We make all our air ducting in our own machine shop, we use galvanized steel with thicknesses between 0.5 and 1.0mm. All our ductwork is made to conform with international and local standards. Our standard duct sizes conform to SNIP RK 4.02-05-2001*. Manufacturing of non-standard sizes is possible.
Rectangular section
We manufacture our rectangular air ducts from zinc coated steel according to the requirements of SNIP RK 4.02-05-2001* using our own equipment, we use a ‘lock form’ seam which does not disturb the zinc coating.
- Our ductwork is manufactured to an air tightness of class «D» (dense).
- Our ductwork is fitted with flanges which can be locked together and use a sealing gasket.
- Large size ductwork has additional stiffening.
Please note that the use of rectangular ductwork with a total perimeter measurement of 1600mm raises the cost considerably both in manufacture and installation. We would suggest changing to circular ductwork and we would be pleased to advise you of the alternative sizes.
All air ducts with height to width ratio of more than 1:3 have additional stiffening.
Circular section
Circular air ducts are made from zinc coated steel according to requirements SNIP RK 4.02-05-2001* our factory is equipped with the equipment of Spiro International Group (Switzerland) which connects the seams without damaging the zinc coating.
Our ductwork is manufactured to an air tightness of class «D» (dense). Connections are made with connection sleeves, together with silicone sealant and rivets.
Our high quality seamed joints, together with construction fittings and sealed connections reduce air leakage and hence pressure loss in the system, this also reduces unwanted noise.
This section shows our extensive range of standard parts and selection from this range will reduced the time taken to for us to complete your order.
Ordering Air Duct
1. Your order can be sent to us by fax or e-mail. The order must be signed by an authorized person and have an order reference.
2. For efficient use of our standard product range we suggest that when making a design:
• Detail up all the standard parts from the catalogue, taps, tees, transitions.
• Straight sections can then be summarized for each size and ordered as a total length, we will ship in the longest transportable lengths (typically 4 to 6 mtrs). Short lengths are cut on site by the installation team
• Any remaining non standard parts can then be detailed
• Finally any site measured parts can be identified and once site measurements have been made these can be separately produced
3. When ordering it is desirable to use the symbols from our catalogue.
Technical matters
1. Ductwork, both straight and fittings, rectangular and circular section are made in the sizes and the types established SNIP RK 4.02-05-2001* «Heating, ventilation and air-conditioning».
2. As much as possible use circular ductwork. In most cases rectangular ductwork can be replaced by round without increasing the required space. When calculating the allowance of space remember the flanges are 40-60mm deep and also you will need access to tighten the bolts at each corner of the mating flanges. When replacing rectangular with circular you can use this space. Circular ductwork with spigot connections do not have any protruding parts and require less space for assembly. Practically circular ductwork occupies less space than rectangular and this is especially important for low false ceilings, corridors and shafts where air ducts are installed in layers.
3. The surface are of circular ductwork is about 12% less than that of the correspondeing rectangular cross section. When the width to height ratio is above 1:4 the difference increases up to 40%.In such instances it is possible to replace the rectangular duct with two or more parallel circular ducts.
4. Due to the reduced surface area the cost of insulating circular ductwork is less than that of the corresponding rectangular ductwork.
5. The smaller the perimeter measurement of the rectangular ductwork the more significant is the cost of the flanges and fastners.
6. When detailing systems it is beneficial to use standard components
7. Order round duct in long lengths and cut to size on site, rememeber that longer lengths means less joints to make and there can be significant savings as rectangular duct cannot be made in the same lengths as circular. You reduce the number of connections and hence the possibility for leaks.
8. Try to use rectangular ductwork only for sizes above 1600mm perimeter. Each section should be a maximum of 1250mm long, above this length the ductwork may vibrate and additional stiffening will be required. When the aspect ratio is above 1:3 additional stiffening is used.
9. Using standard products will allow any modifications to the system to be easily incorporated. Any removed parts may be reused as they are standard.
10. Using standard products will mean less waste during installation. Any unused parts can be used on other projects.