/ What is pressure loss?Air resistance in ventilation system is mainly determined by air speed in this system. Air resistance grows directly proportional to air flow. This phenomenon is known as pressure loss. Static pressure produced by a fan causes air motion in the ventilation system with a certain resistance. The higher the ventilation resistance in the system, the less air flow of the fan is. Friction losses for air in air ducts as well as resistance of the networking equipment (a filter, silencer, heater, valves and dampers, etc.) can be calculated using the tables and diagrams contained in the catalogue. Total pressure loss is equal to all pressure loss values in a ventilation system.
| Type | Air speed, m/s |
| Main air ducts | 6,0 - 8,0 |
| Side branches | 4,0 - 5,0 |
| Air distribution ducts | 1,5 - 2,0 |
| Supply ceiling grilles | 1,0 – 3,0 |
| Extract grilles | 1,5 – 3,0 |
