Protection goal (gas technology)
The protection goals 1 and 2 are stipulations by the technical rules for gas installation ( TRGI ), which among other things guarantee the safe operation of room air-dependent gas devices (device type B 1,1 ).
Protection goal 1
Protection goal 1 ensures exhaust gas dilution during start-up. Due to the fact that a column of cold air in the cold chimney prevents the warm flue gases from rising, the flow protection in the device ensures that the flue gases escape to the left and right of the device in a controlled manner. As a result, the accumulating exhaust gas does not affect the combustion and does not suffocate it. At the same time, the concentration of oxygen in the sucked in air is reduced.
After two minutes, however, this start-up state must switch to normal operation, in which the thermal lift builds up and thus the warm exhaust gases are discharged. To ensure this, a room-performance ratio (RLV) of 1 has been set for protection goal 1 : 1 m³ of room air must be available for 1 kW device output . If this is not the case, a combustion air network must be established with the adjacent rooms. This includes all rooms regardless of windows and external doors.
An adjacent room is connected by making an upper and lower ventilation opening in the door or wall with a minimum free cross-sectional area of 150 cm² each. The lower opening is close to the floor, the upper opening is to be provided at a minimum distance of 1.80 m from the other ventilation opening. Two openings, each with a clear cross-section of 75 cm², can also be used directly to the outside to meet protection goals 1 and 2. However, this solution is not used in living areas (thermal insulation).
Protection goal 2
Protection goal 2 ensures the supply of combustion air during operation. A room-to-power ratio (RLV) of 1.6 (previously 4) applies : 1.6 m³ of room air volume must be available for 1 kW device output . In contrast to protection goal 1, only rooms with doors and windows to the outside that can be opened may be added to the combustion air network so that the air is sucked in through window and door joints. In the case of protection goal 2, the rooms to be counted are connected with a 150 cm² grid at the bottom of the door or alternatively with two openings (top and bottom) of 75 cm² to the outside.
Tables in the TRGI regulate the crediting of neighboring rooms, so that when door seals are removed or the door leaves are shortened, air quantities can be added if no ventilation slots are to be incorporated into the doors. This rule came about because problems with inflowing air caused device malfunctions in the past. These problems arise from the installation of modern, thicker doors and windows. Special rules apply to devices over 35 kW.
Web links
- http://www.dvgw.de
- http://www.kolboske.de/joomla/files/mm/gas/gas_inbetriebnahme_eines_gasgeraetes_txt.pdf