BURNING WITH EXTERNALLY SUPPLIED COMBUSTION AIR
Increasingly throughout Europe many DAN SKAN stoves are being installed in ‘energy-saving’ or low-energy houses, which are insulated to very high standards and where potential heat loss, and therefore the movement of air, is minimised. In Germany they have their own strict building standard covering external air known as DIBt with which the new DAN SKAN MODERN LINE stoves comply. Each of our models feature an external air (also known as direct air) inlet option where a connection pipe is used to draw combustion air from outside the house. The DAN SKAN EX-AIR system automatically delivers tertiary air, which is pre-heated to 300º C as it travels through a series of channels into the combustion chamber where it then enters the after-burning process, just above the top of the flames. This ensures that the fire chamber is not continuously cooled by the colder external air.
EX-AIR-1: CLASSIC SYSTEM WITH PRE-HEATED TERTIARY AIR
Each DAN SKAN Classic stove has the option of supplying the external combustion air from the base (A), where the 100mm diameter connecting pipe can be concealed below the floor or hearth, or from the rear of the stove (B). Outdoor air has the potential to be extremely cold so that pre-heating this air supply is essential to ensure the efficient performance of fire chamber. Both of these options allow a much longer time for the outdoor air to draw heat from the rear of the stove as it moves through pre-heating channels towards the inlet at the top of the fire chamber as normal room pressure pre-heated Tertiary air (C). Thousands of stoves with the DAN SKAN EX-AIR-1 system have proven themselves in low-energy or passive houses because, with this system, it means that the stove acts like a potential pressure balancing safety valve. The external air inlet at the base or rear of the stove, connects with the internal air via the stove‘s convection system ensuring that excessive negative pressure in the installation room, and the potential problems this could cause with the stove‘s safe operation, are avoided. If negative pressure is created in the room where the stove is located and this pressure is higher than inside the chimney system, then additional air can be fed into the room out of the convection aperture at the rear top of the DAN SKAN stove (D).
EX-AIR 2: EXTERNAL AIR SYSTEM WHICH DOES NOT USE INTERNAL AIR
The EX-AIR 2 supplies combustion air via a sealed, ventilation and internal airindependent system, and is especially suitable for modern low-energy houses with high seal windows as well as doors and pressure balance control. This system requires the installation of the DAN SKAN patented AIR-BOX which includes an integrated heat exchanger. The AIRBOX can also be added at a later date since all DAN SKAN stove back plates feature a pre-prepared laser cut aperture which can be easily removed to allow the new connection. As with the EX-AIR 1 system each stove has the option of supplying the external combustion air from the base (A), where the 100 mm diameter connecting pipe can be concealed below the floor or hearth, or from the rear of the stove (B). Within the enclosed AIRBOX the combustion air is pre-heated by the integrated heat exchanger at the rear of the fire box (D) before it is delivered automatically in the correct amount, into the fire chamber as tertiary air (C). This ensures a very high post-combustion air temperature in the upper part of the fire chamber to feed the top of the flames and to make the stove operate with much greater efficiency while also making it much cleaner burning. The highest negative pressure is in the area just above the baffle plate and this allows the pre-heated tertiary air to be efficiently drawn in. When using the EX-AIR-2 system there is no need to use the pull control or to open the stove door to supply combustion air when lighting a standard fire as special air vents at the door sides provide the correct amount of air to get the pre-fire started. Please note: Some Building Regulations do not permit ‘closing off’ the external air supply, even when the stove is not being used. Please refer to your local and national building regulations.
If this is prohibited, DAN SKAN recommend that suitable precautions are therefore taken to avoid potential condensation forming on the external air duct as it enters the warmer room, for example insulating the air duct.