Sturdee Filtered Air Blower

[Sturdee]

I have previously indicated that in my new finishing shed I will be installing an old evaporative cooler converted for blowing clean filtered air into the room.

Similar type units are available from Carbatec at a cost of $ 689. Admittedly they have a timer switch and two filters which filter 100 % of particles 5 microns or larger and around 85 % of particles up to 1 micron.

My unit only has one filter and only filters 100 % of particles 5 microns or larger and has no timer switch. If a timer switch is desired they are easily obtained from old dryers but the way I will be using the blower it is not required.

I used an old Bonaire evaporative cooler collected from my favourite pickup place, the council hard rubbish collection, and purchased the filter from Carbatec for $ 35. The chipboard, timber, some bolts and gap filler I had so it was a cheap machine to make.

Adapting the cooler was easy. I first removed the back and the evaporative bits from inside that are no longer required. I then bolted the chipboard onto the cooler/blower with some nuts and bolts, made the opening at the back to hold the filter, and when installed into the wall I will attach the battens to hold the filter in place with some Sturdee knobs.

If I was making it for the main workshop I would alter the back so that the filter would slide up for cleaning, attach a set of decent castors and some handles for easy moving around and paint it orange of course. :D

These pictures show the details.




Peter.

[ozwinner]

Looks like it will filter 100% ( pssst Peter take the plastic off the filter ).
Good to see you havent been idle while on holiday.

Al

[Wayne Davy]

Sturdee,

Great Job (as usual)!!!! Should work very, very well.

Must say, I am very surprised by the (lack of) colour :rolleyes:



p.s. Glad to see you back btw

[Bunyip]

Peter,

Very resourceful - I may have to borrow that idea :)

Since it is going inside the finishing shed, I presume that you are only going to operate it for your prep work, and not during or immediately post finishing??

I would hate to hear that you injure yourself as a result of explosion or fire. The unit will provide an effective ignition source for flammable vapours, should the conditions be right.

[Sturdee]

The unit will fit into an opening through the wall with only the front of the original blower coming into the finishing shed. The back and the motor will be in the adjacent garden shed. As such the timber will be painted white after the installation which hopefully I will get done tomorrow. :)

Yes I will only use it before and after polishing to make sure that the air is clean and dust free and will be used in conjunction with an exhaust fan.

Al, what holiday? :rolleyes: I have built the bench and shelving on the left side and the deep cupboards that are also to go through the wall.
And I thought that the plastic was to keep the filter clean. :D

Peter.

[Goldy]

Such a great idea have to make one as well. Got a old one from cash converters for $29 bargain still works great.
Just got one question where would be the best place to permanently mount it, the size of my shed is 10 meter bye 6 meter shed.

regards Goldy.

[NewLou]

Hey sturdee didn'y you nick that outta my backyard???? :eek:

:D :D :D :D :D

As always great practical functional idea that I'll help save newbie's like me a squilion .............. keep up the inspirational work sturdee!!!!

Regards Lou

[Sturdee]

Such a great idea have to make one as well. Got a old one from cash converters for $29 bargain still works great.
Just got one question where would be the best place to permanently mount it, the size of my shed is 10 meter bye 6 meter shed.

regards Goldy.

Hard to say where to mount it Goldy however probably as close to the main dust source without tripping over it.

If your shed is high enough mount it against the ceiling like the bought ones normally are but probably the best place would be close to the table saw. Maybe under the saw extension table or put it on castors and wheel it around to the part of the shop you are working in at the time.


Peter.

[Sturdee]

Hey Sturdee didn't you nick that outta my backyard???? :eek:


I know Wagga is the home of big back yards, but surely yours doesn't extend right up to Craig Road, Donvale where I souveneered mine from the nature strip. :D :D :D


Peter.

[Twisty]

Sturdee
Went to Carba-Tec web site what part of the tool shop do I find the Filters, to make the make the air cleaner:((
Cheers Twisty

[Sturdee]

When I got mine I just went to the Melbourne branch of CT and asked for a replacement filter for one of their room air filters. I think it was the CTF1500.

See page 28 of their catalogue. I can't see them listed as a separate item but they did sell them. Hares & Forbes also had them available.


Peter.

[BobL]

Sturdee, I hate to dampen your enthusiasm but I have done a lot of work in airfiltering and have the following to offer.

If you're using your filter unit to blow air from the outside into a dusty shed I wonder if the filter is just a side show and you might be better off removing the filter altogether and just getting the unit to blow a lot more outside air blowing into the shed.

Consider this: While working a shed will contains somewhere between 100 to 1000 more particles per cubic foot than outside air. Running a fan/filter for a couple of hours will bring the particle count down significantly but as long as the ordinary air outside contains less particles than the air inside, a filter on this incoming air won't assist much in bringing the particle count down whereas increased air flow will. These filters will also eventually clog futher reducing the air flow.

The critical factor here that few people appreciate is that unless you cover up every surface (wood metal paint) in your shed with something like a tough plastic, these surfaces continually generate particles (even the plastic generates a few particles) so the air inside the shed will just about always have a greater particle density than outside.

Yes there will be some dusty days when the outside air is more dusty than usual, maybe even dustier than inside the shed, and then a filter will help. This will also depend also on where you live but most days of the year this won't be the case.

Another thing to consider is that the particle size distribution of external air generally hits a peak around 0.3 microns and drops pretty quickly for particles greater than 20 microns, - so a 5 micron filter will not filter out the bulk of the outside air particles anyway.

Using the filter as an internal air scrubber the situation changes considerably but for most sawdust generation situations when the climate is favourable a large volume of outside air is sufficient to keep a relatively clean shed. One of the simplest way to achieve this is to put your final DC outlet outside your shed.

BTW I have a 40 cuf/min 99.997% (no filter is ever 100%) 0.3 micron hospital grade air scubber in my garage that I was thinking of putting up in my shed. However, having my DC outside means I currently get more than enough fresher/cleaner air from the outside exchanged in my shed that I don't think I will bother putting it up - maybe if/when I get a bigger shed.

[Sturdee]

Thanks Bob, your comments are appreciated and informative.

However this thread was started on 8/6/04 and recently reopened by queries on how to build a room air filter and where I obtained the filters from.

You joined in Feb 06 and obviously failed to understand that the room air filter was to blow air into my finishing room. This room, in a converted metal shed, was the subject of a separate post http://www.woodworkforums.com/showthread.php?t=8964 which shows that this room is fully lined, painted and carpeted.

It also showed that it has a good strong exhaust fan hence the need to blow filtered air INTO the room to compensate for the air removed by the exhaust fan.

Using the filter as an internal scrubber is not needed as it is a finishing room not a workshop where dust is generated.

The sanding, scraping, etc is done in the workshop and after final dusting with an air duster the piece that I’m working on is moved to the finishing room for applying a finish, usually french polish where the most dust generated is denibbing with some steel wool.

In my workshop I have proper dust control with all machinery connected via ducting to a cyclone or mini cyclones, located outside the workshop, and yes I regularly clean filters and dust bags.



Peter.

[BobL]

Hi Peter, OK your explanation now makes a lot more of sense. A finishing room sounds like a very nice thing to have - I'm dead jealous.

It's a pity you didn't live in the west, last year I had 2 complete 80 cuf/min and 2 40 cuf/min 0.3 micron HEPA filter units that we decommissioned \ from our clean laboratories that I couldn't give away. One of these would have been ideal for your application. Two of these ended up on someones farm where the metal housing are being used as feed boxes. :oo: