Compressor (or?) recommendation to blow out a HEPA filter

[Ed Mitchell]

I've had an Oneida Mini-gorilla for a bit over a year; it's working well. Its HEPA filter (https://www.oneida-air.com/10-5-19-5-inch-true-hepa-dust-collector-filter) is getting clogged, CFM is down, and the manual makes it clear I should be blowing compressed air, between 30-60 psi, downward at the filter (approx 20 degree angle from a distance of 6 inches) to blow dust off the filter media.

With a shopvac hooked up to the bottom of the filter, the shopvac will remove the dust I blast free, and that's how CFM is maintained throughout the useful life of the filter.

So I guess I need an air compressor. I've never owned one, hoping for recommendations. The filter is a decent size -- it'll be over 800 square inches of surface area to blast with compressed air -- so I'm wondering if I get a small, quiet compressor with a low SCFM and small tank (like this one (https://smile.amazon.com/Makita-MAC210Q-Oil-Free-Electric-Compressor/dp/B084GYHQFY/?_encoding=UTF8&pd_rd_w=TA5qK&content-id=amzn1.sym.5fe95cd4-8512-42fa-bf21-63d83b898785&pf_rd_p=5fe95cd4-8512-42fa-bf21-63d83b898785&pf_rd_r=GVGM74YJJAPMMB0WXT7A&pd_rd_wg=f2hFj&pd_rd_r=c81d6b06-75fd-4683-8f1b-aa9d48f5936a&ref_=pd_gw_ci_mcx_mr_hp_atf_m)) -- will it take 16 hours? Do I need an 80 gallon, 5 hp monster? Are there other tools which produce enough compressed air?

[Sam Force]

I don't have that specific DC but for the 2 I have I use a leaf blower. An air compressor would be like trying to paint a house with a pencil :rolleyes:

[Bill Dufour]

Use a shop vac with a hepa filter to just remove the dust with an upholstery brush attachment.
Bill D.

PS: shop vac went out of business this year

[Mark e Kessler]

I have used a leaf blower with good results…lol. I take it outdoors and let er rip…

[Jeff Ramsey]

I do the same with my Wynn canister filter. I pull it outside, and with a dust mask on, I use my backpack Stihl to blow it off.

[Alan Lightstone]

I did mine earlier this year outside with an air compressor. Big mistake. It's an endless task, and you never really get everything. Didn't see the leaf blower suggestion until it was too late. https://sawmillcreek.org/showthread.php?296701-Just-FINALLY-cleaned-the-Oneida-Dust-Collector-Filter-Oh-the-Humanity!!!!

Use a leaf blower.

[Jim OConnor]

Use a leaf blower from the outside…..if it’s really clogged, you may have to blow out the inside as well. Avoid high pressure “spot” cleaning with an air hose close to the filter.

[Randy Heinemann]

I use these methods with my Oneida V1500:

1. If I don't want to take the filter completely off and take it outside (like in winter), I have a small Dewalt 20V leaf blower. I just blow the dust inward before taking the cup off the bottom and emptying it. I usually have to do this about twice before enough dust is removed. I also usually lightly bump the outsides with my hands which also loosens some of the dust. The blower won't get all of it but enough to make the filter like new each time. The blower is a lower power one which probably won't work well for leaf blowing so it's a one-purpose tool.

2. If I take the filter off and bring it outside, I use my regular gas powered leaf blower; much higher power. I just blow the air through the inside along the length of the filter; usually from each end. Usually no dust comes out the ends after one cycle from each side (can't see much or any coming off). This is the best method. It may not get all the dust out, but there isn't much left.

The one thing you probably want to avoid is blowing directly into the filter pleats from the side with a high powered blower or high pressure compressor nozzle. It's possible to damage the HEPA filter which is expensive to replace.

I have found that either of these methods work. The outside method is best though.

[Ed Mitchell]

I had a feeling the minds at SC would come through -- great suggestion on the leaf blower, and I already own one, so I'll give it a shot. Thanks, everyone.

[Frank Pratt]

I don't have that specific DC but for the 2 I have I use a leaf blower. An air compressor would be like trying to paint a house with a pencil :rolleyes:
A leaf blower will not clean the filter nearly as well as compressed air will. It just can't get enough airflow between the pleats to clear out the dust. I've tried both. I do use the leaf blower to get the dust out of the OH door though.

