Chimneys For A Bath, Including How To Choose, As Well As Features Of Installation And Operation

2024 Author: Bailey Albertson | [email protected]. Last modified: 2024-01-17 22:26

Chimneys for a gas bath stove: material selection, installation and operation features

A properly designed chimney for a sauna stove ensures comfortable use of the sauna for a long time. But the main criterion in the selection of design and materials remains safety. Therefore, the choice and installation of the chimney should be given special attention, not forgetting to consult with specialists.

Content

• 1 Basic requirements for sauna stoves

• 2 How to choose a chimney for a bath

  • 2.1 What are the chimneys

    • 2.1.1 Brick chimneys
    • 2.1.2 Metal flues
    • 2.1.3 Ceramic chimneys
    • 2.1.4 Coaxial flue

• 3 Installation of a chimney in a bath

  • 3.1 Installation of a stainless steel chimney in a bath

    • 3.1.1 Video: how to arrange an internal stainless steel chimney in a bath
    • 3.1.2 Video: device of a stainless steel wall chimney in a bath
  • 3.2 Insulation of the chimney
• 4 Features of the operation of the sauna chimney

• 5 How to check the draft in the chimney of a sauna stove

  • 5.1 Adjusting the draft in the gas oven

    5.1.1 Photo gallery: ways to adjust the draft in the chimney of a sauna stove

  • 5.2 How to clean the chimney from soot

    • 5.2.1 Photo gallery: means for cleaning the chimney from soot
    • 5.2.2 Video: cleaning the chimney of a sauna stove from soot
• 6 Consumer reviews about chimneys and gas stoves for a bath

Basic requirements for sauna stoves

The chimney for a sauna boiler not only removes combustion products from the room, but also ensures optimal use of fuel in the heating unit. At the same time, a properly arranged channel for the removal of furnace gases should serve as a guarantee of safe operation of the heater. This factor is ensured not only by the correct selection of materials and chimney design, but also by the organization of the boiler room infrastructure. It must have sufficient supply and exhaust ventilation to ensure the supply of oxygen for the combustion of the furnace and the removal of combustion products or the gas itself that has entered the room.

To remove flue gases from the bath, an external wall-mounted chimney is often built, since it does not take up space in the room and provides better fire safety

Gas boilers are the safest to operate and the cheapest in comparison with other types of heating units. They do not give off the smell of burned fuel and do not leave debris in the form of ash or slag.

Gas boilers are more economical and safer compared to heating units using other types of fuel

When using a gas boiler in a bath, you need to adhere to some recommendations:

1. If there is no gas supply from the central line, you can use fuel from cylinders. They should be placed outdoors in a specially equipped cabinet.
2. For the safe operation of the gas unit, you need to use an automatic control system that will control the heating mode, as well as a gas analyzer in case of a leak.
3. The base made of refractory materials for the furnace must be at least 10 centimeters larger than its outer dimensions.
4. For the installation of the gas pipeline, only steel or copper pipes should be used.

How to choose a chimney for a bath

Chimneys used in heating systems can be divided according to the installation site into two main types:

1. Outdoor or wall-mounted. When using them, the pipe from the outlet of the furnace is led out through the wall, and the vertical part runs along the outer main wall and is attached to it with brackets.
2. Internal. The vertical part of the chimney is led out inside the building with the intersection of the ceiling and roof. Fireproof inserts are made in the passages, which will be discussed below.

Each of the designs has its own advantages and disadvantages.

What are the chimneys

Structurally, chimneys can be divided into the following main types.

Brick chimneys

These are the most ancient types of chimneys that have not lost their relevance to the present. They are laid out of ceramic bricks, the cross-section can be different in size, but the shape is always square or rectangular. This is the main disadvantage of brick pipes. Combustion products move along a helical line through the smoke channel, and the section angles are stagnant zones. In them, furnace gases move at a low speed, which contributes to the settling of solid particles with the formation of soot. Features of brick chimneys:

1. The inner surface of the brick pipe is rough and this also contributes to the formation of soot.
2. The outer part of the chimney, if there is no insulating layer on it, is exposed to moisture and wind, which leads to its destruction. Experts estimate the service life of a brick chimney at 17–20 years.
3. To improve the working conditions of a brick chimney, it is practiced to sleeve it with the installation of a metal or plastic pipe in the inner channel.
4. The construction of a brick pipe requires certain skills of a bricklayer; not everyone will be able to do this work correctly with their own hands.

The construction of a brick chimney is heavy, so a solid foundation is required for its installation.

