Difference between wet/dry Vacuum and RecordPower style dust extractor of equivalent wattage?

[D_Evans]

Hey - so I am just looking at potential options for a workshop extraction system.

You can get pretty good deals on second hand or graded vacuums like the Hyundai HYVI10030 - I am aware this will likely be fine for most tools in a home workshop, but may struggle with big chips off of something like a thicknesser.

So part of me is thinking of something more akin to a RecordPower - but I am trying to work out exactly why it's airflow is so much higher at equivalent wattage - is it purely down to orifice size or would the motors for something like this actually actually be designed differently to maximise pressure over airflow? ... the three motor RP unit specs it's airflow at over 3x the Hyundai vac.

The Hyundai lists its pressure as 2.7M3/MIN (45.5 L/s) and the RP as 162L/s.

so to expand from this - if you ditched the small vacuum hose and attached the head unit of the Hyundai to a barrel with a much larger hose - would you dramatically increase the airflow?

Also a quick p.s. - does anyone know the dba of the RP units?

 

[mr rusty]

Vacuum and Flow need to be considered together. You get maximum vacuum with zero flow (e.g. when you have your hand over the pipe end), and maximum flow with zero vacuum. Picking stuff up requires suitable air velocity, which is why e.g. a garden vac will pick up leaves but not gravel - lot's of flow, big pipe, not much velocity. This is also why there is no substitute for power - a vacuum cleaner/extractor driven by a 2kW motor is always going to have twice as much "power" than a one driven by a 1kW motor no matter what the figures say* - just comparing max vacuum and max flow in isolation tells you very little.

And to answer the question - yes the turbines will be designed differently for either low flow, high vacuum, or high flow, low vacuum

*not quite true, because the turbine itself limits the power draw, so connecting say a 3kW motor to a small turbine designed for a 1kW motor won't give you 3 x the power because the power draw will be limited by the turbine design itself.

 

[D_Evans]

Thanks, I think thats roughly what I thought. If I can get the Hyundai for a low enough price it will probably make a good starter extractor in any case. Will be interesting to see how much flow it can achieve with a larger orifice.