The basement is an integral part of a modern private house or cottage. It serves to accommodate communications of heating and water supply systems in it, and can be used as a garage, workshop or vegetable store. In any case, the basement needs to maintain a given level of temperature and humidity. Dampness adversely affects the safety of agricultural products, leads to the appearance of mold, destroys the walls of the house and negatively affects other objects. Properly equipped basement ventilation will help to solve this problem.
Pros and cons
We note the positive aspects of the use of ventilation systems in the basement and basement:
- Comfortable microclimate in the housethere is no feeling of dampness on the first floor;
- Possibility to build a storage roomwhich maintains a constant temperature and moisture content in the air;
- Increases the service life of load-bearing structures residential building or cellar, especially if they are made of wood;
- The operation of gas and heating equipment is not possible in an unventilated room for safety reasons;
- Mold spores will never grow in a dry basementthat cause colds, allergies and asthma.
All types of ventilation are divided into several types, depending on its purpose, the complexity of the arrangement and the principle of operation. But the principle of operation of any of them will be based on the laws of physics on the movement of air masses. Cold air goes down and warm air goes up.
Natural supply ventilation
The simplest, airflow system in the foundation or basement. It is equipped at the stage of building a house and is a small hole in the upper part of the basement.
If the basement is below ground level, then the hood is equipped with plastic or asbestos-cement pipes with a diameter of 10–15 cm. They are brought out above the surface to a height of 30 cm and covered with bars from debris and rodents. This method is natural and depends on fluctuations in street temperature, wind strength, and humidity.
When calculating its throughput, 1/400 of the total area of u200bu200bthe basement is taken — this is how we get the total area of u200bu200ball the ducts.
Openings should be located on the leeward side, the least exposed to precipitation. Houses with a complex foundation shape and located in low-lying places can have up to one hole for every 3–4 meters. We close the vents with gratings from the outside.
This inexpensive option is well suited for ventilating garages and non-residential basements, or as an addition to the main ventilation system.
Natural exhaust ventilation
Supply and exhaust type. For proper operation, you will need to install two pipes for ventilation, and the supply and exhaust ventilation device looks like this.
- The first pipe is located under the very ceiling of the basement and is designed to expel warm air. We place the exhaust pipe as high as possible, preferably at the level of the roof ridge. This is necessary to ensure good traction. The part of the pipe that is in the open air must be insulated to prevent freezing in the winter and covered with a visor from precipitation.
- The second pipe for the inflow of fresh air is located at a height of 30–40 centimeters from the floor level, and we place its entrance on the street a meter above the ground and cover it with a grate. Convection will occur due to the temperature difference between the outdoor and basement air. Such a system will work most efficiently when the supply channels are separated on different sides of the basement.
The disadvantage of all natural exhaust ventilation systems is one — it is dependent on weather conditions and prevailing winds. It will not work if the temperature in the basement and on the street is equal.
It is used if natural supply ventilation cannot cope or there is no physical possibility to use it. Usually used in the following cases:
- Basement area from 40 m² or has several rooms isolated from each other;
- High humidity rooms, when the condensate in the exhaust duct freezes in winter and impairs the permeability of air masses;
- The architecture of the house does not provide for high ventilation pipes;
- The basement is equipped with a sauna, cafe, gym, workshop or other source of bad odors.
The device of forced supply and exhaust ventilation has a system of channels and fans that distill air.
The main condition is to make the air constantly circulate., which is ensured by the synchronous operation of exhaust and supply fans. Their number is calculated depending on the volume of the cellar or basement and the capacity of the air ducts.
Supply and exhaust ventilation with heat recovery
For a basement floor where permanent residence is planned, it is not enough to simply install a forced ventilation system. The room must be insulated and waterproofed. The issue of heating and heating is also solved.
Increasingly, supply and exhaust with heat recovery is built into such schemes.
Already well-heated air enters the exhaust pipe, and in order not to throw ready-made calories into the atmosphere, the air is passed through a special ceramic heat exchanger. When heated, it gives off heat to fresh air. The air streams do not intersect. The efficiency of such a device is 50–90%, depending on the design of the heat exchanger. All heat recuperators are very reliable, do not require additional maintenance and can serve for decades.
It is equipped with moisture traps, dust filters, sensors that control humidity and air temperature. For a residential area, these figures lie in the range of 50–65% relative humidity and 18–220C. Such systems are most often found in “smart homes”, and their installation is complicated and should only be carried out by professionals.
Supply and exhaust ventilation device
Now let’s figure out how to make ventilation in the basement. The easiest way would be to make ventilation in the cellar or basement of the supply and exhaust type or forced.
Let’s do the calculation first.
For 1 m² of area there should be 25 cm² of the cross section of the duct.
With an increase in ceiling height or humidity, the diameter of the duct increases. The wooden box can be divided into two halves for supply and exhaust ventilation, but it is best to use plastic pipes or corrugated metal boxes.