The outer part of the brick chimney is exposed to moisture, sunlight and large temperature changes, so it is advisable to protect it with finishing materials

Metal chimneys

For the manufacture of metal chimneys, single-layer or double-layer pipes are used. Black, galvanized or stainless steel sheet 0.4–1.2 mm thick can be used. The first of them quickly burns out, since sulfur dioxide is always present in the flue gases. Together with the moisture always present in the combustion products, during condensation, an aggressive substance based on sulfuric acid is formed, which destroys the pipe walls. A similar story happens with a galvanized pipe, because the protective layer of zinc is quickly damaged by condensation, and then everything happens in the same way as with a conventional black steel pipe. The best material for the chimney is austenitic grade stainless steel. It is easy to distinguish it when buying, using a magnet - it will not be attracted to it … If you are offered a stainless chimney, and its material reacts to a magnet, this may not be deceitful. It's just that it's ferritic or semi-ferritic stainless steel, which is not sufficiently resistant to aggressive environments.

A high-quality stainless pipe has a mirror-like surface on which condensate flows downwards, against the course of the furnace gases. At the bottom of such a channel, you need to arrange a condensate collector with a tap. It needs to be cleaned periodically. The accumulation of soot on the walls of the stainless chimney is much slower.

The stainless steel chimney has smooth round walls, so soot forms much more slowly

Ceramic chimneys

Ceramic pipes are made from refractory clay in 50 centimeter pieces. The ends of each segment are formed for a tongue-and-groove connection.

Ceramic pipes serve for a very long time, since they practically do not react to the effects of aggressive chemical elements contained in the combustion products of furnace fuel

Ceramic pipes are mounted inside special expanded clay concrete blocks. A hole is made along their axis for installing a chimney. The diameter of the hole in the block is 50–70 millimeters larger than the outer size of the pipe - a non-combustible heat insulator is placed in this gap, which is used as mineral or basalt wool. Holes are made in the corners in the blocks for the installation of reinforcement rods that strengthen the structure.

In expanded clay concrete blocks there are holes for installing chimney pipes, ventilation and reinforcement

A distinctive feature of the ceramics is the high quality inner surface, which also prevents the rapid accumulation of large amounts of condensation and soot. The material is chemically passive.

The disadvantages of such chimneys include their significant weight, which implies the manufacture of a foundation and the need for a strictly vertical installation.

In some cases, asbestos-cement pipes are used for chimneys. They attract attention for their low cost and manufacturability of the installation. But it is hardly possible to recommend them for a bath. At temperatures above 300 ^o C, they break down, and this process is explosive. In addition, there is evidence that the material releases asbestos fibers into the air, and this is unsafe for humans. In any case, such chimney pipes are not used in Europe.

Coaxial chimney

The coaxial chimney is a pipe-in-pipe design. In this case, the inner part is designed to remove flue gases, and the outer part is designed to supply air to the furnace firebox. The inner tube is attached to the outer tube with three longitudinal ribs. Hot flue gases move through the chimney, creating a vacuum in the firebox. Due to this, air is sucked into the firebox through the outer pipe. At the same time, it heats up, activating the combustion of gas in the boiler furnace . It is obvious that such a chimney arrangement is possible only in closed-type gas heaters. Thus, the boiler furnace is in no way connected with the room and the air in it always remains clean. As a result, supply ventilation requirements and costs are reduced.

The coaxial chimney is very convenient and easy to install, but it can only be used with closed type boilers

Taking into account the given data, it is obvious that stainless steel pipes will be the best choice of a chimney for a bath, especially since they are made specifically for this purpose and are equipped with all the necessary additional elements.

On sale you can find a large assortment of different adapters, elbows, branch devices and fasteners for making a stainless steel chimney in any configuration

Installing a chimney in a bath

Before proceeding with the installation of a flue gas duct from a gas bath stove, you need to draw up a project and coordinate it with a qualified specialist. All comments made must be taken into account before purchasing materials.

Installation of a chimney made of stainless steel pipes in a bath

It begins with the installation of a furnace or boiler in its place of permanent location. In this case, it is necessary to take into account the requirements of fire safety rules. Next you need:

1. Install the boiler to chimney adapter. It can be vertical or horizontal, depending on the design of the heating unit.

2. Mount and fix on the pipe a flat gate or an internal damper to adjust the draft in the chimney.

   

   A rotary vane damper is usually installed at the very beginning of the flue duct and allows you to adjust the draft during combustion

3. Connect the pipe of the hot water tank to the flue pipe from the bottom and top. The heated gases pass through a branch pipe in the tank and heat up the water required for internal consumption in the bath. The water tank is attached to the building structure according to the design.

4. Install the chimney section from the upper tank outlet to the ceiling. In it, you need to cut an opening three times the diameter of the pipe. A 6–20 millimeter thick sheet of asbestos is fixed to the ceiling of the room with the stove, and on top of it is a sheet of stainless steel of the same size. The choice of material is due to the low thermal conductivity of stainless steel. The sheet must be fixed with self-tapping screws with a pitch of 8-10 centimeters. The void in the opening from the attic is filled with insulation - basalt wool and closed from the attic side with the same stainless steel sheet as below, with a sheet of asbestos gasket.

