Repair of ventilation systems: analysis of popular faults and ways to eliminate them

Ventilation units renew the air, remove harmful components from confined spaces, and maintain a comfortable microclimate.Without high-quality air exchange in the room, there is a risk to the health of all household members. A dangerous situation occurs when the ventilation system malfunctions.

We will tell you how to get rid of stagnant air, which causes problems with the respiratory system and aggravates chronic diseases. Our article describes in detail the methods by which ventilation systems are repaired. Tips for their restoration and maintenance are provided.

Ventilation options

When repairing a system, you need to understand how it is structured and by what principles it works. There are natural and forced types of room ventilation.

Features of natural air exchange

All old buildings are equipped with natural exhaust ventilation systems. The air flows in them move, obeying the laws of physics. They enter through vents, cracks in windows and doors, move along exhaust ducts connected to a common route and exit through holes in the pipe on the roof of the building.

Natural ventilation is inexpensive and easy to maintain, as there is no mechanical equipment. But there are also significant disadvantages - it reacts to weather changes, does not work well in the summer and does not provide the ability to control air exchange.

The movement of air flows in natural ventilation occurs due to gravitational forces: temperature differences, air column pressures, and wind. To enhance the outflow, deflectors are installed at the pipe outlet to improve circulation

Principles of forced ventilation

In modern construction, heat-saving technologies are used that provide for complete sealing of housing. Such conditions provide comfortable living, but prevent the natural flow of air into the room.

Therefore, new houses are equipped with forced or mixed ventilation. Here the flow movement is carried out mechanically using a fan. The supply pipe is located at the bottom of the building, and from it air ducts are distributed throughout the apartments, connected to a common route.

Ventilation consists of a set of devices that help remove air over significant distances:

1. Ventilation ducts. Flexible and rigid pipelines made of plastic, galvanized sheet or aluminum foil, united into one network by tees, bends and adapters. Provide air supply to isolated rooms.
2. Fans. Axial and centrifugal devices with a blade wheel. The gaseous mass is supplied and removed, creating the required pressure in the system.
3. Air intake grille. Permits external air flows, protects equipment from precipitation and foreign objects.
4. Air valve. Prevents outside air from entering the room when the system is turned off.
5. Filters. Protect the ventilated space and equipment from dust, debris, and insects.

The forced system is not affected by temperature fluctuations and pressure in the exhaust pipe. Its effectiveness depends only on the performance and power of the fan.

The forced ventilation system constantly replaces exhaust air and, if necessary, warms it up

However, it is worth considering that such a device consumes a lot of electricity and requires regular maintenance. In the event of a breakdown, repairing forced ventilation systems can cost a pretty penny.

Schemes of ventilation systems used in the arrangement of apartment buildings are described in detail in the next article, the contents of which we advise you to familiarize yourself with.

Threats of air exchange disruption

Malfunctions of ventilation ducts are not immediately noticeable, but sooner or later they result in unpleasant consequences.

The following signs indicate a malfunction of any type of air exchange:

• the smell of rot and rot appeared in the house;
• mold and mildew began to actively multiply, both in hard-to-reach places behind cabinets, the kitchen sink or table, and in open areas;
• Condensation constantly forms on the surfaces of windows, walls and furniture;
• the room becomes damp, cool, oxygen supply is not replenished, it is difficult to breathe;
• the system produces hum and loud sounds, which causes discomfort;
• There is a burning smell coming from the air ducts.

The safe operation of solid fuel units and gas heating equipment. Ventilation ducts lead outside and prevent harmful combustion products from accumulating in the room.

If you have to wipe off mold and condensation on your windows every day, then most likely the air ducts are not doing their job. This means it's time to think about repair and maintenance of the ventilation system.

If at least one sign of a malfunction appears, you should immediately begin diagnostics, identify and eliminate the causes of the breakdown in the system.

How to check the system's functionality?

The easiest way check the air exchange in the apartment or in the house - open a window in one of the rooms and hold a thin sheet of paper near the ventilation. With normal traction it will stay on the grate. This check is rather approximate.

It is not advisable to test using matches or candles. There may be gas present in the channels, and even a minimal amount of it can cause an explosion or fire

Calculation tables and an anemometer - a special device that measures the speed of air movement - will help to determine the performance of the system more accurately. After the measurements, the values ​​of the device and the parameters of the hole cross-section are entered into the table. The result is a figure showing the amount of air passing through the shaft per hour.

