I am putting together a new shop. It's about 600 sq ft in size (20x30ish) with 12 foot ceilings. I have a modest set of power tools but will be getting a new table saw - probably a Griz G1023 3HP or very similar. Only one machine active at a time.
Your shop dimensions are similar to mine, except I have a 10' ceiling and only one (1) six (1) foot overhead door.
I'm pretty serious about dust collection but there are just too many moving parts in the design process. A while ago I picked up a grizzly G1028Z DC for a song (<$100). Specs: 1.5 HP, 5 micron bag filter, 1300 CFM, 9" static pressure. It's probably a bit under powered for the size of shop and the filter is a dog compared to the current level of technology. So, I may eventually replace it but I would like to use it for a while to get a deeper understanding of DC techniques. Fortunately, my shop has 3 garage doors I can open so fresh air is readily available and my area has a pretty good year round climate.
Your Grizzly DC should work find for the tools you have listed. A large CFM does not necessarily maximize your dust collection!!! You are going to have to do more than just have a large CFM DC!!!
I am thinking of getting some sort of cyclone separator - Super Dust Deputy seems like a decent choice - to keep the big stuff out of the DC.
Build your own Thien TOP Hat. It is a great project and has a large improvement on your dust collection. (See above posts for a link.)
So, ducting - I'm thinking a main run using 5" or 6" PVC across the ceiling with 4" flex drops to the tools. Probably 3 drops. The main run will probably be around 20' with a Super Dust Deputy right before the DC input. 5" PVC seems to be pretty rare so maybe I'm stuck with 6".
See the Sandor Nagyszalanczy's book titled "Woodshop Dust Control". There are also a couple of web sites that help you design your system. Here is one of them:
- Is the Dust Deputy going to choke my DC?
All preseparators require some CFM and static pressure. Check out some of the Grizzly systems with cyclones and without. Notice that for the same HP and CFM, the static pressure is much lower on the cyclone units.
Is 1300 cfm too little for a 6" rigid pipe?
NO. It depends on the complete design of the system.
The Super Dust Deputy has a 5" input port - Would putting a 6 to 5 reducer at the cyclone negate the benefit of a 6" run?
Yes, you will loose some static pressure, the question is: Will you loose enough to impact your dust collection? The answer is probably not.
I've read that rigid pipe is much more efficient than flex pipe. Would 4" rigid be as good as 5" or 6" flex? There doesn't seem to be a lot hard of data on this topic.
Check out page 141 in Sandor's book.
Numbers are inches of Static Pressure loss per foot of pipe at 3,500 feet per minute:
4 inch diameter of rigid is .055
6 inch diameter of flexible is .105
The difference is almost twice!
Since I started this thread, with what I thought was a simple question: "Will I get better dust collection performance by running a 5" or 6" flexible hose from the DC to the tools rather than my 4" flexible hose?"
I have found that the answer was a very simple "YES". But, there were a lot more questions that I needed to answer to improve my shop dust collection.
I found a lot of the answers in references such as the Bill Perenz web site or in Sandor Nagyszalanczy's book "Woodshop Dust Control". There are other good references that you can find on this forum or by Googling "woodshop dust control".
I have about the same size of floor space as you. I only operate one (1) piece of equipment at a time, but I use one (1) to four (4) pieces of equipment at a time, that all need dust collection. I only have one (1) six (6) foot wide door to open.
Here are some of my findings:
1. With a small shop like mine, I really had to ask the question: Do I really want to have a dust control system that is fastened to the workshop? I decided the answer is NO. My shop is about 550 sqft with a 12" jointer, 20" planer, 10" table saw, 18" bandsaw, 10" Compound Sliding Miter Saw (CSMS), 17" drill press, router table, work benches, clamp rack, etc.
I only have two (2) full work stations in the middle of the shop. I rotate the large tools into these stations when I am using them. When they are not being used, they are stored along the walls. This allows me the ability to:
A. prepare rough lumber using my jointer and surface planer.
B. cut long strips using the table saw and CSMS
C. prepare curved pieces using the table saw and band saw,
D. etc. you get the idea...
The two work stations need dust collection, but can easily be serviced using a dust collector on a cart with a flexible hose.
2. Dust collection is very important at the source of the dust. This can't be stressed enough. When the dust is collected at the source it is much more efficient to handle and a smaller CFM is required. My table saw is a great example of this. I have a hybrid cabinet style table saw. It has an "enclosed" cabinet with a 4" dust port at the bottom. Unfortunately, it was NOT a sealed cabinet. The dust collection only worked for dust that dropped to the bottom of the cabinet. My 1100 CFM dust collector (DC) should be able to handle the table saw dust collection since it is only supposed to need 350 CFM. In order to improved the dust collection, I needed to seal the cabinet and only allow air to be sucked in at the source. All of my zero clearance inserts have 6 to 8 one (1) inch diameter holes drilled in them to allow for the saw dust at the blade to be sucked into the DC. I also needed to increase the diameter of the flexible pipe and reduce the length to improve the dust collection. I am also in the process of adding an overhead blade guard dust collector.
3. Dust collection filters need to be kept clean. The best way I found is to add a pre-separator. I am on my third generation of pre-separators. The first was just a 35 gallon container using the Rockler Dust Right® 4'' Dust Separator Components. It worked OK, but I wanted better dust collection, so I switched to the next generation, which was the Thien in the barrel separator. It was an improvement, but I wanted more, so I created a Top Hat Pre-separator which is working fantastic. Very little "fine" dust particles make it past the pre-separator. I have emptied my pre-separator barrel (44+ gallons) over 10 times since I started using the Top Hat. The "fine" dust particle bag had about a quart of fines for all the 440+ gallons in the preseparator barrel and the filter had hardly any fines in it.
4. Switch from 4" flexible hose diameter to 6". When you compare the maximum CFM capability for a 6" diameter flexible hose vs a 4" one, the CFM is over double! I created the Top Hat with 6" input/output ports. I switched my jointer and planer to 5" flexible hose and saw a huge improvement. My jointer no longer clogs and my planer has very little dust on the exiting boards. I am in the process of converting the rest of my dust generating tools to take advantage of the 6" Top Hat port.
5. The shorter the length of flexible hose, the better!
6. Keep experimenting with a different dust collection options. Find out what works for your shop.
7. Your requirements will be different from everyone else's. With three (3) full size garage doors to open, you have a big advantage over my work shop. Make sure that you evaluate your options, before you spend your money on a system that you may regret having.