Before installing heating equipment in a private house, first of all, it will be necessary to allocate a separate room for it and organize an effective exhaust hood in the boiler room. High-quality ventilation for a gas boiler ensures that combustion residues are removed from the room and that normal climatic conditions are maintained in it. When arranging it, the requirements of regulatory documents (SNiP) are also taken into account, according to which special organizations should deal with the development of the project and its implementation. If the user decides to do this with his own hands, he will need to coordinate the issue with the local gas services.
The importance of ventilation in the boiler room
Ventilation in a boiler room in a private house that meets the requirements of standards performs the following important functions:
- ensures the flow of oxygen into the room and creates normal conditions for the combustion of gas or solid fuel;
- guarantees the safety of operation of boiler equipment;
- residues of carbon monoxide are completely removed from the room.
When oxygen is deficient, any fuel does not burn completely, and also produces less heat. This reduces the efficiency of the heating system. Other consequences of a lack of fresh air supply include:
- without ventilation in the boiler room, more fuel is consumed to maintain a comfortable temperature;
- the process of equipment wear is accelerated;
- a lot of burning accumulates in the chimney.
Ventilation equipped in compliance with the requirements of MSN 2.02-01-1997 "Fire safety of buildings and structures" provides the following advantages:
- reduces the likelihood of fire or gas explosion;
- the possibility of poisoning with carbon monoxide components is excluded;
- normal operation of the boiler is guaranteed without failures and failure of individual units;
- the load on the equipment is reduced and fuel is saved.
It is important to constantly monitor the tightness of the joints in the gas main and the chimney, in case of violation of which gas will begin to accumulate in the room.
Mandatory requirements
The requirements for a room equipped with ventilation for a gas boiler in a private house primarily relate to the location. According to the current regulations, it is allowed to equip it in the following premises:
- a separate building or annex;
- room inside the house;
- the kitchen of the building with a boiler power of no more than 30 kW;
- attic space.
In private houses, the combustion unit, as a rule, is arranged either in a room specially designated for this on the ground floor, or next to the garage.
In accordance with the main provisions of SNiP 42-02-2002, the following requirements are imposed on such boiler houses:
- when placing the equipment in a separate room, its total volume cannot be less than 7.5 m³, and the area - 6 m² with a ceiling height of 2.5 meters;
- a special room is allocated for boilers with a capacity of more than 30 kW; with a lower indicator, they can be installed in the kitchen;
- the kitchen area must be at least 15 m²;
- in the boiler room d. b. there is a separate exit to the outside.
When determining the dimensions of the openings for the supply of fresh air, it is assumed that, in accordance with SNiP, the cross-sectional area of the ventilation duct connected to the street is selected at the rate of 8 cm² for each 1 kW of power. If the boiler room is connected to an adjacent room, and the supply masses come from it, this indicator is chosen equal to 30 cm² per 1 kW.
Ventilation options
According to the method of organizing air exchange, known ventilation systems can be operated on the principle of natural inflow or forced. The first method refers to relatively simple options, however, the ventilation efficiency of the room in this case is noticeably reduced. However, due to their simplicity, these systems are widely used in private households and apartment buildings.
Natural ventilation
The principle of operation of the natural inflow system is based on the following natural laws:
- layers of warm air always rush upward;
- over time, they move towards lower pressure;
- near the ground, the air density is always higher than at altitude.
To organize natural air exchange, it is enough to provide a certain pressure difference in the room. This can be done in several ways, the choice of which depends on the specific conditions and preferences of the owner:
- a small hole is made between the street and the room, which is the point of inflow of outside air;
- an exhaust pipe is brought out of the room to the roof, the outlet of which is located higher than the inflow point - at its end the pressure will be lower.
As a result, air masses will move from the supply point from the street towards the outlet of the chimney.
The distance between the intake point and the end of the exhaust duct is selected as long as possible. This guarantees high-quality ventilation of the room, since the air flows cover the entire room. Particular attention is paid to ensure that no closed doors are located between these two points. Variations of this method of air exchange are exhaust or supply ventilation systems that do without forced action.
Forced air exchange
If the possibilities of natural circulation are not enough for high-quality ventilation of the boiler room, forced ventilation will be required. It equips itself through the use of special equipment, through which the forced movement of air masses is organized. Usually these are duct fans of various capacities, installed in the following places:
- on the outside of the house;
- directly above the boiler itself in the form of an exhaust;
- inside the duct of the supply and exhaust system.
