How to properly make a hood in the cellar and basement, the calculation of vents

Before starting to build a mansion, they always plan how to arrange ventilation in the basement and put its scheme into the project. But what if you bought an old country house and found mold on the walls and musty air in the cellar? Here you will have to do the calculation of the basement ventilation yourself and install the air duct system. Learn from the article how to properly ventilate the basement. A real craftsman will be able to do such work.

The purpose of the basement and the need for ventilation

For many generations of villagers and summer residents, the cellar served as a storage place for the harvested crop and supplies for the winter. As far as possible, natural ventilation ensured the flow of air so that the potatoes did not rot. But in order to maintain a normal microclimate, it is desirable to make ventilation in the basement more efficient.

In modern cottages, basements are most often used as gyms, billiard rooms, garages or workshops. Under these conditions, only forced ventilation in the basement is able to provide the required air exchange. You will definitely have to decide how to make ventilation in the basement in order to prevent the appearance of mold if the waterproofing is not performed correctly.

Pay particular attention to the ventilation system in the basement where the heating equipment is installed. An uninterrupted supply of air is required for the combustion of fuel in the boiler.

There are various ventilation systems. The main ones are:

• natural, in which the movement of air within the cellar occurs due to the fact that the heated air mass tends outward, and colder fresh air comes to replace it;
• forced, in which air exchange is enhanced due to the operation of fans installed in the air duct network.

When choosing how to properly arrange ventilation in the basement - with natural or forced air exchange - first of all, take into account the peculiarities of the layout and the purpose of the basement.

Air vents for natural air access to the basement

For free penetration of outside air, natural ventilation in the basement is sufficient. During construction, ventilation ducts, the so-called air vents, must be laid in the basement part of the foundation. If this has not been taken care of in advance, you will have to do natural ventilation in the basement with your own hands.

Do air vents under each wall of the house, or at least under two opposite ones. Numerous photos and training videos will help you understand how to properly arrange ventilation in the basement. Our photo shows that the holes must be provided with grates from four-legged "guests". In addition, natural ventilation in the basement provides that the air vents can be partially covered during winter.

How to calculate natural ventilation in a basement? Be guided by the rule to arrange one vent for every 2 running meters, and to determine the diameter of the vents, divide the basement area by 400. For example, the area of ​​your underground is 60 m2, then the total area of ​​the vents will be equal to 0.15 m2. Considering that in all 4 walls you will have a total of 12 vents, then for good ventilation in the basement, the dimensions of the vents should be 10X12.5 cm.

To calculate the number and size of airflows, take into account also the peculiarities of the climate in a given area, the composition of the soil, the location of the house in a lowland or on a hillock.

Supply and exhaust ventilation of the cellar

If your cellar is small in size and is not divided by internal walls, then you can do with the simplest supply and exhaust ventilation, which is included in the category of natural ventilation. Trapped air will rise upward through the exhaust duct. In addition to the exhaust duct, you will need to make a second, inlet, through which air will flow from the yard. Therefore, the hood in the cellar can be easily done by hand.

Basement chimney

Run an exhaust duct from the basement through all floors of the house so that its upper end rises above the roof. Make an exhaust hole at the top of the basement wall, just below the ceiling. If you want to know how to make effective ventilation in your basement, follow the advice of experts. They argue that it is possible to combine the exhaust duct with the chimney or lay close to it. Additional heating of the duct will provide stronger traction.

Insulate the upper part of the pipe, as in winter, when it comes into contact with cold outside air, condensation will form inside the duct. Only by knowing how to properly ventilate in your basement will you protect the air duct from the appearance of a layer of frozen frost, which can partially close the inner lumen. Install a connection at the lower end of the exhaust duct through which condensation drops will drain. That's it, the basement hood is ready.

Basement supply pipe

For ventilation in a small basement, the supply air duct may not be needed, there will be enough air vents. But if your basement has a decent cubic capacity, then it is advisable to install a supply pipe. The supply ventilation scheme allows the installation of the pipe in two ways: directly through an outlet or with an outlet to the roof. In any case, its lower end should not reach the floor level by 20-30 cm.

To ensure good circulation of the air mass, both exhaust ducts from the basement should be located in opposite corners.

Forced ventilation of the basement

In a large basement with a complex layout, natural air exchange may not be enough. Then only with the help of forced ventilation will you be able to keep the air dry and fresh. To do this, you will need to lay an air duct under the ceiling and install a duct fan in it, because a simple basement hood with natural draft will not work here.

To understand how to calculate the ventilation efficiency in a basement, first select the fan power you need. Its performance should be such that in one hour to drive through itself a volume of air, 2.5-3 times more than the internal volume of the basement.

