Selection guide
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Fresh air system type options

Unidirectional flow fresh air system

The one-way fresh air system consists of a host and window (or wall) inlet/outlet. Adopt the form of "natural/in and out air + mechanical fresh air/exhaust air" to send air into or out of the room to achieve the effect of ventilation.

Two-way flow fresh air system

Two-way flow is the "mechanical exhaust + mechanical air supply" method. Fresh air enters the room through the ducts of the air supply system, and the exhaust air is discharged to the outdoors through the ducts of the exhaust system. The flow direction of the fresh air and exhaust air is in line with the fresh air outlet and exhaust outlet. The layout can be designed according to the actual situation and requirements.

Full heat exchange fresh air system

That is to say, a total heat exchanger is added to the main engine to recover the exhaust heat through the heat exchanger. Based on the two-way flow fresh air system, it reduces the influence of outdoor air on the room, thereby reducing the energy consumption of other indoor cooling and heating devices. .

Fresh air ventilation standard

1. "Design Code for Heating, Ventilation and Air Conditioning" GB50019-2003

?Industrial buildings should ensure a fresh air volume of 30m?/h per person.

? The minimum fresh air volume per person in civil buildings (see the table below).

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2. "Indoor Air Quality Standard" GB/T18883-2002

■ The minimum fresh air volume per person is 30m?/h.

3. "Technical Essentials of Healthy Housing Construction" Chief Editor of National Housing and Living Environment Engineering Center



  standard value

  Fresh air volume



  Air changes



Calculation formula of necessary ventilation volume (fresh air volume)

1. Calculated by the number of people


Q: Necessary ventilation volume (fresh air volume) m?/h

n: number of people

2. Calculated according to the number of air changes

Q=N?A ?H

Q: Necessary ventilation volume (fresh air volume) m?/h

N: number of air changes/h

A: Room area ㎡

H: The ceiling height of the room m

*Generally, the fresh air volume of residential buildings such as villas and apartments is calculated according to the number of air changes, and the number of air changes is generally taken once