[Mark e Kessler]

A leaf blower will not clean the filter nearly as well as compressed air will. It just can't get enough airflow between the pleats to clear out the dust. I've tried both. I do use the leaf blower to get the dust out of the OH door though.


that is true, i use compressed air as well and a little spanking will go a long ways….lol

[Tom M King]

https://www.northerntool.com/shop/tools/product_200665751_200665751?cm_mmc=Google-pla&utm_source=Google_PLA&utm_medium=Air%20Tools%20%2B%20Compressors%20%3E%2 0Air%20Tools%20%2B%20Accessories%20%3E%20Air%20Blo w%20Guns&utm_campaign=Ironton&utm_content=45972&gclid=CjwKCAjwoMSWBhAdEiwAVJ2ndoMTS90oKeNUCNDh5RPr j4ulvPBtUIkuyNh_WLUk74VwNEEqVwGdEhoCEUoQAvD_BwE&gclsrc=aw.ds

and a day with a Strong wind.

[Ed Mitchell]

A leaf blower will not clean the filter nearly as well as compressed air will. It just can't get enough airflow between the pleats to clear out the dust. I've tried both. I do use the leaf blower to get the dust out of the OH door though.


Frank, what would you guess to be the minimum requirements for a compressor that can clean the filter in, say, under an hour?

[Sam Force]

I still believe the leaf blower is by far the best tool for the job. Once blown out with the leaf blower there is very little left and not worth the time for a small stream of pressurized air

[Jim Becker]

Frank, what would you guess to be the minimum requirements for a compressor that can clean the filter in, say, under an hour?
The process shouldn't take you more than 15-20 minutes, not including showering off in your driveway to avoid issues with dragging your dusty self inside.

The ideal compressor is a very large one, but "larger small one" or medium sized compressor will do. They will just run nearly constantly for this kind of task.

[John Lanciani]

A leaf blower will not clean the filter nearly as well as compressed air will. It just can't get enough airflow between the pleats to clear out the dust. I've tried both. I do use the leaf blower to get the dust out of the OH door though.

Your leaf blower is too small then. A Stihl BR800 gets the job done 10x faster than a 10 cfm 60 gal. compressor.

[Ed Mitchell]

The process shouldn't take you more than 15-20 minutes, not including showering off in your driveway to avoid issues with dragging your dusty self inside.

The ideal compressor is a very large one, but "larger small one" or medium sized compressor will do. They will just run nearly constantly for this kind of task.

Thanks. I have a friend with a large compressor, he said I'm welcome to try it, so I may in the future.
I did the leaf blower thing this morning, and it did seem to work well. IDK if it did as good a job as a compressor would have done, but the CFM I measured it back to within ~4% of what it was when I measured it brand new.

[Jim Becker]

The leaf blower will get a lot of the loser material. The compressor with a blow-gun will dislodge a lot more stuff that's coating the inside of the pleats. It can be a surprising amount of stuff!!! I just did the canister that is part of the SDD system I have listed here in the Classifieds the other day and it was totally amazing about how much debris was caught in there even after only about 6 months of use with minimal projects. The filter did its job for sure...all that stuff never made it into the air.

[Justin Rapp]

Interesting thoughts on cleaning the filter. My Laguna cyclone has paddles that rotated (manual crank when machine is off) and the sawdust caked up falls to the bag at the bottom. Getting that filter off on is a royal pain but now I am thinking it's time to take it outside and blast it with the leaf blower.

[Jonathan Jung]

I clean my canister filters on a schedule, once a week pat them down, one a month with air, so it's not a 5 hour ordeal every time and to keep CFM up.

[Alan Lightstone]

The process shouldn't take you more than 15-20 minutes, not including showering off in your driveway to avoid issues with dragging your dusty self inside.

The ideal compressor is a very large one, but "larger small one" or medium sized compressor will do. They will just run nearly constantly for this kind of task.
I wore a Hazmat suit and respirator, and still felt like it wasn't enough. It's unbelievable how much wood dust is in those cartridge filters.

[Jim Becker]

Interesting thoughts on cleaning the filter. My Laguna cyclone has paddles that rotated (manual crank when machine is off) and the sawdust caked up falls to the bag at the bottom. Getting that filter off on is a royal pain but now I am thinking it's time to take it outside and blast it with the leaf blower.
The "flappers" really do help keep the filters "less caked", but there is still going to be material that gets stuck deep in the folds. The good news is that you certainly do not need to endure the "totally enjoyable" task of blowing out the filters as frequently as others because you have those flappers... :) :D

[Randy Heinemann]

No one should blow out the filter inside the shop or house for sure. A lot of dust comes out. However, I found that, if done regularly, a good leaf blower really does get almost all of the dust out if taken outside and blown from end to end. There is likely to always be a little residual but, using a compressor requires some care, to be sure the filter pleats aren't damaged by a stream of high pressure air. Lower pressure, for sure. That's what he lear blower works well.

