am in desperate need for advice about my basement woodshop and the
furnace/central air unit. we share the same space, with no separation.
the local utility guy just told me on the phone that my options are as
follows, or I will kill the unit ...
1) Turn off the unit while working (freeze the family.) at the end of
the session, open the front, vacuum it out and the area immediately
around it before turning it back on.
2) Box in the unit and figure out someway to supply air.
a) new outside air supply? sounds expensive.
b) louvered opening in the ``wall'' that backs on to the
laundry room? (lint issues, but obviously much less than sawdust.)
c) cut the access door, with louvers, in the laundry room
wall, which would elimate the workspace used by SWMBO for her jewelry
what do all you guys do about this?
REALLY want to avoid having to move to the garage ...
UPDATE: I currently have a Jet 650 CFM dust collector with two
diverters to handle tablesaw, router, jointer and planer, plus an air
cleaner that I built from the American Woodworker plans a few years
UPDATE 2: anyone in the Trenton area want to go in on an
office/warehouse lease with me? there is a place on Flock Rd. Have yet
to ask the rent ...
Talking up to the vocal ...
(remove the star etc ....)
You should have the furnace in its own room, separate from the workshop.
It should have a return air duct collecting air from the living spaces and
it should get some outside air from a relatively small duct (about 6" dia.
typically). You should not return air from the workshop, or that air will
be circulated to the other living spaces, and spread the dust around (your
wife will NOT like your hobby). Don't circulate heat to the workshop from
the furnace or collect return air from that area.
(I work in a garage with only a 1500 W radiant heater and when its 50 deg F
in there, its "warm". Some days its between 34 and 44 deg F. If you need
some heat, use an electric radiant unit or baseboard.
| am in desperate need for advice about my basement woodshop and the
| furnace/central air unit. we share the same space, with no separation.
| the local utility guy just told me on the phone that my options are as
| follows, or I will kill the unit ...
| 1) Turn off the unit while working (freeze the family.) at the end of
| the session, open the front, vacuum it out and the area immediately
| around it before turning it back on.
| 2) Box in the unit and figure out someway to supply air.
| a) new outside air supply? sounds expensive.
| b) louvered opening in the ``wall'' that backs on to the
| laundry room? (lint issues, but obviously much less than sawdust.)
| c) cut the access door, with louvers, in the laundry room
| wall, which would elimate the workspace used by SWMBO for her jewelry
| what do all you guys do about this?
| REALLY want to avoid having to move to the garage ...
| UPDATE: I currently have a Jet 650 CFM dust collector with two
| diverters to handle tablesaw, router, jointer and planer, plus an air
| cleaner that I built from the American Woodworker plans a few years
| UPDATE 2: anyone in the Trenton area want to go in on an
| office/warehouse lease with me? there is a place on Flock Rd. Have yet
| to ask the rent ...
| Larry Levinson
| Talking up to the vocal ...
| (remove the star etc ....)
we haven't noticed a problem with the dust going from the workshop,
through the furnace, to the rest of the house. apparently, it just
goes from the workshop, to the furnace, AND STAYS THERE. sigh. but
thanks. May be a 6" duct for outside air isn't such a bad idea ..
though, punching that hole in the wall doesn't sound like fun ...
Talking up to the vocal ...
(remove the star etc ....)
| we haven't noticed a problem with the dust going from the workshop,
| through the furnace, to the rest of the house.
Nor have I, with my forced-air natural gas heater, which shares a space with
the shop. Keep in mind that the air supply in the room where the furnace is
generally does *not* mix with the air that's being heated, nor should it
ideally. The air in the furnace room provides the oxygen for combustion of
whatever you're burning in order to generate heat. The air to be heated is
drawn in from the returns in the house and is kept separate from the air in
the shop (and the combustion gases) by a heat exchanger. The only shop air
that mixes with the heated air is what leaks around the edges of the filter
on the return plenum.
If you're going to work in the same room as your heater, you need
ventilation. I always keep a window open, even when I'm not doing anything
woodworkingly that would require it.
I shut off the heater and vacuum it out every week or so. You don't want
sawdust or anything caking up in there and being ignited. Generally I don't
let sawdust aerosolize enough to warrant the danger of explosion. You
really want to think about dust collection for the tools.
I avoid using oil-based products in that room at all, but if I have to I do
it at the opposite end of the room, under a window that has forced
I know this may sound costly, but it may turn out to be about a draw
compared with some other options you listed.
