Hello Ben There are many mistakes in the writing. I myself is not good at writing, but if I try to correct it, then it will be like: For air leakage test, according to EN314 of which all the standard our constructed air ducts should follow, only high-pressure class air ducts need to be leakage test. Our ventilation equipment falls within only low and medium classes and therefore, the related ductworks are not required to be leakage tested.
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