begin to corrode. However creation of standard conditions is not difficult for operation of steel boilers at all. The main condition — temperature in boiler cannot fall below “dew point”. Good design can always create the system allowing to use the equipment during the greatest possible term.
Floor gas boilers are divided by complete set on two groups: with inflatable (which can be called also hinged, replaceable) and atmospheric torches. Atmospheric it is cheaper, more silent and simpler. At inflatable torches bigger efficiency, but they are much more expensive. The boilers intended for operation with inflatable torches are used also for installation of the torches working with liquid fuel. Payment of atmospheric torch is included in the boiler price as is its integral part. Inflatable it is paid separately.
Power of the floor boilers equipped with atmospheric torches generally fluctuates within 10-80 kW (there are models with bigger power), and with replaceable inflatable reaches several thousand kW. It allows the consumer to pick up option which power will be enough and for the huge building, and for small country lodge.
Such parameter of the equipment as dependence of automatic equipment on electricity is important for conditions. It is natural that, before this, it belongs to not electrified areas, it is impossible to miss also option of supply of electricity with interruptions. The majority of the gas boilers equipped with atmospheric torches do not depend on power supply. With foreign boilers there can be problems. Their autonomy is reached in two ways. In the first case guidance system as much as possible becomes simpler — independence of electricity is reached due to almost total absence of automatic equipment (it also belongs to domestic boilers). Such boiler maintains the set temperature and is not guided by indoor temperature. The second way at which the heatgenerator producing electricity, necessary for automatic equipment, from heat is used is more progressive. They can be used with managing directors of boiler of the portable room thermostats maintaining indoors the set temperature. There are non-volatile gas boilers in assortment of the Czech DAKON, the Slovak Protherm and the Italian Beretta.
One more division – working at the only power level (one-stage), at two levels (two-level) or with smooth regulation. At full capacity operation of the boiler is necessary approximately for 15-20% of heating season, all rest of the time it is wasted. It is clear, that more economic use of boilers two-level or with the power modulated.
Main pluses of two-level boiler:
- due to reduction of inclusions/switching off operation term increases;
- work with the lowered power saves gas on the first step;
- the amount of combustion gases in the atmosphere decreases;
- possibilities of sharing with boilers of different capacity extend.
Operation of boilers with the modulated power gives still big efficiency.
Wall gas boilers
Such devices have appeared relatively recently, but have already received wide popularity. Most precisely the formulation “mini-boiler” can describe them. Such term has appeared because in the small body not only the control device, the torch and the heat exchanger, but also circulating pumps (1 or 2) ensuring safety system, the thermometer, expansion tank, the manometer, many other things are located.
Despite the advanced technical developments used in “wall” their cost can be twice less than floor fellows. The convenience of mounting also belongs to advantages. Some buyers mistakenly consider that simplicity of mounting has to concern only workers who will install the boiler. However it should be taken into account that the sum spent for mounting “wall” or separate mounting of the boiler house which will include also separate installation of the boiler, expansion tank, the boiler, pumps, other equipment will significantly differ.
The following plus – opportunity to enter boiler in interior and its compactness.
There is division of boilers and according to way of removal of gases: with natural, created in flue, draft and forced (in boiler the integral fan).
Most often the companies produce the models working both with the first, and with the second option of draft. The natural draft is known to all on flues over roofs. And the forced draft began to be used not so long ago. It have the mass of advantages, such model will be ideal for the room which is not equipped with normal flue, combustion products in this case through flue coaxial for which there is enough opening in wall. Coaxial flues have two pipes in one body, internal brings combustion products to the street, external drives air into fire chamber. Therefore such boilers are used also in cases when the normal flue is, but it is undesirable to take away air from the building. As a result room oxygen does not burn down, cold air of the street does not come to the room, capital investments as the traditional flue is not under construction decrease.
It should be noted CICH, CHAPPEE and BAXI S.p.A. producers which produce the floor models supplied with forced removal of gases. But this rare exception of general series.
The following division – as ignition which can be electric or piezo ignition. The first are more economic, in them there is no pilot light with the flame sustaining continuous combustion that leads to gas economy approximately on 100 kilograms a year One more plus of such system – if supply of electricity is temporarily stopped, the boiler with electro ignition will turn on automatically when resuming receipt of the electric power, the model with piezo ignition needs manual actuation.
Torches are separated into the normal and already mentioned modulation. The boiler with modulation torch will provide more economy mode of work and will regulate power automatically, depending on necessary requirement. Besides it will support hot water at the level exposed in advance.
