Ventilation of the cellar in detail: from calculation to

Any self-respecting summer resident, sooner or later, necessarily acquires a cellar. Sometimes a basement in the house is allocated for it, but more often it is an independent building, buried in the ground. And if in the house the movement of air masses can be ensured simply by opening the window sash, then in the cellar to solve the problem in this way will not work. We have to design and install air ducts, fortunately, the ventilation of the cellar with their own hands is not particularly complex.

Do you really need ventilation?

At first glance, the basement can do without a separate ventilation system, because this room is non-residential, and is used mainly for crop storage and preservation. The price of such a frivolous attitude to this issue can be very high.

The lack of ventilation (or errors in its design) is guaranteed to lead to an unpleasant smell and a general feeling of discomfort in the room, but this is only half the trouble. The main consequence will be the appearance of mold and high humidity.

The ill-conceived ventilation system of the cellar is guaranteed to lead to the deterioration of vegetables and fruits that were stored in it. Preservation may also be affected - metal covers will quickly rust. So maintaining a constant microclimate is vital.

Types of ventilation systems

All types of ventilation can be divided into 2 groups:

• natural - while the circulation of air masses is due to the pressure difference at the exit and entrance to the pipeline;

• forced - in such systems, fans are used to force air into the room and its outlet.

In each of these groups can be divided into subgroups.

So, in the supply and exhaust ventilation systems (with natural circulation) emit:

• 2-pipe scheme. In this case, 2 separate pipelines are used - one is supplied and the other is exhaust;
• with the 1st pipe. Ventilation in a single-tube cellar is much less efficient than a 2-pipe counterpart, so it can only be used to ventilate small rooms.

Note! In one-pipe ventilation, the internal space of the duct is divided by a partition in two. So, strictly speaking, the pipes are still 2, they are just in 1 case.

As for forced ventilation systems, we can distinguish:

• systems that use a fan to force / remove air from a room;
• fully automated climate control systems. They simultaneously control the humidity and temperature in the room. They are used mainly in wine cellars, only in this case, the cost of installing such a ventilation system can be considered justified.

Subtleties device ventilation system

As for how to properly do the ventilation in the cellar, we can recommend to start with the calculation. Quite often, this stage is ignored, as a result, it may be that the selected section of the pipe is simply not able to provide the required air exchange. The rest of the installation technology is reduced to the installation of 2 vertical pipes and verification of the performance of ventilation.

Simple calculation of ventilation

At this stage it is necessary, given the volume of air in the room and the speed of air movement, to determine the dimensions of the duct section.

Instructions for performing calculations looks like this:

1. Determined by the design air flow, which will pass through the duct.

L = V • K,

in this formula, L is the air volume, m³/hour;

V - volume of the room, m³. As an example, set the volume to 20 m³;

K - shows how many times per hour the air in the room should completely change (taken within 1 ... 4).

Note! Proper ventilation should not dry out fruits and vegetables. Therefore, when calculating K, it is not necessary to take too large.

In the example, L = 20 • 2 = 40 m³/ hour, that is, in an hour the pipe should provide an inflow of this volume of air.

1. Determined by the required cross-sectional area of ​​the duct by the formula

F = L / (S • 3600),

where F is the pipe area, m²;

S - air velocity, allowed to take in the range of 1.0-1.5 m / s.

For the considered example, we need F = 40 / (1.0 • 3600) = 0.0111 m².

1. Depending on what section was used, the dimensions of the pipe are determined. If the example used a square section, would the side of the pipeline be A = v0,0111 = 0.106 m? 11.0 cm. If it is planned to use round pipes, then their diameter will be d = 2 • v (F /?) = 2 • v (0.0111 / 3.14) = 0.119 m? 12.0 cm

Features of the installation of pipes for exhaust ventilation

If the cellar ventilation under the house is organized according to a 2-pipe scheme, then for this you can use both ordinary PVC pipes and a home-made air duct from simple thick boards carefully fitted to each other.

Note! The gaps between the individual boards will seriously reduce the effectiveness of ventilation. For greater tightness from the inside, the surface of the duct is coated with molten bitumen or simply painted in several layers.

As already noted, the air circulation will occur due to the difference in temperature and density of air outside and inside, so the ducts should be placed so that this pressure drop is maximum.

The device of ventilation in the cellar is recommended to be carried out in accordance with the following recommendations:

• if the cellar is in the basement, then you can do without the supply pipe, in which case air enters the basement through holes in the basement. But for greater efficiency, it is still recommended to install the inlet pipe, it can be brought out through the base;

Note! The exit of the pipe to the street through the base must be closed with a protective grid, this will protect the air duct from getting into it of small animals, insects and debris. The grid will not affect the movement of air.

• the cellar ventilation scheme provides for separation of the intake and exhaust pipe at different angles;

• as for the installation of the pipeline, they can be fixed to the wall with brackets or clamps. It is necessary to avoid a large number of turns of the pipes, this reduces the air velocity, respectively, and the volume of air transferred decreases;
• the end of the inlet pipe is brought almost to the floor itself, the distance to the floor should be about 20-50 cm;
• it will not be superfluous to install a damper in the intake duct, adjusting the clearance, it will be easy to change the efficiency of the ventilation system;

• the end of the exhaust pipe on the contrary rises almost to the ceiling itself, and its upper part is displayed on the roof and is raised 40-50 cm above the surface of the roof;
• during the winter period, it is necessary to even slightly reduce the efficiency of the system, it is necessary to reduce the cross section of the pipe, otherwise freezing is guaranteed.

Subject to the listed rules, the ventilation of basements and cellars will work effectively in any weather.

Forced ventilation

Sometimes, despite all the tricks, the natural circulation is weak. In this case, forced ventilation in the cellar will help. You can increase efficiency by installing a simple fan in the duct.

Thus it is necessary to consider the following features of the system:

• it is better to install the fan in the exhaust pipe;

Note! Installing a fan in the intake air duct will inject air from the street into the cellar, with it many particles of dust and dirt will get into the room.

• since the risk of dampness is still present, it is best to power the fan with low voltage.

Quality control and minor tricks

When the question of how to make ventilation in the cellar is resolved, you need to check the effectiveness of the system. It is enough to bring a burning match or a candle to the pipes. When approaching the inlet pipe, the flame should be bent into the cellar, and to the exhaust pipe, it should be sucked into the pipe.

If even if all the recommendations are observed in the room, dampness is sometimes observed, then the problem can be solved simply by installing a box with lime (quicklime) or dry sawdust. They will absorb moisture from the air.

When excessive dryness on the floor, you can simply distribute wet sawdust.

In conclusion

Airing cellars - a necessary measure to maintain a constant microclimate in the room. If the recommendations listed in the article are observed, the cellar ventilation in winter, in summer, and indeed at any time of the year will work without failures. As a result, vegetables, fruits and canned food will be stored in the cellar for a very long time.

The video in this article shows an example of the supply and exhaust ventilation of a concrete cellar.