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I am looking to upgrade my old 2hp dust collector and I am mostly using it for my new sawstop 3 hp professional saw and the overarm 4” dust collector. I know each require 400 cfm minimum. What do I gain by going for 2hp and 1200 cfm vs 1 1.2hp and 11oo cfm and save $100? my shop is mobile in my garage and I have not piped any dust collector ducting in it and really dont plan to as I like the mobility the mobile dust collector gives me. I am curious if it’s worth it to get the 2hp and spend the extra moolah.
thanks in advance!
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It's not just HP, the size of the impeller has a lot to do with the air flow gain. I'm guessing the 2 HP has a 12" impeller and the 1.5 has an 11". For me I'd want the larger impeller. More air flow equals better DC function.
I started with absolutely nothing. Now, thanks to years of hard work, careful planning, and perseverance, I find I still have most of it left.
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I doubt you will get 800 actual cfm through two 4" ducts with 1.5 hp. The cfm ratings you referenced are for zero static pressure drop. Look at the fan curves and you will see that they both drop off, quickly, as static pressure increases. A 4" duct has a static pressure loss of 8.5"/100 ft of duct. That's just for the 4" duct. If you have a trunk line that will have additional losses. If you use flex hose the SP is about 3X higher. Say you only had 20 total ft of 4" duct from the inlet of your cyclone to the saw, including both 4" connections. That would be 0.2 x 8.5" = 1.7" SP. Look up 1.7" on the fan curves. Do you have at least 800 CFM?
Also, keep in mind, those fan curves are with a clean filter. When they start to clog up the flow goes down the same way it does by increasing SP on the inlet side.
John
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I have a Delta dust collector that is 1 1/2 HP if wired 110 and it is a 2 horse if wired 220. Mine was wired 110 and I left it that way. The outlet is is controlled by a switch. Actually it is controlled by two 3 way switch's. There are two 4 inch connections at the collector and I ran 4 inch hoses to both my 8 inch jointer and my 3HP saw. My old saw was a General 350 and now my saw is a Saw Stop.
I can turn on the dust collector at either jointer or saw and shut it off at either machine. I do not have blast gates on either and I have been operating it this way for over 25 years If it didn't work well I would have changed it.
Usually a 2 HP machine is wired 220 so it could be a determining factor on what you buy. The 1 1/2 will work just fine for you.
Tom
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(11-05-2023, 10:33 AM)tablesawtom Wrote: I have a Delta dust collector that is 1 1/2 HP if wired 110 and it is a 2 horse if wired 220. Mine was wired 110 and I left it that way. The outlet is is controlled by a switch. Actually it is controlled by two 3 way switch's. There are two 4 inch connections at the collector and I ran 4 inch hoses to both my 8 inch jointer and my 3HP saw. My old saw was a General 350 and now my saw is a Saw Stop.
I can turn on the dust collector at either jointer or saw and shut it off at either machine. I do not have blast gates on either and I have been operating it this way for over 25 years If it didn't work well I would have changed it.
Usually a 2 HP machine is wired 220 so it could be a determining factor on what you buy. The 1 1/2 will work just fine for you.
Tom
Thanks tom. I am only running about 10’ of hose to each as I keep the dust collector close to my sawstop and then also my dewalt planer. the 1 1/2 hp is wired for 110v and i have that outlet and a 220v too so I am not sure if I will change it to 220v.
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(11-05-2023, 10:23 AM)jteneyck Wrote: I doubt you will get 800 actual cfm through two 4" ducts with 1.5 hp. The cfm ratings you referenced are for zero static pressure drop. Look at the fan curves and you will see that they both drop off, quickly, as static pressure increases. A 4" duct has a static pressure loss of 8.5"/100 ft of duct. That's just for the 4" duct. If you have a trunk line that will have additional losses. If you use flex hose the SP is about 3X higher. Say you only had 20 total ft of 4" duct from the inlet of your cyclone to the saw, including both 4" connections. That would be 0.2 x 8.5" = 1.7" SP. Look up 1.7" on the fan curves. Do you have at least 800 CFM?
Also, keep in mind, those fan curves are with a clean filter. When they start to clog up the flow goes down the same way it does by increasing SP on the inlet side.
John
first off great name John! lol. Thanks for the technical input. appreciate it. yes both are coming in at 1100 cfm for 1 1/2 hp and 2hp is 1200 cfm and hose length is about 10’ for each attachment.
