Tag Archives: Wood Burning Stoves

Stove Fans

You’ve installed your beautiful new stove and its roaring away but do you suspect you may not be basking in the direct heat you had hoped for? This can be a side effect of radiant stoves due to the natural cycle of hot air rising off the stove only to be replaced by cooler air filling its place, creating cold spots in your home.

Although the ability to manipulate the density of cold air molecules preventing them from sinking may be beyond us, we do have an alternate and affordable solution to this common issue…

Woolly Mammoth Stove Fans are designed to counter this problem by sitting discreetly atop your stove and evenly circulating the heat on air patterns created by the rotating blades to reduce hot and cold spots in the room. The increased efficiency and reach of heat output will result in less trips to refuel the burner, reduced fuel costs and increased enjoyment.

The stove fan is effectively an engine that uses the heat differential between the base of the unit and the top of the fan to drive the motor which in turn, turns the blades. Place your fan on one side at the back edge of the stove. In this position, it will draw cooler air from the back of the stove area.

The ideal operating temperature is between 205°c and 345°c. A stove thermometer is also essential for ensuring the temperature does not exceed 345°c. When the stove temperature falls below approx. 85°c the fan will cease to turn. If possible leave a gap of 150mm 6” between the back of the fan and the wall.

Reasons to buy a stove fan

  1. A heat-powered fan designed to circulate the warm air created by a wood or multifuel stove. Improved warm air circulation results in greater comfort and less fuel consumption.
  2. Costs absolutely nothing to run… Using the heat from the stove, it is the most economical way to effectively circulate warm air. No cables, plugs or batteries are required.
  3. Stylish black design which blends into décor easily.

Buy your 2-Bladed Woolly Mammoth Swift Stove Fan and 4-Bladed Woolly Mammoth Swift Plus Stove Fans here

 

Please note, reduced heat output can be a by-product of issues with the draw created by the flue system and/or poor fuel. Please see our trouble-shooting guide for further information…

What Size Wood Burning Stove Do I Need?

You can find out the appropriate wood burner size in kilowatts by:

  1. Calculate the cubic space of the room by multiplying the width, height and length.
  2. As a rule of thumb, divide the cubic space by 14 and this will give you a KW output needed for the room.
  3. If your room needs a wood burner between 4-6 KW then you need a small wood burning stove.
  4. If your room needs a wood burner between 7-9 KW then you need a small wood burning stove.
  5. If your room needs a wood burner between 10-15 KW then you need a small wood burning stove.
  6. Using our calculator, you can take into account how well insulated your house is.
  7. Using our calculator you can also take into account if you like the room to be warmer than 20°C or not.

When choosing a wood burning stove it is difficult to know what size stove to buy to suit your home. First thing to note is that people often buy a stove that is really too big for their needs, whilst it is tempting to just buy the largest stove possible this isn’t necessarily the best option.

First, any stove that you get which is over 5kw needs an air brick or ventillation kit installed in the room that stove is in to ensure adequate air flow but it is recomended for any burning appliance of any size.

Second, all stoves have an optimal performance efficiency and to acheive this they need to be running at their nominal heat output, if they are running at less or more than this they become less efficient, meaning that you spend more on fuel and the exhaust is more damaging to the environment. Accordingly getting a stove with a nominal heat output that matches your room is desirable.

To get a better idea of what heat output you will need from a wood burning stove you can use our heat output calculator. You should remember that this is only a guide as factors such as how well insulated your room is etc will affect the output that is needed.

Another important factor to consider is the physical size of the stove, you need to physically have enough room for the stove, allowing 150mm of clearance to the sides and rear and 225mm to the front of your hearth to comply with the building regulations. Your stove should also be 950mm away from any combustable materials, so you should always check the dimensions of the stove and measure up before buying.

Once you have spent some time to consider what size of stove to buy you can then look through our range of wood burning stoves that will best suit you. We have a complete range of small 4-6kw wood burning stoves, medium 7-9kw wood burning stoves and large wood burning stoves from 10-15kw.

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Stove Sizing Guide

It is incredibly important when selecting your new wood burning or multi-fuel stove to consider the Kw output in terms of is it appropriate for the size of your room and will it meet the needs of you and your home?

