You have equipped a ventilation system, but the house still has nothing to breathe, and even damp? So, it's time to think about how to get rid of condensate in the ventilation pipe and prevent its formation in the future. Agree, it is better to solve the problem right away than to endure discomfort for a long time.
We will show you what to do so that you do not have to spend money on replacing ventilation pipes and fighting mold in living rooms. From our proposed article, you will learn how best to prevent and exclude condensation. Our recommendations will help independent home craftsmen.
The content of the article:
- What is condensation and what harm does it cause?
- Removal of condensate outside the ventilation ducts
- Requirements for thermal insulation materials
- Allowable thermal insulation options
- Features of the insulation of the duct from the inside
- The procedure for installing thermal insulation outside
- Condensation control by example
- Construction of a new ventilation system
- Conclusions and useful video on the topic
What is condensation and what harm does it cause?
In air masses, water is present in a vapor state. When cooled, the steam is converted into liquid water and settles on the inner surfaces of the air ducts in the form of drops, which can drain off, forming rivulets and puddles.
Reasons for the formation of condensation:
- errors in the design and installation of the ventilation system;
- high humidity in the premises;
- the proximity of water bodies;
- large temperature difference inside and outside the house.
Of concern should be not only puddles on the floor, but also rust on the pipes, a decrease in the flow of fresh air, the accumulation of moisture in the walls and ceilings through which the air ducts are laid.
Condensation in the ventilation system leads to an increase in air humidity in the house itself, with effects such as fogging of windows
Condensation is a source of dampness in your home. It serves as a breeding ground for mold and other microorganisms that negatively affect human health. Under the influence of ventilation condensate, metal air ducts are destroyed. Even concrete walls can “feel” the harmful effects of high humidity.
Removal of condensate outside the ventilation ducts
The collection of condensate in the vertical and inclined sections of the air ducts is carried out in their lower part. On horizontal air ducts, condensate collection can be organized almost anywhere, except for areas laid in the walls.
V ventilation pipe a tee socket is installed so that the branch is directed downward. The outlet is equipped with a special container - a condensate trap.
Various types of condensate traps for ventilation can be found commercially. They differ in design and materials of manufacture. They can be transparent, which makes it easier to control the filling, but more often they are made of stainless or galvanized steel.
When filling with condensate, containers with a screw lid are emptied manually, which is not always convenient. Moreover, at an outdoor air temperature of -20 ° C and below, condensation forms especially abundantly and the tank is filled in a short period of time.
Before installing the condensate collector, the lowest point in the air duct system is determined, but with their horizontal arrangement, the condensate trap can be installed in almost any convenient place
In this case, a conical watering can is a good option. It is easy to connect a hose to it and drain the condensate into the drain. If it is necessary to organize the drainage of liquid in a hard-to-reach place, a model with a watering can is also used.
When organizing collection and disposal condensate take into account the configuration of the ventilation system. With multiple pipe bends, you will have to install not one, but several condensate traps.
Sorbents - moisture-retaining substances - also help to collect and remove condensate. They look like cassettes and are installed in the filtration section of the supply air duct. Periodically, the sorbent must be removed for drying, after which it is again ready for use.
Condensate removal is seen as a temporary measure, primarily due to the possibility of ice plugs in winter. Warming of branch channels helps to radically solve the problem.
Requirements for thermal insulation materials
For the insulation of air ducts in the ventilation system, materials are required with the following properties:
- low thermal conductivity;
- vapor permeability;
- fire resistance;
- noise absorbing ability;
- biostability.
The thermal conductivity coefficient is the most important parameter of the thermal insulation material.
Even with the correct installation of all elements of the ventilation system, condensate drainage is not always effective, since it may freeze and form an ice plug
The second most important indicator is vapor permeability. Many materials used for thermal insulation of ventilation have the ability to release moisture accumulated under them when the maximum voltage for them is exceeded.
By filling the pores of the material, moisture increases its thermal conductivity, thereby reducing the effectiveness of insulation. To prevent this from happening, a waterproofing coating is mounted on top of the heat insulator - a membrane capable of letting steam out, blocking its access to the inside.
Fire resistance determines how fireproof the thermal insulation will be. There are 6 fire resistance classes in total.
