If you decide to build a private home, you should take a number of important decisions in the design phase. If design and interior are the questions of the field of creativity, there are questions that should be resolved from the standpoint of the hard pragmatism. That is, for any home the most important communications are electricity, water, sewer and heating. And that quality heating affects how comfortable your life will be in the new house and how much money you will spend for its maintenance, especially in winter. When should you start? Often begin to build a private home in the spring or summer.
At the design stage until the moment when the first foundation block is laid you must already know exactly what should be the heating system so you do not have to break the wall, finish building the chimney or boiler room. Also note that the peak sales of heating equipment begin in late summer and early autumn. Therefore, at this time you will not be easy to find good specialists for the design and installation of heating systems. What the heating system consists of?
In brief, boiler is the main unit in the heating system. From it heated water or antifreeze through the circulation pump (in a system with forced circulation) or by natural circulation enters the radiators and gives off heat, warming the air in your home.
The advantages of systems with forced circulation are:
-comfort (you can maintain the specified temperature in each room, saving fuel);
-higher quality of system;
-small diameter of pipes;
-smaller temperature difference between the hot water coming out of the boiler, and chilled, which it received (which increases the life of the boiler).
The disadvantages include the fact that the pump is powered by electricity. So it does not work without electricity. Therefore, in our country, using this boiler, you should think about the emergency power to the pump. This may be a diesel generator or battery. In a system with natural circulation there is no pump. The water in the system moves in consequence of what is known of the course of the physics in school; hot water is lighter (due to lower density), so rises and cold - goes down. For such systems larger diameter pipes are used, temperature control in individual rooms is not possible - you have to heat the whole house, so fuel consumption is much higher.
We can tell a lot about the features of different systems, methods of breeding of hot water in premises etc., but since the purpose of this article is to choose the boiler, therefore we will stop at this issue in more details. First of all you should decide usage of which fuel is good for you and the area where the house is located. There are the following options: gas, liquid (diesel) fuel, electricity, solid fuels (coal, wood, coke, etc.)
If your home is supplied to the gas pipeline, then, in most cases, the best choice is a gas boiler, so that today it is still the cheapest fuel.
Advantages of gas boilers:
-Easy to operate: main gas is supplied continuously (there are boilers that can be powered by gas cylinder, but it is very expensive)/
-Cheap fuel with high efficiency.
-Can heat a large room.
The disadvantages include:
-Before installing a gas boiler you must obtain the appropriate permissions and make certain documents (the procedure we described in detail in the previous issue of "AB"). But often, documentation assumes assembly firm for a fee.
-Many people consider that gas boiler is dangerous because there is an open flame and gas leak is possible.
-It often happens that the pressure in the pipeline is increasing, and then decreasing. Therefore, flame of the burner becomes more or less. Sometimes the flame is so small that the fire burns the burner. Conversely, if the flame is too high, the boiler overheats (in the result body boiler can "burn"). However, there are special, remote burners. These burners cost about 1500 $ (almost the same amount would cost boiler itself).
-For gas boiler you need chimney and well-ventilated room with a separate entrance. In this case, boiler should not be standing up to the wall or between two walls. You also need to have the doors to the room freely opened: the burning of wick and burner required the flow of oxygen. The boiler requires a distance of 30-50 cm from the wall, depending on the model and size of the boiler.
-Gas boiler should always be equipped with the automatic, which prevents leakage of gas and blocks the gas pipe, when suddenly a leak happens.
Gas boilers are wall and traditional, installed on the floor. In traditional boiler heat exchanger is usually made of cast iron or steel. Steel are lighter, not afraid of strikes during transportation. In a cast iron heat exchanger is thicker, that prolongs its life, but more fragile. Wall heaters is a complex device, which usually contains not only of heater, heat exchanger and device for controlling, but also one or two circulating pumps, expansion tank, manometer, thermometer, security system and more. The principal difference, in most cases, between wall boilers and boilers that are installed on the floor, is the material of which the heat exchanger is made. In the wall boilers it is copper, and stationary - either steel or cast iron.
Advantages of wall boilers:
-suitability for every apartment heating systems
The main disadvantages of wall boilers:
-restrictions on capacity (up to 31-35 kW)
-limit of the usage of antifreeze (most manufacturers prohibit pour antifreeze in their boilers)
-high sensitivity to the quality (purity) of coolant and tap water.
According to the way venting exhaust gas boilers are divided into models of the natural and forced draft. In boilers with forced draft gas are drained out through a special tube by a fan, built-in boiler. Boilers with natural draft need the construction of chimney. In general, the higher the chimney is, the better the traction. There are also models with so-called coaxial chimney. This chimney is a double-layered tube, through one channel of which the boiler gets the necessary combustion air (the oxygen in the room with boiler is not burning), and the other through which the products of combustion are discharged outside. By today's standards, these boilers can even be used for heating of city apartments to the 9th floor inclusive because the chimney cannot be attached to multistoried building.
Here are the advantages and disadvantages of this type of boiler.
- Electric boiler is the safest: there is no open flame.
