Fresh air systems have gradually entered our lives in recent years, becoming a popular new type of home appliance. While some may argue that calling it a home appliance is inaccurate, suggesting it should be classified as household machinery, we won't delve into that definition here. Simply put, functionally and accurately, it's a mechanical ventilation system. Ventilation is air convection, a natural phenomenon. Outdoors, it's natural wind; indoors, opening doors and windows creates airflow and exchange-this is called natural ventilation. However, humans, based on production and living needs, use artificial machinery to force airflow and replacement-this is called mechanical ventilation.
Central fresh air systems all use ducts, which are divided into rigid ducts and flexible ducts. Today, we'll discuss fresh air ducts.
Ordinary Flexible Ducts: Common fresh air system flexible ducts generally use composite materials. They have a PVC protective film on the outside, and inside are aluminum foil and reinforcing steel bars to support the duct. The steel bars are there to prevent damage and flattening of the flexible duct.
Advantages of Flexible Ducts:
1. Compared to rigid ducts, flexible ducts are easier to install, resulting in a shorter construction period.
2. Flexible hoses are easy to bend, making it convenient to modify the piping and air inlet/outlet positions later.
3. Flexible hoses have good flexibility and can be fitted tightly to the ceiling and walls.
This is the best choice for users with low ceilings who don't want a low ceiling.
Disadvantages of Flexible Hoses: While flexible hoses have advantages, their disadvantages are also quite obvious.
1. Flexible hoses are not as sturdy as rigid PVC pipes and are more easily cut or scratched.
2. Because flexible hoses are folded and have an uneven inner wall, air resistance is relatively high, reducing ventilation efficiency.
PE Corrugated Pipes: In addition to the above-mentioned ordinary flexible hoses, PE corrugated pipes are also widely used in fresh air systems. PE refers to polyethylene plastic. PE pipes have strong corrosion resistance, good toughness and flexibility, and can reduce the use of pipe bends during construction (the pipes can be bent directly). The biggest advantage is that construction is easy and drilling is convenient.
Furthermore, PE pipes have better environmental friendliness (environmentally friendly and non-toxic), and the outer wall is hollow, resulting in less noise than PVC pipes. However, PE pipes also have obvious disadvantages: they are expensive and have higher air resistance than PVC.
Fresh Air Silencing Pipes
To reduce noise generated during ductwork installation, the fresh air industry has developed silencer pipes. Silencing pipes are generally multi-layered, made of different materials.
A common type is a double-sided aluminum foil flexible tube + sound-absorbing cotton + non-woven fabric (or aluminum foil). This type of silencer tube has good sound absorption. There are also silencer pipes with PVC as the outer pipe; these have decent sound insulation, but the sound absorption effect is barely adequate.
Because of the multi-layered materials, silencer pipes also provide insulation.
Rigid Pipes for Fresh Air Systems
Rigid pipes for central fresh air systems are PVC pipes. The main component is polyvinyl chloride, with other components added to enhance its heat resistance, toughness, and ductility. Common household drain pipes are also made of PVC.
Advantages of Rigid Pipes:
1. Sturdy and durable, with a long service life.
2. Smooth inner wall, low air resistance, minimal airflow attenuation, allowing air to be delivered to farther areas indoors.
Disadvantages of rigid ducts:
1. Compared to flexible ducts, rigid ducts have a slightly longer installation period.
2. Modifying the ductwork or changing the location of the air inlet/outlet is more difficult later.
3. They cannot be used in areas with existing suspended ceilings, or where the ceiling space is complex.
4. Because fixing rigid ducts and making bends requires more space, the ceiling height is generally higher than that of flexible ducts.
In actual installation of a fresh air system, both are usually used in combination. The main duct is rigid, while branches and connections to the main unit use flexible ducts (to eliminate vibration transmission and reduce noise).
If even a small duct in a fresh air system involves so many intricacies, imagine the complexity of the entire system!
Therefore, when choosing a fresh air system, it is crucial to select a reliable system and a reliable installer. Conquer the air with professionalism and experience!
