Garage ceiling air filter location

[ebarker9]

I picked up the ever-popular Jet AFS-1000B air filter on Black Friday for my 2 car garage/shop. I plan to use it in conjunction with my, admittedly rudimentary, shop vac collection system to control dust in the garage because I do park two cars and sometimes a motorcycle in there, especially during the winter. I also use a mask when doing most operations (just heading off the inevitable comments about how it's better to capture dust at the source, etc).

I'm trying to figure out where to mount the unit. I have a 22'x22' garage with a beam parallel to the opening halfway between the doors and back wall. My work is usually on the right side of the garage, depending on exactly what I'm doing.

Per this thread:

Homemade shop filtration system question

I came across this statement "As important as the air cleaner size is how and where you mount it. Try to mount at about 8-10 feet above the floor (no lower than 6'or 2/3 of the floor to ceiling distance if less than 8' ceiling). Mount along the longest wall so the intake is approximately 1/3 the distance from the shorter wall. Mount no further than 4-6 inches from the wall. "

I can't quite envision this. I also see "don't put yourself between the dust source and the intake" suggested a lot. I feel like you're generally standing at the dust source so that's kind of irrelevant. Perhaps spacing out from any walls the 4-6 inches and generally placing towards the center of the garage will be adequate?

[mikefm101]

My basement shop is half as wide as yours, but about 6 feet longer.

My filter is located at one end of the shop. It is a few feet past the blade of the table saw on the outfeed side. There is maybe six feet between the filter exhaust and the end of the shop. It is about four feet from the right hand wall.

This seems to work well as if I am doing a lot of TS work I will start it up a few minutes before I start to get the air flowing.

Also, everything else I do that creates dust is upwind of the intake and because the shop is narrow basically in line with the intake.

However from what I understand the objective is to get a circular flow of air, so you may actually do better having a squarer shop than me.

The AFS has made a big difference, btw. I used to get runny noses all the time and that stopped once I started using the AFS.

Photo below is from one end of the shop. You can see the AFS filter above the TS.

Mike

[Howard Acheson]

Here is some info that may be of interest and may be helpful in answering your question about location.

Here are some general rules based on Nagyszalanczy's "Workshop Dust Control" and some of my own experiences and thoughts.

The two most important criteria for an air cleaner are the CFM and the filters. You want a CFM factor that will clean the size of your shop and a filter that removes the particle size that you are concerned about.

To determine the size or required air flow, use this formula: Volume of your shop (Length x width x Height) times Number of air changes per hour (typically 6 - 8) divided by 60. This will give you an answer in Cubic Feet per Minute which is how air cleaners are measured. MOST AIR CLEANER MANUFACTURERS RATE THE CFM OF THE FAN ONLY, but there are losses due to the filters. If you are building your own or if the air cleaner you are purchasing rates only the fan, figure you will lose about 25 - 40% for filtering losses.

As important as the air cleaner size is how and where you mount it. Try to mount at about 8-10 feet above the floor (no lower than 6'or 2/3 of the floor to ceiling distance if less than 8' ceiling). Mount along the longest wall so the intake is approximately 1/3 the distance from the shorter wall. Mount no further than 4-6 inches from the wall.

The exhaust is the largest determiner of the circulation pattern. You are trying to encourage circulation parallel to the floor/ceiling so ceiling mounting is not recommended. Use a smoke stick (or a cigar) to observe and maximize circulation. Use a secondary fan to direct air to the intake if necessary. Also, consider that a standard 24" floor fan moves a lot of air and, in some shops, just positioning it in a doorway with a window or other door open can accomplish as much or more than an air cleaner. It's all in the circulation patterns.

The exhaust is the clean air so that is where you want to position yourself. Do not place the air cleaner over the a dust producer. That will guarantee that the operator will be in direct line between the dust producer and the air cleaner. The operator wants to be in the clean air stream. If the dust has to pass your nose to get to the air cleaner, you get no benefits. If you have an odd shaped shop, two smaller units may be better than one large one.

DO NOT RELY ON A AIR CLEANER TO ACT AS A DUST COLLECTOR. The purpose of and air cleaner is to keep airborne dust in suspension and reduce airborne dust as quickly as possible AFTER THE DUST PRODUCER HAS BEEN TURNED OFF.

Finally, if you are looking for health benefits, you will not find any air cleaner manufacturer that makes health claims because there are few health benefits. CATCHING DUST AT IT'S SOURCE IS THE BEST LONG TERM GOAL. Rick Peters', author of "Controlling Dust in the Workshop", makes the point that spending your money getting the dust at its source is a better investment than trying to capture it after it is already airborne. If the dust is in the air, it's going to be in your nose and lungs too. Robert Witter of Oneida Air Systems has noted that "overhead cleaners can only lower ambient dust levels AFTER THE SOURCE OF EMISSIONS IS SHUT DOWN, and they take several hours to do this. This is why they are not used in industry." The absolute best answer, if health is the primary concern, is to use a NIOSH approved respirator. The dust cleaner will help keep your shop cleaner but have minimal or no health benefits. OSHA takes this position too. They measure the number of particles per a volume and most air cleaners will not satisfy their specs.

[DFJarvie]

I got the same deal which was great. I have about the same size garage and originally had it above where I mostly work. Once I say the size of it I put it down the other end since it would block some of the light. Works great.