HF dust collector flow measurements - Router Forums
 65Likes
Reply
 
LinkBack Thread Tools Display Modes
post #1 of 118 (permalink) Old 01-22-2017, 10:39 AM Thread Starter
Registered User
 
furboo's Avatar
 
Join Date: Oct 2015
Country: United States
First Name: Rob
Posts: 544
 
Default HF dust collector flow measurements

I wanted to keep track of modifications to my new HF DC, so I built a very simple manometer this morning. My only mod so far is the Wynn filter. Pictures below.

Initial measurements

As close to the HF inlet as I can measure (see picture staticp.jpg), I get 6" H20, which if my calculations are correct, translates to 975 CFM. Note that I live at 7,200' altitude, so any DC will suffer a lot in performance. I'm also using a 4" pipe, a big no-no according to DC experts, but it makes hooking up to my tools a lot easier.

I then measured at the end of a Rockler 4' long expandable hose. See pic hose.jpg (it's unhooked in the picture) and

Dust Right® 4'' Dia. Expandable Hoses | Rockler Woodworking and Hardware

This drops the performance to 2.5" H20, or about 630 CFM. Ouch. This was with the hose compressed and no bends. So, I guess I gotta change how I bring the DC to my tools.

Anyway, as I modify my DC, I want to keep track of performance changes.

Some details

The manometer itself 1/2" tubing with filled with water, with green food coloring. I step that down to a long section of 3/8" tubing (to reach anywhere in my shop), then to 1/4" tubing. I drilled a 1/4" hole in a 4" hose splice, and that's where I measure static pressure. Again, see staticp.jpg. The markings on the manometer are 1/2" apart. Pretty simple.

My measurements may be a bit off, because I need to seal the attachments. But I doubt that they're off that much.

Converting inches of H20 to CFM requires some assumptions, the biggest being current air density. But that doesn't really matter. The bottom line is you want to maximize inches of H20 (the difference in the water levels), and the manometer lets you measure any changes to the DC system.
Attached Thumbnails
Click image for larger version

Name:	dc.jpg
Views:	438
Size:	66.7 KB
ID:	254786  

Click image for larger version

Name:	manometer.jpg
Views:	440
Size:	82.6 KB
ID:	254794  

Click image for larger version

Name:	staticp.jpg
Views:	345
Size:	73.5 KB
ID:	254802  

Click image for larger version

Name:	hose.jpg
Views:	358
Size:	92.0 KB
ID:	254810  


Rob
furboo is offline  
Sponsored Links
Advertisement
 
post #2 of 118 (permalink) Old 01-22-2017, 10:45 AM Thread Starter
Registered User
 
furboo's Avatar
 
Join Date: Oct 2015
Country: United States
First Name: Rob
Posts: 544
 
Default

I should mention that I got the idea for the simple manometer from


where he explains using it for keep track if the Wynn filter needs cleaning. I'll hook it up that way do once I'm happy with my other DC mods.
Danman1957, Daikusan and bwilling like this.

Rob
furboo is offline  
post #3 of 118 (permalink) Old 01-22-2017, 01:04 PM
Moderation Team
 
Cherryville Chuck's Avatar
 
Join Date: Sep 2010
Country: Canada
First Name: Charles
Posts: 14,965
 
Default

That's a great idea to make one for monitoring the filter's condition Rob. Thanks.

Someone I consider a master woodworker once told me that a master woodworker is not someone who never makes mistakes. He is someone who is able to cover them up so that no one can tell.
Cherryville Chuck is offline  
Sponsored Links
Advertisement
 
post #4 of 118 (permalink) Old 01-22-2017, 02:04 PM
Registered User
 
sunnybob's Avatar
 
Join Date: Apr 2015
Country: Cyprus
First Name: Bob
Posts: 1,819
 
Default

Rob, home made manometers arent all that accurate. OK so long as you only use the one and only compare it to your other measurements, but often not transferable to another set up.
Any large plumbing or gas fitting supplier will sell a proper manometer as used for taking gas pressure readings.
This is just the first link I found
https://www.amazon.com/General-Tools.../dp/B001TOHT78
sunnybob is offline  
post #5 of 118 (permalink) Old 01-22-2017, 02:05 PM
Registered User
 
Join Date: Jan 2015
Country: United States
First Name: Eugene
Posts: 59
 
Default

You might want to make one of these carts but you will have to add a sdd, best thing I did, I have great suction, no loss, I fiddled with my dust collection until I finally bit the cart. I work in a 2 car garage I was going to add ducting but still fiddling with my layout in the shop.
Attached Thumbnails
Click image for larger version