[Bill Dufour]

I thought you could leave it all attached and blow it out in place. The dust will settle to the bottom to be removed? Is that how the self cleaning baghouse filters work. Not as good a clean as removing it and doing it from the inside but good enough for in between.
Bill D

[Mark Rainey]

I thought you could leave it all attached and blow it out in place. The dust will settle to the bottom to be removed? Is that how the self cleaning baghouse filters work. Not as good a clean as removing it and doing it from the inside but good enough for in between.
Bill D Yes Bill, that is the case. I have had the Mini-Gorilla for several years. Frequently, after a emptying a filled bin a couple of times, I will clean it by donning a dusk mask and using my electric leaf blower directing air at it from the outside. The dust will settle to the bottom and the black plastic cap is removed and the dust will fall into my trash can. I will then spank the filter really good, repeat the leaf blower and get another dumping of dust. Twice a year I will remove the whole filter, mask up, take it outside and let it rip with the leaf blower and spanking. Dust flies everywhere for 10 minutes, and when things calm down I stop. When I talk to the Oneida people, they like the leaf blower technique.

[Randy Heinemann]

I thought you could leave it all attached and blow it out in place. The dust will settle to the bottom to be removed? Is that how the self cleaning baghouse filters work. Not as good a clean as removing it and doing it from the inside but good enough for in between.
Bill D

You can blow out from the outside with lower pressure compressed air or an electric blower. I also tend to bang lightly on the sides with my hands to shake the dust loose. However, I found that, at least every other time I empty the dust bin, it's best to take the filter off, take it outside, and blow it out more completely. (Winter might be the exception.) One added problem I had is that I didn't think installation through completely and it's a little hard for me to get at all sides of the hanging filter in place and in place cleaning is difficult so I tend to take it off more than I might otherwise.

[Jim Becker]

I agree with Randy...best outside. If the filter has a catch basin at the bottom, it certainly wouldn't hurt to whack it and blow on it from the outside to dislodge some material periodically between thorough cleaning, but "real" cleaning is still needed from time to time, IMHO.

[Mark Rainey]

Ed, how are you measuring CFM?

[Ed Mitchell]

Ed, how are you measuring CFM?

I have an cheap Chinese anemometer I got from Amazon. I can grab the brand for you if you like. I have no idea if it's accurate but as you know, consistency is all that's really necessary. I take off the hose and measure directly at the port, so I have a consistent place to measure, and to eliminate inconsistencies from the variables introduced by the hose.

I don't know if that's actually an advisable way to measure CFM, just the way I've been doing it.

[Pat Rice]

I have used Oneida cyclones for 20yrs now, I like to take my filter outside and using a nozzle on my garden hose and wash out the filter eliminating clouds of dust, you just have to really make sure it is totally dry before placing it back into use. Here in Florida that is not a problem, plus I have a extra filter so I can easily rotate one while the other is drying.

[Mark Rainey]

I have an cheap Chinese anemometer I got from Amazon. I can grab the brand for you if you like. I have no idea if it's accurate but as you know, consistency is all that's really necessary. I take off the hose and measure directly at the port, so I have a consistent place to measure, and to eliminate inconsistencies from the variables introduced by the hose.

I don't know if that's actually an advisable way to measure CFM, just the way I've been doing it.

Thanks Ed, yes if you can let me know the brand.

[Mark Rainey]

I have used Oneida cyclones for 20yrs now, I like to take my filter outside and using a nozzle on my garden hose and wash out the filter eliminating clouds of dust, you just have to really make sure it is totally dry before placing it back into use. Here in Florida that is not a problem, plus I have a extra filter so I can easily rotate one while the other is drying.

20 years of experience is hard to ignore Pat. Perhaps I should give that a go - those clouds of dust are obnoxious.

[Pat Rice]

By the way, I have talked to Oneida about washing the filter and they said that was fine except do not use a high pressure washer and stressed that you must make sure it is totally dry.

[John TenEyck]

Has anyone stopped to think about why you need a filter in the first place? Of course it's because the air is being returned to your shop. But if you discharge that air outside, instead, you no longer need a filter. No filter, no loss in performance, actually higher, stable performance, no dust leaks, no ultrafines that get through the filter, and no maintenance, ever. Can't be done? Why yes it can, all year long and in a northern climate. The dehumidifier runs a little more in the summer and the furnace a little more in the winter, but the temp and humidity stay within a few degrees/% of set point no matter how long I run the DC. Probably not a valid option for someone in the deep south but for many it could be.