You didn't say what kind of furnace you have but sounds like it depends on
inside air to be drawn in for combustion. Look at direct vent furnaces.
Mine is a Carrier that uses 2" PVC pipes to draw in outside air and vents
the exhaust via another 2" PVC pipe. I also have a Central air unit.
Don't know how old the unit is but check with your local utility and see
about any upgrades they may be co-sponsoring with local furnace suppliers to
encourage installing energy efficient appliances. We were pleasantly
surprised when we switched from electric to natural gas and got a $100
rebate from the utility as well as $200 from Carrier.
I too have a furnace in the work area. However my concern is the pilot
light and open burners in the gas furnace. Will these create a problem
in a 21' X 20' garage if I cut a couple of dozen miter corner? or a
several half lap joints in a 2 X 4? The air is circulated to the house
through a return air system, but the burner gets its air from the garage
Larry Levinson wrote:
My shop shares space with a gas forced air furnace and two gas water
heaters. There is no wall separating the shop and I've never had a problem.
I change the furnace filter a couple times a year - and it doesn't look that
bad when I do. All of this is in an unfinished basement with a double
garage door and a Delta 1100 cfm collector. All return air comes in from
upstairs. The table saw (the worst offender with dust) is about 25 feet
away by the garage door, which I open even with the DC connected. I never
paint or use solvents by the water heaters - I get far away, by the garage
door or go outside whenever possible.
On Wed, 21 Jan 2004 14:36:56 -0500, Larry Levinson
You really need to do this, because you don't want to be drawing your
combustion air from heated space. Ideally, the furnace would
be in a little room by itself, with a direct opening through an
exterior wall to the outside air. Alternatively,
you could have a duct to the outside air, and a separated combustion
furnace, with no need to have the furnace in a room by itself.
I do know that there are limits to what you're allowed to do to get
outside air into a furnace. The general idea is that if a long duct
for outside air is required, you're really supposed to be using a
separated combustion furnace. You can't just run a long air duct
right up to an ordinary furnace - that's what separated combustion
furnaces are supposed to be for.
Why would you have lint in your laundry room? Are you running an
unvented dryer in there or something? Anyway, if the laundry room is
unheated and has an opening to the outside air, you're in business.
If the laundry room is heated, you're going to be sending heated air
out of the room and up the vent, while causing cold air to have to
come into the room from somewhere else in the house - not good, it's
just like when you have to open a door to have a decent fire
in a fireplace that was built with no proper combustion air intake.
Is this different form (b).?
Furnace is in a room by itself with an opening right by the furnace
for outside air - this is fairly typical in daylight basements.
Your problem is your dust collector system. If you have fine dust in the
air while the furnace is running, it will draw the dust in with the
combustion air from your shop. The dust goes in with the air into the
burner tubes where it mixes with the gas. The gas/air mixture then
goes up through the burner plate or orifices, but the dust will be left
behind as it settles out of the air stream, eventually plugging the
burners. If the fires are off (shut the furnace down), there is no
air flow and no dust gets transported in and deposited.
HOWEVER, the dust-laden air that plugs your furnace also plugs your
lungs and you are setting yourself up for serious health problems in
the future if you don't eliminate the flour-like dust from the air. It
will get into your lungs as you breathe in and stay there, causing
polyps, cancer, asthma or any number of other respiratory ailments
(anyone for emphysema?).
A well-designed cyclone dust collection system with proper 0.3 micron
filtration after the blower will eliminate the dust problem. If you
have a 10" table saw, you need a cyclone dust collector that provides
a "real-world" 900-1000 CFM, at least, and don't use the cloth filter
bags. You need pleated, high-efficiency filters.
Bill Pentz nearly died from the effects of wood dust aggravating a
pre-existing condition. He has done extensive research on the subject
and has designed a cyclone dust collector. I produce a kit based
on his research and design work by his invitation. I also produce a
matching welded steel blower housing to match. Add a motor, impeller,
filters, and ductwork and you have a first-class cyclone dust collection
system for less than the price of a new Kirby, Rainbow, or Interstate
Engineering household vacuum cleaner. Not only will you get rid of the
furnace problem, but you'll be protecting your health at the same time.
For more info, see Bill's site at:
and the kit and blower-housing information at:
Contact me privately if you have further questions.
Larry Levinson wrote:
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