The Ductwork components and fittings including branch shoes, reducers and couplings in our products category represent only part of our range and are the more popular sizes up to 315 mm diameter. If you require any components or ductwork fittings that are not listed you can contact us using the link in the information menu and we will advise you of availability, cost and anticipated completion date for any non stock items. We intend to expand our range of components and fittings on a regular basis so please keep in touch to follow our progress.
We also have an extensive range of rectangular ductwork which is too large to incorporate on this site, over 1000 different size combinations, again we would be happy to provide details or quotations for specific projects.
Enjoy your visit.
What Cost Unnecessary System Resistance?
Without doubt the resistance to air flow caused by the ventilation systems components and fittings has a considerable effect on costs and profits. Bends, offsets, transitions, branches and equipment all adds up and ultimately dictates which fan is selected to provide the mechanical force required to supply or extract air. Normally the small in-line ventilation system fans operate in the range of 150 pascals and are very popular with spiral wound ductwork systems, but how often do we find that our required duty can only be achieved at the very limit or beyond the fan performance curve.
We are now faced with having to select the next fan up in the range, as the risk of marginal performance is unacceptable. Well their goes fifty pounds or so and it does not end there, we will be required to shell out for a couple of transition pieces, couplings and probably a speed controller as the next fan in the range may well perform far beyond our needs. We could be talking of additional costs in the region of one hundred fifty pounds or so and if attenuation is required we can add another hundred. Of course Butch & Sundance won't be too bothered about the risk but for the rest of us other solutions are preferred.
So What is the Solution?
Well, check out our spiral ductwork fittings, they are a bit special, branch off-takes are incorporated on a reducing main which provides a low pressure loss fitting and results in a more efficient ventilation system. Consider what happens in the main ductwork with a conventional branch off-take, assume air velocity in main ductwork of 5 metres per second, the branch reduces downstream mains velocity proportionally to the percentage volume in the branch as the main is constant diameter. When the reducer is fitted down stream the velocity in the main increases, 'oh dear not so good'.
In the case of the branch off the reducing main there is only one change in velocity and we therefore save on pressure loss. If your system has ten branches or so we are well on our way to that smaller fan with an in-built margin for assurance.
Below are internal links to explanitory documents.
