HVLP dust extractor hose questions

[Julesbarn]

Hello all
I have a new 2hp DE blower which I fitted today, venting outside,so no resistance from filters or cyclone..it sucks like crazy! I plan to extend my workshop in the spring,from 25m2 to 50m2,and fit a proper ducting system with blast gates and use 110 soil pipe..or maybe 100mm if I can find it cheaper. I'd like to know what is the maximum length of pipe run for a 2hp blower/impeller. I'm guessing you're going to say. ."all depends on the number of bends,how many machines will it serve etc". I just dont want to over-do it and expect too much from the system.

If it helps..There will rarely be more than one machine running at a time, and being a small WS, things will be pretty close to each other...small dewalt thicknesser, my NEW table saw (an xcalibur HW110 coming in a few days after an excruciating wait..very exciting!),..bandsaw and lathe.

Another query is..can I reduce the pipe diameter down to,say,50mm or less off the 100mm duct to use with hand held Sanders etc, and a general "hoovering" attachment..or would that create too much resistance for a hvlp system .? It would be nice not to also have to use a shopvac type thing for Sanders n hoovering.

I eagerly await your advice so I can plan the duct arrangement (on paper) and dream of a less cramped space!

Many thanks

Jules

 

[sunnybob]

The smaller the pipe diameter, the greater the resistance and the less flow.
keep it at 100 mm for as long as possible to every machine.
Avoid all flexible hoses whenever possible. The ridges cause air friction and severely reduce air flow.
So a 50 mm flexible hose is going to rob you of more than 50% of your air flow compared to a rigid 100 mm pipe.
Use 100 mm blast gates as close as you can get to each machine.

 

[Julesbarn]

Ok thanks. So best to use a normal shop vac for Sanders etc where smaller diam hose is needed.

 

[sunnybob]

I'm not saying you CANT use small hoses, just that you get reduced suction.

keep the pipe run as big as possible for as far as possible.
keep the smaller hose length as small as possible. you'll still get enough suction to cope with most sanders.
I have a bobbin sander and a lunchbox planer that came with 50 mm hose connections. I modified them both to 62 mm, and use a 62 mm hose to connect them to the main ducting, and they work fine.

 

[PAC1]

The smaller the pipe diameter, the greater the resistance and the less flow.
keep it at 100 mm for as long as possible to every machine.
Avoid all flexible hoses whenever possible. The ridges cause air friction and severely reduce air flow.
So a 50 mm flexible hose is going to rob you of more than 50% of your air flow compared to a rigid 100 mm pipe.
Use 100 mm blast gates as close as you can get to each machine.

The reduction from 100mm to 50mm is not a half but to a quarter. That is before you factor in the ribs or the fact that the air does not speed up to compensate for the small pipe.
For a 2hp system 100mm duct is likely restricting the efficiency. It is well worth looking at the main spine duct at 125 or 150mm

 

[Myfordman]

I use 110mm soil pipe, 23m approx with 8 drops each with a blast gate - one open at a time and a 3hp 14" blower with no problems if that helps. 90 degree bends to the drops are formed from 2 x45 to reduce resistance.

 

[Julesbarn]

Thanks. .helpful info. My blower actually has a 125 inlet and a plastic splitter giving two 100 inlets. Given what you say, I'll dump the splitter and have main run and drops at 125 ( or even 150 with an adaptor at the blower). Using hand held Sanders surely I'll want a metre or 2 of narrower flexi for moveability. 62 sounds ok for that, and for a general hoover upper! I know this has all been discussed in detail before on this forum and elsewhere..it's just nice to ask afresh, stating my own circumstances and queries.
It nearly drove me nuts researching filters and microns so I decided to give venting outside a go. After some experimenting...yes it robs some heat, needs a generous air intake well away from the outlet, and surprisingly doesnt seem to effect the draw of the wood stove! It also feels good to have a change of air, even if it cools the space down for a while. : ) Many thanks for your help

Jules

 

[PAC1]

HVLP is not going to work with power tools. Sadly you need a shop vac for them

 

[Julesbarn]

Aw PAC,just when I thought I had all the basics covered! Out of interest..why not hvlp for an orbital sander for example?..if I keep the smaller pipe to a minimum length? Come to think of it, that's probably the only (fine dusty)hand held power tool I'd want to use in the workshop that would need direct connected DE.

 

[MattRoberts]

It's in the name

HV = high volume. Power tools = small connectors = low volume. If you try and suck air through a small connector with an HVLP extractor, aside from the huge inefficiency, you'll starve the impeller and you can cause damage to the motor

 

[Julesbarn]

Matt and PAC..ok, I'm getting it now! I guess it's like having a bathroom extractor fan on with the door tightly closed, or drinking milk through a tiny straw (I love a good analogy!)

Cheers

Jules

 

[sunnybob]

An ology! He's got an ology!

 

[Myfordman]

An ology! He's got an ology!

and an anal ology to boot!!

 

[Julesbarn]

Ok ok , I wont use that word again!
At least I didn't have an anal orgy : o

 

[PAC1]

Bill Pentz analogy is it is like playing blow football but you can only suck the ball towards you

 

[sunnybob]

OOOH! Blow AND suck, in the same sentence.
Dont look Ethel!