Why akustone

The Akustone soapstone stove is simply
a brilliant natural heat accumulator.
They will heat your home for another 24 hours, for just one load.
For this reason, it is rightly ranked among the most efficient wood stoves in the world.



#1 Ingeniously designed structure made of natural accumulative material

The Akustone stove is made of refractory natural material—SOAPSTONE. This natural mineral has 7 times higher heat accumulation capacity opposed to the commonly used chamotte.

The ingeniously designed structure utilizing flue gas vents in combination with a soapstone firebox guarantees rapid heating of the entire accumulative mass of the stove weighing 960 to 2500 kg.

The Akustone stove structure is manufactured exclusively out of accumulative soapstone which makes up to 97% of the total weight of the stove.

How is it possible that a soapstone stove stays warm for so long after exhaustion?

There are two reasons. The first reason is the utilisation of the natural mineral soapstone as the main construction material. The type of soapstone we use for our stoves mainly consists of talc (50–55 %), fine-grained magnesite (40–45 %) and in a minimal amount of other carbonate admixtures. The high thermal conductivity and thermal capacity together with the high density (talc is 3 times heavier than water) give this material a high thermal sensitivity, or, in other words, the ability to accumulate heat and then gradually release it. Just for comparison with chamotte, which is used for building fireplaces and stoves, it is on average 7 times more.

Sophisticated design of flue gas vents

The second reason is the ingeniously designed system of flue gas vents in combination with a soapstone refractory firebox. This is the only way to achieve rapid heating of the entire mass of soapstone used, maximum accumulation and gradual heat release back into the space. This principle was and is still used, for example, by classic large tiled stoves.

As the weight of the stove increases, so does its accumulation capacity. That is why in our wide range of products you will find stoves weighing from 960 kg to 2300 kg depending on their performance and thus a wide range of possibilities to choose the right model for your home.

What is the difference between a soapstone fireplace and an accumulation stove lined with soapstone or other accumulative material?

There is a plethora of accumulation stoves on the market, but they will never achieve the unique characteristics of soapstone fireplaces. These stoves are just lined fireplace inserts and the accumulative mass is heated from the surface of the insert or from the chimney. Thus, these stoves have no vents to ensure even heating of the entire stove structure. The heat-accumulative mass is in the range of tens to hundreds of kilograms and the stove is capable of radiating heat into the room for a maximum of 6–8 hours (with a stove weight of around 500 kg).

#2 Healthy radiant heat long hours after exhaustion

The soapstone construction of the stove can accumulate heat for more than 24 hours after 2 hours of heating.

Radiant heat is gradually radiated through the entire surface of the stove at a low-rated output, which is ideal for modern passive and low-energy houses.

Radiant heating is the healthiest and most natural way of heating for humans. It does not kick up dust, does not overheat the surrounding space and ensures even temperature distribution in the room for many hours after the stove has gone out.

Why don't lined accumulation stoves also solve the problem of overheating interiors?

In modern new buildings, the heat loss of a room (at a temperature of around 0 °C) with a stove is most often around 2-4 kW and standard fireplace inserts have an average output of 6 kW or more. Due to the high output, the room overheats. Although the stove can be “regulated”, this results in the chimney tarring and most of the heat escapes unnecessarily up the chimney. It is also possible to maintain a very small flame in the stove, but that is really uncomfortable. Last but not least, the inserts stop heating the room immediately after exhaustion.

What does the accumulation value in kWh mean for soapstone stoves?

The accumulation in kWh means how much energy your accumulator (soapstone stove) is able to store and then release. The storage in kWh means how much energy your accumulator (soapstone stove) is able to store and then release. But what do you mean if your soapstone stove has an accumulation of, for instance, 40 kWh? Let’s take the example of a kettle that has an output of 1000 W (1 kW) and which heats water continuously for 40 hours. This is exactly how much energy your stove is able to store (accumulate) if you heat it up for 2 hours, if it has an accumulation capacity of 40 kWh.

Heating curve

#3 Saves nature, your time and finances

Akustone accumulation stoves feature high-efficiency (up to 94%) and low-emission combustion technology. Its low operating costs (about 4 cubic meters of wood per heating season) is no burden to the environment or your finances.

However, the most valuable thing our stoves give you is time. In just 2 hours of heating per day, you get warmth for the entire day and then you do not have to worry about reheating.

Is heating in a soapstone stove just comfortable, pleasant, efficient or also economical?

We come across this question quite often, so let’s focus on the economic domain. We come across this question quite often, so let’s focus on the economics side. The purchase price of Akustone soapstone stoves ranges from 88 thousand CZK. Considering that the smallest model is one tonne of precision-machined and polished accumulative stone, fitted with quality doors and a unique grate, the price is quite understandable. However, compared to “ordinary stoves”, the price is often multiplied. Nevertheless, the price is comparable to a built-in fireplace insert, which mostly only serves an aesthetic function, as it will very easily overheat your interior. In addition, the lifespan of fireplace inserts is about 10-15 years.

Consequently, a soapstone fireplace heats up once a day (2-4 batches of wood in a row). This is a very comfortable way of heating, when you heat up once a day and have warmth for the next 20 hours.

So how long will it take you to get back on your talc stove investment?

