Ductwork & Ancillaries


Ductwork is the key part to any HVAC system, get the size of the ductwork wrong and air volumes and temperatures are not maintained, pressures are not correct and noise levels can soar. Bespoke design of ductwork to suit the needs of the application is a must, NSV have years of experience at designing ductwork and use materials that are ideally suited to the environment.

For offshore fully welded flange connected ductwork (with optional insulation) manufactured from high grade 316L stainless steel offers at least 20 years of high performance air handling. Internal and commercial ductwork is manufactured from light gauge steels to suit the application and designed in such a way to simplify and speed up installation while being easy to maintain yet performing to the design.

Used in conjunction with NSV’s ancillaries to enable management of moisture, airborne particles, temperature, noise and all other air handling considerations our ductwork systems can be relied upon to consistently meet design requirements year after year.


Duct attenuators (or silencers) are designed specifically for the Heating & Ventilation Industry. Careful consideration is taken to ensure the designs, whilst fully meeting the technical requirements of the industry, also provide the most cost effective solution.

All duct attenuators are manufactured in accordance with the requirements of DW141 for high velocity ductwork. The attenuator casings can be of galvanised or stainless steel construction and as standard are faced with mineral based porous material to provide excellent acoustic properties.

Each attenuator is available in lengths designed to provide a range of acoustic performances and in a full range of cross sectional areas to cater for any airflow and flow resistance requirements.

 Grilles / Filters

 Clean air is a crucial part of any ventilation system, we can supply filtration to meet specifications across the whole MERV and European Efficiency Guide classifications.

To handle the distribution of the air, supply and extract grilles and diffusers in a range of designs, materials and sizes can be supplied to meet every air volume.


 Louvres / Coalescers

Any external opening within a ductwork system is a critical point, it has to protect and direct the airflow and stop weather elements entering the ductwork system, and as it is generally the most visible point in the system it has to be aesthetically pleasing as well as functional.

Our double pass External Weather Louvre (EWL04) and double pass High Efficiency Coalescer (HEC01) have been performance tested and verified by independent test authority BSRIA to BS EN 13013:2001, we’re proud to say our EWL01 is rated Class B (Class A best) for rainwater penetration up to 3ms velocity and Class 3 (Class 4 best) for coefficient of entry and our HEC01 is rated Class A for rainwater penetration up to 3ms velocity and Class 3 for coefficient of entry.


Heaters / Terminal Reheat Units