John

[Ed Mitchell]

Thanks Ed, yes if you can let me know the brand.

Here you go:
https://www.amazon.com/Anemometer-Handheld-Backlight-Functions-Measuring/dp/B07V2YYR2H

[Jim Becker]

Has anyone stopped to think about why you need a filter in the first place? Of course it's because the air is being returned to your shop. But if you discharge that air outside, instead, you no longer need a filter. No filter, no loss in performance, actually higher, stable performance, no dust leaks, no ultrafines that get through the filter, and no maintenance, ever. Can't be done? Why yes it can, all year long and in a northern climate. The dehumidifier runs a little more in the summer and the furnace a little more in the winter, but the temp and humidity stay within a few degrees/% of set point no matter how long I run the DC. Probably not a valid option for someone in the deep south but for many it could be.

John, I don't consider exhausting outside to be viable for here in the mid-Atlantic. Why? My shop is (err...will be) conditioned space most of the year. But for folks that don't have that concern, it's certainly a good way to eliminate a good chunk of the fines in the shop as well as remove the need to clean filters.

[John TenEyck]

John, I don't consider exhausting outside to be viable for here in the mid-Atlantic. Why? My shop is (err...will be) conditioned space most of the year. But for folks that don't have that concern, it's certainly a good way to eliminate a good chunk of the fines in the shop as well as remove the need to clean filters.

If "condtioned space" means air conditioned because it's above ground then I understand the logic. My shop is in the basement so it has no trouble staying cool even in summer.

I had a guy over this morning to buy some lumber and we needed to go down into my shop to resaw a couple of pieces he wanted. He saw my DC arrangement and said his was set up almost identically with exhaust out the window. For us basement dwellers it's a viable, low cost, no maintenance option.

My point in making the post was to show there often are alternative solutions, not to be confused with alternative facts, of which there are none.

John

[Jim Becker]

AC and heat, John. Minisplit.

[Mark Rainey]

If "condtioned space" means air conditioned because it's above ground then I understand the logic. My shop is in the basement so it has no trouble staying cool even in summer.

I had a guy over this morning to buy some lumber and we needed to go down into my shop to resaw a couple of pieces he wanted. He saw my DC arrangement and said his was set up almost identically with exhaust out the window. For us basement dwellers it's a viable, low cost, no maintenance option.

My point in making the post was to show there often are alternative solutions, not to be confused with alternative facts, of which there are none.

John

John, are there any concerns of too much venting of air causing problems with a gas furnace if it is in the same room?

[John TenEyck]

John, are there any concerns of too much venting of air causing problems with a gas furnace if it is in the same room?

Mark, you have to provide for make-up air if you vent outside. I open a window on the other side of my shop. Otherwise, back drafting from a furnace, etc in the same space would be a definite possibility.

John

[Mark e Kessler]

Has anyone stopped to think about why you need a filter in the first place? Of course it's because the air is being returned to your shop. But if you discharge that air outside, instead, you no longer need a filter. No filter, no loss in performance, actually higher, stable performance, no dust leaks, no ultrafines that get through the filter, and no maintenance, ever. Can't be done? Why yes it can, all year long and in a northern climate. The dehumidifier runs a little more in the summer and the furnace a little more in the winter, but the temp and humidity stay within a few degrees/% of set point no matter how long I run the DC. Probably not a valid option for someone in the deep south but for many it could be.

John

When you say North, how far North? I can’t image exhausting all that air up here in VT winters and the furnace only runs “a little more” , where does the makeup air come from - outside right?

[John TenEyck]

When you say North, how far North? I can’t image exhausting all that air up here in VT winters and the furnace only runs “a little more” , where does the makeup air come from - outside right?

I live near Niagara Falls, NY. It's cold and snowy in the winter. 20 - 30F is typical and occasionally we get down to 0. Everyone thinks that exhausting your DC outside and bringing in outside make-up air will cause the temperature in their shop to plummet, but they fail to realize that basement shops are giant heat sinks. All that concrete sunk below grade is a giant reservoir of heat. The make-up air has almost no mass compared to the concrete, etc., so the temperature goes down a few degrees while the DC is running but easily comes back to ambient once it's shut off. I heat my shop to 65F, whether or not the DC is running. I regularly run my DC for an hour in the winter. Never has the temperature dropped to 60F. Within 15 minutes after turning off the DC the temperature is back to 65F. I can't tell you exactly how much additional fuel it takes, but I would guess it's less than $30/month. I'm perfectly fine with that.

