AmericanWoodworker-ProjectPlan-AirScrubberTrio.pdf

(978 KB) Pobierz
®
®
PROJECT PLAN
Air Scrubber Trio
This project originally appeared in
American Woodworker
magazine.
For subscription information, visit www.americanwoodworker.com
Please note that pages that appeared in the magazine as advertisements will not be included with this pdf. Page numbering may be
interrupted if an advertisement ran within the original story. Addresses, phone numbers, prices, part numbers and other information
may have changed since original publication
Copyright© 2006 Home Service Publications, Inc. All rights reserved. Unauthorized reproduction, in any manner, is prohibited.
American Woodworker
is a registered trademark and
Workshop Tips is a trademark of RD Publications, Inc.
EDITOR: DAVE MUNKITTRICK •
ART DIRECTION: JOEL SPIES • PHOTOGRAPHY: BILL ZUEHLKE
• ILLUSTRATION: JAN BOER & FRANK ROHRBACH
42
A m e r i c a n Wo o d w o r k e r
JUNE 2000
three shop-made
machines that
clear the air.
ust haze. Even if you have a dust collection sys-
tem you’ve probably found yourself in the
middle of it. This fine dust settles onto all the sur-
faces of your shop where it is a fire hazard (as well
as a nuisance) and can lead to respiratory problems.
A strategically placed air scrubber can trap much of
this dust, keeping your shop cleaner and safer.
Here are three shop-built air scrubber designs:
a between-the-joists design for small shops with
limited headroom; a hanging model for larger
shops; and a benchtop model to catch dust near its
source. Each scrubber is based on a kit available
from Penn State Industries (see Sources, page 47).
Once you’ve gathered your materials, you can
build any one of these scrubbers in a day. The
benchtop and between-the-joists models can be
built for $150, the larger model for $220. If you are
resourceful enough to find a used furnace blower
and use shop scrap, any model can be built for $60.
Although these designs are similar to scrubbers
available commercially, our scrubbers either cost
less or have better features. To make it easy for you
to find components, we’ve used kits and filters
available through catalogs (see Sources, page 47).
Remember that no air scrubber is a substitute for a
D
A m e r i c a n Wo o d w o r k e r
JUNE 2000
43
Air Scrubbers
dust collector attached to your machines. It is always best to
catch dust at its source, before it becomes airborne (see
Q&A, page 104). However, an air scrubber can trap much of
the fine dust that eludes your primary dust-collection system.
WHICH DESIGN IS BEST
FOR YOUR SHOP?
MAKING THE SCRUBBERS
These scrubbers are variations of the same machine, differ-
ing in size and where they are placed in your shop. Choose the
one that’ll work best for you.
The benchtop model is small enough to be used where it’s
needed, whether it be on your bench when hand sanding, or
placed on a stool near your lathe. The between-the-joists
model is ideal for a small (500 sq. ft.) basement shop with low
ceilings. The larger model has two blower fans enabling it to
clean air in a shop twice as large (up to 1,000 sq. ft.) as the
other two models.
The capacity of your scrubber is another important con-
sideration. For occasional woodworking you need a scrubber
that can recirculate all the air in your shop six times every
hour or once every 10 minutes.A scrubber’s performance is
measured by the number of cubic feet per minute (cfm) of air
it can handle.
You can determine exactly how many cfm are required to
change the air in your shop six times every hour by measur-
ing the cubic feet of air space in your shop (LxWxH) and
dividing that number by 10 (professional woodworkers
should divide by 6). For example, if your shop floor space is
25 ft. by 20 feet and your ceilings are 8-ft. high, then your cfm
requirements are: 20 x 25 x 8 = 4,000 cubic ft./10 minutes
which is 400 cfm. Each of the motors in the Penn State kits are
rated at 465 cfm, which is adequate to handle a 500-sq.-ft.
shop with 8- to 9-ft. ceilings. For a 1,000-sq.- ft. shop, use two
of the single-blower units or build the larger double-blower
unit.When in doubt, over do it. This is one case where more
is definitely better.
ABOUT FILTERS
All three models are similarly built.
1. Cut plywood to size.We used Baltic birch, (see Sources,
page 47) but any 1/2-in. plywood will work.
2. Cut the cleats to length.
3. Glue and nail cleats to the top and bottom. Be sure to
position the cleats precisely, as shown for each model
(See Figs.A, B or C), to allow room for the filters, stops and
gaskets on the intake end and for the back and gasket on
the exhaust end.
4. Glue and nail the long stops at the end of each pair of
cleats.
5. Use screws to attach the sides to the cleats on the top and
bottom.
6. Glue and nail the short vertical stops on the exhaust and
intake ends.
7. Lay out the motor flange location on the inside of the
back. Set the motor in place and mark the screw hole
