Basement and basement serve different purposes. Previously, they were held in the vegetable store, housed communication. Now cellars are assigned different functions, from garages to gyms and even offices.
In any case, forced ventilation in the cellar of the building - a legitimate need, dictated by the need for systematic supply of fresh air to replace the hours worked. We offer a good look into the matter.
The content of the article:
- Each cellar has its own ventilation
- Moisture in basements
- Thermal insulation pipe from the condensate
- Calculation of ventilation in the basement
- Calculation of the air with the heat and moisture
- The calculation parameters of air ducts
- Calculation of ventilation network resistance
- The choice of an exhaust fan
- Scheme basement ventilation ducts
- Conclusions and useful videos on the topic
Each cellar has its own ventilation
Deepening vegetable store, located at a private home, forced, ie Mechanical ventilation is not necessary.
Fruit and vegetable products are stored better if ventilation in the basement is minimal. So just produhi and supply and exhaust air ducts will be enough.
Stored winter vegetables in the cellar should not be hard to ventilate. They simply freeze - frost on the street
According to the design standards for vegetable stores NTP APK 1.10.12.001-02, Venting, for example, potato and root should be in the amount of 50-70 m3/ H per ton of vegetables. And in the winter months ventilation rate should be reduced by half, so as not to freezout roots.
Those. during the cold season home cellar ventilation must be in the format of 0.3-0.5 volume of air space per hour.
The need for forced ventilation in the cellar occurs if the circuit with the natural movement of air currents does not work. But also require the removal of sources of air waterlogged.
The forced ventilation unit becomes necessary, if for technical reasons the natural air movement is difficult or impossible
Forced ventilation ensure stable discharge of moisture from the basement and the basement, prevent the development of fungi and settling plenisnevyh
Regardless of whether the cellar is arranged in a basement garage or in a separate building, it must be equipped with air-supply and exhaust openings
Forced ventilation required to withdraw carbon dioxide and toxic volatile substances, often formed during storage of the products, thereby prolonging storage time
Fan for forced ventilation
Removal of moisture from the cellar isbytka
Supply opening in the basement of the house
Conditions for storage of workpieces
Moisture in basements
air musty and damp basements are common problems. The first problem is due to lack of ventilation. Basement recessed at 2.5-2.8 m into the ground, its walls are made with a maximum moisture and air impermeability.
A natural ventilation provided by household vertical channels, in many basements and cellars available.
Before parsing issues cellar ventilation should be waterproofed the walls. basement ventilation does not solve the problem of hygroscopicity wall
Significant humidity in the basement is poor waterproofing of walls. The second reason - the worn lines stretched across the basement utility room. Wherein the condensate deposited on them irrespective of the integrity of the pipe and sealing of detachable joints.
The problem of excess moisture is required to solve the project design and construction of the basement ventilation system. It is necessary to restore or increase the degree of tightness of the cellar walls, seal the pipes and close their isolation.
The latter measure will eliminate the condensation effect on the pipe material. Then determined cellar ventilation needs.
Forced ventilation may be the channel and channel-free. Duct embodiment is used mainly for air intake from outside, particularly if it requires cleaning and heating
Fan forced system with associated equipment can be installed in the middle of the duct. In this case, air resistance increases slightly
Style inducement to the motion of air mass ventilating systems are divided into air supply, exhaust and combined, i.e. supply and exhaust. The supply and exhaust circuits usually works or hood, or the influx of
Depending on the scheme of ventilation fan or put on the exhaust duct or the supply. The combined fan circuits equipped with two openings to the duct or without
Channel ventilation system
Installing the fan in the duct center
Combined ventilation varinat
Fan forced ventilation
Thermal insulation pipe from the condensate
Water drops occur only on the surface of domestic pipelines, which is cold liquid (drinking water and sewage drain). Moisture in the atmosphere is available space condenses on the cold tubes due to temperature differences between their surface and the air.
The colder the tube than the air is saturated with moisture - the more active water condensing process occurs.
