How efficient is my fire?

High Efficiency Gas fires come in 3 forms, Conventional Flue (One that uses a Chimney), Balanced Flue (One that has a pipe through the outside wall like a modern Combi Boiler) and Catalytic Flueless (One that uses a Catalyst to absorb harmful fumes from the exhaust gases).

Standard Non Efficient Fires

These work by having a slight slope to the back of the fire which causes a small build up of heat, just above the burner, while some of this heat allows a to enter and heat up the room, the vast majority is pulled up the flue. This is all to do with really sciency physics as the pressure builds up from the expanded air (Heated air) causing it to rise in the flue, due to the pressure differential from the outside to inside the warm room, this creates suction up the flue and continues to draw (suck) more gas and a lot of heat from the room.

Most of these fires will be a maximum of upto 40% efficient, and the only reason certain models provide a output of upto 4.5kW is that they inject more gas in to burn.

e.g, Standard Inset Gas fire with a 30% efficiency – 4.52p per/kWh (Swalec 26th Jan 2010 – lowest possible rating available) and a 3.5kW output means it will be inputting 11.6kW into the product meaning this will cost 52p per hour while you are only actually receiving 15.8p of heat! That’s wastage of over 36 pence per hour. Now this may not sound a lot but it does add up significantly throughout the year average household using their fire for 4 hours a day (4 x 36p = 144p/per day wastage), 6.2 days per week (144p x

6.2 = £8.93 per day wastage), 20 weeks of the year (£8.93 x 20weeks = £178.56 per year on average) This by no means is the worst it can be, this is just average for a 30% efficiency there are lower ratings still available on the market, some with NO HEAT OUPUT giving a 0% efficacy!! Watch out for them!

High Efficient Conventional Flue Gas Fires for Chimneys

Most people presume that placing a piece of ceramic glass in front of a fire would decrease its efficiency but as we’ve seen it’s the draw that causes heat to be sucked out of the room. High efficient gas fires not only have a glass front, but also a convector box. This is a channel which goes from the front base of the fire to the front top of the fire, wrapping the engine of the fire, this channel will allow cold air to enter underneath the fire and heat-up as it rises around the burner. This then leaves the fire as convected warm air through the convector grill. You also have the glass front which means that the glass holds the heat within the fire box for longer allowing it to escape into the room through the convector channel finally the Glass although ceramic heat proof does allow the radiant heat from the warmed up ceramics to heat also (This is the type of heat you get from a red glow, [infra-red heat]).

From a Glass Fronted High Efficiency Gas Fire you can get efficiencies’ of up to 89% meaning wastage is cut right down to only 11% rather than the 70% seen on Open Fronted fires. A specialist in High Efficiency fires is Apex Fires google them!

High Efficient Balanced Flue Gas Fires

These fires work in a very similar way to Conventional flue High efficient gas fires, as they have a glass front allowing a slower movement of air, a convector box allowing convected heat to warm-up through the convector channel and heat the room, along with radiant heat from the heated ceramics. But has one main difference, it doesn’t need a chimney. Balanced Flue Gas Fires have a unique way of venting any fumes by exiting through a wall to the outside. There are several different ways of doing this, as seen on the left via two pipe one

at the top venting exhaust and the lower one providing fresh air into the burner to supply oxygen to the flames, or through a twin walled system shown on the right, this uses one pipe inside of another, the internal pipe used to exhaust hot fumes, which in turn warms up the fresh air coming in through he exterior pipe allowing a higher efficiency as the air is pre heated ready to burn.

The latter flueing system of the twin wall pipe work also allows much flexibility when it comes to installation, as you can allow several bends and extensions should you be limited with the suitability in your home. This also offers several large glass windowed products along with two sided glass fronted fires which can be used as room dividers along with many other extravagant designs to choose from the best selling being Drugasar, a Dutch make who are adamant they will produce a product of high quality in a high class design (n.b there are several things which must be taken into consideration when designing your flue system always consult a Gas Safe Registered installer before purchase)

Efficiency of Balanced Flue Gas fires is usually limited to upto around 86% as the exhausting system does allow a vacuum like airflow through the item due to the fire having an open flue to the outside. The benefits of the flue flexibility and designs available I don’t think we have to care too much about a loss of 4%. As they are sealed units they will not require a vent in the room.