For air ducts, a zero-grade insulation is required, that is, having the highest fire resistance, and therefore the most fireproof. With multilayer thermal insulation and the fulfillment of a number of additional conditions, the use of materials of the first class of fire resistance is allowed
The air flow passing through the air ducts creates noise. In forced ventilation systems, a running fan also makes noise and vibrates. So that noises and vibrations are not transmitted through rigid structures and not spread through living quarters, damping devices and gaskets are used.
But most heat-insulating materials also have sound-insulating properties and, in addition to their main function, help to protect the house from unpleasant acoustic effects.
Mineral wool is one of the most popular thermal insulation materials in low-rise construction and is also used for thermal insulation of air ducts.
The materials used should not be a favorable environment for the vital activity of insects, molds, rotting bacteria and other harmful microorganisms.
Penetrating through the air ducts into living quarters, they can cause disease, and also damage the material itself, which may require its premature replacement. There are microorganisms whose waste products are so aggressive that they can burn through steel sheets 1.5 mm thick.
The materials used in the arrangement of ventilation communications must comply with sanitary and hygienic standards. The insulation should not release substances that are dangerous to humans and the environment. Environmental friendliness means the absence of the threat of contamination of the natural environment during disposal.
Allowable thermal insulation options
The above requirements are met by many mineral fiber materials, hydrocarbon polymers, foam elastomers, including:
- mineral wool;
- polyvinyl chloride;
- expanded polystyrene;
- polyurethane.
Foam elastomers are produced by extrusion and vulcanization. They have a porous structure, and the pores are bubbly, that is, closed, which reduces moisture absorption and makes them vapor-impermeable. Insulation materials such as polyurethane and polyvinyl chloride are obtained by polymerization of hydrocarbons.
Heat insulators are supplied on sale in the form of rolls, sheets (mats), hollow cylinders (shells). Roll materials and shells are suitable for thermal insulation of pipes and round ducts. Rectangular air ducts can be insulated with sheet material.
The air duct is insulated in all areas located in unheated rooms and ventilation ducts passing through walls, ceilings and roofs require special attention
Insulation sheets and rolls are highly flexible, easy to shape, one side can be smooth. Due to the combination of these properties, the installation of thermal insulation is greatly facilitated. Many materials are not only fire-resistant, but also self-extinguishing, which increases fire safety.
Insulation is chosen taking into account the conditions of the environment in which it will be used, including the operating temperature. For central Russia, materials that can withstand ambient temperatures in the range from -30 ° C to 60 ° C are suitable for thermal insulation of ventilation systems.
A polyethylene (PE) film and a polyvinyl chloride (PVC) membrane are used as waterproofing protection. The insulated ventilation ducts are closed from external damage with boxes sheathed with a board, plywood or aluminum sheets.
Features of the insulation of the duct from the inside
It is necessary to insulate all air ducts outside the heated premises, including areas in the walls. Insulation of both external and internal surfaces of air ducts is possible.
If the insulation is carried out from the inside, already at the design stage, an increase in the duct cross-section is envisaged in accordance with the thickness of the heat-insulating layer. Otherwise, its bandwidth will decrease.
Mineral wool fibers are strengthened with adhesives. This is to prevent the fibers from peeling off by the air blast. The glue used for this purpose should not affect the level of fire resistance of the insulation and its environmental friendliness.
In order not to decrease the aeration properties of the ventilation duct, it is better to carry out insulation from the inside according to the "pipe-in-pipe" scheme. This is how a chimney pipe sandwich is constructed. If there is no time and desire to do them yourself, you can buy ready-made
The thermal insulation laid on the inside should not increase aerodynamic resistance, slowing down the movement of air masses. That is, it is necessary to make its surface smooth.
Due to additional requirements for internal thermal insulation, its use is often impractical. Including if you have to insulate an already built ventilation system with a given cross-section of air ducts. In such cases, the air ducts are insulated from the outside.
The procedure for installing thermal insulation outside
The most economical thermal insulation material for a private house is the time-tested mineral wool. It comes in rolls of various widths and can have one or two outer foil layers.
The thermal insulation material is installed overlapped on the ventilation pipe so that there are no unprotected areas, the joints are glued on top with tape
When determining the thickness of the heat-insulating layer, they are guided by SNiP 2.04.14–88. Heat engineers perform complex calculations taking into account the diameters of the pipes, the coefficient of thermal conductivity of the used heat-insulating material.
They take into account the average annual air temperature and even possible heat loss through joints and fasteners, as well as other parameters, most of which can be found in reference books and the above SNiP.
