1 Jun 2023

What are the best materials for ducting?

If you’re looking to improve your HVAC system, then you’ll know all too well how ductwork forms the backbone of it. Essentially, ductwork installation is what provides conditioned air (filtered, cooled or otherwise) into the workplace for a safer, more pleasant environment to work in. But how do you pick the right materials for your ductwork?  You’ll need to consider the main function of your ductwork, its purpose and how it’ll be maintained in the long run.

Today, we’ll discuss the various materials you can use for your HVAC ductwork system, so you can make an informed choice on the best ducting solution for your business. 

Why is ducting important in HVAC?

Ducting plays an important role in HVAC (Heating, Ventilation, and Air Conditioning) systems by facilitating the distribution of conditioned air throughout a building. This conditioned air may be rid of harsh and dangerous particles, or regulated in temperature for a safer environment to work in.

Without ductwork, employees are at risk of developing health concerns which can be detrimental to their overall well-being. They can help reduce noise levels which can also cause discomfort at work, allowing employees to not be disturbed by the HVAC system.

Plus, properly designed and sealed ductwork can have a significant impact on the energy efficiency of your HVAC system. Leaky or poorly insulated ducts can lead to air leaks, unnecessary energy losses, and reduced efficiency. Properly installed, sealed and insulated ducts minimise air leakage and ensure that conditioned air reaches its intended destination without wasting energy unnecessarily. This is great news for businesses, as it reduces energy consumption and utility bills.

Types of ducting material

Good ventilation in the workplace comes with a good ductwork solution. Below are the most common types of materials used to develop a ductwork system for commercial use.

1. Sheet metal ducts

Sheet metal is by far the most common type of air ducting material. This may be in the form of galvanised steel, mild steel or aluminium. They can be made into various shapes depending on their use and fit, such as rectangular, oval or round. You may come across the term “corrugated metal” when choosing a material – this is basically any type of sheet steel that has been strengthened for use in construction, by having a series of alternating grooves and ridges forced into it. It’s a preferred choice for those who want a material that’s rust-resistant. 

At Airmatic, we manufacture rectangular and circular ductwork to the DW144 specification by using either galvanised steel or 304-grade stainless steel. The layer of zinc added to steel (galvanisation) acts as a protective barrier for the underlying steel to protect it from scratches and rust. Alternatively, our fully-welded high-integrity ductwork is perfect for challenging dust, fume, and odour issues in industrial environments. 

Advantages

  • Cost-effective solution
  • Can be painted to match the interior (or exterior) decor
  • Good resistance against water and mould (non-porous)
  • Lightweight for easy installation

Disadvantages

  • Not as bendable
  • Can be costly in some cases (particularly for large commercial buildings)

2. Fibreboard ducts

Fibreboard air ducts are made from compressed resin sheets with organic glass fibres glued together. These ducts may have a foil finish on the outside and can be embossed to look like other ducts, or painted to match the interior of the space they’re installed in. They’re the perfect solution for those after reduced noise levels that can come with HVAC solutions. Plus, it’s self-insulating and acts as a kind of insulation and is resistant to rodents and other pests. Fibreboard-lined ducts have the ability to be manufactured in any size and configuration is also a major advantage over different types of materials. 

Advantages

  • Cost-effective compared to other solutions
  • Self-insulating
  • Good for noise-reduction

Disadvantages

  • Shorter life expectancy
  • Not suitable for outdoor applications

3. Fibreglass lined air ducts

Fibreglass air ducts are a type of sheet metal duct lined with a fibreglass liner inside or outside the duct. This liner isolates the duct from air leaks and – similar to sheet metal ducts – helps prevent problems with condensation.

The fibreglass liner also provides good sound insulation which can reduce the noise coming from your HVAC system. For this reason, they are common in various office and commercial buildings. However, fibreglass degrades over time, causing particles to become airborne and potentially a health concern. This can heavily counteract measures taken to reduce EH40 exposure limits, so if this is a concern to begin with, then a fibreglass ductwork solution may not be suitable. Plus, cleaning fibreglass air ducts can be difficult as they can be prone to mould if not maintained properly.

Advantages

  • Sound dampening
  • Reduced air leaks
  • Thermal insulation
  • Corrosion resistant

Disadvantages

  • Particles from fibreglass can release into the atmosphere and can raise health concerns
  • High upfront cost
  • Limited fire resistance

4. Flexible air ducts

If rigid ductwork just isn’t feasible in your place of work, then flexible air ducts are an alternative. These ducts can be made of plastic and steel, and are usually cylindrical in shape. However, as the length of these ducts increases, there is a greater loss of energy. Plus, despite their intended flexibility, the efficiency of flexible air ducts decreases as the number of bends and folds in the ducts increases.

Advantages

  • They’re versatile
  • Ideal for smaller working environments
  • Minimal air leakage
  • Easy to install

Disadvantages

  • Restricted airflow
  • Can be damaged easily
  • Not built to last

What material is best for ductwork?

The application of your HVAC air ducting system totally depends on your requirements, place of work and the substances that need to be regulated in your working environment. As listed above, there are various advantages and disadvantages for each ductwork material. 

Typically, sheet metal is one of the best materials for air ducts due to its tailored approach to a business, reduced air leakage, easy maintenance and longevity. Plus, galvanised steel sheets as duct material, is high in strength, durability, and rust resistance and are widely used in industrial settings. Plus, they can be welded into a variety of shapes to fit their intended purpose, and welded with similar materials for reinforcement.

Flexible ducts are decent as interim or low-budget HVAC solutions or as add-ons to existing ductwork. With rigid ductwork (such as sheet metal) it can be costly to start with, due to the length of time to create, move and install. However, flexible ductwork can go wrong quite easily, which can increase costs in maintenance and replacements further down the line.

Not sure which ducting material is right for your business? Contact Airmatic to find out more about our bespoke ducting and fabrication solutions. We’ll work with you to build a tailored approach to your business from concept to completion.

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