What is the difference between rigid and flexible ductwork?

When it comes to ductwork, there is a long-running debate among HVAC professionals about whether rigid or flexible ductwork is the way forward.

If you are looking to replace, repair or upgrade the ductwork in your home or properties, it important to do your research and carefully look into the advantages and disadvantages of both options.

We’ve put together a round-up of the key differences below, but there is also a wealth of further information you can access on the topic, including https://www.finehomebuilding.com/2018/03/01/bath-fan-venting-cold-climates.

Rigid ducts

As the name suggests, rigid ductwork tends to be made from sheet metal or rigid ductboard with foil facing. Using equipment such as Euromac punching machines such as http://www.cotswold-machinery-sales.co.uk/euromac/punching-machines/, sheet metal can be shaped to form a durable and long-lasting duct.

Typically, homes that were built back in the ’50s and ’60s were installed with rigid ducts, and many of these still work well today. Rigid ducts usually provide less air resistance compared to flex systems. They are also hardy and do not easily collapse under force.

However, they do often require more planning and work at the outset as they have to be properly designed and well laid-out. This means that they can cost more due to labour costs and timings.

Flex ducts

At the other end of the spectrum, flex ducts are made from flexible plastic tubing, which is then wrapped in insulation and finally coated with a plastic outer cover.

They are easier to install than rigid ducts and are often the least expensive option. In addition, because they are so flexible, they can be installed in small or hard-to-reach places where putting in rigid ductwork would be almost impossible.

However, they do have a downside in that they are not nearly as long-lasting as their rigid counterparts. In addition, using plastic is perhaps less environmentally friendly. While they are easy to install, it is easy to do this poorly and therefore make the whole system inefficient, which will ultimately cost more.

The right solution for you

The right duct for your building depends on your needs, budget and where it is to be installed. An expert should be able to advise on the whether rigid or flex ducts will suit you best.