Anybody ever heard of or done an HVAC plenum in plywood? Would/could it
work???

In article , "Tim Taylor" wrote:
Anybody ever heard of or done an HVAC plenum in plywood? Would/could it
work???

I can't even begin to imagine that it would meet fire-safety codes...

--
Regards,
Doug Miller (alphageek at milmac dot com)

It's time to throw all their damned tea in the harbor again.

On Mon, 31 Jul 2006 22:03:50 -0400, "Tim Taylor"
wrote:

Anybody ever heard of or done an HVAC plenum in plywood? Would/could it
work???

Why? Constant hot air flow & THIN wood?

"Tim Taylor" wrote in news:_OOdnT4PS50YK1PZnZ2dnUVZ_t-
:

Anybody ever heard of or done an HVAC plenum in plywood? Would/could it
work???




For AC it might work. For heat? Forget it.

"R. Pierce Butler" wrote in message
. 1...
"Tim Taylor" wrote in
news:_OOdnT4PS50YK1PZnZ2dnUVZ_t-
:

Anybody ever heard of or done an HVAC plenum in plywood? Would/could it
work???




For AC it might work. For heat? Forget it.


Yea, that's what I was talking about, just air. He's got electric heat. It's
just in a garage, and was tossing around the idea of just a plenum box and
about 20 feet of ductwork to say. It would be at the back of the garage on
the ceiling just something to distribute the air a little more evenly. Metal
is no big deal, but he's got about 50 sheets of plywood laying around and
was just asking me. I don't have a clue as I did mine in metal since it's
heat and air. That's why I wanted to ask here. Didn't mean to get the code
police after me and to ruffle any feathers.

The air return in my old house was hardboard nailed between
floor joists. Plywood should be fine for A/C or return.

Tim Taylor wrote:
Anybody ever heard of or done an HVAC plenum in plywood? Would/could it
work???

Tim,

Something your friend may want to consider is the possibility of mold
growing on the inside of that plenum. Unless it's coated, the wood will
absorb moisture and he will have the potential for some bad mold problems.

Bob S.


"Tim Taylor" wrote in message
m...

"R. Pierce Butler" wrote in message
. 1...
"Tim Taylor" wrote in
news:_OOdnT4PS50YK1PZnZ2dnUVZ_t-
:

Anybody ever heard of or done an HVAC plenum in plywood? Would/could it
work???




For AC it might work. For heat? Forget it.


Yea, that's what I was talking about, just air. He's got electric heat.
It's just in a garage, and was tossing around the idea of just a plenum
box and about 20 feet of ductwork to say. It would be at the back of the
garage on the ceiling just something to distribute the air a little more
evenly. Metal is no big deal, but he's got about 50 sheets of plywood
laying around and was just asking me. I don't have a clue as I did mine in
metal since it's heat and air. That's why I wanted to ask here. Didn't
mean to get the code police after me and to ruffle any feathers.

"BobS" wrote in message
...
Tim,

Something your friend may want to consider is the possibility of mold
growing on the inside of that plenum. Unless it's coated, the wood will
absorb moisture and he will have the potential for some bad mold problems.

Bob S.

Bob, you know that's something I never thought of!! That's why I wanted some
others thoughts on the matter. It's like looking for something dropped in
the grass, extra pairs of eyes are always helpful! Thanks so much!!! And
thanks everybody else!! Metal it'll be.

Tim,

Read the 'answers' to date . . . a lot of validity . . . HOWEVER . . .

Half of my basement is finished {NO - I didn't do it - crappy idea and
crappy work}and the duct from the heater is 'covered' {boxed in}with the
wood paneling. When we bought the house it was gas-fired hot-air HEAT ONLY.
Later we replaced the old heater with a newer Heat & AC unit.

I am now in the process of 're-furbishing' out up-stairs bathroom. While the
'air out' grill is about a 4 x 11 inch rectangle, the ducting that feeds it
seems to be a 4in circular 'pipe'. For I don't know how many reasons
{'paranoid' being one}, I wouldn't want a 'hot air' duct of thin wood ONLY.
Some 'el cheapo' insulated 'Dryer Duct' - even the flexible kind - would do
for the actual 'transfer conduit'. It could then be 'disguised or
'supported' by the plywood.