Failure to precisely calculate the appropriate stove size will result in issues such as poor performance of the stove, uncomfortable room temperatures and the uneconomical use of fuel. By following our simple guide you will be able to accurately calculate the right size of stove for you to provide your home with a comfortable room temperature:

Step 1) Calculate the volume of your room in metres (Length x Width x Height = Volume m3)

Step 2) Multiply this by the appropriate factor in the table below:

Stove Sizing Chart

 

Step 3) Once you have a total from above, add the following if you tend to keep windows open or like additional ventilation:

  • 0.65kW for a 28m3 to 56m3
  • 1.3kW for 57m3 to 84m3
  • 2kW for 85m3 plus

Step 4) Add 10% for exposed locations.

It is worth noting that sizing a stove to heat anything other than rooms directly adjacent should be discouraged; high ceilings may also have to be taken into account.

With regards to the physical size of a stove, when installing into an existing fire place you must allow at least 100mm to 150mm (4″ to 6″) behind and at the sides to allow adequate air to pass around the body of the stove. For the sizing requirements of the hearth, please click here and for stove distances to combustible materials, please click here.
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Distance To Combustibles

Due to the high levels of heat emitted from flue pipes and stoves it is essential these are installed at a safe distance from any combustible material. The clearances required vary from Single to Twin Wall flue and are controlled by building regulations and despite some seeing them as a nuisance to their installation, they are designed to keep you safe and protect the construction of your property. For stoves, the safe distance is determined by the manufacturer and recorded on the data plate.

As these have no insulating material, Single skin pipes lose a lot of their heat and become very hot on the outer surface. It stands to reason that to be safe you must maintain quite a substantial distance between these and combustible materials. Building Regulations state this clearance must be at least 3 x the diameter of the flue pipe as illustrated below. If the surface is constructed from a non-combustible material or you have shielded it with fire proof boarding such as our Vermiculite Boards, then this distance can be reduced to 1.5 x the diameter of the flue pipe.

SW Distance to Combustibles

Due to the 30mm layer of compressed Rockwool insulation within these pipes, the heat emitted from a Twin Wall flue is greatly reduced and so is the safe clearance to combustibles. For our Convesa Twin Wall, this distance must be at least 60mm. This figure is included within the designation number applicable to your brand of Twin Wall pipes. There is no regulation for the distance of Twin Wall flue pipes to a non-combustible material.

  • STOVES

Stoves require the greatest clearance to any potentially combustible material but this does come down to the individual brand and model of appliance and is stated on the data plate. This measurement could be in the region of 600mm, 800mm or even greater and may be different for the sides and rear. There is no regulation for the distance of a stove to a non-combustible material, only clearances recommended by the manufacturer (usually in the region of 100mm to allow air to pass around the appliance).

Data Plate

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Defra Smokeless Zones

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BRIEF BACKGROUND

For centuries we have burned coal in our homes with little impact on the environment. With the birth of the industrial revolution came increased levels of coal burning by heavy industry which inevitably led to pollution on a scale never before seen in our towns and cities. Over time this led to poor health and even premature deaths in the industrial powerhouses of London and the midlands and by the 1950s created the Great Smogs that hung over our urban centres.

CLEAN AIR ACT 1956 & SMOKE CONTROL AREAS

The first of the Clean Air Acts was introduced in 1956 to start combatting these increased levels of pollution and smog churned into the air by coal burning in industrial areas. This legislation gave local authorities the power to set emission limits on smoke and fumes from factories and heavy industry. This was taken a step further with a second Act in 1968 which focussed on domestic coal burning and the introduction of the first Smoke Control Areas (or Smokeless Zones). This Act ushered in a complete ban on emissions of smoke from domestic properties by declaring entire towns or districts as Smokeless Zones.

defra Logo

EXEMPT APPLIANCES & THE INTRODUCTION OF D.E.F.R.A.

If you find you are living within a Smoke Control Area you have two options open to you:

  1. Burn wood or coal on a DEFRA Approved stove
  2. Burn Smokeless Fuel on a multi-fuel stove

DEFRA is an abbreviation for the Department for Environment, Food and Rural Affairs and their Approved stoves (sometimes referred to as DEFRA Exempt) have been tested and certified to meet the low emissions levels permitted in Smoke Control Areas. You can view our extensive range of DEFRA stoves by clicking here.

The second option is to burn authorised smokeless fuels only on a standard multi-fuel stove.

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