Re-thinking dust collection... a 'new' way to do it?

[Stacy E. Apelt - Bladesmith]

Venting outside is by far the best choice.
My new setup brings in outside air (six-inch powered duct blower) and exhausts the fine grinder dust outside into a catch barrel. There is surprisingly little in the outside barrel, as the heavy stuff gets trapped in the spark collector/cyclone. Because I live in a fairly moderate temperature climate, I don't need to worry about the air temp from outside.

I use a dedicated grinder for wood which has a separate cyclone collector, and then gets vented into the same outside barrel.

A HEPA hanging filter to filter the free air in the shop is also a wise choice. Mine comes on when I turn the lights on in the grinding room.

An important thing to remember is that no filter will do any good if you don't regularly clean it out and change the filters. A regimented schedule of PM written on the shop calendar is a good idea. Dump the buckets, vacuum the fitters, put in new consumable filters, etc. once a month or on whatever schedule your shop needs.

One thing that needs to be considered for any air system that exhausts the air outside is AIR EXCHANGE. Whether it be a window fan, a dust collector, or a whole shop vent system, there needs to be an equal or greater amount of incoming air or you will have negative air pressure. Depending on the amount or exhausted airflow, it can be an open door or window, or a forced air vent bringing in fresh air.

 

[REK Knives]

Venting outside is by far the best choice.
My new setup brings in outside air (six-inch powered duct blower) and exhausts the fine grinder dust outside into a catch barrel. There is surprisingly little in the outside barrel, as the heavy stuff gets trapped in the spark collector/cyclone. Because I live in a fairly moderate temperature climate, I don't need to worry about the air temp from outside.

I use a dedicated grinder for wood which has a separate cyclone collector, and then gets vented into the same outside barrel.

A HEPA hanging filter to filter the free air in the shop is also a wise choice. Mine comes on when I turn the lights on in the grinding room.

An important thing to remember is that no filter will do any good if you don't regularly clean it out and change the filters. A regimented schedule of PM written on the shop calendar is a good idea. Dump the buckets, vacuum the fitters, put in new consumable filters, etc. once a month or on whatever schedule your shop needs.

One thing that needs to be considered for any air system that exhausts the air outside is AIR EXCHANGE. Whether it be a window fan, a dust collector, or a whole shop vent system, there needs to be an equal or greater amount of incoming air or you will have negative air pressure. Depending on the amount or exhausted airflow, it can be an open door or window, or a forced air vent bringing in fresh air.

Thanks Stacy, good points.

So based upon your last paragraph, would I need a blower on the supply side as well as the exhaust side? I was thinking of only doing one on the exhaust side and just matching the diameters of the hose...

Also, does anyone have any recommendations of what exterior wall vent I can hook my duct work up to? I was thinking something like a dryer vent would work for exhaust (unless I have it go into a bucket, then I'll need some sort of pass through - recommendations welcome).

 

[Stacy E. Apelt - Bladesmith]

The air IN vent can be a plain vent opening or an open door or window. as long as it is around 150% - 200% the size of the air exit vent. This varies somewhat depending on the CFM of the exhaust blower.
As a rule of thumb, a 4" exhaust needs a 6" to 8" fresh air vent opening (unless it has a blower).
By using a simple and cheap duct blower on the IN duct, it can be the same size as the OUT duct. A 6" inline duct blower runs around $30 on Amazon.
Look on Amazon for duct vents. The ones with a screen are best because they keep bugs and birds out. They come from 4" to 12". I like used square ones.

I mounted the vent through the wall and snapped the blower on it from the inside. It is plugged into a socket wired to the vacuum switch.

 

[REK Knives]

The air IN vent can be a plain vent opening or an open door or window. as long as it is around 150% - 200% the size of the air exit vent. This varies somewhat depending on the CFM of the exhaust blower.
As a rule of thumb, a 4" exhaust needs a 6" to 8" fresh air vent opening (unless it has a blower).
By using a simple and cheap duct blower on the IN duct, it can be the same size as the OUT duct. A 6" inline duct blower runs around $30 on Amazon.
Look on Amazon for duct vents. The ones with a screen are best because they keep bugs and birds out. They come from 4" to 12". I like used square ones.

I mounted the vent through the wall and snapped the blower on it from the inside. It is plugged into a socket wired to the vacuum switch.

those are some great thoughts and pointers Stacy, thank you!

I'm initially going to try this intake/exhaust set up for a new 50w fiber laser I just ordered... if it works well there I'll set it up for the rest of my shop.

 

[Stacy E. Apelt - Bladesmith]

I plan on doing the somewhat the same with my mew 50W fiber laser. I will run a 2.5" hose to the vacuum port on the dust collector ducting and the vapor will vent outside.

Adding a 2.5" port on your ductwork, with a cap on it when not in use, allows a vacuum hose to be quickly attached to vacuum up the benches, floors, and other equipment in the grinding area,

 

[REK Knives]

I plan on doing the somewhat the same with my mew 50W fiber laser. I will run a 2.5" hose to the vacuum port on the dust collector ducting and the vapor will vent outside.

Adding a 2.5" port on your ductwork, with a cap on it when not in use, allows a vacuum hose to be quickly attached to vacuum up the benches, floors, and other equipment in the grinding area,

That would be awesome if I had a dust system/duct work already set up but unfortunately I don't haha

 

[Stacy E. Apelt - Bladesmith]

When you build it add a spare port or use an adapter to plug into the grinder port. Places like Woodcraft and Rockler sell adapters for almost any size ductwork.

A spare port is very useful as it allows mobile tools to be rolled over ti the port and dust collection hooked up easily.