Speaking specifically about mineral wool, then when insulating ventilation systems in private houses located in central Russia, roll material with a thickness of 100 mm is usually used. You can buy 50 mm mineral wool and wrap the pipe twice.
To determine the required width of the insulation, measure the diameter of the pipe, add the thickness of the mineral wool multiplied by two to the obtained value. Multiply the resulting amount by 3.14 (pi).
Before getting started, prepare in advance a rubber spatula, a construction knife, a stapler, an aluminum tape 7-8 cm wide, a marker and measuring instruments - a square, a ruler and a tape measure (better metal). Be sure to wear protective clothing.
For work in the open air, they choose a day without precipitation. Otherwise, the mineral wool may get wet. The roll is unrolled, marked and cut to obtain the desired size cut. Separate the foil along the edge so that the pipe can be wrapped with an overlap of mineral wool and cover the connecting seam with a foil layer.
In hard-to-reach places, a modern type of heat insulator is used - the so-called shell, which must be selected taking into account the outer diameter of the pipe
Then the connecting seam with a step of 10 cm is fixed with a stapler and glued with tape along the entire length. To fix the insulation to the pipe, both special fasteners and ordinary wire are used.
To protect the joints of the air ducts, the insulation is cut into fragments of the appropriate shape and size. Do not forget to clean the pipe from dirt before insulation.
Insulation can also be performed using segmented heaters. The monolithic casing is in the form of a pipe and is threaded onto the duct. It is mainly used during the installation of a ventilation system "from scratch".
Having measured the geometric parameters of the duct, select a casing that is suitable in size and stretch it along the entire length of the pipe. Foil is wound over and fixed with stainless steel or copper clamps.
The collapsible shell consists of two semi-cylinders, which are applied to the pipe from both sides and fixed. On the sections passing through the wall, it is difficult to wrap the pipe in a roll of insulation, and it is much easier to put on the shell. The collapsible shell can be put on an existing air duct.
Condensation control by example
Let's consider a specific situation. The one-story private house has a ventilation system that provides air exchange in the bathroom and kitchen. Metal ventilation pipes are connected to these rooms.
They are laid in the attic with a subsequent exit to the roof. With daily temperature fluctuations, condensation forms in the pipes. But especially its large amount is observed in winter, when water drips from the hood, collecting in a puddle.
Attics are usually not heated, so ventilation pipes laid in this room need to be insulated along their entire length.
The problem is solved comprehensively. Insulation of the exhaust and supply pipes is in progress. The pipes are insulated from the entrance to the ceiling to the exit to the outside. In areas passing through an unheated attic space, pipes are insulated with rolled mineral wool 70-100 mm thick.
In the places of passage through the ceiling and overlap, shells are used. At the lowest point, a tee with a condenser collector is installed.
If the ventilation ducts do not pass through the roof, but through the wall, a section in the wall is insulated with the help of a shell. Outside the house, a 90-degree tee is installed on the ventilation pipe, a condensate trap and an umbrella (deflector) are mounted.
Construction of a new ventilation system
Due to errors in design and installation, when using low-quality pipes, all measures to combat condensate may be in vain.
In this case, it is economically feasible to drown out the old and equip a new ventilation a system that would cope with its functions of removing contaminated and supplying fresh air masses.
Design is carried out only after analyzing air exchange processes and calculations in accordance with the standards specified in SNiP, based on the characteristics of the ventilated premises and the number of residents. It may be necessary to abandon natural ventilation in favor of forced ventilation with a change in the configuration of ventilation ducts and the installation of equipment for heating the supply air.
Conclusions and useful video on the topic
How to determine if condensation is forming in the air ducts:
Condensate discharge from the ventilation system to the sewerage system:
The installation of condensate traps in combination with insulation of ventilation pipes solves several problems at the same time. The intensity of condensation formation is reduced.
That small amount of moisture that can nevertheless condense on the surface of the duct is quickly removed outside of it, without having time to cause harm. The level of noise and vibration is reduced, which is especially noticeable in forced ventilation systems. As a result, the microclimate is normalized, the house becomes more comfortable for living.
Do you have your own experience of dealing with condensation in ventilation pipes in the country or in a country house? Do you know the technical nuances of retraction or prevention that are worth sharing with your site visitors? Please leave comments, post photos, ask questions in the block below.