Regards & Good Luck,
Ron Magen
backyard Boatshop

"Tim Taylor" wrote in message
...
Anybody ever heard of or done an HVAC plenum in plywood? Would/could it
work???

"Ron Magen" wrote in message
news:BzKzg.4713$zV6.4427@trnddc03...
Tim,

Read the 'answers' to date . . . a lot of validity . . . HOWEVER . . .

Half of my basement is finished {NO - I didn't do it - crappy idea and
crappy work}and the duct from the heater is 'covered' {boxed in}with the
wood paneling. When we bought the house it was gas-fired hot-air HEAT
ONLY.
Later we replaced the old heater with a newer Heat & AC unit.

I am now in the process of 're-furbishing' out up-stairs bathroom. While
the
'air out' grill is about a 4 x 11 inch rectangle, the ducting that feeds
it
seems to be a 4in circular 'pipe'. For I don't know how many reasons
{'paranoid' being one}, I wouldn't want a 'hot air' duct of thin wood
ONLY.
Some 'el cheapo' insulated 'Dryer Duct' - even the flexible kind - would
do
for the actual 'transfer conduit'. It could then be 'disguised or
'supported' by the plywood.

Regards & Good Luck,
Ron Magen
backyard Boatshop


Thanks Ron. As I said, it's air only and in a garage and he has a ton of
plywood laying around. That's why we even thought of it. The thing is just
blowing straight out of the a-coil now hitting the ceiling and dispersing
air real random. I think that everyone has talked me out of doing it in
wood, mold being the biggest reason. And if he wants to cover the metal duct
with it, then he can have fun doing and get rid of some of the ply too.
It'll just be the width of the garage with a half dozen or so vents pointed
out to the working area, no other ducting would be needed. Thanks for the
tip!

"Tim Taylor" wrote in message
...
Anybody ever heard of or done an HVAC plenum in plywood? Would/could it
work???

"Tim Taylor" wrote in
m:


"BobS" wrote in message
...
Tim,

Something your friend may want to consider is the possibility of mold
growing on the inside of that plenum. Unless it's coated, the wood
will absorb moisture and he will have the potential for some bad mold
problems.

Bob S.

Bob, you know that's something I never thought of!! That's why I wanted
some others thoughts on the matter. It's like looking for something
dropped in the grass, extra pairs of eyes are always helpful! Thanks so
much!!! And thanks everybody else!! Metal it'll be.




I can't see where moisture or mold would be a problem. The air is dry,
cold, and that alone should keep things free of mold. I would not hesitate
to use plywood as a AC only plenum. I might paint or some other water
based coating for the inside but that is just to keep things clean on the
inside.


On the plus side you don't need to insulate the plenum as much (if at all)
if it is made of plywood.

"R. Pierce Butler" wrote in
. 1:

snip

I can't see where moisture or mold would be a problem. The air is
dry, cold, and that alone should keep things free of mold. I would
not hesitate to use plywood as a AC only plenum. I might paint or
some other water based coating for the inside but that is just to keep
things clean on the inside.


You don't think that there would be any condensation issues?

Molds seem to grow easily in many systems, if the HVAC folks are telling
any truths...

Patriarch,
thinking the metal isn't terribly expensive...

On Tue, 1 Aug 2006 08:50:13 -0400, "Tim Taylor"
wrote:


"R. Pierce Butler" wrote in message
.1...
"Tim Taylor" wrote in
news:_OOdnT4PS50YK1PZnZ2dnUVZ_t-
:

Anybody ever heard of or done an HVAC plenum in plywood? Would/could it
work???




For AC it might work. For heat? Forget it.


Yea, that's what I was talking about, just air. He's got electric heat. It's
just in a garage, and was tossing around the idea of just a plenum box and
about 20 feet of ductwork to say. It would be at the back of the garage on
the ceiling just something to distribute the air a little more evenly. Metal
is no big deal, but he's got about 50 sheets of plywood laying around and
was just asking me. I don't have a clue as I did mine in metal since it's
heat and air. That's why I wanted to ask here. Didn't mean to get the code
police after me and to ruffle any feathers.



If it is just for distribution and the duct is in the conditioned air
area, that is, it is not going through your attic or other
unconditioned area it would be fine.