If the pipe is cold water, condensation will collect on it. Each such pipe requires close thermal insulation
Air temperature difference and the surface of the cold water supply pipes in private homes is usually small. After all, with infrequent consumption household cold water have its movement through the pipes, so the home atmosphere temperature and the pipeline is almost equalized.
However, in high-rise buildings, residential or office, cold water is used substantially continuously and constantly cool the tube.
The simplest way of dealing with the condensation on the pipes - equalizing heat pipe and the atmosphere. It is necessary to close the cold steam pipe and insulating material over the entire length.
The condensate is collected on the cold pipe regardless of which it is made. Polymers, ferrous metal, cast iron or copper - not important. Insulate all pipes have "cold" communication!
Isolate the water pipes from condensation and damp impact of the slurry in the air is easy. All you need is a tube made of foamed LDPE, wallpaper knife and reinforced tape
Prevent contact with cold air pipe allow a tubular heat insulator made of foamed LDPE. Insulating wall "tubes" - not less than 30 mm. The diameter of the tubular heater is chosen slightly greater than that from atmospheric moisture insulated conduit. Dress insulation simple - cut the length, followed obtyanut trumpet.
Right after sealing conduit insulator you need to wrap him up and reinforced with tape for pipes. foiled winding tape (aluminum) is conducted for the maximum insulation and greater appeal.
Valves and complex-curved portions of cold piping which can not be closed tubular insulation tape are wrapped in several layers.
Calculation of ventilation in the basement
Before you search for ventilation equipment and plan location of air ducts in the basement, it is required to determine the air exchange needs. In its simplest format, ie exclude the possible content of noxious substances in the atmosphere basement breathability it is calculated by the formula:
L = VMob • KR
- L - estimated need of ventilation, m3/ч;
- VMob - the volume of the basement, m3;
- KR - minimal multiplicity of air exchange, 1 / h (cm. below).
The resulting value air will install the power characteristics of a forced ventilation system basement.
Calculation of the air volume of the basement is done by multiplying the height, width and length
However, the formula for calculating the required data on the air volume of the room and the ventilation rate.
The first parameter is calculated as follows:
VMob= A • B • H
- A - the length of the basement;
- B - width of the basement;
- H - height basement.
To determine the volume of the room in cubic meters of the width measurements of length and height are converted to meters. For example, for the basement 5 m wide, 20 m long and 2.7 m high, the amount will be 5 • 20 • 2,7 = 270 m3.
The need for air exchange of premises directly depend on the number of people staying in it. Also takes into account the degree of physical activity of visitors
For spacious cellars minimum ventilation rate KR determined by the rate of one person needs fresh (supply) air per hour. The table presents the regulatory needs of the person on the air exchange depending on the use of the premises.
Also, ventilation can be calculated according to the number of people who will be (for example, work) in the basement:
L = Lpeople• Nl
- Lpeople - on the air exchange rate for one person, m3/ч•чел;
- Nl - the estimated number of people in a basement.
Norms approved by the needs of people in 20-25 m3/ H inlet air at low physical activity, a 45 m3/ H when performing a simple physical work and 60 m3/ H at high exertion.
Calculation of the air with the heat and moisture
If necessary, the calculation of ventilation, taking into account the removal of excess heat formula is used:
L = Q / (p • Cp • (tat-tP))
- p - density of air (at 20 ° C t is equal to 1,205 kg / m3);
- CR - heat capacity of air (at t 20 ° C is 1,005 kJ / (kg • K));
- Q - amount of heat generated in the basement, kW;
- tat - temperature of the air removed from the room, ° C;
- tP - inlet air temperature, ° C.
The need for heat metering, eliminated by ventilation, it is necessary to maintain a certain temperature balance in the atmosphere basement.
gyms are often held in the basements of private homes. In this embodiment, the use of particularly high-grade basement ventilation important
Simultaneously with the removal of air in the process air removed moisture Dedicated therein various water-containing objects (including human beings). The formula for calculating the air with the separation of moisture:
L = D / ((dat-dP) • p)
- D - the amount of moisture released when air exchange, g / hr;
- dat - moisture content of the exhaust air, g of water / kg of air;
- dP - moisture content of the supply air, g of water / kg of air;
- p - density of air (at t 20aboutC was 1,205 kg / m3).