In the majority of wall boilers the devices ensuring safe functioning are built-in. The sensor of availability of flame will turn off supply of gas at disappearance of flame, the blocking thermostat will switch-off the boiler if temperature of boiler water increases to emergency level, the special device will switch-off the boiler at disappearance of power supply, another will block boiler if gas is disconnected. There are both sensors of draft, and the devices which are switching-off the boiler if the volume of the heat carrier decreases below norm.
The main directions for use of wall gas boilers
First of all it is, of course, individual heating services of cottages and country houses. Depending on the brand of the boiler and firm of the producer the power of devices can fluctuate within 12-42 kW therefore range warmed and rooms is very wide – from small in 50 squares, houses, to huge rooms in 400 sq.m. Simplicity of mounting, low cost, opportunity to build in boiler any interior, its compactness become indisputable advantages of this class.
One more range of application — apartment heating of multi-storey town houses. At us similar systems meanwhile have not found wide circulation though they help to solve problems with deliveries of heat, its losses on old heating mains, distribution of the heat carrier in necessary sizes, etc. But it is separate subject.
Boilers of very many producers, including with world name: ACV (Belgium), Sime (Italy), Modratherm (Slovakia), Bosch (Germany), CTC (Sweden), Kiturami (South Korea), Chappee (France), Beretta (Italy), Ariston (Italy), Dakon (Czech Republic), Rinnai (Japan), Buderus (Germany), Lamborghini (Italy), Saunier Duval (France), Roca (Spain) and others.
There are several reasons limiting wide circulation of electric boilers:
- not each site is equipped with electricity or has opportunity for allocation of the power demanded for heating (the house in 200 square meters will demand about 20 kW);
- rather big cost of electricity;
- interruptions in power supply.
But if similar problems do not concern you, the electric boiler can become the ideal choice. Among its advantages:
- simplicity of mounting;
- rather low price;
- the compactness and small weight, boiler can quite take the place on wall and save the area;
- safety, work without naked flame;
- does not demand flue;
- does not demand the special boiler house;
- simplicity of operation;
- silent work;
- ecological purity;
- lack of smells and emissions.
In cases of interruptions in supply of electricity the boiler can be used with reserve, using solid fuel. This option is admissible also for the purpose of economy. The house is heated by cheap solid fuel, and then in the automatic mode on maintenance of the set temperature the electric boiler turns on.
It should be noted that installation of the electric boiler in the cities where strict environmental requirements are made and arises the need for numerous approvals, becomes more favorable, than mounting of any other equipment (including boilers gas).
Device and complete set
Electric boilers have rather simple device. Basic elements: the heat exchanger which is dollar fixed by Tenami (electro heaters) and the block which is responsible for regulation and management. Boilers of some manufacturers at factory are completed with expansion tank, circulating pump, the filter, the safety valve and programmator.
Electric boilers of small power with small power can be single-phase on 220 V and three-phase on 380 V. Boley powerful (from 12 kW) are made only in three-phase option.
Absolute majority of boilers which power exceeds 6 kW are issued multistage. It allows to spend rationally electricity and to turn on the equipment on not ultimate power in the transition autumn and spring periods.
Rational use of the energy carrier in case with electric boilers becomes the most relevant. Installation of the portable programmator maintaining indoors necessary temperature according to the schedule established by the owner in advance allows to receive considerable economy. The cost of such programmator is rather small and fluctuates within 50-150 euros. Besides programmator not only save, but also increase usability of the equipment and comfort of accommodation.
The most noticeable brands of electric boilers in the market: EVAN, RUSNIT (Russia), Wespe Heizung (Germany), Roca (Spain), Protherm (Slovakia), Kospel (Poland), Eleko (Slovakia), Dakon (Czech Republic), Bosch (Germany), ACV (Belgium).
Solid propellant boilers
Can use firewood, stone or brown coal, coke, etc. exist even such which use straw. There are models using any fuel and those which are intended under the specific energy carrier efficiency is higher than such boilers.
The main advantage of these devices – possibility of creation completely autonomous heating services. Are most often used in areas in which there is no possible connection to electricity and the gas pipeline. It is possible to carry the low price of fuel and its availability to other advantages.
However also the shortcoming inherent in the most part of solid propellant boilers – impossibility of work in the automatic mode and requirements for regular loading of fuel is obvious.
