It is sealed over the sump hole. The house is new so things are pretty tight. The system draws a vacuum on the sump hole and this vacuum is communicated to the air under the slab. The slab is also sealed. The plan is for any radon that is in the air under the slab to be pulled by vacuum to the sump hole up through the blower and vented to the outside. Any suction that I create above the slab to move dirty air out of my basement shop would be pulling against the suction of the radon system. I really don’t think that this is a problem because I have turned on all three vents and there is no change in the radon suction manometer reading. I suppose that I could install much larger blowers that could create a suction large enough to pull radon into the basement…Rob
if the sump suction is sealed then there would no negative pressure problem… I really don’t think that you have major problem on your hands…even if not sealed… by measuring radon levels with the exhausts running you already have solved your problem.
I know that I really didn’t have a problem. I am just throwing this out there for others to consider who might either be too shy or just not know enough to ask the question. I have been a teacher all of my life. Teachers learn to recognize what others need to know, even if they don’t know it at the time, and put it out there for them to consider when the time is right. Unlike many discussion boards where people just go on about what they know, Orchid is a place where you can be fairly certain that, if you have a question and ask it, it will be answered in a non-judgmental and practical way by someone who knows the answer and what they need to understand it…Rob
getting another opinion is never unhelpful. People can share their own experiences which makes our community a great place to be… everyone has something positive to contribute. thank you .
what I’m concerned about is the presence of radon in the first place. the uranium content of the bedrock or sedimentary strata determines the radon levels that seep into basements. I don’t have that problem in m neighborhood but there are others not that far away that do… I don’t know where you are situated but you don’t have to say if you don’t want to… just whether your house is situated on granite or on sandstone or shale.
Learn something new every time I visit.
Didn’t know that radon accumulation in basements was a thing! Not a problem in Australia. Thanx for sharing.
aren’t you a physcist? If you are, you should be teaching us laypersons about this subject. Even though I have some scientific training myself, your knowledge base would exceed by far most of ours’, collectively… This is a personal question, so it’s your option to reply… Thanks, jsfandskh@rushmore. com…
Much of what I know and do is by trial and error and a bit of the science that I learned years ago. I have a lot of air moving through my shop. I can tell because it is no longer covered with polishing dirt. The blower over my polishing hood is rated at 900 cfm. That’s a lot. It pulls air through my polishing hood and directly to the outside through a 6" metal duct. A path of about 6 feet. I have a coarse wire filter at the inlet near the back of the hood. This quickly gets covers with polishing dirt (duff) and acts like a filter to capture what precious metal might be in the air stream. I vacuum this out when needed and store it in a plastic bag to send to the refinery. My hood is very large and has gone through many redesigns in the 50 years since I built it out of scavenged plywood from my father’s barn. I now use a 1/2 HP single spindle polishing motor that is taller than the typical polishing motor because I polish larger pieces and need access under the motor. I have built a tapered area around the spindle out of 1/4" plywood that directs dirty air to the blower inlet. My blower is 900 cfm because that is what was on sale at the time that I bought it. It could be smaller. I have discussed my radon abatement system. It is sealed and is technically totally separate from the open space of my shop and cellar. There were many cracks in the cellar floor compliments of an inattentive mason 25 years ago when we built our house. I spent a lot of money sealing the cracks to insure that the radon system did not pull air from the cellar through the cracks. I also have a typical stove vent over my soldering bench with a 4" metal duct exhausting directly to the outside. Finally, I have a 4" inline powered vent that is connected to a hood over my multipurpose bench where I do casting, resin work and other operations that might produce gases or dust that I would rather not have in my shop. It is on the small side (maybe 200 cfm) and I am looking to increase its size. A consideration with all of this ventilation is that I am pulling heated air out of the cellar and exhausting it to the outside. This is a waste of money, but I feel better knowing that dirt and gases that I generate when I make jewelry don’t hang around for very long. Finally, I have a cyclone filter that is connected through a 3" duct to a hole in my grinding/sanding bench top. The cyclone is powered by a typical shop vacuum and allows me to collect the grinding/sanding dirt to be sent to the refinery. This goes a long way to keep this area clean. All of my shop design is again based on trial and error and what little science I may know. There are places online to research the state of the art and I have spent some time looking at them over the years to get ideas. The cyclone in particular, while not new technology, Is fairly new to home based jewelry shops. I think that Rio and others now sell cyclones as a part of the very expensive dust removal systems that they sell. You can take a look at Oneida Air Systems for ideas about how to use cyclones in a smaller shop. They are at: https://www.oneida-air.com. My goal is to make jewelry and pursue my creativity. I have enjoyed designing and building my shop, but it is towards my goal of making jewelry that it is directed. Each element in my shop has a purpose and it is designed to allow me to stay focused on making jewelry in a safe, well lighted and efficient operation. Thanks…Rob
WOW! thanks for the great details about your home system. Sounds like it’s set up for a commercial workshop but scaled down…you’ve got the perfect set up for a home studio…everything is designed for it’s specific purpose, nothing, even the dust is wasted… congratulations on having designed and built what fits your safety and ventilation needs as well as not wasting anything… 900 cfm is also great, overkill, but you got it on sale…and better overkill than underkill… again congrants and thank you very much…
Dust removal is always an issue. I remember early on being aware of the jewelry works and watching Dad polishing but not with any particular venting or dust removal system. He had worked in the heating business for a number of years and understood air volumes and the movement of air through ducted systems. When I became aware of the dust collection issues he developed a polisher with a kitchen type hood and with a squirrel cag exhaust fan inside a kitchen cabinet. The fan drawing air through a series of furnace filters. As the filters filled up the cloud of lint returned. He kept the polisher on the porch in the winter and in the barn during the warmer months.
My polishing ducts and vents are very similar to Rob’s. I have a 3/8 inch screen inside the bell or funnel of 4" air duct and a large Harbor Freight dust collector that draws air through the system. The 3/8" screen isn’t to catch lint, It’s there to catch bracelets that I occasionally drop. When you have fired a bracelet through the blades of a squirrel cage fan you appreciate that 4" disc of 3/8" mesh.
My shop window has a removable exhausting fan that pulls both soldering fumes and airborne polishing particles. I know this system works fairly well because I don’t hear my wife complaining anymore about the fine coating of dust that somehow found its way to the kitchen.
Don
Thank all of you so much for this discussion. I’ve been using small air filtration systems next to my soldering area and my polishing area. I knew they were insufficient
My asthma doc gave me a stern lecture on my last visit. Uh oh…
Also, I share my studio space with my husband’s 2 vintage and lovingly restored Triumph motorcycles and a recently restored 1967 El Camino., plus our two Can Am Spyders. I think he is starting to notice the dust.
I knew I was in trouble when I started moving the black El Camino out when I was grinding and polishing. Things got worse when I moved from small scale jewelry to large copper and bronze vessels and sculptures. More dust, weird patina recipes.
I’m sharing this great discussion with my husband and it looks like an extensive planning session on venting is in store.
I’ll likely have some questions