Hello all and welcome to todays article where we will be learning about the differences between open fires and stoves.
Firstly what is an open fire?
An open fire is just that, it is a fire sat within an opening on a grate, insert, chairbrick into an open flue/ chimney. The only control you have over an open fire is the amount of fuel you put into it.
What is a stove? A stove is a closed appliance; therefore its air intake is controlled by the user which, in turn controls how quickly the fuel burns.
- Efficiency; what is the difference in efficiency? A typical open fire will have an efficiency of around 5-35% on a 24 hour cycle with a maximum of around 60% efficiency. The efficiency of a stove varies with each stove but must have a minimum efficiency of 65%, most modern stoves average around 80% efficiency eith some exceeding 95% efficiency.
- Safety; the stove is undoubtably safer when in use as the flame is contained within a cast iron or steel box behind a piece of toughened glass wheras an open fire has no such saftey features except for maybe an after market spark guard. However, statistically a chimney fire is much more likely when a woodburning stove is installed this is not down to the appliance but down to the individual user over regulating the air supply causing the fire to slumber or burning wet wood.
- Economy; the initial outlay is more expensive when installing a stove due to the relining of the chimney with a suitably sized liner, but the running costs of a stove are very much lower due to the efficiency being able to regulate the air intake on the appliance and having a physically smaller burning area than most open fires. You also have to burn less fuel to get the same heat output from a stove.
- Aesthetics; the open fire takes a clear win here. An openfire is seen as a primal thing you really feel like the fire is in room with you, you cannot beat the crackle and roar of a true open fire. The stove has a controlled burn for efficiency. Toast tastes better on the open fire too ?.
Environmental impact; to put this in perspective open fires burning anything but smokeless coal has been banned from virtually every major city in the UK due to the smog they produced in the 50s and 60s. There is an argument today that woodburning stoves produce particulate emissions similar to that of diesal cars this is also true of open fires though and in much higher concentrations than in a quality closed appliance .
Ventilation requirements; an open fire must have an airvent in the room of the appliance, this must have a minimum free air space of 50% of the cross sectional area of the throated part of the flue, which is indeed a large vent and in most cases brings in lots of cold air.
Whereas most stoves under 5kw do not require additional ventilation unless installed in a new build property post 2008.
Flueing requirements; open fires and stoves work in different ways, because of the uncontrolled nature of an open fire and the weak draught due to diluted flue gases from the room it must have a large flow in order to evacuate the exhaust fumes from the property. This is accomadated by having a minimum 200mm diameter sized flue. A stove on the other hand requires a powerful draught to draw air forcefully into the firebox through the small air intakes, this is done by having a much smaller diameter flue, often a flue liner with a smooth internal surface that gets hot often helped by additional insulation around the liner. Both require N2 class flues rated T450 as a minimum.
In all the stove the takes the prize with efficiency and economics but you cant really beat a natural flame a crackle and a pop.
Thank you for reading,