/ Field knowledge · IMC 510.1.3
Missing one of the three → exhaust outdoors.
IMC 510.1.3: default is discharge to outdoors. Recirculate only if all three are on the drawing: 99.9% at 10 µm, vapor < 25% LFL, and approved continuous monitoring. Missing one → exhaust outdoors.
Educational 2024 IMC 510.1.3. Confirm adopted edition. Distinct from hazardous exhaust and 501 discharge. Environmental agencies may also permit recirculation of certain dusts — confirm that separately. This is not a collector sizing.
- Dust / stock / refuse conveying exhaust must discharge to the exterior, either directly by flue or indirectly through the bin/vault the system discharges into, unless contaminants are removed.
- Recirculation is allowed only if all of the following are met: (1) particulate removal minimum 99.9% at 10 microns; (2) vapor concentrations < 25% of the LFL; (3) approved equipment continuously monitors vapor concentration.
M-001: “DISCHARGE TO OUTDOORS” or “RECIRCULATION PER 510.1.3” with the three criteria. Schedule: filtration efficiency, monitor type/location, alarm/shutdown if specified by manufacturer/AHJ. Do not treat dust conveying as general return air. Do not leave discharge routing for the field to guess.
“Recirculating dust collector” with no basis
No 99.9% @ 10 µm, no LFL monitoring, no statement of where the air goes. A system designed for recirc that later has to exhaust outdoors is a significant redesign. Confirm AHJ and environmental-agency permission for the specific dust before the collector is selected.
Source: DCT 510.1.3 · tool: 3-part recirc check · hazardous: 510 hub.
What to send
Whether the collector is labeled recirculating, the filter rating, and whether a vapor monitor is shown.
If the collector is labeled recirculating
Send the schedule. Masterbuild will say whether 510.1.3 even has all three — or this is still outdoor discharge.
Send Project Background+1 (786) 398-6940 · osmany.portal@masterbuildconsulting.com
Masterbuild provides engineering services under a written scope. Nothing on this page is project-specific engineering advice, a code interpretation for your project, or a representation about permit approval. Confirm the adopted edition. Recirculation numbers below are 2024 IMC 510.1.3 education from Daily Code Talk — not a dust-collector selection. This page is not an air-quality permit.