Air exchange is the most important characteristic of any ventilation system. Air exchange characterizes the frequency of air replacement in the room. According to regulatory documents, the performance of the system or the frequency of air exchange in the premises is indicated, that is, how many times the entire volume of air is replaced in the room per unit of time (for example, per hour). The performance of ventilation systems is usually measured in cubic meters per hour (m3/ h) — how many cubic meters of air per hour leaves the room and comes into it.

one What air exchange is required for living quarters?

Firstly, it must meet the requirements of building codes and regulations for each specific type of premises, specifically — SP 60.13330.2016 «Heating, ventilation and air conditioning». Secondly, the number of people in the room should be taken into account.

Air exchange rates for residential premises

Living quarters less than 20 m2 per person 3m3 per 1 m2 area
Residential premises over 20 m2 per person 30 m3 per hour per tenant

Air exchange rate

Room type Air exchange rate
Kitchen 5-8
Bathroom 7-10
Toilet 8-10
Living room 3-4
Bedroom 2-4
Smoking room ten

How to calculate air exchange

Calculation of air exchange in the room is made according to the formula: B=V*n, where B — air exchange, V — volume of the room (area multiplied by the height of the ceiling), n — air exchange rate.

For example, for a living room of 20 m2 and with ceiling heights of 3 m, the recommended air exchange capacity is approximately 180-240 m3/h Another calculation option is by the number of people in the room. The calculation of the air exchange rate can also be performed online, on many construction calculator sites, for example, calc.ru

2 What threatens non-compliance with air exchange standards?

Insufficiently intense air circulation makes housing uncomfortable and even hazardous to health. Stuffy air, odors that do not disappear for a long time, dampness and mold may appear about problems with the ventilation of the premises.

3 What ventilation system will ensure normal air exchange?

Air exchange in residential premises is carried out through natural or forced ventilation systems.

natural ventilation

Natural ventilation is air ducts located in the bathrooms and in the kitchen. Air is extracted through them, and the inflow is carried out through cracks and other leaks in windows and entrance doors.

Natural ventilation is able to withstand the required air exchange rates only in the presence of the aforementioned «leaks» and only with significant (at least 10-15aboutC) the difference between the temperature of the outdoor and indoor air.

Therefore, if you use natural ventilation, be sure to provide for the possibility of an influx of outside air. These can be, for example, special ventilators built into modern window frames with double-glazed windows. Monitor the condition of the exhaust ventilation ducts so that they are not clogged with dust. Their condition can be judged by bringing a lit match to the ventilation grill: the better the hood works, the more the air flow deflects the flame. And keep in mind that in summer, when the air temperature outside and inside is the same, even the best natural ventilation system will not work.

Forced ventilation

Forced ventilation systems work efficiently regardless of the season and outdoor air temperature — this is their main advantage. Also, they do not depend on the state of cracks and leaks, they do not need to constantly keep the windows open.

These can be both complex supply and exhaust climatic complexes, and ventilators that are simpler in design. Ventilator — a device that is a ventilation duct with a diameter of 10-15 cm with a built-in fan. It is installed in the thickness of the outer wall of the building. Ventilators can work both for air supply and for its extract. A pair of ventilators installed in rooms far from each other (for example, an exhaust hood in the kitchen, and a supply in the bedroom) can solve the problem of air exchange. There are, however, two-in-one models, in which the fan alternately operates in direct and reverse mode, either for supply or exhaust air. For more comfortable operation, the ventilators are equipped with incoming air filtration and heating systems. The cost of one such ventilator is 10-20 thousand rubles.

Blauberg Fresher 50 ventilation unit

Blauberg Fresher 50 ventilation unit

In addition to air exchange, ventilation according to SNiP must provide an influx of heated air so that cold air flows (drafts) do not occur. This is achieved by heating outdoor air supplied in natural ventilation systems to heating radiators (a cold air stream from window slots and vents quickly heats up above radiator batteries — which is why they are recommended to be placed under windows).

Air handling unit SIEGENIA Aeropac SN

Air handling unit SIEGENIA Aeropac SN

In systems of forced supply and exhaust ventilation, heat exchangers-recuperators can be used. In them, the heated and polluted air at the exit from the room passes through the heat exchanger and gives off a significant part of the heat to the fresh air entering the room from the street. The procedure for removing air is also regulated according to SNiP: its removal from the premises by ventilation systems should be provided from areas in which the air is most polluted or has the highest temperature.



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