Date posted: 24.05.13

Advances in Gas Fire Design

Peter Mintoft, Technical Director of Charlton & Jenrick Ltd looks at the development history of the realistic gas fire and how it influenced the highly popular aspirational range of Infinity gas fires the company produces:


Living flame gas fires have moved on immensely since their rapid rise in popularity during the 1980’s and 90’s to a level of realism, controllability and efficiency completely unforeseen in those early days. Features such as battery powered thermostatic remote controls with automatic electronic flame safety and ignition are now commonplace whereas when the living flame fire first became widespread this technical wizardry would have been thought of as nothing but a pipe dream.

First attempts at gas fires that looked closely like a real fire focussed on the 16” wide open coal fire found in millions of homes countrywide. Every gas fuel effect was usually based on a simple tray filled with granular materials through which non-aerated gas percolated from a basic gas cock to burn with a sooty yellow flame and precious little efficiency or heat output. These fires were lit with a match, often had no pilot or any safety devices, gas consumptions were large and complaints about high gas bills combined with little room-warming output were rife. Safety was also not a major concern in the early days although that quickly improved with piezo ignition then flame-failure devices and subsequently spillage monitoring devices became mandatory during the 90’s. At this point UK gas fires were very specific to the UK with our coal burning heritage, something which would not really change significantly until the first decade of the new millennium.

Over a period of time in the 80’s and 90’s improvements were made to the combustion efficiency obtained from these 16” coal effect yellow flame fires by producing burners that at least partially aerated the gas being burned before it was released, together with rapid developments in the forming of realistic fuel shapes from ceramic fibres. In some cases complete burners and fuel beds were formed from ceramic fibre producing a depth of hot fire bed that finally began to give the customer some useful heat output for their money. Stainless steel burners began to be adapted and sometimes designed specifically for gas fires and special aerated burners of every variety were designed in bespoke shapes and configurations so as to give a tailored flame that could be used to heat the centre of a ceramic fibre bed to temperatures in excess of 1000 degrees Celsius.

During the 80’s a variety of hearth standing gas fires became popular through British Gas, all of which sought to give the customer an efficient version of the living flame fire. Whilst these were typically 60% efficient, they stood out on the hearth in a relatively unrealistic way and had a very obvious glass front which at the time was not an ideal feature. These fires did fulfil a need but customer demand for realism pushed development work on the open fronted inset fire to continue apace.

Concurrently with burner developments it was realised that part of the efficiency problem was the fireback surrounding the open fronted gas fire. Refractory ‘Milner’ fire backs were very tough and adequate for radiating coal fire heat into the room but did not restrict the draught up the chimney enough and needed to radiate more efficiently for gas. A lining of ceramic fibre inside a metal convector or radiant box plus clever designs of reduced top outlets began to remove this obstacle as well. Finally an open fronted fire was producing efficiencies around or in excess of 50%, better than an open fire at approximately 20% but slightly less than hearth standing glass fronted gas fires of about 60%.

During this time, British and European standards had developed out of all recognition which meant safety took a big leap forward and gas fuel as well as handling of products of combustion which had once seemed so hazardous became much safer. Installers became strictly controlled through UK law which means that today you are much more likely to have a successful and safe gas fire installation experience.

With the property building, development and improvement boom in the 2000’s people began to look much further than the traditional coal fire for something to provide a realistic and convenient live fire feature in their living space. A brief surge in open fronted ‘hole in the wall’ gas fires then ensued, but this was not to last. It had become obvious through pioneering inset glass fronted fires such as the Charlton & Jenrick Matchless Heat Machine that a consumer could have a really efficient inset gas fire that looked great but did not throw away heat up the chimney by having an open front. This technology could be applied to bigger, wider, better fires that really formed the centre point of a room. Gone was the traditional 16” wide limitation – why not create something much bigger and bolder? Large format European gas fires, although not tailored to the UK market and in most cases very difficult and costly to install began to sell in larger quantities for the first time.

So the gas fire had finally come of age, an efficient, glass fronted inset fire with a realistic flame and fuel effect which could either be built into the wall or alternatively built in to a bespoke fireplace package….. Or had it? The engineers at Charlton & Jenrick knew there was still a great deal of important work to be done and set to, creating the Infinity range of gas fires which we believe offers more than any other range of large format gas fires and all at a competitive price for such substantial units.

Early UK large format gas fires were often just gas guzzling EU fires – or copies, more often than not balanced flue – requiring their own flue system and air supply and a great deal of building work. This would be no problem if a room was being gutted and re-built but what if there was already a chimney in place and a new chimney breast making the room smaller was just not desirable? Energy price rises across the board meant that high gas consumptions for big flames were now something of the past. So C&J engineers first developed a range of fires that could be fitted into existing properties with relatively small amounts of building work, no flue liners or adapter kits required as standard and a control system built into the firebox itself – not requiring a pit under the fire or a separate control box to be built in. A trimmed model and trim-less versions were prepared to meet the real needs of the UK gas fire market, not adaptations or variations of a theme. A bespoke burner system was developed that could provide a substantial flame effect at greatly reduced gas consumption which when coupled with a brand new firebox design provides state of the art heating efficiencies of 80% from units which are often coveted just for their good looks. High quality ceramic shapes are used to create the fuel effect which has now changed from the obligatory matt black coal to attractive and very realistic log forms together with barks chips and ash or glowing ember effects. Servicing is not ignored either, C&J engineers have field experience and knowledge of UK installation regulations so they have developed special panels for inspection of the flue and chimney in situ where required, something often ignored or not known by other manufacturers. Various different sizes have been introduced and balanced flue versions are in development.

Upper end gas fire remote control systems are steadily improving in terms of usability, features and energy consumption. Modern fires of this type are usually equipped with battery operated remote controls to maintain the advantage of fuel autonomy that a gas fire can bring – in a power cut a central heating boiler is useless whereas an autonomous gas fire can continue to be used to provide vital heating in living spaces. Thermostatic controls can be used for reduced gas consumption whilst maintaining comfort levels without switching on the whole house heating in the autumn or spring. Whichever gas fire you choose always look for a control which is ‘full sequence’, i.e. one that ignites the pilot automatically as well as the burners – control systems that only have a manually lit ‘standing’ pilot flame are a nuisance and wasteful of valuable gas. Costs to run a standing pilot for a year can amount to £100 in some cases, not to mention the unnecessary CO2 emitted.

When looking at the past few decades of gas fire development we can see how far things have come and that gas fires remain relevant today. Charlton & Jenrick invest substantial amounts into R&D every year to ensure that the state of the art moves on. Infinity gas fires represent modern gas fire design at its very best – efficient, convenient, simple for both customers and installers, effective, very attractive and useful in more ways than many other lifestyle choices.

Charlton & Jenrick Ltd are a UK fireplace product market leader. They manufacture the Paragon, Matchless and Infinity ranges of gas fires, Fireline range of stoves and stone fireplaces and Katell range of timber fireplaces. The Infinity fires dealer network cover most of the UK so for more information and advice contact the C&J marketing department on 01952 200 44.

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