At present, in apartments and private houses one can still find old-style heating equipment that no longer meets the increased requirements — inefficient, uneconomical and does not meet safety conditions. For a long time, the main type of household gas-heating equipment was AOGV gas floor-standing boilers (autonomous heating and hot water supply). These household boilers — heating gas units were equipped with atmospheric type burners and provided heating of housing by natural circulation of hot coolant in the heating system. Significant advantages of this technique are energy independence and high reliability. AOGV was equipped with primitive automation, which quickly failed, but the heater continued to successfully perform its functions without it. Such a household gas boiler is the only heating unit that does not consume electricity.
Modern household gas heating boilers of domestic and foreign production represent a new generation of heating equipment that meets not only the increased requirements for safety and efficiency, but also the aesthetic needs of the consumer.
Let us consider in more detail what modern boiler equipment is, and how functional this heating technique is.
Gas boiler — the main element of an autonomous heating system
An autonomous domestic water heating system based on a gas boiler consists of the following main parts:
- heating boiler with pump;
- automation system;
- ventilation system;
- pipe wiring of the coolant;
The main element of the heating system is a gas boiler that provides heating and circulation of the coolant. Let’s consider this unit in more detail.
Purpose and functions of gas water heating boilers
The main task of gas boilers is to heat the interior and provide DHW (hot water supply systems). Household autonomous boilers, gas heat generators use natural gas as fuel, supplied to the autonomous heating system of housing from the central highway. The use of gas heating boilers for domestic heating and hot water systems is due to their following characteristics:
- performance (power) gradation;
- relative ease of installation;
- ease of use due to a high degree of automation.
Identical industrial equipment differs from household equipment in power, dimensions and technical equipment, therefore the operation of industrial gas boilers requires professionalism and constant monitoring of the operation of the unit from the service personnel.
The use of gas boilers in everyday life should be safe, so the management and maintenance of these units should be simple and do not require the consumer to have special skills. Modern models of gas boilers, due to the use of special technologies in their production, fully meet the requirements.
Modern heating boilers, unlike outdated models, have an efficiency close to 90%. In addition to heating the interior, modern household gas-heating equipment of the latter is able to automatically ensure the operation of the hot water supply system for housing.
Boilers of modern models are optimally automated, the degree of automation depends on the purpose of the unit and the performance class. The consumer market for water heaters is represented by household appliances of various types and types. Customers have a wide variety of models at their disposal, from powerful floor-standing household boilers for heating large private houses to compact wall-mounted units for city apartments. For each type of housing and operating conditions, you can choose a boiler of the appropriate type — a single-circuit or double-circuit gas boiler, a unit with an open firebox or with a closed-type combustion chamber, boilers with cast-iron or bimetallic heat exchangers.
Important! The high degree of automation of gas boilers has reduced the share of human participation in their operation, but has not reduced its role — the fulfillment of all the requirements for the safe use of gas heating equipment set out in the operating instructions is strictly necessary.
Classification of domestic gas boilers
A review of household gas boilers will be incomplete without considering the types of classification of these heating units:
- by location;
- by functionality.
Depending on the location and method of installation, autonomous gas domestic boilers are produced in two types:
- floor execution;
- wall type.
Household gas boilers in the floor version are more powerful units (up to 1000 kW), capable of providing heat and hot water to large houses. The performance of the boiler is indicated in the instructions for its use in order to facilitate the choice of the unit for specific areas and operating conditions.
Important! The large volume of the water tank causes a significant weight and dimensions of such units, therefore, for the installation of outdoor equipment, it is necessary to specially equip a separate boiler room, equipped with a chimney and ventilation.
The requirements for a home boiler room are determined by GOST and are mandatory. In particular, for gas boilers with a power of up to 30 kW, the area of u200bu200bthe room must be at least 4 square meters, and the volume — 8 cubic meters.
A household wall-mounted gas heating boiler has a compact size, but its power is limited, since mounting a boiler with a large water tank on the wall places increased demands on the bearing capacity of the base.
Boilers of wall models can be easily installed in the utility room, in the kitchen, in the bathroom. To save space, you can use the existing niche in the wall for installation. In this case, it is not required to allocate a separate room for the heating boiler, the necessary air flow into the combustion chamber and the output of combustion products to the outside will provide a double-acting chimney — coaxial, replacing bulky traditional structures.
When it is installed on the wall, according to the location of the boiler, marking is performed, and then a hole is made along the diameter of the coaxial chimney with an addition of 3–4 cm for subsequent complete sealing of the gaps with a caulk or other method. The installation of additional air ducts or the connection of this chimney to the common shaft of the house is not required.
If you want to have at home, in addition to heating, an autonomous hot water supply, a wall-mounted boiler should be selected with a heat capacity of at least 24 kW (not to be confused with the electrical power consumption of the unit).
