Fireplace Energy Efficiency Explained

Fireplace Energy Efficiency Explained

With sustainability and energy saving being a hot topic at the moment I thought it would be worthwhile explaining a little about fireplace efficiency, how the different design styles of fireplace also have different energy efficiency ratings. This energy efficiency rating has implications on the overall cost of heating. However the total heating cost analysis must also include the different fireplace fuel types.

Fireplace Energy Efficiency Explained

When looking to buy a new fireplace for a property, especially new modern homes, the rated fireplace energy efficiency should be one of the prime deciding factors before looking at design styles or finishes. Each of the different fireplace styles on the market perform differently in terms of energy efficiency ratings. Here is a summary of what to expect in terms of efficiency from the different design styles of fireplace. In terms of cost of heating the energy efficiency rating needs to be combined with the cost of the fuel that is being used. A direct energy efficiency comparison is to ask what is the cost of 1Kw of heat that actually heats the room. Not the cost of generating 1Kw of heat that is mostly wasted to the outside air.

Using a Chimney, Flue System or No Chimney

The first factor which affects fireplace energy efficiency rating, regardless of the fuel type, is if there is, or not, a chimney or flue system that is attached to the appliance. A chimney is used to take the harmful emissions away from the appliance and vent them to the outdoor air to be dispersed. There are different types of chimney or flue system, brick built, precast, flue liner pipes and balanced flue. Excluding the balanced flue, the other chimney types all draw fresh air from the room, this air is used to feed the fire with oxygen and to create a draw so that the emissions go outside. That fresh air will be already heated by your central heating system so you are wasting that heat even if you do not switch the fireplace on. The balanced flue system is different from the others as it has two concentric pipes. Ones provides fresh air from outside to the appliance, the other exhausts the emissions, the same as a combi boiler.

Burning fossil fuels like gas, wood or coal produces smoke, this is harmful if you breath it in hence a chimney or flue system is required in the room. The only appliance which goes against that rule is a flueless gas fire, more on that below. By introducing a chimney or flue system you have already reduced the energy efficiency by anything up to 70%. That means you pay for 100% of the heat the fuel produces but only benefit from 30% of it.

Efficiency Ratings of Different Fireplace and Heating Products

This is a general list of what type of efficiency ratings you can expect from different fireplace products. It is not exhaustive, but it shows the main products that are on the market.