Air exchange comprising selection moisture is calculated for the moisture of objects (e.g., pools). Also, the allocation of moisture is taken into account for basements, visited by people to exercise (eg gym).
Consistently high levels of humidity greatly complicate the work of the forced ventilation of the cellar. Require addition ventilation filters for collecting condensed moisture.
The calculation parameters of air ducts
With the data volume of the air ventilation duct proceed to define characteristics. We need one more parameter - the speed of air transport through the air ducts.
The faster the air flow is run, the less voluminous air ducts can be used. But also increase noise resistance and networking. Optimally, the air pump at a speed of 3-4 m / s or less.
Knowing the design section of the duct, it is possible to choose their actual cross-section and the shape of the table. And also determine the air flow at certain speeds its feed
If the interior of the cellar allows us to use circular ducts - is more profitable to use them. In addition, a network of air ducts round ducts easier to collect because they are flexible.
Here is the formula that calculates the area of the duct cross-section:
Sbinding= L • 2,778 / V
- Sbinding - calculated cross-sectional area of the ventilation duct (duct) cm2;
- L - air consumption during pumping of the duct, m3/ч;
- V - velocity at which air moves through the duct m / s;
- 2,778 - factor value, which allows to harmonize inhomogeneous parameters consisting of Formula (centimeters and meters, and the second time).
sectional area ventkanala calculate easier to see2. In other units of measurement of this parameter of the ventilation system is difficult to perceive.
For each element of the ventilation system air flow is better to fail at a certain speed. Otherwise, increase the resistance in the ventilation system
However, the definition of the calculated cross-sectional area ventkanala not allow to choose the correct section of the duct, because it does not take into account their form.
Calculate the required duct area the following formulas can be in its cross-section:
For circular ducts:
S = 3,14 • D2/400
For rectangular ducts:
S = A • B / 100
In these formulas:
- S - ventkanala actual sectional area, cm2;
- D - the diameter of the circular duct mm;
- 3.14 - the value of π (pi);
- A and B - the height and width of a rectangular cross section duct mm.
If air line channel one, the actual cross-sectional area is calculated only for him. If the main line will be executed branches, this parameter is calculated for each "branch" separately.
In the construction of air ducts are used with steel pipes coated or galvanized, asbestos and plastic tubes. Currently, the most popular plastic
paves the way open ducts satisfied from polymeric or steel pipes and shaped elements of the same material
The horizontal sections of the ventilation system are suspended on the bracket to the ceiling cellar. The vertical parts are fixed on the walls of the collars
Selecting a location for the fan setting determines the ventilation system layout and calculations made for her
Galvanized steel ducting
Components for assembly of the ventilation system
Fixing the ventilation pipes
The fan on the exhaust pipe inlet
Calculation of ventilation network resistance
The higher air displacement velocity in the air ducts, the higher the resistance to movement of air masses in the complex ventilation. This unpleasant phenomenon is known as "loss of pressure."
If the cross section of ventilation ducts gradually increase, it will achieve a stable air velocity over its entire length. The resistance of air movement does not increase
The air handling unit is to develop air pressure, allowing to cope with the resistance of the air distribution network. Only in this way will achieve the required air flow in the ventilation system.
The air speed, transported by air ducts, defined by the formula:
V = L / (3600 • S)
- V - velocity calculated pumping air mass m3/ч;
- S - channel sectional area of the duct, m2;
- L - the required air flow, m3/ч.
Selection of the optimal model for the fan of the ventilation system should be done by comparing two parameters - static pressure developed by the ventilation system and the calculated pressure losses system.
Placing the ventilation unit in the center of the branched duct system, will stabilize the air flow rate throughout its length
The pressure loss in a long vent complex complex architecture are determined by summing the resistance of air movement in the curved zone and its composing elements:
- in the check valve;
- in silencers;
- in diffusers;
- a fine filter;
- in other equipment.
