Diermayer damper, thermal

Conventional flue systems operate with a negative pressure and so generate a suction effect. When the appliance is idle, heat is drawn from it. More energy is lost when warm room air escapes through the draft baffle and unwanted drafts can occur in the room. Where several gas appliances are connected to a common flue system, the leak air entering through the draft baffle adversely affects the operation of the system. Where several appliances are in operation, hazardous flue gas may escape into occupied areas through appliances that are idle. The requirements and tests governing thermally controlled flue gas dampers are very stringent. They are laid down in DIN 3388 Part 4, which requires the dampers to be tested and approved together with the gas appliance or assembly for which they are intended. As a result, the configuration, the housing form, the thermal rating of the control elements, the flow resistance and the operating times are all perfectly matched to the function of one or more gas appliances, making for optimal operating conditions. A special feature of the thermal Diermayer dampers is the design of the control element that is made from special bimetal in the shape of a closed triangle. One end is attached to the isolation plate and the other end to the cross strut. This patented technical solution needs neither shafts nor bearings. The efficiency and safety of the operated appliances can be improved by the use of Diermayer dampers. They prevent the escape of heated room air by opening the flue gas path during operating times and sealing it off again during idle times. Where several appliances are operated on a common flue gas line, Diermayer dampers with their thermal control protect each appliance individually. Here again, the damper opens during operating times and closes safely during idle times. As a result, each individual appliance operates safely and efficiently while being simultaneously operated with other appliances. Damper starts to open as low as approx. 40°C From 70°C or 90°C flue gas temperature, fully open to allow flue gas passage Flow resistance < 2 Pa At least two independently operating control elements Corrosion resistant stainless steel Robust construction that resists fouling Because of its large surface area, the bimetal is optimally washed by the flue gas and so can react very rapidly and with a very high positioning force. Its design makes for a high degree of elasticity, so it is able to withstand high flue gas temperatures without sustaining permanent distortion. Thermally controlled flue gas dampers may only be used for gas fired appliances with burner and without a fan, and as directed by the manufacturer. Flue gas dampers are installed after the draft baffle without the need for major modifications to the existing flue gas line. Installing a thermally controlled flue gas damper saves energy and improves the reliability of the system as a whole. The investment pays for itself within one to two heating periods.