Someone re-installed the thermostat in the Wood Shop, and started the unit. Experience has shown that the dust in there will plug up the filters in a short time (depending on the amount of CNC router use), and the AC unit will freeze, and dump water through the ceiling. This is something that the Wood Shop Committee needs to address.
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Hear is my suggestion,
We move the intake for the AC to the warehouse and install filters in the doors between the wood shop and the warehouse. That way the filters that will clog the fastest will be at floor level and easy to inspect / replace. I know this means that the wood shop will constantly be under positive pressure, thus some of the saw dust could be circulated out of the wood shop. But, I believe this already happens with the walking in and out the doors. This solution might increase that a bit, but I hope it solves the larger issue of freezing up and damaging things with water.
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Chuck,
Brian Davis replaced the filters for the unit, so I reinstalled the thermostat.
What really needs to happen is for Woodshop to have waaayyyyy more air filters. The two small units are insufficient.
What really needs to happen is about $20000 in dust collection. We are severely under collecting now, and the second collector unit (yellow one, electric has to be done first) will put a dent in the deficiency.
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Can’t we just blow it outside with a Really Big fan? It’s biodegradable, right? 
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It seems that wood shop doesn’t want to exhaust outside, there are probably many reasons for this and I bet cost is probably one of the keys.
So what are we doing to solve the problem? I’m personally working to getting an idea on cost for supplemental filtration system for the HVAC and Dust Collection System. My main goal is finding a solution for dust collection first, because as that system is improved the issue with the HVAC is lessened.
I have a call out to Camfil a company that specializes in pollution and particulate filtration. Here is an example of one of their self cleaning filter systems.
We’ve priced complete dust collection systems, received quotes from Donaldson, Stiles (Belfab vendor), and Oneida. Woodshop then received the donation of an additional Oneida unit and decided to go with two (three, if you count the CNC) units. We are going to install it when the electrical is completed. This should put a dent in our collection deficiency.
We are severely limited on ceiling height for the large units. Generally, units of this size are outside for fire protection reasons, among others. Units over 5000 cfm require additional systems to prevent and mitigate explosions. As motors get larger, the number of hot and cold motor starts becomes important because they are designed to be run continuously, outside of automatic (or manual) cleaning cycles. Large industrial systems require large industrial maintenance.
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The example that I showed is a large system, but it does show the pulse feature that I think will help us. having a quickly cleanable filter is a need for our system as the filter should be cleaned much more often than they currently are.
Even with the addition of the second Dust System, we will be running into the issue of clogged filters. The current solution to this is to take the filters outside and blow them out when clogged. This solution isn’t that effective as the filters clog quickly and should be blown out multiple times in a day. We don’t clean the filter consistently because the process of blowing it out is time consuming and difficult. You currently have to un-mount the filter, not a small task as it is 2 foot in diameter, 4 or 5 feet tall and mounted off the ground. Then you take it outside, blow it out, clean up the mess you made, and reinstall the filter. It takes one person probably 15 minutes if they are fast and even longer if they are not versed in the process. If we estimate this as a process that should be done 2 or 3 times a day on week days and 4 to 6 time on weekends, that is a lot of down time. I’d estimate 234 hours of labor over a year conservatively and that is estimating that you are only cleaning one filter, this number could double if you have to clean 2 filter. Another issue is most likely that down time will happen when the shop is in high use. This makes the down time have a larger effect on the membership.
I’m also not pricing out a full system. I’m pricing out a supplemental filter option for the system we have. The current system could cost wood shop $800 per month in filter replacement. The way I come to $800 is that the replacement exhaust filter we use are $400 each and we will be running two in the room. The manufacturer suggests that you replace these filter monthly. In speaking with Andrew (@Azalaket) , he is hoping that having two units will double the lifespan of the filter to 2 months. I understood that at as a hopeful scenario not a guarantee. This would still keep costs at $400 per month in just filters. These are not small costs and could already be higher than the monthly allocation to wood shop can support.
So when we think about the costs on dust management for the wood shop, a real world number for the year might be $9600 with the require labor input of 234 to 468 hours of volunteer work. Doesn’t this feel like an expensive continual cost, while also being difficult to run properly?
