A standard ventilation system to be tight, the connection of the sealing can be used soap bubble test, the same a standard test stand frame to maintain airtight, otherwise it will affect the filter resistance, rated air volume, wind speed, into the air filter The resistance of the air duct, the supply air volume of the air supply system, the maximum resistance test of the measured air filter, the resistance test of the air flow measuring device, and so on are inaccurate.
