Enclosed Space HEPA Vent System for Rock Carving
Jun 5, 2017 1:45:00 GMT -5
hardroks, 1dave, and 1 more like this
Post by gmitch067 on Jun 5, 2017 1:45:00 GMT -5
I just started a project to help another member with a system that would provide some ventilation in his basement. Although any vent exhaust would ideally be directed to the outside, there might be instances where all that carving dust needs a vent with an adequate filter system which helps control dust in the work room. The use of this vent system should NOT be considered as a stand-alone solution. Proper PPE clothing and equipment must also be utilized by anyone working around silica rock dust!!! This is a work in progress, but I thought I would share it with others.
(Note: The following is a copy of some comments I made in another post in the thread "need h/Vac tips" by Hardroks)
I am putting some pieces and parts together to create an overhead stove vent hood that is mounted to a portable frame. The frame/vent hood will sit atop my small work table and catch the dust cloud as I work below. It will then exhaust through a HEPA filter back into the closed garage or basement.
I bought the vent/fan unit at the nearby Lowes - expensive... ~$100... But I wanted one that had a good high airflow driven by a very quiet fan (140 CFM). The fan is designed for continuous operation and utilizes a rotating squirrel cage of blades instead of a noisy propeller. I figure that (especially in an enclosed room like a basement) running the vent unit for a half hour AFTER working with the rocks will be enough time to cycle the room's air through the HEPA filter to remove any harmful silica dust.
To test all this out... My frame is one of my geriatric walkers (SEE... old men are good for something!). The vent/fan unit will attach to the underside of the walker's seat - for now with bungee cords. That will put the vent/fan unit about 2 ft above my dremel grinding area. The vent/fan unit exhausts to a 6" hose port, on which I plan on mounting a sheet metal pre-fab thingie that has a 6" hose fitting on one end and a 12"x6" rectangular opening on the end (like you see in floors with heater vent openings - no grill work though). (NOTE: LOTS of Duct Tape, tie wraps, and bungee cords will be harmed during this creation!!! 'Can't destroy my walker though... I might need it later!)
I ordered a HEPA filter from Amazon (~$33) that had one side dimension of ~12" and a length of ~16" - a little scissor work and duct tape will create a couple of filters to go on the exhaust (one will be a spare). The filter comes with a thin charcoal activated pre-filter that gets the heavy stuff first (I substituted a section of an air conditioning allergy filter as a pre-filter - I hope both filters do not cut down the CFM airflow too much). There were cheaper replacement filters for various commercial HEPA filter air purifiers on the market, but they did not fit the exhaust opening and would cut down on the surface coverage - which would probably cut the 140 CFM airflow down a little (I think the HEPA filter alone might do that too, but it is a necessary evil).
The vent/fan even has a light fixture that I can utilize 2 energy efficient bulbs in. There is a plastic light cover that will protect the bulbs and can be easily cleaned of rock splatter. I still have to figure out the electrical connections though... lots of wires to hook up, users manual to read, and switches to purchase still. I DID purchase a 3-prong 16-gauge 75 ft. extension cord that I can chop off the female end and wire up as a power cord (I would not make it in the construction industry! LOL!).
Here is what I have so far... I still have to attach the power cord... Not sure if I will need any switches. Being as my work bench is a folding table, and I need to disassemble and stow everything after each work session. Everything is either all-ON or stowed away. Sooo... I will make it "Plug-n-Go" for now.
More to come!
(Note: The following is a copy of some comments I made in another post in the thread "need h/Vac tips" by Hardroks)
I am putting some pieces and parts together to create an overhead stove vent hood that is mounted to a portable frame. The frame/vent hood will sit atop my small work table and catch the dust cloud as I work below. It will then exhaust through a HEPA filter back into the closed garage or basement.
I bought the vent/fan unit at the nearby Lowes - expensive... ~$100... But I wanted one that had a good high airflow driven by a very quiet fan (140 CFM). The fan is designed for continuous operation and utilizes a rotating squirrel cage of blades instead of a noisy propeller. I figure that (especially in an enclosed room like a basement) running the vent unit for a half hour AFTER working with the rocks will be enough time to cycle the room's air through the HEPA filter to remove any harmful silica dust.
To test all this out... My frame is one of my geriatric walkers (SEE... old men are good for something!). The vent/fan unit will attach to the underside of the walker's seat - for now with bungee cords. That will put the vent/fan unit about 2 ft above my dremel grinding area. The vent/fan unit exhausts to a 6" hose port, on which I plan on mounting a sheet metal pre-fab thingie that has a 6" hose fitting on one end and a 12"x6" rectangular opening on the end (like you see in floors with heater vent openings - no grill work though). (NOTE: LOTS of Duct Tape, tie wraps, and bungee cords will be harmed during this creation!!! 'Can't destroy my walker though... I might need it later!)
I ordered a HEPA filter from Amazon (~$33) that had one side dimension of ~12" and a length of ~16" - a little scissor work and duct tape will create a couple of filters to go on the exhaust (one will be a spare). The filter comes with a thin charcoal activated pre-filter that gets the heavy stuff first (I substituted a section of an air conditioning allergy filter as a pre-filter - I hope both filters do not cut down the CFM airflow too much). There were cheaper replacement filters for various commercial HEPA filter air purifiers on the market, but they did not fit the exhaust opening and would cut down on the surface coverage - which would probably cut the 140 CFM airflow down a little (I think the HEPA filter alone might do that too, but it is a necessary evil).
The vent/fan even has a light fixture that I can utilize 2 energy efficient bulbs in. There is a plastic light cover that will protect the bulbs and can be easily cleaned of rock splatter. I still have to figure out the electrical connections though... lots of wires to hook up, users manual to read, and switches to purchase still. I DID purchase a 3-prong 16-gauge 75 ft. extension cord that I can chop off the female end and wire up as a power cord (I would not make it in the construction industry! LOL!).
Here is what I have so far... I still have to attach the power cord... Not sure if I will need any switches. Being as my work bench is a folding table, and I need to disassemble and stow everything after each work session. Everything is either all-ON or stowed away. Sooo... I will make it "Plug-n-Go" for now.
More to come!