Cascade system of gas boilers
When designing the heating of private houses of a large area, in order to save money, they use the use of a cascade of gas boilers of small and medium power, united by a single system of hydraulics and electrics (not to be confused with the parallel connection of a group of boilers, where each of them is controlled separately).
This technology, depending on the time of year and the need for hot water, makes it possible to use not the only available huge floor-standing unit, but the required number of boilers from the cascade.
Ways to control the cascade system of units can include not only the use of a certain number of cascade boilers, but also a combination (using a cascade controller) of heating devices operating with different power settings.
The cascade use system is mounted both from floor-mounted boilers and from wall-mounted units.
In addition to heating private housing, the cascade technology for installing heating equipment, but from units of higher power, is used for heating public buildings (train stations, shopping centers, exhibition and concert halls).
It’s important to know! For heating an apartment with an area of 50–70 m2 5–10 kW of the total heat output of the boiler is sufficient. The rest of the power will be required to heat water in the DHW system. The more hot water intake points, the more powerful the boiler should be.
If the power of the unit is not sufficient to provide the GHS in the required volume, the installation of an additional device is used — an indirect heating boiler, which is connected to the gas boiler by piping.
Classification by functionality
The division of boilers according to the type of placement is directly related to the functionality of the gas unit, which depends on the number of circuits in the design of the device — one or two.
Single-circuit boilers are used only for heating residential premises, which is provided by the only water circuit available in the design of the unit.
For the full life support of a residential facility, double-circuit gas boilers look more attractive, which, in addition to heating, ensure the functioning of the hot water supply system, using its second circuit for this. Double-circuit heating devices differ in the method of heating the coolant:
With a small consumption of hot water and a small number of hot water intake points (1 or 2), it is better to use double-circuit boilers with instantaneous water heating. Such devices have less power and are economical.
With a significant need for hot water, you should purchase a double-circuit boiler with a capacitive method of heating water, but even in this case, its consumption has limits — if the consumption of hot water with a temperature of +450With and above exceeds 20–40 liters per day, the boiler will not be able to cope with space heating, as it will work only for heating water.
Models of wall-mounted boilers with instantaneous heating are compact and quickly heat hot water. The disadvantages of the design of such equipment are high gas consumption and a drop in the temperature of the coolant with intensive consumption of hot water. The way out of this situation is to install a storage boiler, which will reduce fuel consumption and allow you to maintain the desired temperature of the coolant. However, this operation will significantly increase the cost of arranging the heating system, in addition, a certain location is also required to install the boiler.
For reference: owners of private houses, who are less limited in living space than apartment residents, and who have single-circuit boilers at their disposal, can additionally install an indirect heating boiler of the required capacity as an alternative to a double-circuit unit.
Household gas heating equipment can have significant design differences and features, including differing in the material of manufacture of heat exchangers, which are divided into the following types according to this feature:
- steel — on the equipment of budget models;
- cast iron — for floor-standing boilers;
- stainless steel — used in wall-mounted boilers;
- bimetallic (bithermic) — the most common type.
Each type of heat exchanger has its own advantages and disadvantages, so the heat exchanger must be selected with reference to operating conditions and personal preferences:
- steel heat exchangers are cheap, but subject to corrosion.
- cast iron products are practical and durable.
- bimetallic products are lightweight and therefore are installed in wall-mounted models of double-circuit boilers.
- stainless steel heat exchangers are strong, durable, do not change the chemical composition of water, but due to the high cost of the material and the complexity of manufacturing technology, they have a high price.
Gas heating boilers are also classified according to the design of the combustion chamber:
- open type;
- closed furnace.
The difference between them is that when the wind blows, harmful combustion products can enter the room. In addition, the air necessary for the combustion of gas enters the open combustion chamber from the room, which leads to the burning of oxygen in the room. Both of these factors oblige to periodically ventilate housing.
And the closed type of the combustion chamber isolates the combustion process from the atmosphere of the room, the air enters there from the outside, and the oxygen in the room does not burn out.
Currently, condensing gas boilers and turbocharged units are gaining popularity, which, with less fuel consumption, have greater efficiency, but, accordingly, a higher price.
See also: why does a gas boiler blow out?
Each model of a domestic gas boiler has its own functionality and resource. When choosing a device model for yourself, it is necessary to take into account the conditions for the upcoming operation of the unit and the tasks that it will have to solve. Budget models are able to meet the minimum requirements of consumers, while expensive appliances significantly expand the capabilities of the inhabitants of an apartment or residential building.
According to these reflections, it is not worth saving on heating equipment, just as it is not worth paying for the potential of equipment that will not be in demand as unnecessary.