Dust collection system sizing

[stanmillnc]

Setting up my new 26' x 38' wood shop and need a larger dust collection system. Just purchased a 43" planer / sander Timesaver machine, which will be the biggest chip producer. Also all my small standard small shop equipment will be ducted to this system: table saw, miter saw, jointer, downdraft table, etc. Considering adding my sawmill as well, but it's not located in the shop, so I'd have to run a separate line outside for it. I'm currently a one man operation and haven't run multiple machines simultaneously, but want to plan for the future as that may change.

It seems like the rotary air lock system with an outside collection system dumping into a bin is ultimately the best way to go. Space will be at a premium in the shop and seems like keeping a loud collection system outside makes sense. Shop is not currently air conditioned / heated, but will be in the future, so I may be concerned later on about the cost of dumping conditioned air outside.

Just looking for input on what HP and cfm size system I might need. I'm thinking 5 to 7.5HP? Would 10 HP be overkill and cost too much in electricity to run if I'm just running one machine at a time? I am getting three-phase power run now, so I could run a 10HP unit if I happen to find a good deal on the used market. And what size main trunk line should I run? Seems like 26ga is the minimum duct thickness - but then I've seen others use as thick as 20ga - is that overkill? Watched Yellowhammer's Youtube videos and that is one sweet setup, but I'm small time compared to him....

Any input appreciated!

[K-Guy]

Many of the dust collection system manufacturers offer free online software for this.

[YellowHammer]

Thanks watching the video. 

Rotary air locks are incredible.  No substitute.

I wouldn't go under 7 hp for what you are describing.  At some point you may be running two machines at once and my old 5 hp dust collector couldn't do it.  So if you look up the CFM requirement of your two highest machines, probably the sawmill and the planer, then size for them running at the same time and see what it comes out to.

Pipe gauge is catch 22.  The better the dust collector the thicker the pipe needs to be because the higher the suction.  

[stanmillnc]

Thanks @YellowHammer ! I'll be budgeting for the 7.5HP unit then; like the Oneida model you posted in another dust collection thread I found here. Another question - it seems you have your unit outside exposed to the elements? Did you put a small roof over it to keep the motor from getting wet? And is the 20ga pipe you used the minimum gauge recommended for your unit, or did you go that heavy just in case you wanted to upgrade to a more powerful system later?

[Don P]

I'd check that with the manufacturer, that timesaver when abrasive planing flat out throws the dust, explosively fine and can fill an inadequately suctioned shop in minutes. If the fan is handling the dust and pushing at the cyclone you don't need an airlock now. Just drop the dust out the bottom into a container or truck and exhaust out the top. In the future off the cyclone exhaust you can duct into a baghouse, install a rotary airlock on the cyclone and return the filtered air back inside.

[YellowHammer]

The motors are totally enclosed fan cooled, so I don't haven cover over them, although it wouldn't hurt. The main reason is to prevent snow from building up in the motor fan housing and packing.  I don't have that problem here in Alabama.

Both this one and my previous ones are mounted outside, because I have seen too many people with the "Lumber Cough" even with some of the best dust collectors, HEPA filters, etc, mounted inside building.  All it takes is one little leak, and they do leak, and there is fine dust going in your lungs.  When dust collectors are outside, they solve that problem entirely.

Also, these things aren't quiet, so putting them outside solve that problem, also.  

Yes, they move a lot of air, so it can get cold, but it's not that bad, and most times we leave the door open anyway, for forklifts and such. 

I've used two styles of exterior cyclones, one with no airlock, one with an airlock, and although they both work, the airlock has a lot less spillage and much more accurately drops chips and dust straight down into a hopper.  Its very neat and clean, and has a very low footprint and almost zero effort to maintain.  No hoses to unhook, no clamps, no nothing.  Just pick up the bin with a forklift and dump it.

I bought the heavier gauge pipe because as the dust collection system increases efficiency and velocity, light weight pipe just won't last.  It will start to pinhole over time, and I was having to start replacing my El Cheapo pipe and wasn't going to deal with that again.  This latest dust collector of mine is a one and done system, and so far it has been perfect.  We use it 8 to 10 hours a day, pretty much every day, and it works as good as it did when we installed it.  I don't have to take a dust bath changing bags, don't have to shut down to change things, it just works and runs.