- The length of the barrier board 2.5 to 3 m
- The minimum inclination of the board - 20 °
- Obstacle-free ceiling - substrings, lamps, etc.
- The maximum depth of the chamber - 12 to 15 m
- Ridge not too high - otherwise bad air mixing
- From the outside to the central corridor is an area
- 1.5 cm2 of inlet provides 1 m3 of air per hour
- Maximum temperature in the central corridor 5 ° C below that required in the chamber