An anemometer quickly measures the speed of movement of the air conditioning object in ventilation shafts and makes it possible to accurately assess the quality of operation of ventilation equipment

Normal air circulation values ​​in the apartment:

• kitchen – 60 m³/h;
• bathroom and toilet – 25 m³/h.

When there is a real speed of gas flow, it can be used to determine the volume. This does not require additional tables or reference books.

The volume of air passed through is calculated without tables using a simple formula:

Q = V x S x 360,

Where:

• S – cross-sectional area of ​​the hole;
• V – reading taken from the anemometer.

It turns out that at a speed of 22 m³/h and a cross-sectional area of ​​110 mm, the amount of gases passed through will be equal to: 22x110x360 = 871.2 m³.

Basic faults and solutions

Ventilation systems fail for various reasons. Often this is incorrect installation and operation, neglect of maintenance, the appearance of mechanical damage and corrosion processes, and natural wear and tear of parts and devices. All of them are fraught with typical malfunctions. Let's take a closer look at them.

The most common problem is insufficient air flow in naturally ventilated rooms. Its reason lies in the high tightness of the premises.

The natural system is designed for air flow from doors, wooden windows and other cracks, which we try to carefully eliminate during repairs. Sealed plastic windows, unlike old wooden analogues, do not allow air to pass through, blocking all possibilities for its normal circulation.

The same applies to doors that make it difficult for him to move between rooms. Because of this, condensation and mold stains constantly accumulate on the windows.

Air valves “depressurize” the room exactly as much as required by the conditions for normal operation of natural ventilation. They will not affect the room temperature in any way.

The way to solve the problem is this: cut small holes in the doors, installing grilles or decorative sleeves in them. And also arrange regular through ventilation, install valves with a microcirculation function on windows or walls.

The hinged valve for the window is fixed with short self-tapping screws on the flap of the sash. Air supply device into the wall mounted by drilling an opening and attaching the housing with sealant.

Another problem is difficult extraction. Its cause may be either a debris plug in the channel, or insufficient power or a breakdown of the compressor.

To fix this, you will need to clean the air ducts and replace/repair the compressor. The new device must carry out air exchange in a volume of at least 3 cubic meters per hour for each square of room area.

The appearance of unpleasant odors from the ventilation duct is caused by leaks in the air duct, corrosion processes, and damage to the integrity of parts.

Way to get rid of the problem: replace damaged soft inserts, wafer seals, repair or replace areas and elements of the air duct with defects. And also adjust the tightness of the connections.

A problem may arise such as a significant deterioration in air quality and increased resistance of ventilation ducts. Its reason lies in the accumulation of contaminants in the air duct and low filter efficiency.

The solution is to clean it as much as possible ventilation duct from debris, wash and dry the filters or replace them with new ones.

Anyone can replace worn out and excessively dirty filters. Thus, high resistance is removed and air circulation through the channels is established.

The occurrence of loud noise from air ducts is associated with the penetration of insects, birds, small rodents into the pipeline, insufficient lubrication of moving equipment elements, and strong wind.

To get rid of the problem, you need to attach a protective mesh to the sockets of the supply/exhaust channels with self-tapping screws, regularly lubricate the mechanisms, wrap the pipe with sound-proofing material, and install mufflers.

If it is necessary to replace individual parts and carry out major ventilation repairs, you cannot do without the help of an experienced specialist. Otherwise, there is a risk of doing more harm than good.

It is recommended to carry out only routine repairs of ventilation systems on your own, which does not involve significant intervention in the structure or complex dismantling work. For example, sound insulation or cleaning of ventilation ducts. In most cases, this is enough to eliminate basic problems.

Methods for reducing system noise

Fans, valves, air duct pipes and forced ventilation dampers create certain sound vibrations that can be heard in the room. According to sanitary and building standards, the noise level should not exceed 30-40 dB. Violation of norms is indicated by chronic fatigue, headaches and other health problems.

Noise arising during operation can be aerodynamic or mechanical. In the first case, it appears due to poor depreciation, unsatisfactory condition of components, friction and violation of balancing parameters. In the second, it is the result of the operation of electric motors and fans.

