Basic Terms
Flue Damper
A flue damper can be part of a wood-burning stove/fireplace insert, or it can be installed on the flue pipe. The flue damper is used to regulate the chimney draught and thereby control the combustion itself. We recommend fitting all wood-burning stoves and fireplace inserts with a flue damper — in the case of excessive chimney draught, you can effectively regulate combustion. When the damper is open, it does not obstruct anything and has no effect on the chimney draught or the operation of the stove/insert.
External Air Supply
An external air supply is, in short, an external supply of combustion air to a wood-burning stove/fireplace insert. Combustion always requires a sufficient supply of combustion air — insufficient air can cause combustion problems and, in extreme cases, may even pose a health risk. The need for an external air supply arises particularly in passive houses, where the level of airtightness is such that the room containing the appliance does not have adequate air exchange, and therefore the appliance does not have sufficient oxygen for proper combustion. An external air supply is also used where the space housing the appliance includes a functioning extractor hood, which, when switched on, creates negative pressure that can cause combustion problems in wood-burning stoves/fireplace inserts. It is best to leave the installation of an external air supply to professionals, who will correctly size and carry out the work. The external air supply can be drawn from well-ventilated spaces such as a loft or cellar, or it can also be connected directly from the exterior.
Primary Air Supply
This is the primary air supply delivered beneath the firebox grate. This air supply serves mainly to ignite the fuel. Under ideal conditions, this air supply should be closed during combustion; burning is then regulated by the secondary air supply.
Secondary Air Supply
The secondary air supply is a "supporting" air supply that serves to convert emission particles so that they can be fully combusted, resulting in higher efficiency and reduced particulate emissions from the appliance. This air supply is introduced into the combustion chamber through openings in the upper part of the firebox and is also used for glass washing. The secondary air supply is used to regulate the output of the stove and is an essential component of all modern wood-burning stoves/fireplace inserts.
Convection Heating
Convection heating is, in short, heating by convection (double-cased) stoves, and the heating principle is based on air circulation. This circulation occurs between the casings, where air is heated and exits through vents at the top. Its advantage lies in greater circulation of warm air within the room and rapid heating of the room once the fire is lit in the wood-burning stove/fireplace insert.
Cooling Loop
A cooling loop is used in wood-burning stoves/fireplace inserts with a hot water heat exchanger. Its function is to protect the system against overheating, for example in the event of a power failure. Via a safety thermostatic valve, cold water (from the mains water supply, which is independent of electrical power) is admitted into this loop. Should the temperature in the heat exchanger rise, the heat transfer surface of the loop itself cools the water in the exchanger to prevent potential damage to the appliance and the heating circuit. This cooling loop is included in all our products fitted with a hot water heat exchanger.
Hot Water Heat Exchanger
A hot water heat exchanger in wood-burning stoves and fireplace inserts is used to heat central heating or domestic hot water. Wood-burning stoves and inserts with a hot water heat exchanger can be connected to a hot water heating system, or used to heat a thermal storage tank. When determining the required output of the heat exchanger, this must be discussed with a heating engineer/designer, who will specify the required heat exchanger output based on the particular hot water system. Wood-burning stoves/inserts must not be operated when the heat exchanger is not filled with water and connected to the hot water system. The connection of wood-burning stoves and fireplace inserts with a hot water heat exchanger should always be carried out by a qualified installer.