In a recent BSRIA test, a new ductwork system outperformed the conventional approach. It cut installation time in half, significantly reduced air leakage, and cost less – all without the need for sealants.
Innovation is always possible in every sector of industry even one as traditional as ductwork.

This is the view of Lindab, which has developed a system that is touted to reduce air leakage and wasted fan power, and with substantial cuts in overall system cost.

It is a new approach to circular ductwork, which cuts installation time and needs no on-site sealants.

And, according to the company, a recent study by BSRIA shows that this new ductwork system, the Lindab Safe, outperforms the conventional approach without the need for sealants.
In the test, both Lindab Safe and the traditional ductwork system were installed by an experienced contractor under actual site conditions in a test area created within a London warehouse.

Identical configurations were used to represent the type of ductwork runs typically used during office fit-out projects. Installation time was carefully monitored and both systems were subjected to an air leakage test when completed.

According to Lindab, the results were dramatic enough to make even the most traditionalist ductwork contractor think again.
The Lindab Safe system cut installation time in half and cost 20% less when compared with the traditional approach.

Crucial savings in air leakage were just as significant. At a static duct pressure of 500 Pa the air leakage rate from the Lindab Safe ductwork was 43.8% of that from the system constructed with traditional components.

The tests showed that Lindab Safe achieved better than Air Tightness Class C (EN 12237) while the conventional approach achieved only Class B.

While delighted with the report's findings Iain Robertson, joint managing director, Lindab Ventilation, stressed there were no short cuts to leak-free performance. 'The tests were carried out using the proper self-tapping screws which are specially designed for the Lindab Safe system.
'They ensure a tight leak-free fit every time, other cheaper products may not be so efficient. This is a case where it definitely pays to fit the best.'

Lindab's Safe system consists of a complete range of pre-sealed components designed to create a circular ductwork system with minimum leakage in the shortest possible time.

The double-lipped gasket ensures a sealed joint without the need for additional sealants. And Lindab Safe fittings have rolled edges for greater dimensional accuracy and to make them more rigid and safer to handle and install.

The comprehensive Safe range is available in Eurovent sizes from 80mm to 2,000mm diameter.
The BSRIA test programme threw a spotlight on the key differences between Lindab Safe and the conventional approach. The latter employed plain-ended fittings requiring mastic sealant, or sealing tape wherever fittings were connected to the lengths of ductwork.

No sealant or tape was required for the Lindab Safe system, which is factory-fitted with an integral double seal. This means that there is no waiting time - a Lindab
Safe system can be tested or put into operation as soon as it is connected up.

Systems relying on tapes or sealants to prevent air leakage require a 24-hour curing period before they can be put into action.

Sealant alone counted for just under 10% of the overall cost of the conventional system, says Lindab. And, in addition to financial savings, the sealant-free approach has benefits for the environment and workers' health. In a large commercial project a large number of sealant cartridges may be required - which require disposal.

The BSRIA report describes the air tightness of the Lindab Safe system as 'significantly better' than that of ductwork constructed from traditional components.

'Low air leakage performance,' says the report, 'helps reduce energy consumption through decreased fan workload. Ensuring that a greater percentage of conditioned air reaches the intended areas also improves control of the internal environment.'

Both ductwork systems used in the comparative tests were installed by operatives from industry specialist FCS Ductwork.