- Simplicity of installation and operation.
- Small size.
- Electric boilers are made of steel, so they are relatively lightweight and can be hung on the wall. This saves space.
- No need to construct of a separate room and chimney (for both gas and liquid fuel boilers).
- They do not require special care - no need to clean them of soot (both gas and liquid fuel boilers).
- Runs silently.
- Environmentally friendly - no harmful emissions and odors.
- Convenient for the elderly.
- Requires a separate wiring, and if the boiler output exceeding 6 kW, three-phase power network is required (380 V).
- Limited capacity (for heating a large house you will have to buy several separate units, for example, for each floor).
- Electric boiler has great power consumption.
- High consumption of electricity at low efficiency.
- Inconvenient where electricity disappear more than for a day.
Electric boiler is a simple device. Its main elements are: heat exchanger consisting of a tank containing heaters, control unit and temperature controller. Some manufacturers include circulating pump, expansion tank, safety valve and filters in the kit. Electric boilers can be single phase (220V) and three phase (380V). Boilers with capacity more than 12 kW, tend to be a three-phase. Therefore, these boilers require certain calculations and the organization of power supply of house.
BOILERS WITH REMOVABLE BURNERS USING GAS OR LIQUID FUEL
If you install a boiler of this type, you will have absolute autonomy, which is very important in our country where you cannot rely on the stability of gas or electricity. In addition, the boilers with removable burners are useful in situations when the gas is in your home is not piped. You can first use the burner for liquid fuel and after the onset of gas install gas. But keep in mind that the cost of mounted gas burner can be equal to the cost of the boiler.
Costs of liquid fuels can be approximately calculated by the formula: Fuel consumption (kg / h) = power burners (kW) x 0.1. When using liquid fuel you will need a container for its storage. For this purpose you will have to buy a plastic or steel tank of domestic, Russian or other foreign production. Their cost ranges from $ 200-500.
Advantages of these boilers:
- Power of liquid fuel boilers - from 19 kW, so they can heat large areas.
- For their installation you do not need special permits (as for gas boilers).
- The use of diesel fuel is much cheaper than electricity.
- High efficiency.
- For any fuel oil boiler must be purchased and attached a special tank of diesel fuel.
- Separate room with an extract is necessary.
SOLID FUEL BOILERS
The fuel for these boilers can be wood (wood), brown or stone coal, and coke. There are models that can run on all types of fuel, or that only work on one, but give higher efficiency. Previously, these boilers were very primitive and had almost no automation; today this statement is no longer true. Much of modern boilers can automatically maintain the desired temperature. This is achieved by raising and lowering damper, which slows down or speeds up the combustion. This unit does not require electricity. Of course, this boiler requires a properly organized boiler chimney for combustion gases. Traction depends primarily on the height of the chimney. Speaking of updates, we should mention the pyrolysis boilers. Their main advantage is high for this type of boiler coefficient of performance (COP) - up to 85%, and ease of power adjustment. The difference of these boilers from conventional models is that they do not burn firewood but gas released from the wood under high temperature. In this combustion ashes and soot don’t almost form. Solid fuel boiler is suitable for summer house of area of 60 square meters.
Advantages: If you are able to prepare firewood (and many), you will not have to spend money on fuel.
Disadvantages: It is necessary to constantly monitor the furnace and lay the wood - this process cannot be automated.
BOILERS RUNNING ON MULTIPLE FUELS
Often there are boilers with combustion chamber for solid fuels and the possibility of installing burners using gas and liquid fuel. This is useful when you temporarily or periodically have no possibility to use gas, or simply want to have a variety of options for the future. Less common are boilers that can run on either gas, liquid and solid fuels, and have built-in electric heater for heating. At first glance it is ideal. But if you think, you will see that not so often there are situations when you need to use all fuels. If we take into account that this boiler often cost more than the sum of three separate boilers that run on fuels listed above, it becomes clear that the demand for these boilers is limited. The main advantage of combined boilers is that they can run on different fuels.
Advantages: In the absence of one fuel it can run on another.
Disadvantages: The higher price compared with mono fuel boiler.
CHOOSING POWER OF BOILER
To find the required boiler capacity, allowing heating your room for minimal energy, you should consider the following. Approximate capacity of the boiler for a well insulated house with a ceiling height of 3 m is defined by: 1 kW boiler output of 10 m2 heated area. Clearly, if your home is poorly insulated, or you want to heat the glass porch, you will need to increase capacity. In addition, it is desirable to take into account that if you choose to except heating by boiler still get hot water, the required power may increase by 20-50%. But the final calculation of the required capacity must be trusted a specialist heating engineer - it is important to not save. Having determined which the power you need, you can roughly estimate the cost of equipment and its parameters (size, weight, etc.). And the last concerning the power of boiler. In brochures or manuals for the boiler its capacity is indicated that calculated under conditions of normal level of pressure. In the national network pressure is often much lower and, therefore, the real power, which will have a boiler, may differ significantly from its characteristics (of course, in a smaller way).
