What is a Twin Wall Flue Fireplace?

If you would like to add a fireplace to a room, but your property doesn’t have a chimney, then a twin wall flue system offers the perfect solution.

These units are safe, easy, efficient and seamless to add, in properties of all types and sizes. 

In this guide, our fireplace experts have shared their tips for property owners considering a twin wall flue system. Keep reading to find out more about what a twin wall flue system is, how it works, its benefits and key considerations for installation.

What is a twin wall flue system?

A twin wall flue chimney system consists of two layers of stainless steel (with insulation added between these layers). 

By adding this insulation, the system can maintain high temperatures within the flue, with less energy required, thereby maximising thermal efficiency. 

At the same time, combustion gases are safely expelled through the system, into the outside of the property. 

Another quality that makes twin wall flue systems unique is their freestanding, modular design. This means that, unlike traditional brick chimneys, twin wall flue systems can be installed almost anywhere in a property. For example, they can be designed to run internally through floors and ceilings, or along an external wall of a property. 

How does a twin wall flue system work?

When the fire is in use, the twin wall flue system works by: 

1. The system draws the smoke (created by the fire) out of the property. 
2. The heat generated by the fire is kept high, thanks to the system’s insulation. 
3. Combustion and thermal performance are maximised, while condensation and other common issues are minimised. 

The process of installing a twin wall flue system is as follows: 

1. The position of the fireplace (and so the system) in the property is selected.  
2. The route of the flue is then mapped out and the system laid in place, based on the position of the fireplace (i.e. the position of the fireplace will determine whether the flue will be rooted along an external wall, or through the property’s floors and ceilings).
3. The route will conclude with the flue exiting the property, either via the roof or a wall. A specialist will need to confirm that the flue’s exit extends a sufficient distance away from the property (so that there is no risk of smoke re-entering). 
4. Once positioned the stove is connected to the twin wall system with a single-skin flue pipe, and a chimney cowl is added. 

What are the benefits of a twin wall flue chimney?

The key benefits of twin wall flue chimneys include: 

• They are ideally suited to homes without a chimney 
• They can be used across a huge range of property types (more on this below) 
• They are designed to be flexible, particularly regarding their installation and routing 
• They boast fantastic thermal efficiency 
• They represent the highest safety standards 
• They come with a long lifespan, and minimal maintenance requirements 

Where can a twin wall flue chimney be installed?

One of the main advantages of twin wall flues is their ease and flexibility of installation. This is all thanks to the fact that these systems don’t require a property to have a chimney in place. 

As a result, twin wall flue chimneys can be installed in:

• New builds 
• Extensions 
• Conservatories 
• Orangeries 
• Loft conversions 
• Garages

These systems are also compatible with a huge range of fireplace types, including wood-burning fireplaces, multi-fuel fireplaces, and pellet stoves.

Key considerations for a twin wall flue chimney 

If you’re looking to install a twin wall flue chimney in your property, you will need to consider the following: 

• Full compliance with HETAS guidelines and all other relevant building regulations (a professional fireplace installer will be able to advise you here) 
• The correct height clearance
• Maintenance and cleaning requirements 
• Enlisting a fireplace installation specialist, to ensure safe and effective installation 

To find out more about twin wall flue systems, or to arrange an installation for your property, Rotherham Fireplace Centre’s skilled team are on hand to help.