1. L083A L083B has a total of about 230 adjustment dampers, which are all done in the same way as UDETAIL "Y", I do n’t know UDETAIL "K "Measure negative pressure or flow. So the question is how to adjust so many adjustment dampers to evenly distribute the air intake? The ducting have been designed with the concept of equal velocity, so that the system result approximately self balanced, the ventilation system can be started with the dampers positioned open 50%, velocity measured on sample points “K” and in case needed damper adjusted, sample points will be used then for periodical checking of the flow to detect no dust accumulation in the ducts create air flow decreasing and unbalancing. Sample points K can be used for both flow and negative pressure measurement.2. The working temperature of L083A L083B is the ambient temperature. Can the material of the air dusts be changed to PP or PVC?It’s advisable to have ducts steel fabricated, because offer better resistance to dust abrasion and heat than PP/PVC and do not increase the fire load of the building.