The answer is simple, the more you use them, the sooner. One kWh of piece wood costs about 1 CZK, while 1 kWh of gas or electricity with all fees costs about 3.5 CZK. Thanks to the fact that talc stoves can store energy from burnt wood and then gradually release it, so you don’t heat the god for windows like with ordinary stoves. With this efficiency, you achieve significant economic savings.

If the accumulation of the stove is, for example, 40 kWh, then one “charging of the stove” costs you approximately CZK 40. You will pay approx. CZK 140 for the same amount of thermal energy from gas or electricity. Every time you flood the stove, you will save about 100 CZK in the case of a stove without an exchanger. The moment you connect the exchanger to the system, the savings will be doubled. The heating season has about 250 days, so it can be a financial saving for one heating season thanks to talc stoves with an accumulation of 40 kWh and 25 or 50 thousand. CZK in case of using a model with an exchanger. For the model with an accumulation of 70 kWh, it is also 43 thousand. CZK / year without exchanger and 68 thousand CZK / year.

Comparing the savings of different models

Stove model Stove accumulation [kWh] Price for heating the stove with wood [CZK] Savings – without exchanger [CZK] Heating tank 1000 l at 35°C [CZK] Savings tiwh exchanger [CZK]
Ip 42 40 100 100 200
Ip2 50 50 125 100 225
Fx 54 60 150 100 250
Fx2 76 70 175 100 275


Stove model Stove accumulation [kWh] Price for heating the stove with wood [CZK] Savings – without exchanger [CZK] Heating tank 1000 l at 35°C [CZK] Savings with exchanger – total [CZK]
Ip 42 40 100 100 200
Ip2 50 50 125 100 225
Fx 54 60 150 100 250
Fx2 76 70 175 100 275


#4 Technology far above current standards and requirements

Innovation and development of current heating technologies is a matter of course for us. That is why we have designed Akustone stoves to be as efficient as possible, not only for heating modern homes, but mostly for you in your everyday usage.

  • Double-glazed and triple-air-rinsed door concept
    The unique triple-rinsed door design increases the insulating properties of the door several times over and reduces the amount of heat escaping into the surroundings.
  • High-efficiency combustion with minimal emissions
    The triple-combustion sliding double grate achieves up to 94% efficiency and leaves minimal ash. Akustone stoves are extremely environmentally friendly and meet the world’s most stringent emission standards.
  • Heat exchanger technology
    Our heat exchanger technology allows the stove to be connected to the house heating system and heat water quickly. Stoves with a hot water heat exchanger can also benefit from subsidies by the NEW GREEN SAVINGS Programme!

Can a soapstone stove with a heat exchanger heat the whole house?

In order to heat the whole house with a stove, you need to use an exchanger to heat the water that is stored in the storage tank. There are several brands of soapstone stoves on the market, but only the Akustone soapstone stove has a designed heat exchanger through which the flue gases pass. The heat exchanger, located above the firebox with direct flue gas flow, allows immediate heating of the water once the fire is started. As a result, up to 1000 litres of water can be heated to 60 °C in 2 hours of heating. The heat exchanger is also able to supply heat to the system for a few hours after the stove has been extinguished from the heated accumulation structure.

Finnish manufacturers of soapstone stoves and fireplaces only have an exchanger that heats the water from the heated stove structure. This type of heat exchanger has a very low output (about 1 kW) and can only heat 60 litres of water to 60 °C for one hour of heating.

The soapstone stove with heat exchanger is thus a solution for heating new modern buildings even after 2020

The principle of the soapstone stove with and without heat exchanger is explained in this video: Video on the principle of the stove with heat exchanger

#5 Retaining its value in time

Things of value always last over time. Our stoves and all their components are designed to bring benefits not only to you, but also to your descendants’ generation after many years of use.

That is why we give a superior 10-year warranty on the material from which our stoves are made.


10 year

warranty for stone

akustone kamna hodnota přetrvávající v čase

Together from Design to Implementation

How do we CO-OPERATE when designing soapstone stoves?

We fully understand that construction or reconstruction of a house is a difficult, complex and time-consuming project. We will be more than glad to offer you assistance in areas in which we specialise. Everything around soapstone stoves and chimneys is a matter we will take care of for you!


Meeting in the office or online meeting? The decision whether you would like to know more about soapstone stoves in person in our office is entirely up to you.


Assessment of criteria such as heat loss of your project for an adequate model selection. We assure you to prepare all the necessary steps for future realisation of your soapstone stove in advance!

Everything about stoves is your/our concern?

Setting the boundaries of cooperation, drafting a contract for work and adapting to your pace of implementation. We will arrange and agree on every step in advance.

Technical support

Client = partner. We will therefore be glad to offer you our know-how whenever you are in need of a piece of advice.

Installation and delivery of soapstone stoves

A chimney, a soapstone stove or perhaps both? We will arrange everything for you, deliver you the implemented project with the required documentation and revisit everything together regarding stoves afterwards.

Where are we able to lend a helping hand?

  • Project assessment, design and selection of stoves
  • Structural design of subsoil and specifications of central air supply
  • Design and implementation of bespoke chimneys
  • Technological solution for soapstone stoves with heat exchanger
  • Assessment of specifications for construction readiness
  • Implementation of bespoken soapstone stove