High Efficiency Catalytic Flueless Gas fires

The main question being asked is ‘How do Catalytic Flueless gas fires work?’ This is easy to answer difficult to understand– Catalytic flueless gas fires work by having a sealed flame behind glass which forces the fumes to rise up through the fire and into a catalytic converter. The catalytic converter is a honeycomb membrane which is impregnated with a catalyst chemical put simply this is a noble metal which speeds up reactions and allows modification of molecules into others with less energy. Any harmful chemicals are turned into CO2 which is completely harmless in the proportions of a room. It can also be so effective that it will also aid in cleaning out allergens in the air from your room as well as providing heat.

A lot of people and gas fitters are still wrongly cautions about catalytic gas fires and this is all to do with a very successful internal marketing campaign by British Gas after they lost the license to produce the engine from Lexus of America who own

the technology patent. British Gas completed a full campaign and disallowed all fitters to install the fires as they owned a couple of fire manufactures including Matchless Fires who also wanted to produce flueless fires, knowing their market value and long term benefits. This was a Marketing marvel which has not yet subsided, this has caused a slower take up in the UK of Flueless models, but throughout the world they are the only fire which can be used in several states in America, Australia and are the largest selling fire in Japan, due to the size of homes and lack of flues.

From a safety point British Gas were wrong to stop their installers from fitting the products, like most gas fires, they are installed with an Oxygen depletion sensor, which measures the ratio of oxygen in the air and cuts the fire off should it fall below a safe limit (limited to a 1.5% difference from average oxygen content) they also have a Flame supervision device which shuts the gas off should the flame itself go out. They also have several safety benefits over conventional flue fires as the flues in these products can be susceptible to blockages or downdrafts which increase carbon monoxide into the home if not monitored and serviced on a yearly basis.

All Flueless fires are designed as a supplement to your primary heating source, as burning Natural Gas produces a wet flame due to one of the products of combustion the primary heating will make certain that there is no condensation. Catalysts have been thoroughly tested and have a lifespan extending beyond 16,957 hours!!! This is equivalent to about 27 years average use (4 hours a day, 5 months of the year)!! The Catalyst also has a constant effectiveness; it is as good on day one as it is 6000 hours of use later.

Flueless fires over the years have won several awards most recently the House Beautiful Award in 2008 where a gold medal was awarded to the Bemodern Monza fire shown opposite.

Efficiency of Catalytic Flueless Gas Fires is set at a fixed 100% as these items require no flue to vent flue any gases stopping the availability draw up the flue. The only downfall of Catalytic flueless gas fires is that they require an Air vent in the room, although most home do have these, if you are not used to one.

Note: information correct as of January 2010 information provided from Advantica Technologies Limited for the Health and Safety Executive 2004 and also the Carbon Dioxide Information Analysis Center. Electric Fires & Heaters There are several methods to provide heat from an electric source; they are Convector heaters, Fan Heaters and Oil Filled Radiators. Convector Heaters and Fires

These items provide heat into the room up to a maximum of 2.4kW (2400watts). They work by having a heating element, which is a piece of metal wire which heats up due to electrical current, this in turn heats up a proportion of air within the product. As this air heats up

and expands it rises through the product and creates a draw (suction) in through the grills at the base, allowing cold air to be pulled up through the heating element and into the cavity of the fire to be heated. This then starts a cycle which will eventually provide a circle of air around the room until the fire cuts of as the air temperature within the room has hit the limit on the thermostat (Not available on all Products just look for Thermostatically controlled) These items are 100% Efficient, much like the Tesy Wall Mounted Panel Convector Heater CN01 240 shown opposite. Oil Filled Convection Heaters & Radiators

Benefits Gas and Electric Heating through Fires and Radiators Zonal Heating, Cost saving by non wastage throughout house, quicker to heat than central heating

What is the efficiency of an Electric Fire? Electric Fires and Heaters are all 100% Efficient