The calculation of fresh air volume is diverse and is an essential part of a new air heating system. The calculation method of fresh air volume is directly related to the selection of equipment. If the results of the calculation method of fresh air volume are small, the ventilation of indoor ventilation will be insufficient. Therefore, what is the calculation method of the fresh air volume, in order to calculate the most suitable fresh air volume, the following introduces several new wind volume calculation methods.

First, the determination of the amount of fresh air

According to GB50019-2003 "Code for Design of Heating Ventilation and Air Conditioning", the minimum fresh air volume of the room should be consistent with: the fresh air is not less than the fresh air volume required by the personnel, and the larger the air volume required to compensate for the exhaust and maintain the positive pressure in the room. value.

In the actual design, the fresh air volume can be calculated according to the new air volume required by the room occupant or the number of room air changes:

1. New air volume calculation method

Calculated by room capacity: (for civil buildings)

Qm=N ×qm

N—number of people; (the number of people in a unit area can be calculated based on the floor area ratio per unit area)

Qm—new air volume, unit: m3/h;

Qm—The amount of fresh air required by each person (see table below).

"Code for Design of Heating, Ventilation and Air Conditioning for Civil Buildings" GB50019-2011

2. New air volume calculation method 2

Calculated by the number of air changes in the room: (applicable to residential buildings and hospital buildings)

The proportion of building pollution in residential buildings and hospital buildings is generally higher than that in personnel pollution. The new air volume determined according to the existing fresh air volume indicators does not consider the construction pollution, so it cannot guarantee that the indoor hygiene requirements are always fully met; therefore, for this The two types of buildings should consider the pollution composition of the building according to both construction pollution and personnel pollution, and give the minimum required fresh air volume in the form of the number of air changes.

Qm=N ×V

N—the number of air changes in the room (see table below)

V—room volume

Qm — fresh air volume, unit: m3/h;

Second, the determination of the amount of exhaust air

The amount of exhaust air can be determined according to the number of room ventilation or the percentage of fresh air:

1. Exhaust air volume calculation method

   
   

Calculated by the number of air changes in the room: (applicable to split, multiple small rooms)

Q exhaust air volume = N × V

N - room air exchange times

V—room volume

2. Calculation method of exhaust air volume (applicable to areas with large area)

Calculate 80 to 90% of fresh air volume according to exhaust air volume

Q exhaust air volume = Q fresh air volume × 80 to 90%

What is more noteworthy is that when determining the new air volume required for the calculation of the fresh air volume in the room, it is necessary to consider the size of the room and the number of indoor personnel. The above is a partial introduction to the calculation method of fresh air volume. The products of the fresh air system are different and different. Remind everyone to buy new air products, please ask the designer to calculate the new air volume required by the room, and purchase the model reasonably. .