Size recommendation of air filtration unit for my garage – workshop

[Daniel Hillmer]

Hi,

I’m considering buying a dust filtration unit for my garage to help keep the dust down from my machines. I do have a dust collector for my floor equipment, just want to cut down airborne dust as much as possible to reasonable limits.
My garage measures 20 x 22 feet, and accounting for the pitch of the roof, is a total of approximately 4,700 cubic feet.

What would be the proper sized unit for my space?

Also, any brand/model recommendations for a decent and hopefully economical filter unit?

[Bob Slater]

The JDS er750 seems to get good reviews. I have a couple of them. One in a 450 sq foot room, the other in a 250 sq ft room. . They used to be US made (One of mine is) The box construction is very good. They have a remote, and timer. They seem well made. One would be more than adequate for your space. They also have a washable front pre filter.

[Gary Lange]

In the Grizzly Manual for there G9956 Double unit they have the following calculations and recommendations.


The G9956 Heavy-Duty Double Air Filter is
designed to recirculate the entire volume of air
in a 20' x 20' x 8' room approximately 26 times
in one hour. For the best filtering effect, the volume
in a room should be recirculated at least 6-8
times every hour.
To calculate the recirculating rate for a given
volume:
Step 1. Calculate, how long it takes to circulate all
the volume of air in a room with the double air filter;
where W = Width, L = Length and H = Height
of your room, in feet. The rate of air movement for
the air filter is 1400 cubic feet per minute.

W' x L' x H' = Minutes for circulating 1 time
1400

Step 2. Calculate how many times per hour the
volume is recirculated through the double air filter
by dividing 60 minutes by the amount of time it
takes to circulate the volume once. The result is
listed as times per hour.

Step 1: 20' x 20' x 8' =
3200 = 2.28 Minutes
1400

Step 2:
60 = 26.3 Times per Hour
2.28

[Jim Ciesla]

I have a JET AFS-1000B, 3 speed & remote control in a small 10 x 13 shop. It clears that room in 10 minutes on the low setting. It works great.

[Daniel Hillmer]

I figured for my garage, the minimum CFM rating given the above calculations would be around 500 CFM. Can anyone recommend a good make/model in that range?

[glenn bradley]

My dad runs the JDS-750 (636 CFM) in a three car vaulted ceiling garage. Very surprising performance. Despite the numbers the JDS did best in actual tests (http://www.woodmagazine.com/woodworking-tools/reviews/dust-collection/air-scrubbers-under-300/). I was surprised at the actual differences in dust capture among units that have similar specs (the Griz at 630 CFM did poorly IIRC). I helped him install it and it doesn't look that different than others but the actual quantity of dust the other units failed to collect doesn't lie.

There are better "looking" units but this one seems to have had all the right functional things come together. I'm asking for one for Christmas even though my shop made one does a pretty good job. I have the mag but won't be near it for a couple days if you like, PM me and I can send you speocofocs if that will help. Like most folks I learned late the a DC should be one of your first shop investments. May as well get the good stuff. It your health, eh?

[Travis Rassat]

I have a JDS-750 in a 600 square foot garage with a 9' ceiling, and it works great.

Once you decide on a model, placement will be a big factor in the overall performance. There are a couple of threads discussing the best location for an air filter. JDS also offers system design on their website, although I have no idea at what cost:

http://www.jdstools.com/index.asp?PageAction=VIEWCATS&Category=22

[Daniel Hillmer]

Looks like on the low end I'm at 175 bucks for a GrizzlyG5955 and on the high end around 330 bucks for the JDS.Anyone make one for less? I imagine for less than that it will most likely be junk...

How much do the replacement filters for the JDS cost?

[Chris Padilla]

Frankly, I don't see the point in such a device. Do a better job of catching the dust at the source and you'll breathe in less stuff. The air filtration may eventually clear the air in your shop/garage, but you are still breathing that stuff in. Keep your garage door open and stick a fan in the back or a window and keep air circulating.

[Joel Earl]

Couple issues with the simple way.. lol .. - one is snow and minus 30 temps in winter. #2 is when it's windy more junk comes in than goes out.

I try to use both - fresh air is great when I can and the AF is always available.

[glenn bradley]

Frankly, I don't see the point in such a device. Do a better job of catching the dust at the source and you'll breathe in less stuff. The air filtration may eventually clear the air in your shop/garage, but you are still breathing that stuff in. Keep your garage door open and stick a fan in the back or a window and keep air circulating.


I understand Chris' statement and felt the same until I'd seen one too many tests. With properly sized DC systems operating and specific amounts of waste created, the rooms were ambient scrubbed after and the collected 'fines' were pretty amazing. It's one of those things I have tried to ignore for quite awhile but, when 2 plus 2 is four, its four :mad:.

P.s. I have been getting by with a shop made unit and leaving the garage doors open. God bless SoCal weather ;-)

[glenn bradley]

Looks like on the low end I'm at 175 bucks for a GrizzlyG5955 and on the high end around 330 bucks for the JDS.Anyone make one for less? I imagine for less than that it will most likely be junk...

How much do the replacement filters for the JDS cost?

If you're going to go part way (like I did) I wouldn't go past $50 or so. That's just me, check the reviews the drop off from the top three performers was drastic. I got a gable fan on sale at Lowe's for $35, some 20" x 20" filters on clearance at Wal-Mart and built one out of scrap. I am not where I can get pics right now but a "starter" unit is pretty cheap and easy to slap together. The amount of stuff this captures is what got me first thinking there just might be something to these doomsayers about ambient cleaners.

More good discussion here: http://www.sawmillcreek.org/showthread.php?p=481526#poststop