Gas Fire Flue Types
Your property could have a flue box and a liner, a brick chimney and inglenook or maybe just a flat wall and no chimney at all. With all of these instances there are various options to install a gas fire. The main consideration when choosing a heating solution for your home is to decide if you will use an existing chimney or install a flue system. Using the existing chimney will give you the cheapest installation costs overall and will mean you spend most of your budget on the actual gas fire or fireplace. For each type of chimney or flue system there is a specific type of gas fire which can be installed. Whilst the pictures and information below may be of help to you, the only reliable way of establishing what chimney or flue type you have is to ask a gas safe engineer to visit and perform a survey. This should be done in all cases to check the compatibility of your chimney or flue with the type of gas fire you intend to purchase.
Why Use Gas? Gas is the cheapest fuel to use per Kw of heat generated. Natural Gas is over 70% cheaper as a fuel than using electric, wood or bio-ethanol. By selecting one of our modern gas fire designs with a high energy efficiency rating you can dramatically reduce your utility bills. Read about Energy Efficiency.
No Chimney in the Property?
Most modern properties are now being built without a chimney, mainly to save the cost of construction. If your home has no chimney there are 4 types of fire to consider installing.
Flue Application Types
A brick chimney is easily recognised by a chimney stack, with either a pot or gas terminal on your roof, which relies on the natural circulation of air through the room and up your chimney to expel the products of combustion. The minimum internal diameter will be 7” (or greater) and it may have had a real solid fuel fire in previously, especially in the case of older properties sometimes identifiable by an existing chair brick at the back of the fire opening. If you have a chimney (class 1 flue) you will be pleased to know that you will be able to have all types of chimney fires within our range. See CHIMNEY GAS FIRE Range.
These are usually a metal interlocking single or twin wall flue pipe connected to a flue box, with a gas terminal on your roof. Creating the same circulation of air as a chimney. A flue pipe with a minimum internal diameter of 7” or more is recognised as a class 1 flue and a flue pipe of less than 7″ generally around 5” internal diameter is recognised as a class 2 flue. There are a large selection of gas fireplaces for class 1 & 2 applications available within our range, dependent on the size of flue and flue box you have in your property. See HIGH EFFICIENCY GAS FIRES Range.
Many new properties that do not have chimneys are fitted with Pre-cast flues. This flue is manufactured into rectangular hollow concrete or clay blocks that travel vertically, up through the cavity wall of your property, to a ridge vent or metal flue terminal on the roof. These flues tend to be very shallow in depth, although suitable deeper, appliances may be able to be installed with the use of either a spacer kit or deeper rebate on the fireplace. Choose from a wide range of smaller precast gas fires.
A power flue fire is available for new homes built without a chimney or older properties where the flue is no longer of sound integrity. The fire has an electronically driven fan system on the outside of the wall to expel the flue gases and as such a sound is to be experienced when the fan is turned on. When the fire is not in use, some natural air circulation may occur through the flue terminal, which is quite normal. As the fire relies on a fan system customers can complain of noise if the fire is installed in a very quiet environment. This aside the fires provide a solution to installing a gas fire almost anywhere in a property. Read More about POWER FLUE GAS FIRES.
A balanced flue is a glass fronted gas fire, which is completely sealed from the room into which they are installed and vents directly to an outside wall. Air is drawn in from the outside for combustion purposes increasing its efficiency through an outer pipe whilst the inner pipe vents the combustion gases safely away to the outside of the property. These appliances have very high heat outputs and can be too over powered if installed in the wrong type of room. Most clients opt for a flueless gas fire with an open flame, higher efficiency and fraction of the cost. SEE BALANCED FLUE GAS FIRE RANGE.
| Appliance | Appliance Cost | Running Costs | Install Costs | Positives | Efficiency |
| Flueless Gas Fires | Low | Low | Low | Easy to Fit | 100% |
| Balanced Flue Fires | Mid to High | Mid | Mid to High | High Power | up to 85% |
| Chimney Gas Fires | Low to High | Low to High | Low to High | Many Designs | up to 50% |
| HE Inset Fires | Low | Low | Low | Easy to Fit | up to 85% |
| Bio Ethanol Fires | Low | High | Low | Easy to Fit | 100% |
| Power Flue Gas Fires | Mid to High | Mid | Mid to High | High Power | 90% |
| Electric Fires | Low | Mid | Low | Easy to Fit | 100% |