 

[Rick Marchand]

I try to minimize air movement as much as I can. My shop has in-floor heating and my water heater is electric. The only ductwork I have is for the dust system. A semi-closed loop still creates a small negative pressure... I definitely do not want a furnace/water heater that has a pilot light or creates CO exhaust, for fear that the negative pressure will pull harmful gases into the room.

I also run an exhaust hose off of my shop vac, that vents outside. Nothing worse that a shop vac kicking up more dust than it consumes. I use that for localized dust removal, like when I'm sanding/dremelling or rasping a knife handle in a vise.

I rarely us a broom to clean as well... might as well use a leaf blower! I actually new a guy who used a leaf blower to "clean out" his shop every morning... every morning before he started his workday... and he did not use a respirator... just let that sink in.

 

[REK Knives]

Got my test set up done with the laser... Installed 2 inline fans (~200cfm ea), 1 on supply 1 on the exhaust side. Seems to work perfect but I need some baby power or something haha. You can only feel the air stream right between the two ports (supply at front of the laser, exhaust at the back).

Since these fans don't have an on/off switch I ordered 2 smart plugs that I can control from my phone



For full blown dust collection I imagine it will get interesting!

 

[Stacy E. Apelt - Bladesmith]

Some suggestions on your laser setup:
1) The Incoming air should be directed as close to the laser beam as possible in many cases. This is called Air Assist. Normally it has a small nozzle on a flexible arm. If you don't want/need air assist (which isn't always best) your setup is OK.
2) Make a 4" deep box the laser bed can sit on. Just four 2X4's and a plywood bottom. Put a port on it for your exhaust hose. An air conditioning floor vent box is perfect to make the port from. You can also just put the port through the bottom of the box and cut a hole through the bench, table, or cart. That puts the big exhaust hose out of the way.
Putting the exhaust draw under the laser bed will make the downdraft pull the smoke and fumes straight down through the table holes and away from the beam and lens.

 

[REK Knives]

Some suggestions on your laser setup:
1) The Incoming air should be directed as close to the laser beam as possible in many cases. This is called Air Assist. Normally it has a small nozzle on a flexible arm. If you don't want/need air assist (which isn't always best) your setup is OK.
2) Make a 4" deep box the laser bed can sit on. Just four 2X4's and a plywood bottom. Put a port on it for your exhaust hose. An air conditioning floor vent box is perfect to make the port from. You can also just put the port through the bottom of the box and cut a hole through the bench, table, or cart. That puts the big exhaust hose out of the way.
Putting the exhaust draw under the laser bed will make the downdraft pull the smoke and fumes straight down through the table holes and away from the beam and lens.

I'm gonna start a new thread for this Stacy, this is good info but I want to get some clarification if possible.

 

[Brad Martin]

Venting outside is by far the best choice.
My new setup brings in outside air (six-inch powered duct blower) and exhausts the fine grinder dust outside into a catch barrel. There is surprisingly little in the outside barrel, as the heavy stuff gets trapped in the spark collector/cyclone. Because I live in a fairly moderate temperature climate, I don't need to worry about the air temp from outside.

I use a dedicated grinder for wood which has a separate cyclone collector, and then gets vented into the same outside barrel.

A HEPA hanging filter to filter the free air in the shop is also a wise choice. Mine comes on when I turn the lights on in the grinding room.

An important thing to remember is that no filter will do any good if you don't regularly clean it out and change the filters. A regimented schedule of PM written on the shop calendar is a good idea. Dump the buckets, vacuum the fitters, put in new consumable filters, etc. once a month or on whatever schedule your shop needs.

One thing that needs to be considered for any air system that exhausts the air outside is AIR EXCHANGE. Whether it be a window fan, a dust collector, or a whole shop vent system, there needs to be an equal or greater amount of incoming air or you will have negative air pressure. Depending on the amount or exhausted airflow, it can be an open door or window, or a forced air vent bringing in fresh air.

Once I move I will lose the great outdoors self venting system.

New place the great outdoors is communal property and part of the driveway, the roller door takes up much of the width.

Extracted air must be released to a safe place and not create another hazard. If discharged outside the building. I would think that even a flush vent over head high would bring complaints no matter how clean the air is.

I get the feeling there will be a wood dust collection system, metal system including forge, welders and grinder and general whole of building 5 micron filter.

Laws are nothing compared to getting dust into her upstairs domain...

 

[Stacy E. Apelt - Bladesmith]

Build a small shed outside the wall and put the catch container there. If you are really worried, put a furnace filter on the louver vents on the shed.

 

[Brad Martin]

2nd from left is where I will be. Currently it is used as parking for 4 cars for the office staff.

 

[Stacy E. Apelt - Bladesmith]

For the wood grinder, I would get a cyclone and drum type dust vac system with a sound reducing muffler. Dust Deputy has several that will do the job. You can put a filter bag over the muffler to catch fine dust that gets past the cyclone. Wash the bag and blow/vacuum out the muffler occasionally.
For the metal grinder, get a spark bong and a metal Dust Deputy with a metal catch drum.
Put both inside.

 

[Dennis Towns]

I don't know if this thread is too old but are there any YOUTUBE searches that shows outside exhaust set ups? I am cramped into a 12 x 16 2 story shed after moving from my 70' shop down south. I put 2 small louvered fans but not enough. I leave the door open for in air.Need to know how many cfm and size a good exhaust fan is? Thanks

 

[Dennis Towns]

Never mind , I found where Mr. Stacy already gave me some advice over a year ago. Do I duct off of the rear of the fan and convert to say a 6"-8" round duct and just hang it under the bench near each grinder?