Joan,
Goorah also added some very good points. The overall sound issue must be analyzed for all components. The sound of the dust collector itself must be known and this data can usually be requested for the manufacturer. The velocity of the duct will add noise but usually if there is...
I am not sure you have a problem.
If you check with the vendor for the A/C unit you may find that you can turn the airflow down to levels that are close to what you need (resheave the unit and reduce the airflow).
Many a/c units today can operate from 300 to 500 cfm/ton (3000 cfm to 5000 cfm...
I have project that is showing signs of what appears to be galvanic corrosion on the domestic water lines. The water source is well water. The corrosion is showing up at water heater connections and at flanged connections. That is where we would expect to see it, but the interesting condition...
