Choosing the material of the ventilation ducts depends on the type and purpose of the building where the system will be installed. A ventilation duct is categorized according to the material type, which includes steel, stainless steel, aluminum, copper, and plastic.
Material selection is largely determined by:
the transported medium,
the operating temperature,
the space designed by the designer.
The advantages of such materials include durability and resistance to atmospheric and chemical factors, life up to even 100 years, good insulation and acoustic properties, lower manufacturing costs or subsequent recycling possibility.
Plastic ducting is lightweight, have smooth surfaces, do not absorb water and are easily joined by means of gluing, sealing or welding.
Additionally, by adding appropriate plasticisers, pigments, flame retardants, or other fillers, the range of applications expands greatly.
The classic areas, where plastics are used, include laboratories, chemical industry, pharmaceuticals, plating industry, hospitals, clean rooms and chlorine treatment rooms (e.g. swimming pool engine rooms).
Also in the HVAC industry, where the resistance to corrosion and chemical factors is of decisive importance, plastic ducting replace high-grade steel duct.
PVC ventilation ducts are the most common and the most frequently installed ducts. PVC is the most popular and economic choice - it is characterised by high chemical resistance, and furthermore, it can be joined by bonding.
PVC ductwork is used in many industrial facilities, mainly in sectors where ventilation made of stainless steel or galvanised steel is insufficient in terms of corrosion resistance.
The properties of plastics affect the chemical resistance of the material, the highest density among the available materials is that of PVC (polyvinyl chloride), it is the only material that can be joined by adhesive bonding (up to a diameter of Ø400), above this diameter it is recommended to weld the installation.
| Plastic | Density g/cm3 | Colour | Chemical resistance | Application temp. | UV resistance | Electrical conductivity | Method of joining |
Application |
|---|---|---|---|---|---|---|---|---|
| PVC | 1,42 | dark grey (RAL7011) | high (acids, alkalis) |
0oC to +60oC |
weak | insulator | welding, glueing |
inside |
PVC ductwork is durable, rigid, light and convenient to install. They are often confused with PVC pipe used in sewerage systems, they are completely two different systems, which find different applications.
PVC in a domestic ventilation system is often used in single-family housing and public utility buildings. It is ideal for fume extraction from above the cooker hood to the ventilation riser.
In application, it is important to remember that PVC materials should not come into contact with solvents, esters, ketones and chlorinated hydrocarbons.
The cost of manufacturing such fittings is cheaper, due to the production which is series production - using an extruder.
PVC in a chemical-resistant ventilation system is often used in industry, where high rigidity of the material and high mechanical resistance are required. The main feature of the material is resistance to toxic chemicals, i.e. acids, bases, alcohols, esters.
The production of these types of ventilation systems is done on a one-off basis due to the segmented joining of plastic sheets. Prices of such ducts and fittings are higher than materials available in supermarkets.
PP ducts and fittings are distinguished by durability, tightness and corrosion resistance
The temperature resistance of PP (polypropylene) pipes and fittings is higher than that of PVC elements, additionally, the flame retardant PPs version and PPs-el-s version, which conducts electricity, are available.
Typical applications for PP ducts are:
construction of chemical equipment and apparatus,
electroplating,
construction of equipment and containers,
construction of laboratories,
The bio-industry and the pharmaceutical industry,
chemical installation.
The PE ducting is fit for mounting from outside because of the temperature resistance up to -50C and UV radiation resistance.
Last but not least, the range of typical materials includes PVDF, which is characterised by high resistance to the impact of halogens and other oxidants, resistance to temperatures up to +120°C, UV radiation and low flammability.
Chemical-resistant round ducting and fittings made of PVC, PP, PPs and PE are available in stock, while PVC (white), PP-EL-s, PVDF - upon a special request.
The plastic ductwork includes, among others: ducts, bends 90° to 15°, tees, female couplings, symmetrical and asymmetrical reducers, end caps, dampers, roof cowls, grilles and duct silencers.
Rectangular ducting and fittings are custom made from sheets - simply send us technical drawings and/or dimensions to export@alnor.com.pl
Circular duct is the most popular, while rectangular ducting and fittings are used in low and medium pressure ventilation systems. The method of making ventilation ducts depends on the following factors:
air velocity in the duct
pressure in the ventilation duct,
Rectangular ducting and fittings are installed in industrial buildings, halls, wherever round ducting cannot be used, e.g. in garages and other places where a small duct height and large air volume are needed.
In the case of large sections, additional straight or cross reinforcements are made in the installation designs, depending on the duct size and the anticipated pressure in the installation.
Would you like to learn more about plastic ventilation? Take a look at our guides: