Indoor air exchange is a key element in ensuring health, comfort and productivity. The microclimate, oxygen content, and humidity level depend on the correct organization of air exchange. One of the most important criteria for air quality is the air exchange rate. This indicator helps designers, engineers, and building owners understand and adjust ventilation systems to achieve the optimal balance between efficiency, cost-effectiveness, and environmental friendliness. In this article, we will look at the main methods for calculating the air exchange rate, its importance for different types of rooms, and recommendations for optimizing air exchange.

What is the air exchange rate?

The air exchange rate is an indicator that indicates how many times the air in a room is completely renewed in an hour. For example, if the air exchange rate is 2, it means that the air in the room is completely renewed twice in an hour.

It is the air exchange rate that shows how comfortable and safe people will be in a particular room.

Factors that affect the air exchange rate:

  • Type of room – living rooms require a lower air exchange rate than, for example, production workshops.
  • The number of people – the more people in the room, the higher the air exchange rate should be.
  • Equipment – some equipment can emit harmful substances that need to be removed as quickly as possible.

The permissible air exchange rate at home and in industrial premises is regulated by state building codes, which define different requirements for all constructed buildings.

Methods for calculating the air exchange rate

There are different methods for calculating the air exchange rate:

  • based on the volume of the premises – it takes into account the area of the room and the power of the ventilation system;
  • sanitary method – takes into account the human need for fresh air;
  • based on heat emission – takes into account the heat emissions in the room from equipment, appliances, people, etc.
An example of calculating the air exchange rate

Let’s consider the simplest option: determining the required volume of mechanical air exchange under standard conditions in the absence of a large number of people and harmful impurities in the air. This calculation method is suitable for bathrooms, kitchens, bedrooms, and utility rooms at home.

First, let’s determine the volume of the room in cubic meters using the formula:

L x W x H = L,

Where L is the length of the room, W is the width, and H is the height, respectively.

For example, let’s take a bedroom 5 m long, 7 m wide, and 2.7 m high. Substitute the data into the formula: 5 x 7 x 2.7 = 94.5 m³. This number is the volume of the room.

After that, you need to multiply the volume of the room by the standard value for a particular type of room. You can find the standard value in the table below. For a bedroom, it is 0.6.

94,5 × 0,6 = 56,7 м³/h

Thus, the required ventilation capacity in the bedroom is 56,7 м³/h

                            Accommodation Air exchange rate
Private house, apartment (bedrooms, living rooms)                                     0,6
Bathroom (bath, shower, toilet)                                     54 м³/h
Kitchen                                     72 м³/h
Utility rooms (pantry, dressing room)                                     1-1,5
Basement                                     4-6
Office                                     30-50 m³/h per 1 employee
Study room                                     16 м³/h per 1 student
Restaurant                                     30 м³/h per 1 visitor
Garage                                     5-8
Air exchange rate: the norm for a home

According to DBN B.2.5-67-2013, the air exchange rate in residential premises should be at least 0.6 times. Additional recommendations:

  • Air exchange rates also depend on the area, ceiling height and other features of a particular room.
  • It is also important to take into account the presence of additional sources of pollution, such as tobacco smoke, pets, plants, animals, etc.
  • In the cold season, monitoring air exchange is no less important than in summer.

Ensuring optimal air exchange in the house is an important part of creating a healthy and comfortable living environment for all its inhabitants.

Required air exchange rate in the office and at work

Properly organized air exchange in office and industrial premises is an important factor in ensuring the comfort, health of employees and the efficiency of the production process. The operation of industrial facilities is often associated not only with the simultaneous presence of a large number of people in the room, but also with the vapors of harmful impurities.

Office premises

The purpose of air exchange: to provide comfortable conditions for employees, reduce CO2 concentrations, remove odors and provide sufficient oxygen.

Recommendations: In general, for office spaces, the recommended air exchange rate is 2-4 times per hour or 30 m3/hour per employee. This rate may vary depending on the number of people and the specifics of the room.

Production

Purpose: removal of pollutants associated with production processes (dust, smoke, gases, etc.), maintaining temperature and humidity at an optimal level.

Recommendations: Depending on the production specifics, the air exchange rate can vary significantly.

When calculating the required air exchange rate, you should always take into account specific conditions – the presence of air conditioning, the number of people, the type of equipment, the specifics of production, and the geographical location of the facility. Also, effective air exchange depends not only on the air exchange rate, but also on the proper organization of the ventilation system, which ensures even air distribution in the room.

Methods of air exchange control

Properly regulating indoor air exchange helps to ensure a comfortable and healthy environment for occupants and employees. There are two methods of air exchange control:

  1. Ventilation. The use of ventilation systems to control air exchange.
  2. Natural ventilation. Opening windows and doors for air exchange.

Unfortunately, natural ventilation often cannot provide the necessary microclimate, so the installation of ventilation is the best solution for private houses and apartments, as well as for offices, industry, etc.

 

Ventilation systems with heat recovery from PRANA provide not only efficient air exchange, but also microclimate control and heat preservation. We offer efficient ventilation solutions for private homes, offices, and industrial facilities. To get a consultation, don’t hesitate to call!

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