3HP Dual-Bag vs 2HP Single-Bag + Cyclone - System Choice

Got some great advice on placement, now working out which model.

It seems that 3HP single bag systems are not common.
Just a weekend woodworker, not particularly concerned with frequency of emptying. Mainly just looking for effectiveness and whether the addition of a cyclone is worth the suction loss.

Will the most effective system for me be a 3HP, dual-bag system or a 2HP single-bag + cyclone?
I would rather not have the footprint of the dual bag + cyclone. Interested to hear whether this is necessary despite the footprint and which of the 2 other options would suit me better.

Shop will include a tablesaw, jointer, planer, bandsaw, belt grinder mostly. 8m x 6m.

Example:
Option 1: W329 - DC-7 Dust Collector | Hare & Forbes Machineryhouse

Option 2: W394 - DC-3 Dust Collector | Hare & Forbes Machineryhouse and W316 - CDS-2/3 Cyclone Dust Separator | Hare & Forbes Machineryhouse

a bit of reading here in the dust extraction forum will clearly show for fine dust collection, CFM is king. Everyone will suggest you go the DC-7 and expand it to 6" inlets and expand machine ports to 6" as well.

Thanks for that. Yes that seems a good summary.

Thinking the DC-7 with 1-micron pleated filters is the way to go, to get that 3HP. Think I can fit it

More air = more better.
2hp isn't really enough to run a cyclone anyway, too much flow loss.

Just a heads up that the impellers on the DC7 and DC3 are the same size and rotate at the same RPM so nominally pull the same amount of air.
Just the 3 V 2 HP doesn't really make a difference to the flow although under load (full flow) the 3HP will be able to work harder and can handle higher currents and so won't slip as much but this is not much of an issue.

The reason the 3HP is used on the bigger machine and why it has a better flow is due to the two usually bigger filter bags. These significantly reduce the back pressure so more air can flow and this requires a bigger motor. If a 2HP is used on a twin 2 bag machine it may draw too much current and overheat and die.

If you add a cyclone to either a DC3 or 7 the cyclone will dominate the back pressure and the two bag factor won't be as significant.

So is the W316 any value in a system? I used to have a home made Thein baffle in line that I retired to free up space in the workshop a while ago. I noticed the increase in flow taking it out of the system, but conversely the ease of emptying bags side of the scale took a big hit and the dusty impeller has also take a few hits as well since taking out the preseparator. I'm about to move houses and rethinking dust collection. Do you think a W316 would loose more or less airflow than a Thein Baffle?

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Originally Posted by Fuzzie

... Do you think a W316 would loose more or less airflow than a Thein Baffle?

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The cyclone will cause less flow loss than a cyclone. A Super Dust Deputy has about one third the pressure drop of a tophat style (side entry) Thein .5 m diameter with 125mm inlet. The W316 probably has slightly less pressure loss than the SDD. You didn't describe your implementation but Thein baffle pressure loss will vary inversely with the fourth power of scale factor (just like everything else). A top entry has more loss due to the sharp ninety at the entrance.

How much the pressure loss affects flow depends upon the rest of your system, i.e., where you are operating on the pressure vs flow curve.

The DC-7 with a W316 would likely have about the same airflow performance as a DC-3 by itself.

Here's a link with a pic of my Thein implementation. It would appear then that the W316 could be a substantial upgrade at a commensurate cost.

Quote:

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Originally Posted by dmorse

The cyclone will cause less flow loss than a cyclone.

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Edit required I think. :)

Quote:

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Originally Posted by Fuzzie

Here's a link with a pic of my Thein implementation. It would appear then that the W316 could be a substantial upgrade at a commensurate cost.

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It certainly does appear that way. Just be sure you use something bigger than 100 mm hose between the cyclone and fan (and everywhere else).

If you've been following this thread then you know I'm not a big fan of leaving a redundant centrifugal separator in the system. A cyclone should be used as a part of a system, not just an add-on.

Attachment 477649

Hey, one of those is mine! :)