- 5 questions about chimney inserts
- Which power of insert to choose?
- Maintenance of the fireplace insert
- Works: the imperatives for the installation of a fireplace insert
- Insert: for a successful installation
- VERY ECONOME
- ALL IN CAST
- PANORAMIC GLASS
- UP TO 12 HOURS OF AUTONOMY
It installs easily and inexpensively into an existing chimney to increase its performance. The wood insert is the ideal solution to combine aesthetics with heat output and create a powerful, less polluting heating system.
5 questions about chimney inserts
Answers from Mallereau Thierry Expert Wood commission to the Union of renewable energies:
What are the advantages of an insert?
An insert is undeniably an ideal solution for anyone who wants to improve the performance of an open fireplace, while retaining the charm and pleasure of a traditional fireplace. However, wood burning remains an auxiliary heating which, under certain conditions, can very well become a main heating - and even complete, in the presence of the inhabitants - under certain conditions of volume of the habitat, insulation, outside temperature, etc.
Can inserts fit all types of chimneys?
This depends mainly on the type of construction of the hearth (thermal resistance of the walls and the drain, partly dismountable construction) and compatibility with the existing flue. Other parameters are of course to be taken into account, such as the feasibility of supplying fresh air or the circulation of convection air around the insert.
What are the criteria for a wise purchase?
The choice must be dictated by the use (approval, top-up or main), therefore the operating time and recharging intervals. It must also be guided by the requirements of thermal comfort and use. Buyers often focus on design, while the most serious criterion is the Green Flame label. Recognized by industry and professionals, it helps identify appliances with high energy and environmental performance.
Are there any particular points to be vigilant about?
To take full advantage of its insert and in complete safety, it is essential to have a suitable and safe flue. This must allow the proper evacuation of fumes while ensuring the safety of users. In addition to this, the high temperatures generated by such an installation require in all cases the thermal insulation of the flues (in the casings very often) and the technical hood (backing walls), as well as supply of fresh air adapted and efficient convection system.
Is the investment profitable?
Absolutely! And this for several reasons: an insert means significant energy savings, high performance, long battery life, optimum safety and improved air quality. It is also considered that for a house of 100 m2, the return on investment is only of the order of four to five years.
How to make sure of the quality of an installation?
In order to help the individual choose a competent company to carry out its energy saving work, Ademe and the State have set up a commitment charter grouping eight quality signs with the mention RGE (see box). To install renewable energy systems that meet the rules of the art, recognized professional qualifications attest to the competence and reliability of the installers. With regard to wood heating systems, the recognized quality mark is the Qualibois Air label.
Which power of insert to choose?
According to the Agence Qualité Construction (AQC), the power of an insert must not exceed the losses of the room where the appliance is installed.
It depends on the volume of the room, the outside temperature, and the insulation. If the insert is associated with a distribution network or a very open architecture, the calculation of the power must integrate the other parts.
The operation of the insert at nominal speed should be preferred: the search for autonomy should not lead to offer a more powerful insert than necessary.
If the power of the device is much higher than necessary, it will operate below the nominal operating range, which may change its thermal and environmental performance and lead to an accelerated duct bire (risk of fire).
Thus, if the need is 11 kW, it is better to choose a device of 9 kW rather than 13 kW.
If it is possible to make yourself the installation of an insert, this is nevertheless strongly discouraged. The chimney and its accessories are part of high-risk equipment and must meet national housing standards.
Maintenance of the fireplace insert
- It is necessary to carry out regular deashing (while leaving some ashes hot).
- The grid must be cleaned for good air circulation.
- The connection to the duct and the control system must be checked once a year.
- The chimney sweeping must be done twice a year, including once during the heating period, by a qualified company which must provide, after intervention, a chimney sweeping certificate.
The heat transmitted by an open fireplace in the dwelling is only 30%. The rest goes up in smoke.
By installing an insert in an existing chimney, this problem is eliminated while avoiding heavy work.
Works: the imperatives for the installation of a fireplace insert
Casing improves the characteristics of the flue (sealing, section adapted to the appliance, ease of connection, better resistance to the corrosion of fumes), but it can not have the effect of restoring the integrity and stability of a conduit. In some cases, it may be interesting to improve the thermal resistance of the duct by filling insulating materials (Technical Notice).
It may also sometimes be necessary to apply a coating inside a flue, this is called the jacketing. If the duct has cracks, it is imperative to eliminate the causes beforehand. This work requires special know-how and must be carried out by a specialized company *.
Finally, roof outlet must imperatively exceed the ridge of at least 40 cm.
* The work must comply with the standards NF DTU 24.1 and NF DTU 24.2 or have a Technical Notice.
Insert: for a successful installation
• Ideally, the insert should be in the most frequented living room, against a thick wall (wall of slit, for example) in order to preserve the maximum heat inside the dwelling.
• A fresh air supply is mandatory, it must be located closer to the unit.
• The total mass of the various components can be significant (sometimes several hundred kilograms), it is imperative to verify that the floor is designed and sized to accept this load (not to mention to check the compressibility of insulation).
Composed of a steel structure and a door with black screen-printed glass, this pellet insert has a power of 5.8 kW and a yield of 85%. Its tank has a capacity of 11 kg of granules. "Gigio", Chazelles fireplaces. Public price: € 2,918 excluding tax.
STRONG POINT: integrated temperature sensor and remote control for easy adjustment.
Available in natural convection, forced ventilation or Comfort Air versions, this closed hearth insert offers a temperature output of up to 80° C and particularly efficient heat extraction. "Boxtherm 80", MCZ. Public price: from 1 350 € HT.
THE STRONG POINT: very design, the vents of the air offer more functions of lighting and aromatherapy.
ALL IN CAST
This 100% cast iron insert accepts 55 cm logs. Its maintenance is facilitated by a system of permanent scanning of the glass. Available in black blue enamelled finish, it offers a maximum power of 12 kW. "Jøtul C 33", Jøtul. Public price: € 1,790 excluding tax.
STRONG POINT: it fits easily into all open fireplaces.
Suitable for most open fireplaces, this 5 kW insert is available with a slightly domed panoramic cast iron door or a double hinged door. Rate of return: 75%. "Insert i5 with panoramic door", Contura. Public price: € 1,856 excluding taxes.
STRONG POINT: its panoramic window (55 cm) and its discreet frame.
UP TO 12 HOURS OF AUTONOMY
All steel, this insert from 5 to 20 kW offers up to 12 hours of autonomy. With a yield of 74%, it consumes 4.25 kg / h of wood at normal pace. Closed door, a maximum of heat is recovered thanks to the circuit of the smoke box. "Insert V100 L", Fondis. Public price: € 2,180 excluding taxes.
THE STRONG POINT: the precise adjustment of the power and the duration of combustion.