My kitchen uses the soffit above the cabinets for distribution only,
with three registers. But it is in the insulated, conditioned air
area, so it works just fine. it is fed from the attic area by
insulated metal duct.

Frank

Patriarch wrote in
. 97.136:

"R. Pierce Butler" wrote in
. 1:

snip

I can't see where moisture or mold would be a problem. The air is
dry, cold, and that alone should keep things free of mold. I would
not hesitate to use plywood as a AC only plenum. I might paint or
some other water based coating for the inside but that is just to keep
things clean on the inside.


You don't think that there would be any condensation issues?

Molds seem to grow easily in many systems, if the HVAC folks are telling
any truths...

Patriarch,
thinking the metal isn't terribly expensive...


Metal is not cheap. Have you seen the price of copper lately? Go check
out copper wire at HD or Lowes.

When I put a furnace in my house it cost as much for the ductwork as it did
for the furnace and the furnace was very expensive. I did all the labor
installing the ductwork and furnace.

Condensation? There shouldn't be any. If you get condensation with wood
then the condensation with metal would be worse. Wood is an insulator and
metal a conductor.

"R. Pierce Butler" wrote in
. 1:

Patriarch wrote in
. 97.136:

"R. Pierce Butler" wrote in
. 1:

snip

I can't see where moisture or mold would be a problem. The air is
dry, cold, and that alone should keep things free of mold. I would
not hesitate to use plywood as a AC only plenum. I might paint or
some other water based coating for the inside but that is just to
keep things clean on the inside.


You don't think that there would be any condensation issues?

Molds seem to grow easily in many systems, if the HVAC folks are
telling any truths...

Patriarch,
thinking the metal isn't terribly expensive...


Metal is not cheap. Have you seen the price of copper lately? Go
check out copper wire at HD or Lowes.

When I put a furnace in my house it cost as much for the ductwork as
it did for the furnace and the furnace was very expensive. I did all
the labor installing the ductwork and furnace.

Condensation? There shouldn't be any. If you get condensation with
wood then the condensation with metal would be worse. Wood is an
insulator and metal a conductor.



The duct tubing in my CALIFORNIA home is aluminum, or galvanized steel.
An insulating blanket is wrapped around it.

I realize that we're different here in the Bay Area, and folks do things
their own way elsewhere. Copper, though, would be pretty 'special'.
The local newsies have run stories about lowlifes stealing copper from
construction sites for the recycling cash. And some fool tries to strip
a power junction box, getting partway before something struck him...

Nope. No copper here. YMMV.

Patriarch

Patriarch wrote in
. 97.136:

"R. Pierce Butler" wrote in
. 1:

Patriarch wrote in
. 97.136:

"R. Pierce Butler" wrote in
. 1:

snip

I can't see where moisture or mold would be a problem. The air is
dry, cold, and that alone should keep things free of mold. I would
not hesitate to use plywood as a AC only plenum. I might paint or
some other water based coating for the inside but that is just to
keep things clean on the inside.


You don't think that there would be any condensation issues?

Molds seem to grow easily in many systems, if the HVAC folks are
telling any truths...

Patriarch,
thinking the metal isn't terribly expensive...


Metal is not cheap. Have you seen the price of copper lately? Go
check out copper wire at HD or Lowes.

When I put a furnace in my house it cost as much for the ductwork as
it did for the furnace and the furnace was very expensive. I did all
the labor installing the ductwork and furnace.

Condensation? There shouldn't be any. If you get condensation with
wood then the condensation with metal would be worse. Wood is an
insulator and metal a conductor.



The duct tubing in my CALIFORNIA home is aluminum, or galvanized steel.
An insulating blanket is wrapped around it.

I realize that we're different here in the Bay Area, and folks do things
their own way elsewhere. Copper, though, would be pretty 'special'.
The local newsies have run stories about lowlifes stealing copper from
construction sites for the recycling cash. And some fool tries to strip
a power junction box, getting partway before something struck him...

Nope. No copper here. YMMV.

Patriarch


all metals have gone up in price. Copper is 4 times what it used to be a
year or so ago. Aluminum, zinc, steel and more have had increases too. I
looked at some copper tubing at Lowes two weeks ago. It was close to $5.00
per foot! A machinist across town told me that alumunim has had similar
increases. Steel and zinc and the rest are starting to go up too.