  1. Bio Ethanol Fire – energy efficiency 100% Efficient – These high energy efficiency appliances use clean burning bio ethanol fuel bottles, basically alcohol. As the fuel source is not organic the emissions are very small, meaning these appliances therefore do not need a chimney.
  2. Electric Fire – energy efficiency 97% – As the electric element generates heat, and there is no chimney, they are classed as high efficient however there are some losses due to the light bulbs. Also, one area to consider is the environmental impact. In order to get the electric either gas, coal or nuclear energy is burned, only a small proportion comes from wind farms and hydro. The maximum heat allowable from an electric fire is 2Kw.
  3. Gas Fire – Glass Fronted with a Chimney – energy efficiency 75% to 85% – The addition of a glass panel reduces the heat drawn from the room. These are modern gas fires and are built to the latest energy efficiency standards. You will still need a chimney or flue system that is working to install one.
  4. Gas Fire – Open Fronted with a Chimney – energy efficiency around 35% – By having an open front the chimney will draw away more heat from the fire, plus you should consider that you are losing the heat produced by your central heating system at the same time, making that less efficient also. You will most likely, depending on the design, also need an air vent in the room.
  5. Gas Fire – Flueless, no Chimney – energy efficiency 100% – Flueless gas fires were introduced a number of years ago and are designed to be used without a chimney making them have a high energy efficiency rating. The gas produces harmful emissions which is counteracted by having catalytic convertors in the top of the fire, to do this the fire must be glass fronted. Also, a large air vent is required through the wall to supply fresh air to the room. Modern flueless gas fires are built to very strict CE regulations and must include safety devices like an ODS pilot system. If the emissions build up in the room, if the catalytic convertor fails or the air vent is blocked, the fire will switch off before the emissions reach a deadly level. In order to ensure these fires are safe they must never be tampered with, only ever maintained by a qualified gas engineer and serviced in line with the manufacturers guidelines. Never try to repair or service a flueless gas fire if you are not qualified to do so.
  6. Gas Fire – Balanced Flue System – energy efficiency 70% to 85% – Balanced flue gas fires are very popular in some European countries like Norway, Holland, Belgium etc and are installed in homes and apartments where there is no ability to install air vents, and to maintain the efficiency rating of the property. The appliances can operate on a fairly short flue pipe that can include a 90 degree bend therefor allowing the flue to exit the top of the appliance rise vertically, bend 90 degrees and go out of the wall. The outlet of a balanced flue gas fire looks the same as a combi boiler with an outer and inner pipe. The combustion chamber of the gas fire is sealed and for the gas to burn it requires oxygen. This is drawn in from the outside pipe into the fire burned and the emissions are vented out through the inner pipe. The above is a very general description and there are many different styles of balanced flue gas fire on the market, some requiring complicated installation considerations, some need a long vertical flue pipe and cannot be bent 90 degrees.
  7. Wood Burning Stove – Chimney or Flue – energy efficiency 25% to 75% – Personally I do not like wood burning fireplaces and stoves. Chopping trees down using the argument that the other trees absorb the emissions from the stove is a lame excuse for burning wood. You cannot grow new trees as fast as they are burned. I consider stoves to be dangerous as there are many instances where faulty installation of the flue pipes has caused fatalities. Unlike a gas fire, which has safety devices, a wood burner does not, you are left to rely on a smoke alarm or CO2 monitor to warn you of any dangers. Older stoves that are not sealed properly can be very dangerous. Smoke and emissions from a wood burner can be 10x greater than a gas fire, or more. Modern stoves have better energy efficiency and are built to higher safety regulations but still produce ash, mess, smoke and minute particles that can be harmful if breathed in.
  8. Wood Burning Fireplace – Open Flame – Chimney – energy efficiency 25% – This requires a chimney and like the stove is not my choice and the low energy efficiency caused by the open flame means they waste a lot of energy.

Summary of Energy Efficiency Ratings

As can be seen from above the choice of fuel to burn and the design of the appliance can have a great impact on the efficiency rating of the fireplace plus the running costs, or if you like, the wasted money buying fuel to heat the sky. This is why bioethanol fireplaces are worth considering for you next fireplace installation.

Also, take a look at some of our fireplace technical guides as they cover many different issues like safety, fuel handling and storage, fireplace lighting and shut off, safe use of the burner and installation. Above all with any appliance that burns fuel and generates heat the usual safety precautions apply. Always use a qualified engineer and follow the manufacturers instructions when installing and servicing any heating product.

Latest New Bioethanol Products and Posts

Below are the latest posts and new bioethanol fireplace and gel fire products that have been added to the web site. We are adding new products and blog posts all the time. Bookmark the site or join the mailing list to keep up to date with new product releases and special offers.

Also, check out our Fireplace Style twitter account and Bio-ethanol fireplace facebook pages, to follow and like so that you keep up to date with new releases.

Why Change to a BioEthanol Fireplace?

There are number of positives to look at when considering your next fireplace purchase. Buying a Gas, Electric or Wood Burning fireplace from a retailer may involve complicated installation work that can be costly and, especially in the case of wood there are issues over storage of the fuel and the mess caused by the ash. Also, apart from the electric fire, a gas or wood burning fire will need a chimney, something that a lot of modern houses do not have.

Did you know that bioethanol flueless fire designs do not need a chimney or flue system to be used? This means they are perfect for new, modern homes. They are also a great solution for older homes that have a faulty chimney that needs to be repaired. Or you may be looking to block up or remove an existing chimney to reduce your heating bills.

Either way, flueless bioethanol fireplaces are a great, cost effective heating solution for a room where secondary heat is required. They are also good for the environment, unlike burning gas or coal. That is why it is best to look at the options and guides that are shown on the website before making a decision on your next fireplace purchase. Choose a flueless fire, or if you like a, no chimney fire, that uses clean burning bioethanol fuel.