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wiki:tools:laserfilter [2025/08/18 20:57] – created - external edit 127.0.0.1wiki:tools:laserfilter [2026/02/21 17:36] (current) – Added Wayback Machine permalinks for the PDF references, fixed some spelling mistakes, and deleted some conflicting info about the filters ddq
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 ====== Laser Filtration System ====== ====== Laser Filtration System ======
-It is well understood that depending on the material being "lased" that the fumes from a laser cutter can be detrimental to human health, either through the release of particulates, or volatile organic compounds (VOCs). (reference: [[https://seas.yale.edu/sites/default/files/imce/other/ISAM%20Makerspace%20Emerging%20Safety%20Items.pdf|Download PDF]]) In particular, wood creates a significant amount of small particulate matter, while most plastics create various VOCs that must be removed from the exhaust stream before it is ducted either inside or outside the space.+It is well understood that depending on the material being "lased" that the fumes from a laser cutter can be detrimental to human health, either through the release of particulates, or volatile organic compounds (VOCs). (reference: [[https://web.archive.org/web/20250405083356/https://assets.pubpub.org/11oas02j/22%20Herrick%20Klein%20Emerging%20Health%20and%20Safety%20Issues%20in%20Makerspaces-31691084105595.pdf|Download PDF]]) In particular, wood creates a significant amount of small particulate matter, while most plastics create various VOCs that must be removed from the exhaust stream before it is ducted either inside or outside the space.
  
 Many commercial systems exist in order to address these concerns, and in general follow the same design principles: Many commercial systems exist in order to address these concerns, and in general follow the same design principles:
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 ===== Filter Setup ===== ===== Filter Setup =====
 In most cases, a prefilter, bagfilter, HEPA filter is the preferred option. This provides the longest lasting filter media for this application of the systems reviewed. However VHS has a modular setup that is arranged to accept standard 20"x25" furnace filters. Therefore the arrangement above was created using: In most cases, a prefilter, bagfilter, HEPA filter is the preferred option. This provides the longest lasting filter media for this application of the systems reviewed. However VHS has a modular setup that is arranged to accept standard 20"x25" furnace filters. Therefore the arrangement above was created using:
-  - 2x reusable/washable plastic prefilters to capture large particles entrained in the flow from the laster+  - 2x reusable/washable plastic prefilters to capture large particles entrained in the flow from the laser
   - 4x Filtrete 1900 MPR 1900 "Maximum Allergen Filtrete Furnace Filters" (Can be replaced by a single deep pleat MERV 14 or higher commercial filter as necessary).   - 4x Filtrete 1900 MPR 1900 "Maximum Allergen Filtrete Furnace Filters" (Can be replaced by a single deep pleat MERV 14 or higher commercial filter as necessary).
-  - 6x trays of 1" Jacobi Ecosorb GXB Activated Carbon (or equivilant)+  - 6x trays of 1" Jacobi Ecosorb GXB granular activated carbon (or equivalent), 4 or 5 mm particle size
  
 This system is designed to: a) reduce particulate entrapment in the fine particulate phase, b) ensure removal of particulate matter which is roughly similar to tobacco smoke as per literature on laser exhaust, and c) have sufficient residence time of the air in the carbon bed, while not increasing the overall dP of the filter system. This system is designed to: a) reduce particulate entrapment in the fine particulate phase, b) ensure removal of particulate matter which is roughly similar to tobacco smoke as per literature on laser exhaust, and c) have sufficient residence time of the air in the carbon bed, while not increasing the overall dP of the filter system.
  
-According to literature from the EPA ([[https://www3.epa.gov/ttn/ecas/docs/cs3-1ch1.pdf|Download PDF]]) it is suggested to use a minimum bed depth of 3", along with face velocities of between 50-100 fpm to reduce streaming and breakthrough, while providing sufficient residence time. It should be noted that in this setup, the number of trays and flow area has been maximized in order to lower dP, and increase residence time. At the specified 350 cfm, and the 1/2 filter box area currently in use, the residence time in the current design is approximately 0.3s. +According to literature from the EPA ([[https://web.archive.org/web/20240617062356/https://www3.epa.gov/ttn/ecas/docs/cs3-1ch1.pdf|Download PDF]]) it is suggested to use a minimum bed depth of 3", along with face velocities of between 50-100 fpm to reduce streaming and breakthrough, while providing sufficient residence time. It should be noted that in this setup, the number of trays and flow area has been maximized in order to lower dP, and increase residence time. At the specified 350 cfm, and the 1/2 filter box area currently in use, the residence time in the current design is approximately 0.3s.
- +
-The current filter setup is shown below: +
- +
-{{:tool:vhs_filterbox.jpg?direct&400|}} +
-(Replace with updated and rotated photo)+
  
 ===== Filter Maintenance ===== ===== Filter Maintenance =====
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   - No particulate breakthrough   - No particulate breakthrough
  
-At any time if there is a concern over filter operation or maintenance, please call the space at (778) 330-1234, or contact any member of the LCC on #laser on slack and take the laser offline for further use. +At any time if there is a concern over filter operation or maintenance, please contact any member of the LCC via #laser on Slack.
- +
-===== Other References ===== +
-**Note:** The Google Doc linked below contains additional maintenance information, but conflicts with some of the information on this page. As of April 2025, the LCC is working to reconcile these two sources into one definitive reference.  +
- +
-https://docs.google.com/document/d/1_UN9pxrlWqTYGtY5TYYHc2xuRvDM5CxSscJ_hM80spY/edit?usp=sharing+
  
 ===== List of Past Maintenance Logs ===== ===== List of Past Maintenance Logs =====