   

   In the ceiling, cut out an opening 3 times the diameter of the pipe, fill it with a non-combustible insulation and close it on both sides with asbestos and stainless steel plugs

5. Extend the chimney with successive sections (they are 50 and 100 centimeters long) until the roofing cake is reached. The connection of pipes to each other inside the transition through the floors is not allowed.
6. In the same way, you need to cut an opening in the roofing cake and the topcoat, and then bring the pipe out.

7. The height of the pipe from the burner to the upper end must be at least five meters. Its position relative to the skate is set by the following rules:

   • the excess over the roof ridge is 50 cm if the pipe is located at a distance of up to 1.5 m from it;
   • when the pipe comes out at a distance of 1.5–3 m from the ridge, its upper part should be at the level of the highest point of the roof;
   • if the pipe is located at a distance of more than three meters from the junction of the slopes, its upper end should be at the level of an imaginary line drawn from the ridge at an angle of 10 ^o to the horizontal.

   

   In order for the chimney to create good draft, its head must be at a certain height, which depends on the distance to the ridge.

8. The opening in the roofing pie from the outside on the pitched roof must be protected with a special apron. Its design depends on the angle of inclination of the slope and the material of the roof covering.

   

   To eliminate the possibility of leakage at the intersection of the chimney with the roofing cake, a special apron is installed

9. Mount the protective cap or deflector on the upper end of the pipe.
10. If the overhead part of the chimney is more than 1 m long, it must be fastened to the braces using a special clamp with three brackets.

When the pipe passes through the room where the boiler is installed, single-wall pipes of the selected design are used; in the attic and on the outside, insulated two-layer pipes must be installed or single-layer pipes must be insulated. For the transition from single-wall pipes to double-wall (sandwich pipes) there is a special adapter.

Video: how to arrange an internal stainless steel chimney in a bath

If it is decided to arrange an external chimney, the pipe is led out through the wall of the bath, for which a hole is cut in it. The rules for fire-prevention sealing are the same as when passing a floor. It should be borne in mind that the length of the horizontal part of the pipe should not be more than one meter. If it is possible to arrange the output at an angle of 45 degrees, this solution should be preferred.

Further actions are as follows:

1. Install a tee, the upper branch pipe of which is the place for connecting the vertical part of the chimney, and the condensate collector is connected to the lower one.

   

   At the point where the chimney exits the wall, a tee with a condensate trap and a wall bracket are installed, which takes the load of the vertical section of the structure

2. Assemble the vertical section of the chimney to the required level. As the height of the chimney increases, brackets are attached to the wall along which it is installed and the pipe is fixed to them.

   

   It is advisable to install brackets for attaching the chimney to the wall at the junction of pipe sections

3. Install a cap or deflector on the upper end of the pipe.

For the device of the chimney inside the boiler room, single-walled pipes are used; for output through the wall using an adapter, double-walled sections are connected. The length of the sections is 50 and 100 cm.

Docking of individual pipe sections is carried out "by smoke", that is, from the bottom up to specially made seats. It is allowed to seal the joints with a special high-temperature sealant.

Video: device of a wall-mounted stainless steel chimney in a bath

The installation of a coaxial chimney is very simple. It is necessary to punch a hole in the wall, remove and fix the pipe, and then close up the opening.

Chimney insulation

The main unfavorable factor when using heating is the clogging of the chimney with soot. As a result, its cross-section decreases and the thrust decreases. But the main danger of soot is its ability to ignite and burn, producing very large amounts of heat. In this case, the building structures of the house often catch fire.

Over time, a thick layer of soot forms on the walls of the chimney, due to which the flow area of the channel narrows and the draft is noticeably reduced

The reason for the formation of soot is the fallout of condensation on the inner walls of the chimneys, where solid combustion products, which are always contained in the furnace gases, are deposited. Condensation forms due to the temperature difference between the inner surface of the chimney and its outer part. Therefore, chimneys must be insulated regardless of the type of material from which they are made. Warming can be done as follows.

1. Covering the chimney with a layer of rolled or slab insulation on the outer surface.

   

   To insulate the chimney, it can be wrapped with heat-insulating material and protected with an outer pipe of a larger diameter - you get a homemade sandwich chimney

2. Installation of a protective coating for insulation made of foil or durable foil film. On the outer part of the pipe, the coating is installed from bottom to top in layers, fastening - using a metal tape or building clamps.

3. Application of plaster on a brick chimney with the addition of reinforcing elements in the form of fiber shavings to the solution.

   

   The easiest way to insulate a brick chimney is to plaster it

4. There is no need for additional insulation of ceramic chimneys, since their installation is carried out using a casing of expanded clay concrete and an insulating layer of basalt wool inside the block.