In Western Europe the solid propellant boiler often is chosen not because there is no other fuel but because the prices of the same gas rise constantly, and the cost of fuel firm remains at one level. Besides there production pallet — the granulated fuelwood having high combustion heat and allowing to automate loading process is well arranged.
It should be noted that there are boilers using solid fuel and combining at the same time the main advantages – automatic maintenance of the set temperature of the heat carrier and independence of the electric power. Automatic temperature maintenance happens by means of the sensor which is mechanically connected to valve. At increasing temperatures above the set norm of valve burning process is covered and slows down. At fall of temperature the valve opens. The device is completely mechanical, that is also irrespective of the power supply network. Products from the Czech company OPOP can be example of these boilers.
If the choice stops on the boilers working from wood it is better to pay attention to the modifications adapted for this fuel. So the Czech firm DAKON most of all known to buyers, has as models, with DOR modification (for any solid fuel), and DOR D – for burning of tree and wood waste. The device of the last differs in the fact that their combustion chamber is complemented with the boards improving combustion of wood and serving as the catalyst. Such boilers can use wood which humidity reaches 35%.
Some models are supplied with useful additions: the thermometer for tracking temperature and manometers for tracking of size of pressure in heating services. One more useful addition – protection against overheating. It is provided with contour of cooling water. The system is controlled both manually, and automatically. In feather case at rise of temperature the valve which is taking away cooling water opens. In the second on branch pipe with cold water the valve which is automatically turning on at achievement of maximum temperature is installed.
Except the fuel choice, it is necessary to pick up correctly and the power of boiler. Approximately, heating of 10 square meters of rooms up to 3 meters high will require 1 kW of power. But this formula is rather approximate, it does not consider such factors as thickness and material of walls, apertures of windows, etc. Therefore it is better to entrust final settlement to professionals.
It is necessary to mention also gas-generating boilers – the devices using pyrolysis combustion of wood. These are rather new models. In difference from usual boilers, in them not only wood, but also the wood gas which is emitted at the increased temperature burns down. At its combustion high temperature is formed, gas passes through nozzle and gives very clean flame. Hydrolytic burning does not form soot and leaves ashes minimum. Efficiency of such boilers reaches 85%, and power is regulated automatically. The main shortcoming – big, in comparison with other solid propellant boilers, cost.
The choice and installation of the solid propellant boiler has to be based on requirements imposed to the internal section and height of flue. The size of smoke pipes depends on power and on specific model. To determine its final height and section, it is necessary to adhere strictly to the management, on mounting and service.
The range of the solid propellant boilers made abroad considerably concedes to boilers gas, electric or liquid-fuel. It is possible to call the German companies Viessmann and Olymp, and also Czech Opop, Dakon and Atmos.
Boilers liquid-fuel and universal
The boilers working for three, and that on four types of fuel are called universal.
Number of producers offers boilers which camera is intended for combustion of solid fuel, but the installations of torches giving opportunity which will work from gas or liquid fuel. The VIADRUS, DAKON companies (Czech Republic), ROCA (Spain), DEMIR DOKUM (Turkey) and JAMA (Finland) release the boilers working from three types of fuel. In the JAMA models there is coil for hot-water supply – they are double-circuit. The Swedish firm CTC sells boilers, oil-fired and gas, but having the built-in TEN operating from the electric power.
Models with the built-in TENG can use all four types of fuel. But at the same time it should be taken into account that such opportunity will involve additional costs, and not small.
Liquid-fuel boilers have replaceable torches for gas and provide autonomy and independence of external sources. The only thing that will be necessary – supply of diesel fuel. Besides, they are convenient in situations of expectation of supply of the main pipeline. Before there is gas, the liquid-fuel torch is used, and gas is established later.
Let’s note that inflatable torch – expensive and difficult device. The average price of the blowpipe working with power of 50 kW – is more than 1000 euros. Such cost is explained by the high efficiency (about 94%) and complexity of design.
The list of producers of boilers with the replaced torches almost completely is similar to the list of the companies offering gas boilers. Wolf (Germany) Viessmann (Germany), Sime (Italy), Roca (Spain), Protherm (Czech Republic), Lamborghini (Italy), Ferroli (Italy), Kiturami (South Korea), De Dietrich (France), CTC (Sweden), Dakon (Czech Republic), Chappee (France), Bosch (Germany), ACV (Belgium), Buderus (Germany), Mora (Czech Republic) are most noticeable from them.