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FAQ - Questions and answers

faqPurchase of stove outside your country
faqPellet stoves
faqStove or inset?
faqTypes of firewood
faqOther types of solid fuel besides wood
faqHow much is a cubic measure of wood?
faqRAIS dealers?

Purchase of stove outside your country
Can a RAIS stove purchased in another country be installed in my home country?


Any stove must be installed according to local rules and regulations. You should consult your local chimney sweep or stove professional about the rules and regulations that apply in your area.



Since approval guidelines differ from country to country you should ask your RAIS stove dealer if the stove you are interested in purchasing is approved for the country you want to install it in. It is also advised that you contact a local chimney sweep to find out if the stove can be installed according to local rules and regulations.

Pellet stoves
Does RAIS manufacture pellet stoves?

No, RAIS does not manufacture stoves that use pellets as fuel.


In the Danish market a pellet stove based on the RAIS Mino is available through A/S Dansk Shell under the name BioLine.


You can get more information regarding BioLine from Energihuset Dansk Shell A/S (tel. +45-70 10 27 50).


Stove or inset?
What is better, a stove or an inset?

They are equally good, and very different sources of heat.


A stove and an inset can be best compared in their effectiveness and efficiency. In practice a freestanding stove gives out quicker warmth than an inset. However, an inset is able to accumulate heat to emit even warmth, which a freestanding stove can also do if it has plenty of soapstone covering it.


Fireplace insets are highly efficient sources of heat in contrast to traditional open fireplaces that allow valuable energy to go to waste. Fireplace insets can be designed to fit into an existing open fireplace or in a new construction.


Both solutions are good, and the choice can be made based on the design of the living space and individual taste.

Types of firewood
Which type of wood has the best heating value?



All types of wood heat the same per kilogram if they have the same water content. However, there are large differences between various types of wood. For example, spruce weighs a third less in cubic meter than beech, which means that it takes 50% more spruce to give out the same amount of heat as beech. So, 2 cubic meters of beech when heated gives out the same warmth as 3 cubic meters of spruce.


Therefore it is important to compare the price of various types of wood, especially when buying a pallet.


How a type of wood behaves during actual use determines which wood is best for your heating needs. Woods such as beech and ash are good for burning because they produce a nice flame and have a high burn value, which means they emit a large amount of heat when burning. In addition, woods with high burn value also create a beautiful layer of ember. On the other hand, woods such as birch burn calmly and are beautiful to look at with their white bark, but have a low burn value.


Relative weight between various types of wood:


Wood type

Relative weight













Mountain pine


Forest pine






Other types of solid fuel besides wood
Can coal or coke be used instead of firewood in a RAIS stove?



The firebox and air supply system in a RAIS stove is developed and manufactured for optimal combustion of firewood. The approval of RAIS stoves in your country is based on it being a wood-burning stove or inset.


Only wood must be used in a RAIS wood-burning stove or RAIS inset.


Some manufacturers of wood-burning stoves claim that coke and brickets may be used as fuel in their stoves. These types of fuel have considerably higher burn values than wood and when used to heat can surpass the maximum heat designated for the stove. Using fuel that has such a high burn value in a wood-burning stove may cause over firing, which can destroy the stove.


If a RAIS stove breaks down due to over firing, the guarantee is void.



How much is a cubic measure of wood?
What is the difference between a box cubic meter of firewood and a forest cubic meter of firewood? (Danish expressions)?



In Denmark firewood is measured and sold in various unit measures. It is important to ask the seller which unit measure is being used for particular firewood to evaluate and compare prices accurately.


A box cubic meter of wood (in Danish: "kasserummeter") is the amount of split firewood that can be tossed randomly into a box that measures 1x1x1 meter. Since the wood is not tightly stacked in the box there is a lot free space in between the pieces of firewood. Therefore there is only about 0.45 cubic meter of wood in a box cubic meter. However, this amount can vary since wood is stacked randomly in the box.


A forest cubic meter of wood (in Danish: "skovrummeter") consists of whole logs about 2 m long that have not been split or cut. When whole logs are stacked in the forest less of open space is there between the logs. There is approximately 0.65 cubic meter of wood in a forest cubic meter.


A stacked cubic meter of wood (in Danish: "stablet rummeter") consists of cut and split pieces of wood about 33 cm in length stacked tightly. There is approximately 0.70 cubic meter of wood in a stacked cubic meter.

What kind of chimney is necessary for a stove?



The chimney:

One of the most important prerequisites for a well-functioning stove is that the chimney be well-functioning as well. The chimney can be considered the "engine" of the stove, and if it does not get the correct draught it does not perform optimally. New and modern stoves place higher demands on the chimney and draught than older stoves. You can always consult with your local chimney sweep, who can also check whether your chimney is functioning optimally.


Regardless of whether your stove is installed with a masonry or brick chimney, or a steel chimney, the same rules apply.


Installation of brick chimney:

When a stove is installed with a brick chimney, a wall thimble is placed in the chimney, and the stove pipe is then inserted into the wall thimble. The connection between the stove pipe and the wall thimble must be sealed using a special sealing rope to avoid any ventilation that can cause improper draught in the chimney.


Installation of steel chimney:

From the stove and up to 225 mm below combustible ceiling material you can use a single wall stove pipe. From 225 mm below combustible ceiling material and up through the ceiling and roof you must use double wall chimney pipe.


Good draught results when:

  • There is a big difference between the inside and outside temperatures.
  • In clear weather
  • The chimney has the right height. Please speak with your stove dealer or your local chimney sweep to find out what the right height for a chimney in your area should be.

Poor draught results when:

  • The temperature difference is too small, for example the temperature in the firebox and chimney is quite low compared to the outside temperature. This can happen if the wood is not burning with a good flame, or if the chimney is poorly insulated, thus allowing heat to be released through the chimney walls and not up through the chimney.
  • The outside temperature is too high, for example in the summer.
  • The chimney is not high enough, so that it is covered by tall trees or rooftops, in which case there is a big danger of return smoke.
  • False air can enter the chimney through a missing or broken joint.

RAIS dealers?
Where can I purchase a RAIS stove?



RAIS stoves are sold through authorised RAIS dealers and speciality stove shops.


RAIS dealers are trained to give advice to customers regarding RAIS stoves, the use of the stove and their installation, as well as additional products, such as accessories and chimneys.


An authorised RAIS dealer will have a sticker on the store front, either on a door or window, or the dealership may carry an authorisation letter inside the store.


You can find the RAIS dealer nearest you under "Find your nearest authorised RAIS dealer."

Rais - FAQ - Questions and answers


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