Emissions and CFM
2/12/14
I'm trying to analyze our dust collection system and I'm going through all of the machines and some machines, like the weeke cnc router, list an emission (2mg/m^3). How does this number relate to required CFM?
2/24/14 #2: Emissions and CFM ...
Sarah, The emission is 2 milligrams per cubic meter. Air flow volume for metric system is normally shown as cubic meters per hour (cu. m/h). That figure can be converted to cubic feet per minute (cfm).
1 meter = 3.281 feet. The CNC info should show a rating of cubic meters per hour that you have to convert to cubic feet per minute.
Curt
2/25/14 #3: Emissions and CFM ...
The emissions would be related to CFM, (air flow.) If you don't have enough air flow you will likely have higher emissions. So the manufacturers statement should read something like X grams of emissions @ XX cfm or it may be expressed as " of water at XX cfm to define how much suction you system can create. The hood design will greatly affect the flow pattern and therefore the emissions even if you have enough cfm available. Dust collection fan/system manufacturers seem to use different ways of expressing their performance. Those showing the greatest CFM for a given power often are using free air flow rather than real world. Fans designed to handle solids will have a lower flow than those designed to be on the pull through side of the filters. Systems can show high flows with clean/new filters but have too small of filter area to work well once the filters start to load. Long runs of duct &/or lots of bends add friction and reduce the real CFM the system can deliver. All of this can affect your emissions at every machine. Clear as Mud?