Edit:
Forgot to add thanks to @MathewBusby, the discussion of these issues are essential to the growth and development of DMS. We all come from different views, knowledge bases and techniques for solving problems. In my work with the finances I’m starting to favor tackling the larger problems like dust management with yearly cost and labor view, rather than a fix it now view. But, the fix it now view is great as well, because it gets it fixed NOW! I hope to find a supplemental fix that can be incorporated to the fix being done currently. That way we get up time now and more reasonable costs of capital and labor in the long term.
If I had more capabilities, I’d be giving the sonic a try:
I really think people would do it more often if it were fun and a show.
Alas, I am not the guy to build such things…
As it stands, compressed air blast is more practical, but
a) we don’t actually have it, either
b) much less entertaining.
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That makes me smile every time I see it. But, we have an issue of dust stuck in filters, and I doubt the sonic could be considered a good solution. But, I’m open if you have an example of it being used on filter like our’s.
Making the process a show on the other hand is a great idea. If we had a large window that showed the air blast cleaning I’m sure it would be used regularly. Making clouds of dust by pressing a button is fun to do.
The filter (and cleaning apparatus) you linked is incorporated into a baghouse (or a cartridge filter housing unit), not added on to another collector. That baghouse is the dust collector, not an after filter. Sometimes these baghouses have cyclonic separators, sometimes they don’t. Either way, the filter is usually the dust collector - that system generates the vacuum, filters the airstream, and cleans the bags. Bins still have to be emptied and the bags still have to be replaced, albeit less often. They may be available as an after filter, though. I highly doubt using these as an after filter would be a configuration that would benefit us in the future.
The filters we have currently probably shouldn’t have to be blown down multiple times per day – a system that is not overtasked is separating a large portion of the dust at the cyclone. We have a gauge on the filter plenum, the filter needs to be blown down when that gauge hits 3"WC IIRC. I’m not sure how often that happens on our system. When the bin is full, it doesn’t separate as efficiently. The filter should be blown down while on the collector and the bottom cap emptied afterwards.
I disagree with the notion that this is a fix-it-now solution. The total collection demand of our tools is around 4000cfm, the two collectors (running in optimal conditions) produce around 3000cfm. Generally, not all tools are running at the same time, so we are probably sitting pretty good with our proposed improvements.
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I’m just hoping that the additional collection that we are adding will be enough to solve it.
You spoke of man hours, but not expense. The current solution if done properly to the manufacturer specks is $9600, do you consider this correct? Or am I miss lead by this number as well?
I will try and note the pressure and frequency of needing to blow out the filter with the method you suggest. I’ve previously always taken the filter outside and done a full cleaning. The method you suggest does sound much easier, but possibly at the cost of less time till the next blow out is needed. I’ve noticed the filter after being blown out still reading max on the dial. But, the dial I’ve also heard is broken. So in that case I’m unsure as to how to tell the pressure the system is running at or when you need to blow it out. This make both of our assertions difficult to prove.
Also, I wasn’t trying to say the video was of the unit we would have, instead I showed the video to high light the technology for cleaning the filter that I think would make things easier. The company I’m working with makes many solutions and in conversation they said that they have options for our scale already. Plus, they may even have an option for our HVAC filters that can be as easy to clean, solving the issue of constantly replacing the filters in the ceiling or dealing with the indoor rain from the unit freezing up.
Just out of curiosity… Where is the $400 filter that is supposed to be changed monthly? On the roof?
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He is talking about the HEPA filter on the dust collector.
Personally, I think HEPA filtration in a Woodshop is completely pointless. It should be replaced with their normal filters that are significantly cheaper.
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Are we talking about the difference between these two?
$270 18" x 39"
$415 18" x 36" hepa
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Yes
Twentytwenty twenty
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I agree with Matt,
The HEPA filters do seem pointless, especially with the fact that the room is swimming in dust. Thanks for the links Brandon, I like this option to bring down cost. Not having the cage allows you to blow it out better. Plus, the 35% cost reduction makes the need to look for an alternate option less needed.
Do we know when the next wood shop meeting is? It would love to put filter selection on the agenda. Also if you have a good reason for keeping the hepa
Wow I know several guys who own woodworking shops and if a salesman came in and told them to replace that monthly they would get a swift kick in the…
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