Commercial Flue Systems

Deltavent Twin-Wall
Flue Systems

Single-Skin
Flue Systems

Twin-Wall
Flue Systems

Flue
Installation

Excellence • Pride • Passion • Precision

A1 Flue Systems is the UK market leader in the design, manufacture and installation of commercial and industrial chimney, flue and exhaust systems.

Our commercial flue systems have earned a well-deserved reputation for their quality, performance and durability.

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Bespoke commercial flues, any size, anywhere.

We have a solution for any size of the building, ranging from the sets of famous TV shows to The Shard.
We excel in producing single-skin and twin-wall flue systems produced at our UK manufacturing facility in Nottinghamshire using high-quality stainless steel. Because we make the flue pipes, components, joints and the structures that support them, we know that every element doesn’t just meet our exacting standards but also complies with the requirements of the CE Mark.

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Our high standards also apply to installing our products

This is why we have specialist teams that cover the UK installing our commercial flue systems. On the vast majority of projects, contractors trust A1 teams to supply and install the flue systems. On the rare occasions where we have a ‘supply-only’ arrangement, we’ll still always go the extra mile and provide advice and assistance to ensure the system is installed to the level we expect.

Deltavent twin-wall flue systems

Deltavent is A1 Flue Systems’ unique twin-wall flue system that is used in installations where the reduction of heat transfer from the hot omission gases inside a flue to the external environment is required.

This double-lined ducting is available as Deltavent 25 (with a 25mm insulating gap) or Deltavent 50 (with 50mm mineral wool insulation). There are also 75mm and 100mm annuli available on request.

The complete range of A1 Flue Systems’ Deltavent twin-wall chimney products has been successfully tested by B5476 Part 20 for stability and integrity during a four-hour fire test. They have also been CE Marked by British Standard (BS)1856.

Application examples include:

Diesel generator exhausts
Condensing boilers
CHP systems
Fan-assisted flue systems
Kitchen extraction systems
Smoke extraction systems
Incinerators/cremators
Heavy-duty flanges for joining

Deltavent twin-wall flue systems are designed for use where:

A four-hour fire rating is specified
A positive-pressure high-temperature exhaust/duct system is specified – such as a watertight flue system

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Single-Skin Flue Systems

Single-skin flue systems are what most people think of when it comes to the construction of commercial and industrial ducting, flue systems and chimneys, as they carry combustion gases away from boilers in CHP units.

Their stainless steel construction is ideal for both internal and external usage within a commercial property. If they are maintained within the manufacturer’s recommended guidelines, they can function to optimum levels of performance for years.

Single-skin systems are designed for use where:

A four-hour fire rating is specified
A positive-pressure high-temperature exhaust or duct system is specified
A watertight flue system is specified

Application examples include:

Condensing boilers
CHP systems
Fan-assisted flue systems
Kitchen extraction systems
Smoke extraction systems
Flue dilution

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The complete range of A1 Flue Systems’ single-skin flue systems has been successfully tested in accordance with B5476 Part 20 for stability and integrity during a four-hour fire test. All our single-skin flue systems are have been CE Marked in accordance with British Standard (BS) 1856.

Twin-Wall Flue Systems

Twin-wall flue systems, as the name suggests, are double-lined ducting systems that usually contain a layer of insulation between the walls to ensure the reduction of heat transfer.

Relatively low external skin temperatures can be obtained with twin-wall systems through the selection of the correct material grade and annulus thickness, depending on the flue gas temperature.

A minimum 50mm clearance must be maintained from the outer skin to all combustible materials.

At A1 Flue Systems, we offer two specific types of twin-wall products:

TF – this is a general-purpose chimney flue for use with gas- or oil-fired appliances
HG – this is a high-grade twin-wall flue that can also be used for gas- and oil-fired appliances. It is the recommended option when a higher specification is required

Twin-wall flue systems are designed for use where:

A four-hour fire rating is specified
A negative-pressure exhaust/duct system is specified

Application examples include:

Pressure jet burner
Atmospheric burner
Gas fires
Flue dilution
Ventilation/extraction

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The complete range of A1 Flue Systems’ twin-wall chimney products has been successfully tested in accordance with B5476 Part 20 for stability and integrity during a four-hour fire test. They have also been CE Marked in accordance with British Standard (BS) 1856.

Flue Installation

This is a simplified step-by-step guide to flue installation (based on our most popular Deltavent twin-wall flue systems).

Before Installation

In a vertical application, the components must be installed with the male spigot down against the flow of gases. This will allow condensates, if any, to remain within the flue.

Important notes:

It is extremely important for nothing to pierce either the internal liner or the outer case at any point of the installation
If Deltavent is exposed to external elements (e.g. rain or snow), it is essential to apply a bead of sealant to the grooves underneath the band

Flue installation:

Ensure all the components that require sealant are clean from any dirt, grease and other contaminants. Once the decontamination has been achieved, apply an adequate amount of sealant to the male flange connection. Using the locating spigot of the male as a guide, simply push/slot the two parts of the Deltavent twin-wall flue system together (so the male spigot runs down)
The next step is to fit the v-band. This has been designed as a two-piece item for easy assembly and must also be free from any contaminants (e.g. grease or oil)
Apply sealant into the groove of the v-band before fitting
Position both v-band parts around the Deltavent with the 10mm connection flange located within the groove
Tightly fasten both joints using the stainless steel nuts and bolts

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