The calculation of the exhaust system and natural ventilation - the general formulas and rules

Need for ventilation both residential and warehouse, and production can not be questioned, and is not discussed in the project must be present from the beginning.The lack of properly designed ventilation in the drawings is an indisputable reason not to take a job with the designers.The correct calculation of exhaust and natural ventilation will not only ensure the comfort of the people who use it, but also required to maintain the premises in a normal climate, as a permanent replacement air masses prevents high humidity and, as a consequence, the emergence of a damp feeling.


general features of calculation of natural ventilation ↑

calculation of natural ventilation, which is most often used in homes and apartments, is onl

y possible inif the ventilation channel is implemented in a manner that is in the walls and ceilings of the duct system is provided, through which air exchange is carried out in the building.

Natural ventilation space can also be carried Underground way - ventilation and natural air infiltration through door and window cracks and pore walls.In this case, the ventilation process is disorganized and is uncontrolled, and the calculation of the ventilation system is not possible as part of the necessary data for it is constantly changing.

Natural ventilation at home
Natural ventilation at home based on the property when heated air to rise upwards, leaving the waste heat discharged through the air vent on the roof of the house

Important!ChannelFree method of ventilation of any premises accompanied by significant heat loss is considered low efficiency, and in some types of premises can not in general be used.

necessary formulas for calculations ↑

ventilation calculation begins with the definition of the house is usually air or air capacity, which is measured in cubic meters per hour.Also on hand should be site plan indicating the destination premises and the area.All calculations should be carried out by state guided by accepted norms and standards: SNIP 41-01-2003 MGSN or 3.01.01.

Important!Experts are usually used in the calculation of the norm SNP 41-01-2003, as they stiffer, hence, the result is more consistent with the interests of the customer.

It happens that in some areas natural ventilation, for whatever reasons, is limited (the old building or incorrectly planned ventilation system), however, the conditions for the people living in them need to create the most comfortable, for what and set forced ventilation.

Calculation of performance ventilation
This formula calculates the performance of ventilation

In one hour, the air in the room where there are people who should be fully updated at least once.If this upgrade is not enough, you need to calculate how much time you need to carry out the replacement exhaust air fresh.This is called a definition by the multiplicity of air.

Calculation of air by the multiplicity
formula for determining the air by the multiplicity

a result of calculations obtained two measures, of which experts recommend to select a larger to make the most appropriate safety standards.

In some cases, a forced ventilation?↑

If indoor air is stale and damp, and the ventilation does not solve this problem, most likely, it is a lack of natural ventilation.In this case, it is recommended to calculate the exhaust air, and then install the fan optimum power.Power hoods in the kitchen depends on the type of gas stove: electric or gas burners 2 will not adversely affect the microclimate of the kitchen, if the power of the hood is 60 cubic meters / hour, 4-burners gas stove hood capacity should be at least 90 cubic meters.m / h.If in an apartment bathroom unit, the power ventilation shall be not less than 50 cubic meters / hour, and for a separate bathroom and toilet enough 25 cubic meters / hour.

Driving ventilation bathrooms
This bathroom is better to install two exhaust fan less power than a large one as the screen is an obstacle in the way of air masses

Ventilation - an important addition to the ventilation ↑

In that case, if the power ventilationis too great, the room may have a problem with drafts and heat loss, so you need to calculate the ventilation, which would compensate for the operation of the exhaust.In homes, cottages, apartments ventilation is can provide, on average, two-time ventilation, which can be adjusted by means of windows, doors and air conditioners.

Driving ventilation
Driving ventilation demonstrates the optimum layout for ventilation equipment and air flow direction

optimal calculation of ventilation parameters based on the coincidence, that is on the balance between supply and exhaust air.

Aerodynamic calculation of ventilation ↑

Aerodynamic calculation of the ventilation system is carried out for buildings with forced air exchange, which consist of a large number of premises, and the calculation of natural ventilation of the room shows that it is unable to provide the necessary air to maintain a normal indoor climate.Aerodynamic calculation of ventilation used in the planning of hospitals, schools, office buildings, designed for the permanent presence of a large number of people, and trust the best professionals perform calculations as well build a perspective view of the building and take into account all the nuances of a person with no special skills are very hard.

main objective smoke ventilation ↑

calculation smoke ventilation provides for the establishment of such a system of ventilation, which in case of danger, can block and limit the spread of gas, smoke and combustion products in the room, safe for people, as well as escape routes.

Important!Smoke ventilation system is effective only in the initial stage of a fire, then it is no longer able to provide fresh air in the required quantities.

Calculation of smoke ventilation
main objective smoke ventilation - to prevent smoke from entering the room, based on the action of heat flow

in residential areas to install smoke ventilation is usually not necessary, it is necessary only in industrial buildings where the manufacturing process involves the use of fire-risk technologies.Smoke ventilation system should provide fresh air, limiting the spread of smoke.