Install system elements soundproofed so that the noise of the vibrating fan does not irritate your hearing. To completely eliminate the noise, there is an option to install an exhaust fan outside the house.

The best way to arrange ventilation in the basement is to install an automated forced ventilation system. Its main advantages:

• automatic regulation;
• equipped with filters;
• heating of incoming air;
• moisturizing to a comfortable level.

Another option for how to make ventilation in your basement can be an air conditioner. It is desirable that one that can be programmed with the switching frequency. The use of an air conditioner is important for basements equipped with real rooms. In this way, your duct costs will be significantly reduced.

How to pre-calculate ventilation in the basement

Prepare a project that will contain the calculation of the forced ventilation of your basement. It should take into account the following indicators:

• basement volume;
• speed of movement in air ducts;
• hourly rate of air exchange;
• section of air ducts;
• loss of pressure in the channels;
• climatic features.

The creation of such a project will require specialized knowledge from you, therefore, if possible, entrust the problem of how to calculate ventilation in the basement to specialists. As an example, we can give the averaged version of the recommended parameters:

The choice of materials for the ducts of the cellar

Air ducts for the ventilation system in the basement are the main elements, the correct choice of which will depend on whether the entire system is efficient enough. When calculating basement ventilation, you need to think about what materials to make the air ducts.

Earlier in the villages they decided in a simple way how to arrange ventilation in the basement. A wooden box made of planks was used to freshen the air in the cellars. To save materials, it was often made two-channel, combining supply and exhaust.

The hood for a cellar made of wood is short-lived, the boards rot from dampness, and new technologies have replaced the old-fashioned methods. Now it is more logical to use metal and plastic air ducts for the ventilation device in the basement.

According to the material of manufacture, air ducts are:

• Metallic. Made of galvanized sheet, stainless steel, aluminum alloys. They are durable, fireproof, reliably mounted and serve for a long time. The disadvantage is the relatively high cost;
• Plastic. Made from environmentally friendly polypropylene. They are lighter than metal ones and provide excellent tightness of the joints. Disadvantage - they can crack from strong shocks and deform from high temperatures;
• Flexible corrugated. Made of polymer materials, reinforced with steel wire for strength. The disadvantage is increased noise and resistance to air flow.

For DIY ventilation in the basement, circular air ducts are the most popular. Such pipes are easier to install and they slow down the air flow less. Compared to them, rectangular air ducts look more aesthetically pleasing under the ceiling, but their aerodynamic properties are somewhat worse.

Together with air ducts, you will find on sale unified fittings for them and hoods from the cellar. These are tees and crosses, transitions and bends, dampers, plugs and more.

Installation of air ducts in the basement and cellar

For ventilation in your own basement, you need a minimum amount of materials. Basically - ventilation pipes, clamps for fixing them, dowels and screws, protective grilles, visors and deflectors. You will also need the usual set of tools for installation work: a drill and a side cutter, a hammer and pliers, a knife, and various screwdrivers.

Most clearly, the process of installing ventilation in the basement is shown on video and photo, but you should first understand the main stages of work and their sequence.

• Mark the installation locations of the air ducts according to the project;
• Punch holes in the walls for ventilation system elements;
• Install fasteners on the prepared places;
• Assemble sections of the duct from separate fragments on the floor;
• Lift the mounted part of the system and fix it on the fasteners;
• Seal the joints of the parts with sealing tape.

Functional check and preventive maintenance

You can check the operability of the installed ventilation device in the basement in any of three simple ways: bring a thin paper towel, a burning candle or a smoking cigarette to the air duct opening. If there is air movement, it will be immediately noticeable.

How to properly arrange a hood in the cellar so that it never gets clogged? Unfortunately, it doesn't work that way. After a few years, the draft force of forced ventilation in the cellar may noticeably decrease. The inner surface of the air ducts is gradually overgrown with cobwebs and dust deposits, so you have to periodically clean the ventilation system in the basement with your own hands. For this, professionals use the method of cleaning with chemical aerosols or use hydromechanical devices and vacuum pumps. But it shouldn't be difficult for you to do preventive maintenance yourself.

The easiest way to clean the supply and exhaust ventilation of a basement at home is to lower a bag of sand on a string into a vertical air duct.

Look at the video of the ventilation option in the basement, assembled from scrap materials

Last tips

You have already learned in theory how to properly make ventilation in the basement, and you can start creating it yourself. When developing a project, take into account all factors, from the natural features in your area to the specific operating conditions of the basement. If you carry out the installation work competently, accurately and without fuss, then soon you will be able to breathe freely.