|Home » Forums Ľ Dust Collection, Safety and Plant Operation Ľ Message||Login|
You are not logged in. Consider these WOODWEB Member advantages:
Building codes for residential dust collection11/5
I'm building a garage with a woodshop above it for low volume cabinet construction and was planning on installing my dust collection ducting in the floor between the shop and the garage. That is until the building inspector said I had to comply with the California Mechanical Code (same as UMC) for ducts conveying explosive dust. These codes require "explosion venting" and 18" clearance to combustibles. The later requirement makes it impossible to put ducting in my floor (12" joists). One dust collection company pointed me to NFPA 664 which has an exclusion for small shops, but that didn't satisfy my inspector.
Does anyone know what codes relate to residential or small woodshops and dust collection? My inspector didn't seem to know. Does anyone have advice on this topic? How often do dust collection systems catch fire or explode? Seems like small shops would be making the news if they were blowing up all the time.
if your inspector can't find the code, maybe it dosen't exsist. don't start your shop part until it has been inspected.(duct work ect.)
I thought that there was an exception for ductwork under 10" diameter. Have you seen the code?
I haven't seen the exemption for <10" ducts. Any idea what code book that might be in? Couldn't find it in the 2007 Calif. Mech. Code. I did find that <10" ducts don't need sprinklers in them.
There must be code that speaks to the small shop and dust collection. I don't have tons of experience, but I have never seen the requirements in the Mech code implemented in any small shop.
Ask the inspector to cite the specific code(s) he is referring to and read everything pertaining to that particular code.
You might find that the inspector is citing commercial building codes when only residential building codes should be used.
Codes, Permits, Etc
Can someone please tell me what I have to do ? What type of dust collector is
No wonder everyone is confused. Some years ago, I provided a turn key installation for a couple of industrial spraybooths and make up air units. I was told I had to pull the permit for the installation. The application required pricing for all equipment provided and drawings of said equipment. I went to the town hall with all of the information that they requested. The secretary forwarded my paper work to one of the inspectors.
Do you follow NFPA, SMACNA, OSHA, EPA, DEP, UMC, CMC, NIOSH, ANSI Ö?
As a manufacturer, supplier, and installer of dust collection systems, we had to make sure all various parties involved were satisfied with the installation. It was our utmost objective to provide a safe and operational system. The codes, regulations, and guidelines that had to be met, may have come from various sources. Confusing ? You bet. Well, how many pages is the Health Care Bill ? Why canít tax legislation be simpler ?
Another thing confuses me. We all know the United States of Americaís rise to success was based on manufacturing. Why has our government destroyed the manufacturing sector in our country ? Now itís so bad a fellow canít even have a woodshop at his home. Many successful businesses have started in a garage or basement. Common sense and
Hereís the latest. OSHA is now working on a study of Combustible Dust. They have provided an advance notice of proposed rulemaking (ANPR). Looks like woodworking facilities are included, though it appears to me, they have had the least amount of combustible dust incidents.
Chris, I looked over Chapter 5 of the Uniform Mechanical Code (2009). Looks like a dust collection system would be classified as a Product-Conveying System. Class 2 includes sawdust. Duct thickness is based on negative pressure. Fittings must be 2 gauges heavier than straight pipe, angle of entry no more than 45 degrees. These are typical specs for dust collection pipe. The 18Ē clearance is stated in 506.7.2 It says, duct systems operating at elevated temperatures above 140 deg F shall have clearances from combustible building construction or any combustible material of not less than 18Ē.
The only other mention I noticed referencing 18Ē, was if ducts were run in a crawl space, there must be 18Ē clearance from bottom of duct to floor. 506.4 Explosion Venting. Ducts conveying explosive dusts shall have explosion vents, openings protected by antiflashback swing valves , or rupture diaphrams. Openings to relieve explosive forces shall be located outside the building. This stipulation is normally applied to aluminum or other highly explosive dusts. But, at this point who knows.
(The preceding is for informational purposes only.)
I am looking at the permit package that the city gave me when I installed my collector. They included a page from the 2003 International Mechanical Code. Section 510.7 requires automatic fire suppression system, but exception #2 states that it is not required if duct cross section is less than 10".
I guess in the end, the only code that matters is the one that the inspector is citing. One other note: I argued successfully that my duct layout was 100% temporary from the point where the main duct entered through the wall because my machinery location changed frequently. I also cited use of Nordfab quick connect to support this. As a result, they did not even look at the interior duct specs.
Curt and JR thank you for your posts. I had found those passages in Chapter 5 of the UMC/CMC (roughly identical). Those requirements are what is making it difficult. To run the ducts in the floor is precluded by the 18" clearances. Explosion venting would be an option, but the three vendors of duct I looked into that sell the small (<7") duct don't even have explosion vents in their catalogs.
The permanent nature of my installation is what is giving my inspector pause, although I don't see where in the code that is specified. In any case, what makes a permanent installation any more dangerous than a temporary one? I can certainly give a few arguments in the reverse.
So what have you dust collection installers run into for small installations?
Mark, your point is well taken. A separate post topic might have been to ask whether putting the duct work in the floor is just plain foolish from a practicality point of view.
So this might be a case of "be careful what you ask for."