Name:	2017-01-22 14_1485111781986.01.40.jpg
Views:	600
Size:	2.99 MB
ID:	254890  

Herb Stoops, bryansong and furboo like this.
Eugd is offline  
post #6 of 118 (permalink) Old 01-22-2017, 04:41 PM Thread Starter
Registered User
 
furboo's Avatar
 
Join Date: Oct 2015
Country: United States
First Name: Rob
Posts: 544
 
Default

Quote:
Originally Posted by sunnybob View Post
Rob, home made manometers arent all that accurate. OK so long as you only use the one and only compare it to your other measurements, but often not transferable to another set up.
Any large plumbing or gas fitting supplier will sell a proper manometer as used for taking gas pressure readings.
This is just the first link I found
https://www.amazon.com/General-Tools.../dp/B001TOHT78
Bob, I'm not claiming that my measurement of water level or CFM is accurate. I certainly don't want HF to sue me for misrepresenting their DC performance

My motivation is to see the effect of changes in DC setup, and I claim homemade is good enough to do this, at least for changes large enough to have a noticeable effect on dust collection. The fact that I'm doing this at 7,200' altitude will mean my water level and CFM numbers will be far from most others on this forum.

The manometer in your link might add precision to the readout, but will not compensate for the assumptions required to back out CFM from the water height. I suspect these assumptions create bigger errors than from reading the water level. If you really want to increase the accuracy of the reading, save your $27.99, use longer tubing on a tilted table, and a well characterized fluid.
whimsofchaz likes this.

Rob
furboo is offline  
post #7 of 118 (permalink) Old 01-22-2017, 04:48 PM Thread Starter
Registered User
 
furboo's Avatar
 
Join Date: Oct 2015
Country: United States
First Name: Rob
Posts: 544
 
Default

Quote:
Originally Posted by Eugd View Post
You might want to make one of these carts but you will have to add a sdd, best thing I did, I have great suction, no loss, I fiddled with my dust collection until I finally bit the cart. I work in a 2 car garage I was going to add ducting but still fiddling with my layout in the shop.
Nice setup, Eugene. My DC is on rollers, and it looks like I'll keep it that way when I add a chip collector. It looks like you're using smaller bag than stock, and I was considering the same thing, in order to shorten the DC.

Rob
furboo is offline  
post #8 of 118 (permalink) Old 01-22-2017, 04:49 PM
Registered User
 
RainMan 2.0's Avatar
 
Join Date: May 2014
Country: Canada
First Name: Rick
Posts: 15,892
 
Default

Rob I was thinking it wasn't so much about accuracy, but to monitor whether or not an improvement has taken place .
bryansong and furboo like this.

I don’t always insulate , but when I do .
Ok ,I never insulate
RainMan 2.0 is offline  
post #9 of 118 (permalink) Old 01-22-2017, 04:53 PM
Moderation Team
 
Cherryville Chuck's Avatar
 
Join Date: Sep 2010
Country: Canada
First Name: Charles
Posts: 14,965
 
Default

I certainly never thought of it as being able to take an accurate reading but it is an excellent way to monitor system and filter performance since you'll obviously take a reading when the system is new and that will allow you to be able to track performance over time and with filter cleanings. Since the set up is static it will respond accurately to changes even though it isn't particularly accurate in terms of absoluteness. That's all I would really be interested in knowing, since there is very little I can do to change the system, is to be able to monitor how well it is performing under it's relatively fixed parameters.

Someone I consider a master woodworker once told me that a master woodworker is not someone who never makes mistakes. He is someone who is able to cover them up so that no one can tell.
Cherryville Chuck is offline  
post #10 of 118 (permalink) Old 01-22-2017, 05:56 PM Thread Starter
Registered User
 
furboo's Avatar
 
Join Date: Oct 2015
Country: United States
First Name: Rob
Posts: 544
 
Default

Quote:
Originally Posted by RainMan 2.0 View Post
Rob I was thinking it wasn't so much about accuracy, but to monitor whether or not an improvement has taken place .
Yes, exactly.
RainMan 2.0 likes this.

Rob
furboo is offline  
Reply

Quick Reply
Message:
Options

Register Now



In order to be able to post messages on the Router Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.

User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.

Password:


Confirm Password:
Email Address
Please enter a valid email address for yourself.

Email Address:
OR

Log-in











Currently Active Users Viewing This Thread: 2 (0 members and 2 guests)
 
Thread Tools
Show Printable Version Show Printable Version
Email this Page Email this Page
Display Modes
Linear Mode Linear Mode



Similar Threads
Thread Thread Starter Forum Replies Last Post
Tips for Installing a Dust Collection System Router Forums Featured Topics 121 02-24-2017 12:20 PM
Small shop dust collection Barry747 Shop Safety 4 10-12-2015 12:04 PM
A Dust Problem rrrun The Finishing Touch 15 01-19-2015 11:44 PM
Index of Dust Collection Solutions and Comments allthunbs Shop Safety 28 03-14-2014 02:40 AM
My Dust Collection System MAFoElffen Tools and Woodworking 19 05-23-2013 04:39 PM

Posting Rules  
You may post new threads
You may post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On

 
For the best viewing experience please update your browser to Google Chrome