Features of the operation of the sauna chimney

The use of gas heating units for heating a bath is the best option in terms of chimney maintenance. There are several reasons for this:

1. The temperature of furnace gases in the chimney does not exceed 150 ^o C. With normal thermal insulation, especially in the case of using double-walled sandwich pipes, the temperature difference will be insignificant. The dew point (condensation temperature) is located above the end of the flue. In this case, the amount of condensate inside the pipe is reduced to a minimum.
2. There are very few solid particles in the smoke when burning gaseous fuels, therefore, little soot is formed.
3. The level of automation of modern heating units makes it possible to establish the optimal mode of fuel combustion, at which its most complete combustion occurs.
4. Sauna stoves are switched on periodically, as a rule, no more than once a week, which increases the time between repairs.

Therefore, the main operations for servicing the chimney are the timely drainage of condensate from the accumulator and periodic check of the condition of the chimney twice a year - before the start of the heating season and after its end. In this case, cleaning the chimney from soot is carried out as needed and not after each inspection.

The wire brush is a reliable tool that allows you to clean the chimney efficiently

How to check the draft in the chimney of a sauna stove

The presence of a draft in the chimney can be checked in the simplest ways - by deflecting the flame of a candle or a match brought up to the air intake window of a gas column or stove. With normal draft, it is directed inside the unit. Before checking, you must fully open the gate or damper.

The thrust is checked by the deflection of the flame of a match or candle

A strip from a napkin or toilet paper is also suitable for checking the presence and direction of traction by the degree of its deviation from the vertical. This method can be recommended when monitoring a gas unit, it is safe even if there is gas inside the device. Draft in coaxial chimneys is not controlled, so it occurs only when fuel is burning, and its strength depends on the intensity of combustion.

Adjusting the draft in a gas oven

Signs of abnormal draft in the oven include discoloration of the flame and some other signs:

1. The appearance of a smell of burning or unburned gas indicates that the draft has overturned and the reverse movement of air in the chimney occurs.
2. A change in color to red indicates incomplete combustion of the fuel due to insufficient oxygen in the air. You will need to adjust the thrust in the direction of its increase.
3. The white flame of the burner and the hum of air in the chimney indicate excessive draft in the chimney, which must be reduced by the position of the damper or by turning the damper of the internal regulator.

The reason for the change in draft in the chimney can be weather conditions, in particular, a change in the strength and direction of the wind. In this case, the chimney is simply clamped by the wind force. Such phenomena can be eliminated by installing a vane-deflector on the chimney head, which turns in the wind and, by virtue of its design, creates a vacuum over the pipe, improving traction.

Draft can be dramatically increased by special devices with an electric drive installed on the chimney and forcibly creating a vacuum.

Photo gallery: ways to adjust the draft in the chimney of a sauna stove

You can adjust traction using a homemade damper

The torsion bar automatically adjusts the cross section of the chimney duct depending on the draft force

Draft stabilizers are available in different designs Automatic draft control device

Automatic devices adjust thrust depending on the readings of special sensors

How to clean soot from a chimney

Clearing layers inside the pipe is the most unpleasant, but, unfortunately, inevitable moment in the process of operating heating units. For certain types of ovens, it is performed more or less often. The least frequent need to clean the stainless chimneys of gas stoves is that this work is done with special tools using cleaning agents that soften the soot layer. The means for cleaning such chimneys must be gentle on the mirror-like inner surface of the pipes in order to maintain their most important quality - the minimum retention of condensate inside the pipes.

The chimney can be cleaned in two ways:

1. Above - in this case, ruffs or hedgehogs with a load are used. They are moved down the chimney to completely remove carbon deposits. In this case, the oven must be carefully covered with a wet cloth so that soot does not get into the room.
2. From below - they penetrate to the pipe through the firebox, the tool is fixed on a flexible shaft. With this method, the brushes are given rotation. This is often done using a drive, such as an electric drill.

Cleaning is carried out mechanically from top to bottom with a soft ball-shaped brush. If the walls of the wall pipes are heavily clogged with soot, you can dismantle them and clean each section separately.

Photo gallery: means for cleaning the chimney from soot

Do not use a wire brush to clean stainless steel pipes

Plastic brush cleans the chimney without damaging its surface

A homemade tool made from scrap materials allows you to quickly clean the chimney

For independent work, you can buy a ready-made set of tools for cleaning chimneys of any shape

Video: cleaning the chimney of a sauna stove from soot

Consumer reviews about chimneys and gas stoves for a bath

A chimney of any design needs constant care and maintenance. And this is the main requirement for ensuring its long-term and safe operation. Currently, the market is filled with quite perfect complete products for the chimney, so you can assemble it yourself. I wish you success!