John

One might wonder why I don't use a filter system and return air to my shop. I did at one time, but then I bought a new bandsaw and the DC couldn't handle all the sawdust it makes when doing wide resaws. In looking to understand why I started measuring the static pressure drop at various locations in the DC system. The cyclone I had added resulted in a huge loss in SP, over 4" I think. The one or two micron filter bags I was using were at least that bad, too. Some poor piping choices added a few more inches lost. So it was either time to get a higher capacity DC or make some changes. I'm an engineer and I'm generally frugal so I started looking at ways to improve what I had. Just getting rid of the filter bags and ducting the exhaust out the window got me close, but actually not quite there. I ended up tearing apart the DC and mounting the fan inlet directly on top of the cyclone, with an expanded inlet diameter. I think that move alone gave me back 3" of SP. I also increased the outlet diameter of the exhaust from the fan, another gain of an inch or two. I also reconfigured some of the piping to smooth out the flow from the bandsaw. Combined, I now had enough SP at the bandsaw to handle all the sawdust it can make, and it never falls off because there is no filter to get blinded over time. Motor amps are still comfortably under the limit. These changes cost nothing but my time and a few DC fittings. The benefit of zero maintenance has been an added bonus.

John

[Mark e Kessler]

I live near Niagara Falls, NY. It's cold and snowy in the winter. 20 - 30F is typical and occasionally we get down to 0. Everyone thinks that exhausting your DC outside and bringing in outside make-up air will cause the temperature in their shop to plummet, but they fail to realize that basement shops are giant heat sinks. All that concrete sunk below grade is a giant reservoir of heat. The make-up air has almost no mass compared to the concrete, etc., so the temperature goes down a few degrees while the DC is running but easily comes back to ambient once it's shut off. I heat my shop to 65F, whether or not the DC is running. I regularly run my DC for an hour in the winter. Never has the temperature dropped to 60F. Within 15 minutes after turning off the DC the temperature is back to 65F. I can't tell you exactly how much additional fuel it takes, but I would guess it's less than $30/month. I'm perfectly fine with that.

John

One might wonder why I don't use a filter system and return air to my shop. I did at one time, but then I bought a new bandsaw and the DC couldn't handle all the sawdust it makes when doing wide resaws. In looking to understand why I started measuring the static pressure drop at various locations in the DC system. The cyclone I had added resulted in a huge loss in SP, over 4" I think. The one or two micron filter bags I was using were at least that bad, too. Some poor piping choices added a few more inches lost. So it was either time to get a higher capacity DC or make some changes. I'm an engineer and I'm generally frugal so I started looking at ways to improve what I had. Just getting rid of the filter bags and ducting the exhaust out the window got me close, but actually not quite there. I ended up tearing apart the DC and mounting the fan inlet directly on top of the cyclone, with an expanded inlet diameter. I think that move alone gave me back 3" of SP. I also increased the outlet diameter of the exhaust from the fan, another gain of an inch or two. I also reconfigured some of the piping to smooth out the flow from the bandsaw. Combined, I now had enough SP at the bandsaw to handle all the sawdust it can make, and it never falls off because there is no filter to get blinded over time. Motor amps are still comfortably under the limit. These changes cost nothing but my time and a few DC fittings. The benefit of zero maintenance has been an added bonus.

John

Ok, suppose in a basement could work but i am on a slab at grade and that slab is always cold, great for the 2 months of summer but there are multiple months of 0f and weeks of below zero…. Also no issues with combusting making devices or wood stove?

[John TenEyck]

Ok, suppose in a basement could work but i am on a slab at grade and that slab is always cold, great for the 2 months of summer but there are multiple months of 0f and weeks of below zero…. Also no issues with combusting making devices or wood stove?

Not "could work", does work, in any shop that has a lot of mass. Not just basement shops but any shop that has a lot of mass from the structure AND the contents that are maintained at a temperature comfortable enough to work at. It would not work for light weight structures with little mass inside, nor ones where the heat is turned off/down at night. In that case, the furnace/stove is needed just to heat the air back up to some workable temperature during work hours, but the structure and mass in the building never get to that temperature before the heat is turned off or idled back again.

John

[Mark e Kessler]

Not "could work", does work, in any shop that has a lot of mass. Not just basement shops but any shop that has a lot of mass from the structure AND the contents that are maintained at a temperature comfortable enough to work at. It would not work for light weight structures with little mass inside, nor ones where the heat is turned off/down at night. In that case, the furnace/stove is needed just to heat the air back up to some workable temperature during work hours, but the structure and mass in the building never get to that temperature before the heat is turned off or idled back again.

John
Yup, definitely sounds like it could work in some situations…