locations. Make lines 3/4-in. inside the motor flange out-
line for the exhaust port cutout. Cut holes for the exhaust
port and electrical box with a jigsaw.
8. Drill bolt holes for the motor. The holes need to be
countersunk on the outside face of the back to allow for the
exhaust louvers.
9. Mount the motor to the back (Photo 1).
10. Mount the electrical box and wire according to your
choice of switches (see Figs.A, B or C). (Between-the-joists
model must be wired after the back is attached.)
11. Apply gasket to back stops.
12. Fasten the back to the scrubber with screws.
13. Screw the exhaust louvers over the port.
14.Add the filter clips and apply gasket material to the fil-
ter stops. Install the filters.
15. Ease the edges with a router and a 1/8-in. round-over
bit or sandpaper.
There are usually two filters used in an air scrubber: a pre-fil-
ter and a pocket filter. The pre-filter prolongs the life of the
pocket filter by capturing most of the larger particles first. The
pocket filter has a much greater surface area for trapping the
finer dust.
To make a scrubber small enough to fit on a bench we sub-
stituted a 4-in. pleated filter for the pocket filter. Pleated filters
can provide as much or more filter area as pocket filters and
are available from Grainger in different levels of efficiency (see
Sources, page 47). For our air scrubber we chose a 75-percent
efficient filter ($28) which is more efficient than the pocket fil-
ters found in most air scrubbers on the market. A 90- to 95-
percent efficient filter is available for $84. If you’re willing to
fork over the money, it’ll last longer and catch finer dust.
44
A m e r i c a n Wo o d w o r k e r
JUNE 2000
1
APPLY GASKET MATERIAL
around the cutout
after the bolt holes have been drilled. Be sure to countersink
the holes on the outside face of the back or the bolt heads
will interfere with mounting the exhaust grate.
Fig. A
Between-the-Joists
Exploded View
The between-the-joists model is especially well suited for small shops
with low ceilings. Mount to joists with corner brackets.
MATERIALS LIST
ALL MODELS
One sheet of 1/2" plywood
One 1" x 4" x 8' pine board
No. 8 x 1" finish head screws
Four 1/4" x 3/4" machine bolts,
washers and nuts
Ten ft. 1/8" gasket material
16/3 SJ power supply cord
Wire nuts
Insulating bushing
Grounded plug
Ribbon
BETWEEN-THE-JOISTS
Penn State Industries kit
#ACAW1 (includes motor blower
and exhaust grate)
11-1/2" x 11-1/2" pre-filter and
pocket filter (see Sources, page 47)
Four 2" corner brackets
2-1/2"-deep switch box with inte-
gral cable clamps and plaster ears
Spring-wound timer with hold
HANGING
Penn State Industries kit
#AC930 (includes 2 motor blow-
ers, 2 exhaust grates, pre-filter and
pocket filter)
3-1/2"-deep switch box with inte-
gral cable clamp and plaster ears
Pull-chain switch
Single gang blank cover plate
(drill for pull chain)
Four (additional) 1/4" x 3/4"
machine bolts
Four 1/4" x 2" eye bolts
Twelve 1/4" nuts and washers
Four 60 lb. ceiling hooks
#2 twin-loop chain
Four connector links
BENCHTOP
Penn State Industries kit
#ACAW2 (includes motor blower,
exhaust grate and pre-filter)
2-1/8"-deep handy box with 1/2"
knock-outs
1/2" chase nipple
1/2" close coupling
3/8" 2-screw cable clamp
In-line rocker switch
Blank handy box cover
Two 6-1/2" handles
Eight rubber feet
12" x 24" x 4" pleated filter
ADD-ONS
10" x 3-1/4" x 4" stack boot
Flexible dryer vent hose
Hose clamp
Remote control
One-hour timer switch with hold
See Sources, page 47.
THE FINISHING
TOUCHES
Detail 1
Wiring Diagram
Mount the between-the-joists
scrubber with corner brackets
(Photo 3). The larger model
should be hung using eye bolts,
ceiling hooks and chain. Add
handles and rubber feet to the
benchtop model so it can be
used vertically or horizontally.
It’s best to place a scrubber
where you make the most dust,
and as low as is feasible. None of
the three models are heavy, but
mounting the overhead models
safely is a two-person job.
ADD-ON FEATURES
CUTTING LIST
Overall Dimensions:
12-3/4"H x 12-3/4"W x 30"D
Part Name
A
B
C
D
E
F
Top & Bottom
Sides
Back
Cleats
Stops
Stops
Qty. Dimensions
2
2
1
4
4
4
1/2" x 11-3/4" x 30"
1/2" x 12-3/4" x 30"
1/2" x 11-3/4" x 11-3/4"
3/4" x 3/4" x 26"
3/4" x 3/4" x 10-1/4"
3/4" x 3/4" x 11-3/4"
Material
Baltic birch ply
Baltic birch ply
Baltic birch ply
softwood
softwood
softwood
Add ribbons to the exhaust lou-
vers so you know when it’s time
to replace or clean your filters
(Photo 2). A timer switch
enables you to leave the scrubber
on when you’re not in the shop.
The exhaust port of the air
scrubber can be ducted outside,
like a bathroom fan, to vent low-
concentration fumes when
brushing or rag-applying finish
(Photo 3). The cost for parts is
less than $30. To make, simply
cut a piece of plywood slightly
A m e r i c a n Wo o d w o r k e r
JUNE 2000
45

Plik z chomika:

Inne pliki z tego folderu:

Inne foldery tego chomika:

Zgłoś jeśli naruszono regulamin