Wooden ventilation parts must be treated against mold and painted.
The supply and exhaust ventilation device can be supplemented with a deflector on the roof of the house. It will create additional vacuum in the pipe and improve the output of warm air.
A controlled forced system will be much more efficient with comparable labor costs. To do this, we need special duct fans that operate on a voltage of 36 V. This feature is associated with the category of all basements that allow the use of only such currents.
Therefore, a transformer is installed in the electrical panel that lowers the voltage from 220 V to 36 V. And the wiring must be laid in cable channels. These and other rules can be found in SNiP 41–01-2003 heating, ventilation and air conditioning.
For small rooms, only one such fan per exhaust arm will suffice. The influx of fresh air will be carried out due to rarefaction in the basement. But the efficiency of the system will be much higher if you install a second supply pump and combine their work on one control panel.
Now on sale you can find programmable control panels with temperature and humidity sensors, and the duct fans themselves are available in all sizes and are compatible with almost any ventilation ducts. For convenience, they are already built into the case, have a protective grille and replaceable filters.
It is preferable to use PVC as pipes for ventilation ducts in your own house. They are strong and light enough to attach to walls and ceilings with standard wall plugs. They are not afraid of moisture and temperature changes, and the cost is lower than steel structures.
Condensation will always form in the exhaust ventilation ducts, which must be removed periodically. To do this, you can provide a special hole for draining water. Excess moisture leads to corrosion of metal structures and increases the likelihood of freezing of the air duct in winter. If this happens, then you should definitely clean and defrost the channel.
Determining air circulation is quite simple. To do this, you can use the open flame of an alcohol burner or candle, or attach a paper sheet to the hole in the exhaust channel. A good hood will securely hold the sheet. The thermometer installed in the area of the supply air duct will not damage either.
The following signs speak of poor ventilation of the basement, garage:
- The appearance of condensation on the wallsand the humidity is over 95%. Permissible maximum humidity for storing blanks and crops is 85–90% at a temperature of 3–40C. For residential premises, a garage, humidity indicators should not exceed 40–50%;
- Mold and fungi on walls and ceilings;
- Bad smell indoors and heavy stale air;
- Sudden temperature changes they talk about an incorrect device for supply and exhaust ventilation or errors in calculating the cross section of channels;
- In warm weather, condensation may not be noticeable, but in winter the walls will be abundantly covered with frost;
- Cellars with vegetables can accumulate carbon dioxide. You can determine it by an extinguished candle or match. In this case, it is necessary to open all dampers and ventilate during the day, without going down into the room without protective equipment.
The installation of ventilation systems will be much more effective if, together with it, measures are taken to maintain the microclimate:
- Periodic ventilation with the opening of all doors and hatches. This requirement is especially relevant for cellar owners. It is best to do this in the summer, and get all the wooden items from the cellar;
- Treat walls regularly lime or special compounds. They will protect against the appearance of mold and unpleasant odors in the room. An approximate recipe for such a composition: for a bucket of water 3 kg of lime and 50 g of copper sulfate;
- With excess moisture in the air, you can fight with a box of sand, sawdust, salt, quicklime. Periodically, the box is taken out and thoroughly dried in the sun. In the cellar, you can leave the hole unlocked, and cover it with old blankets or mattresses to improve air circulation;
- It helps to install an additional heat source (small stove, brazier, heater, lamp) or just a burning candle;
- Waterproofing the basement or cellars with bituminous compounds;
- Install adjustable dampers for supply and exhaust ventilation. With their help, it will be possible to exclude drafts and freezing of the basement in winter;
- If the cellar is located in the garage, then it should have a separate ventilation system. The increased humidity of the vegetable cellar is contraindicated for the car;
- Install a regular home fan.
How much does ventilation cost
Providing a good microclimate in the basement is inexpensive. Simple options can be made from construction waste and improvised materials, more complex ones will require additional investments.
The following factors will affect the cost of the entire system:
- The area of u200bu200bthe basement and the height of the entire building. According to these parameters, the number and size of air ducts are calculated, which will be a significant part of the entire project;
- Air box material. PVC is cheaper, but has limitations in size and maximum pipe diameter. Galvanized steel is more reliable and allows ventilation of any degree of complexity and configuration, but is much more expensive, heavier and may require special equipment;
- Degree of automation (a simple duct fan costs from 20 dollars, a switch from 14$);
- The presence of complex and expensive additional devices — split systems, recuperators, dehumidifiers, hygrometers and sensors (the cost of such a turnkey system can exceed 1000 $);
Ventilation in the basement is important both for the safety of the food stored there and for the well-being of the whole house. The simplest options can be made independently or laid down at the construction stage. More complex types of ventilation will require special skills and experience. In any case, this system should always be serviceable and serviced in a timely manner.