In the latter case, in accordance with the current regulations, purification filters, water heaters and noise absorbers are installed in the same air ducts.
A set of equipment for forced ventilation guarantees high-quality cleaning and dosing of air masses, ensuring their constant renewal.
How to make a hood
Before equipping the hood in your home, it is important to correctly determine the necessary equipment (including the type of boiler), the materials used and the type of branch ducts. You should start with a set of equipment, selected taking into account the following factors:
- the area of the future boiler room;
- safe distance to flammable objects;
- the type of the room itself;
- the amount of estimated costs.
It is also important to decide on the type of boiler chosen for heating a private home. The best option for this case are electric, gas or solid fuel (pellet) units. In case of frequent power interruptions, it is recommended to install combined boilers using several types of fuel.
As an example, a medium-power gas unit was selected, which is explained by the comparative cheapness of the energy carrier used in them and the efficiency of the heating method itself. The working temperature in the combustion chamber of such a sample is significantly lower than in other models.
Hood materials
When choosing a material for arranging the hood, they proceed from the possibilities and specific conditions of the work. Most often, for these purposes are selected:
- brick;
- ceramics;
- metal.
Brick is usually used for the manufacture of hoods in solid fuel boilers. Despite the fact that it is rather difficult to clean it, the service life of units with such a hood is quite long. This material is not suitable for gas units, since at low combustion temperatures, condensate will accumulate in the pipe.
Ceramic is much better suited for gas - it can withstand temperatures up to 650 ° C. But in this case, it is necessary to provide protection against the ignition of soot in the chimney, having foreseen a condensate drainage channel. As an option - insulation of the outlet channels with mineral wool.
Steel pipe is a good choice for solid fuel and gas heating systems. At relatively high temperatures with solid pellets, a hood made of heat-resistant metal with thicker walls (up to 1 mm) is selected, and when using gas, this indicator is taken to be 0.6 mm.
Selection of the type of exhaust duct with a fan
Coaxial flues are available in two different designs: horizontal and vertical. The former are traditionally mounted along the walls, while the latter are laid in any acceptable place with an outlet through the ceiling to the attic and the roof.
When choosing a vertical chimney, you should be prepared for the fact that the costs will increase, since it is longer and more difficult to install. It will also require a separate condenser collector. The disadvantages of horizontal design include the risk of freezing of condensate in the part brought out to the outside. In order to solve this problem without high costs, it is enough to insulate it with mineral wool or similar heat-insulating material - in case of not very severe frosts, this partially helps. To prevent the formation of ice at the end of the pipe, a lattice head is mounted.
For the correct installation of a horizontal chimney, it is important to adhere to the following recommendations:
- the outlet of the pipe is made approximately at a height of 2 meters from the ground;
- the distance from the outlet channel to the window located above it is at least 1 meter;
- when laying the pipe at an inclination of 3-12 degrees, it is not necessary to make a condensate collector;
- it is forbidden to bring the highway to an adjacent room;
- the distance from the outlet of the chimney to the nearby gas pipe must be 0.2 meters or more.
The classic configuration of the horizontal outlet includes the pipe itself, adapters of various types, as well as a set of decorative linings and ferrules with fastening bolts.
Ventilation calculation
To obtain the required parameters of the supply system at a given power, it will be necessary to sequentially perform the following calculations:
- The volume of the room is determined (in this case, it will be 45 m3).
- To determine the highest point of the chimney, it is assumed that it should be located a quarter above the ceiling of the room (at a height of 3.75 meters).
- It is taken as an indicator or coefficient of air exchange efficiency.
- Next, the volume of air circulating through it is found: the found coefficient is multiplied by the area of the room.
For the case under consideration, the obtained value is 168.75 m3. Taking it as the basis for the calculation, there is a table on the Internet, according to which the required duct diameter is determined. In this situation, it is equal to 225 mm.
In heating systems operating entirely on gas, a scheme or ratio is used in which for every 10 kW of power there is 0.01 m3 of supply air per second. With a declared indicator of 30 kW, ventilation will require a capacity of about 0.03 m3 / s with a small margin. After that, from the table given in SNiP, the diameter of the hood is found - at least 130 mm. If this indicator does not provide normal air exchange, a forced supply system is installed in the room.
Making reliable and efficient ventilation in a private house is not at all as easy as it seems at first glance. You will need the help of specialists who are involved in the design of ventilation systems and are well versed in these issues.