The following measures will help reduce the noise of the ventilation system:

• installation of the fan on vibration-isolating bases;
• careful fitting of parts and balancing of rotating parts;
• strong fixation of the fan, valves and gate valves;
• installation of a removable soundproof casing;
• inserting rubber or canvas pads between the fan and the duct;
• lining the internal surfaces of air ducts with sound-absorbing materials (fiberglass, mineral felt);
• lubrication of moving compressor elements.

In natural ventilation, the noise is very noticeable in windy weather, since the wind entering the system at high speed creates a strong roar. A chamber, plate or tubular silencer can cope with it, reducing the sound pressure on the walls.It is installed at the top of the exhaust pipe.

For sound insulation of ventilation ducts, mineral wool from trusted manufacturers in rolls 5 cm thick is suitable. The insulation will not only absorb sound, but will also maintain optimal air temperature, prevent the formation of condensation and protect the structure from fires

Another way to dampen vibration is to install a concrete frame around the air duct on the roof. If technical reasons do not allow such an operation to be performed, the channel is wrapped with insulation.

Cleaning instructions

Dust, small debris and kitchen grease, which constantly accumulate in the ventilation ducts, cause numerous breakdowns and poor-quality operation of the system. Undesirable consequences can be prevented through scheduled cleaning of the system every 3-6 months.

When starting to clean the air duct, it is advisable to follow a certain procedure:

1. Wear thick protective gloves and a mask, and prepare a working, stable stepladder or chair.
2. Remove all ventilation grilles, wash them with detergent, and then rinse thoroughly. If they are very worn, replace them with new ones.
3. Clean the inner walls of dirty crusts with a small construction spatula (plastic, wood or rubber), making sure that it does not deform or damage the channel.
4. Vacuum the hole in accessible places and wipe with a damp sponge.

IN forced system Instead of a grille, there is an exhaust fan in the niche. It is first turned off and carefully removed by unscrewing the screws securing the body. Then wash the blades and grate with a special product that breaks down fat and wipe dry.

To fully restore normal air circulation, you need to try to clean the channel as deeply as possible, using the tools at hand. It is necessary to move carefully, with gradual rotational movements.

At the end of the work, a control check of draft is carried out with an anemometer or a piece of paper.

Making a tool for cleaning ventilation ducts is not difficult. A strong and long steel cable will do for this. You need to attach an ordinary brush and a small weight to it

It should be remembered that residents of apartment buildings are prohibited from accessing the main shafts. Therefore, if cleaning some of the channels inside the apartment did not help solve the problem, it makes sense to call special services.

They carry out effective large-scale treatment with a vacuum cleaner and brush machine, disinfecting the internal surfaces of pipes with chemicals.

Ventilation holes become clogged quickly. During cleaning, a lot of waste can fall from them, including the remains of rodents and insects. The floor surface under the vents should be cleared of furniture in advance and covered with newspapers or film

You can disinfect the canals yourself by preparing an inexpensive universal solution of chlorhexidine, boric acid, fir oil and alcohol. The ingredients are placed in a spray bottle, which is used to treat the walls of the air ducts.

Disinfecting treatment will eliminate allergenic factors and neutralize all germs and bacteria living in the pipes. It should be carried out at regular intervals immediately after cleaning the exhaust ducts.

How to improve ventilation performance?

Any breakdowns are always easier to prevent than to fix. This will save effort and money on calling a technician and purchasing new equipment to replace the broken one.

Simple preventive measures will help:

• checking the ventilation draft force;
• maintaining cleanliness of ventilation grilles;
• visual inspection of air ducts, fastenings, equipment;
• lubrication of moving mechanisms, cleaning of fans;
• ventilation of premises.

The main condition is the regularity of these events. For example, the quality of the traction force is checked annually, channels and equipment are cleaned as they become dirty, and a visual inspection is necessary every few months.

Useful video on the topic

Video #1. How to check the operation of ventilation shafts yourself:

Video #2. What to do if ventilation is not working well:

Video #3. Instructions for arranging soundproofing of the ventilation duct:

Ventilation is the most important engineering network of a building, which is assigned serious functions. By paying enough attention to prevention, you can protect the system from global breakdowns and make do with routine repairs, easily coping without the participation of specialists.

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