Independently calculate the pressure loss in each such "obstacles" need not. It suffices to use the pressure loss graphs relation to air flow offered by manufacturers of equipment and the associated air ducts.
However, when calculating the complex ventilation simplified construction (without composing elements) is allowed to use standard pressure loss value. For example, in the basement area of 50-150 m2 Duct resistance losses amount to about 70-100 Pa.
The choice of an exhaust fan
To determine the AHU with a choice, you need to know the necessary performance and resistance to complex ventilation ducts. For a cellar forced ventilation only one fan built into the suction channel.
The air intake duct, as a rule, does not need an air handling plant. Enough small pressure difference between the air supply and sampling points provided by the exhaust fan operation.
Knowing the estimated (desired) pressure in the duct system can determine whether the model is suitable ventilation installation for a full air supply areas. It is enough to find a position on the pressure to draw a line graph, then down
Need fan model, whose performance is slightly (by 7-12%) is higher than rated.
Check the suitability of the ventilation unit can be from a plot of the performance of pressure loss.
Using data on the calculated air flow rate, pressure loss can be set in curved duct portions
If forced to choose between the obviously more powerful and too weak an air handling plant - it remains a priority for the powerful model. However, it will somehow reduce its performance.
Optimizing too powerful exhaust fan is achieved by the following ways:
- Mounted in front of an air handling plant balancing throttle valveThat allow "smother" her. Airflow in the partial overlap of the exhaust duct will decrease, but the fan will operate with a high load.
- AHU include work in small and medium speed conditions. It is possible, if the unit supports 5-8 speed adjustment and smooth acceleration. However, support for multi-speed operation mode to the low-cost models do not have fans, they have a maximum speed control 3 steps. And for the correct performance of the three speed setting is not enough.
- Reduce the maximum performance exhaust installation to a minimum. This is feasible if the fan allows automatic management of its maximum speed.
Of course, one can not ignore the overly high performance ventilation. However, you have to pay more for electricity and heat, as the hood will be too active to pull heat from the room.
Scheme basement ventilation ducts
Supply channel is output for a basement facade openings arranged with fence netting. Its inverse output, which supplies air, is lowered to the floor at a distance of two feet from the latter.
To minimize the formation of condensate inflow conduit must be insulated from the outside, particularly the "street" portion.
To determine the pressure loss in straight duct system, it is necessary to know the velocity of the air and use this chart
The air intake hood is placed on the ceiling, in the opposite direction from the point of the supply hole end of the room layout. exhaust hole and place the supply channel on one side of the basement and on the same level is meaningless.
Since housing construction regulations do not allow the use of vertical channels of natural extracts for mechanical ventilation, make them impossible ducts.
The case when positioned input and exhaust-intake channels on different sides of the reset cellar air impossible (there is only one exterior wall). Then dilute the point of air intake and a vertical reset is 3 meters or more.
Conclusions and useful videos on the topic
This video clearly showing signs of poor ventilation basement. Channels of supply and exhaust ventilation in the cellar seem to exist, but the air does not go on them. There are all the problems of the basement - damp, musty air and abundant condensation on the protective structures:
The video below provides a practical solution to the forced extraction cellar using cooler PC and a solar battery. Note the original performance of the ventilation project. For cellars such as "Growers' implementation of such air is quite acceptable:
As a full-fledged low humidity in the basement can not be non-insulated "cold" pipeline, we present a video about applying the tubular insulation. Note that with the technical assignment rational full basement winding insulated pipes reinforced with tape - so reliable:
"Stray" cellar is quite possible to turn in the desired destination room. It is only necessary to solve the problem of air in it and eliminate sources of moisture. In any case, the basement floor of the building, must not be wet, overgrown mold space. After all, its walls - the foundation of the structure, whose destruction is unacceptable.
You want to build your own ventilation in the cellarBut are not sure that everything is done correctly? Ask your questions on the topic of the article is located in the block below. You can also share the experience of self-arrangement of ventilation in the cellar or basement.