COMPARISON OF ENERGY-DEPENDENT AND ENERGY-INDEPENDENT GAS BOILERS
For energy-dependent wall boilers power of about 220 V with capacity about 200 W is required, and 460 W for boilers, installed on the floor.
-meet the stringent requirements of safe gas burning without the presence of man, that is intended for use in a country house;
-is completely automatic, including automatically cut in the work after the renovation gas or power supply;
-may be added regulators of heating due to external or ambient temperature, that is to provide economical gas consumption;
-manage priority preparation of hot water, that provide optimal use of the boiler capacity;
-are able to provide any uses of the boiler (heating "warm floor", pools, winter gardens, etc.)
Energy-independent boilers do not need a power supply, because are equipped with manual ignition and gas control valve by thermocouple.
-under gas safety they are not allowed to be left in the absence of the man, that they should be used only during residence in the house;
-are not fully automatic, since after any interruption of the gas supply require manual reset;
-not designed for regulation of heating and hot water.
ON WHAT YOU CAN NOT SAVE
1) On boiler efficiency
Coefficient of performance (COP) of most modern domestic boilers of foreign production is on technically maximum possible level - 91-94%. The range of the efficiency of domestic boilers is quite wide: from 80 to 90% depending on the manufacturer and type of fuel. You can calculate that for three or four years economical boiler will pay for the money that you overpaid for it, and will start to "earn" you a certain amount each year, and vice versa.
2) On the reliability of the boiler
Let's start with gas boilers. Their reliability and security is above all reliable automatic burners. Gas automatic in cheap boilers is flawed and unreliable. Electrical and mechanical defects of the hardware force manufacturers to restrict operate their boilers without constant human presence. Not excluded boiler, leaving to work, for possible consequences answer yourself! Is it possible to estimate the loss of your money when returning home and turning on the light, you thereby cause an explosion of gas accumulated in the house? Question: due to what, without changing anything outside manufacturer can reduce the cost of the boiler (to increase sales)? First of all, they are saving on the cost of raw materials - metal of boiler. In steel boilers with the same parameters (power, efficiency, etc.) you can meet the thick walls of the boiler even 2.5-3 mm. Where the wall is thinner, there is, of course, lower lifetime. In cast iron boilers weight is also an indicator of reliability. In "light" boiler there are smaller volume of water sections, less perfect flow part, resulting in uneven growth of the local wall temperature sections, amplitude and frequency changes in temperature of the metal, that also reduce the reliability and service life of the boiler.
3) On the equipment of control
How to run your heating equipment most efficiently and effectively? The only way is to establish the necessary automatic control and regulation that will provide: - support the optimal temperature in the house at any outside temperature and any graphics you live in a house; - support optimal temperature of hot water, readiness and capacity PRT system for any water schedule; rational use of net power of your boiler, depending on the configuration of the building thermal circuit, the parameters and the type of loading (permanent, seasonal, with a daily schedule or "peak", etc.) of various heat consumers. Do you know that reducing the room temperature by just 1 C reduces heat consumption for heating by about 3%? Ensure such tight control of temperature manually is impossible, so you always or overheat the room or freeze. Spending on set of automatic for diesel boiler certain amount of money you can save each year not less than: 3% efficiency by reducing the temperature by 1 C in the house in the mode of stay (comfortable temperature that is recommended - 20 C); 3% efficiency by reducing, on average, 1 C temperature in the house while you sleep, or in a mode of temporary absence (economic temperature is recommended - 16 C) as well as the long absence (temperature, recommended - "frost protection" - 6-10 C); 2% efficiency by reducing operational capacity of the boiler and the water temperature in the boiler by adjusting of heating depending on the outside temperature and hot water temperature control according to the schedule of water use. In this way, the cost of automation will be recouped in about 3 years.
4) On service
Remember that any manufacturer protects your equipment from unqualified interference in his work, removing guarantee in the absence of qualified commissioning. Beware of cheap services installation. Cleaning the boiler and the chimney of soot with incorrect installing of diesel burner or the cost of repairing the boiler/burner with incorrect connect easily block your imaginary savings in case of cancellation the more expensive, but really skilled services.
ON WHAT YOU SHOULD SAVE
1) On wages of foreign workers
Put two boilers of various European manufacturers. With careful analysis you can see that the main components that determine the efficiency and reliability of boilers are manufactured by the same specialized firms as a result of European integration. Now compare price - and you will understand that the higher the level of wages in the country where the boiler produced, the higher the price.
2) On services of intermediaries and interior of shops
You should analyze in detail the offer on the market, using, for example, price-lines placed in local advertising and information media. It is almost always the same boiler can be found for 10-20% less expensive than in the store.
3) On the redundant complexity of equipment
Clearly, the more certain product has complex devices or functions, so it is more complex, the greater the probability of its failure and the more expensive the cost of maintenance and repair. So try not to pay for features that you do not intend to use. For example, if the boiler with diesel burner is installed in a warm room (in the basement), you do not need a burner with heating fuel. Also analyze which feature has automatic boiler control. You may not need the function of boiler control using a mobile phone, or perhaps his programming work on weekdays?