Noise Levels

  • Thread starter Guest_Paul Stoops
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Guest_Paul Stoops

Guest
Hi all,

There have been some inquiries related to the noise levels produced by the Clear Vue cyclone systems, so I decided to make a few measurements to provide some reference information for other users. I used a Radio Shack Sound Level Meter to make the following measurements taken approximately 10 ft. away and 5 ft. high from the cyclone. All measurements on the C Weighting Scale.

Original installation with filter stack directly under stock 90º transition: 98 dB
Modified configuration with straight metal transition & 6' of insulated HVAC duct to filter stack: 90 dB. Still loud, but much better.

Fortunately, the cyclone is located behind an insulated wall in an adjacent garage.
The noise level measured in my shop was an acceptable 73 dB after the modification.
For comparison, I also measured the noise level of a couple of shop tools:

General 350 cabinet table saw: 82 dB
DeWalt 735 planer: 98 dB

Interestingly enough, the noise level in the shop with the tools on only went up a couple of dB with the DC on.

I found this data interesting and I hope it will be useful to the forum. Please contact me via email if you have any questions.

Paul
 
I forgot to mention that at the time these noise measurements were made, the cyclone was operating at 17.6A and about 700 CFM air flow.

Also, as has been mentioned by others, most of the noise seems to occur near the top of the filter stack. With the stock 90º transition, there appeared to be quite a bit of buffeting noise in the transition at the top of the filter stack. The straight metal transition seems to have reduced that condition. To accomodate the straight transition and the Ø8" HVAC duct, I relocated the filter stack about 4 feet away from the cyclone. This made the footprint larger, but the noise reduction was worth it.

Paul
 
Paul,
Matt and I installed a new 15" blower/impeller on his system last weekend and while I was over there I took sound measurements. I too used the C-scale, but on the way home I did a mearurement inside my van. I have a 1996 Dodge Caravan.....It is pretty quiet, but it measured 90 DB. I was talking to Dave Belliveau, a friend and customer, and he told me that we should use the A scale....it is more representive of human hearing. On the A scale I got 74 db on my unit @ 10' and 86 @ 3'. Router table with a Dewalt router 94, CNC router with vari-speed Hatachi router was 72 Low - 88 High speed. Band Saw 88. 20" Planer 86 running and 115 cutting, Jointer 76 running and 86-88 cutting, Belt sander 82 running and 88 sanding. Machine measurements were made a 3' away.

Your current measurement agrees with mine, but the CFM measurement seems very low. Was that thru a 6" pipe or a 4" pipe? FFW is doing a review of dust collectors which should be out in the next couple of months. They have tested our unit. What they got was 1450 CFM @ 4" SP (through a 6" pipe) and going to 8" SP they got almost 1200 CFM.

Ed
 
Hi Ed,

I ran some quickie retests of the noise levels using the A scale. All measurements (with equipment running but not cutting) at 3 ft. except as noted. DC = 84 dB @ 10' & 88 dB @ 3' in garage, 69 dB in shop; Table saw = 84 dB; Bandsaw = 76 dB; DW 735 Planer = 98 dB; Belt sander = 90 dB.

I ran some quickie current measurements as well: 6" DC inlet duct open = 21.1A; All drops closed = 7.5A; 6" duct to table saw open (about 39' of ducting, calculated SP loss per Bill Pentz's info = 7.28" W.C.) = 16.4A; (1) 4" drop open on short (10') 6" duct (with 4" calculated SP loss) = 14.6A; (2) 4" drops open on same 6" duct = 17.5A Are any of these numbers close to where they should be?

I will try to rerun some of my airflow tests tomorrow. However, I don't think I have even come close to your FFW test results. It seems unlikely, but it is possible that I may have an obstruction in the main duct. I sure hope not, tho, because it is not easy to get to (all of my ducting is sitting on top of the ceiling joists under a hip roof).

Have any of the forum members made any air flow tests with their ducting hooked up to the DC?

Paul
 
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