Has anyone tried to use a heat exchanger of any kind on their dryer
vent, or better yet, is there any commercially available product to do
this? I have a gas dryer so simply venting indoors likely isn't a good
option, as welcome as the extra humidity may be the few months out of
the year that I'd actually want to do this.

I realize that it's probably inconsequential in the grand scheme of
things, but it does seem wasteful to heat all that air and then just
blow it outdoors when it's 20 degrees out.

I tried to do a quick online search, but all I saw was a little
discussion and not much in the way of actual plans, products, or results.

nate

--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel

On Jan 14, 9:52*pm, Nate Nagel wrote:
Has anyone tried to use a heat exchanger of any kind on their dryer
vent, or better yet, is there any commercially available product to do
this? *I have a gas dryer so simply venting indoors likely isn't a good
option, as welcome as the extra humidity may be the few months out of
the year that I'd actually want to do this.

I realize that it's probably inconsequential in the grand scheme of
things, but it does seem wasteful to heat all that air and then just
blow it outdoors when it's 20 degrees out.

I tried to do a quick online search, but all I saw was a little
discussion and not much in the way of actual plans, products, or results.

nate

--
replace "roosters" with "cox" to reply.http://members.cox.net/njnagel

my dryer had some rotten cardboard lining the inside of the door that
served to insulate, i ripped that off, now the front door gets nice
and hot so some heat is recovered there..

also use an extra long METAL vent hose and a lot of the heat will be
recovered that way too....

if you put any significant money into this, it is unlikely that you
will get a return on the investment..

Mark

On Thu, 14 Jan 2010 19:06:23 -0800 (PST), Mark
wrote:

On Jan 14, 9:52Â*pm, Nate Nagel wrote:
Has anyone tried to use a heat exchanger of any kind on their dryer
vent, or better yet, is there any commercially available product to do
this? Â*I have a gas dryer so simply venting indoors likely isn't a good
option, as welcome as the extra humidity may be the few months out of
the year that I'd actually want to do this.

I realize that it's probably inconsequential in the grand scheme of
things, but it does seem wasteful to heat all that air and then just
blow it outdoors when it's 20 degrees out.

I tried to do a quick online search, but all I saw was a little
discussion and not much in the way of actual plans, products, or results.

nate

--
replace "roosters" with "cox" to reply.http://members.cox.net/njnagel

my dryer had some rotten cardboard lining the inside of the door that
served to insulate, i ripped that off, now the front door gets nice
and hot so some heat is recovered there..

also use an extra long METAL vent hose and a lot of the heat will be
recovered that way too....

if you put any significant money into this, it is unlikely that you
will get a return on the investment..

Mark
You don't want to recover TOO much of the heat unless you use a
"condensing" heat exchanger, otherwize the moisture you took out of
the clothes is going to run back into the dryer or make a big icycle
at the vent.

Nate Nagel wrote:

Has anyone tried to use a heat exchanger of any kind on their dryer
vent, or better yet, is there any commercially available product to do
this? I have a gas dryer so simply venting indoors likely isn't a good
option, as welcome as the extra humidity may be the few months out of
the year that I'd actually want to do this.

I realize that it's probably inconsequential in the grand scheme of
things, but it does seem wasteful to heat all that air and then just
blow it outdoors when it's 20 degrees out.

I tried to do a quick online search, but all I saw was a little
discussion and not much in the way of actual plans, products, or results.

nate

--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel

It's one of those things that has been contemplated for eons. The reason
that there is not a product for the purpose is that there are too many
issues to overcome, like humidity, condensate, corrosion, back pressure,
lint buildup, etc. and too little to gain, something like 15,000 BTU for
30 min.

wrote in message
...
On Thu, 14 Jan 2010 19:06:23 -0800 (PST), Mark
wrote:

On Jan 14, 9:52 pm, Nate Nagel wrote:
Has anyone tried to use a heat exchanger of any kind on their dryer
vent, or better yet, is there any commercially available product to do
this? I have a gas dryer so simply venting indoors likely isn't a good
option, as welcome as the extra humidity may be the few months out of
the year that I'd actually want to do this.

I realize that it's probably inconsequential in the grand scheme of
things, but it does seem wasteful to heat all that air and then just
blow it outdoors when it's 20 degrees out.

I tried to do a quick online search, but all I saw was a little
discussion and not much in the way of actual plans, products, or
results.

nate

--
replace "roosters" with "cox" to reply.http://members.cox.net/njnagel

my dryer had some rotten cardboard lining the inside of the door that
served to insulate, i ripped that off, now the front door gets nice
and hot so some heat is recovered there..

also use an extra long METAL vent hose and a lot of the heat will be
recovered that way too....

if you put any significant money into this, it is unlikely that you
will get a return on the investment..

Mark
You don't want to recover TOO much of the heat unless you use a
"condensing" heat exchanger, otherwize the moisture you took out of
the clothes is going to run back into the dryer or make a big icycle
at the vent.

Could make a J tube of sorts, to catch any condensate.

I think the suggestion about using more ducting was good. It's perty cheap,
and you can just run it around all the floor or ceiling corners, or some
kind of serpentine config.

Unless you can control the humidity, that warm air is just too damp to vent
inside..
They make indoor lint traps (water baths), and even with those, we
eventually just vented it right outside.

Ditto "ventless" gas heaters -- they'll soak a wall.

Proly the best thing for saving money on a dryer: A front loader with a
high-rpm spin cycle. You can almost hang the clothes right out of the
washer.
Rarely do you find a win-win-win-win-win-win situation as with front
loaders.
--
EA

On Jan 14, 10:28*pm, "Pete C." wrote:
Nate Nagel wrote:

It's one of those things that has been contemplated for eons. The reason
that there is not a product for the purpose is that there are too many
issues to overcome, like humidity, condensate, corrosion, back pressure,
lint buildup, etc. and too little to gain, something like 15,000 BTU for
30 min.

Once in a while, I will vent the dryer into the house. I try to keep
the lint dust down by covering the far end of the dryer hose with a
knee high nylon hose.
hth....
Linda H.

"Pete C." wrote in message
ster.com...

Nate Nagel wrote:

Has anyone tried to use a heat exchanger of any kind on their dryer
vent, or better yet, is there any commercially available product to do
this? I have a gas dryer so simply venting indoors likely isn't a good
option, as welcome as the extra humidity may be the few months out of
the year that I'd actually want to do this.

I realize that it's probably inconsequential in the grand scheme of
things, but it does seem wasteful to heat all that air and then just
blow it outdoors when it's 20 degrees out.

I tried to do a quick online search, but all I saw was a little
discussion and not much in the way of actual plans, products, or results.

nate

--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel

It's one of those things that has been contemplated for eons. The reason
that there is not a product for the purpose is that there are too many
issues to overcome, like humidity, condensate, corrosion, back pressure,
lint buildup, etc. and too little to gain, something like 15,000 BTU for
30 min.

Well, the avg electric dryer is over 4,000 watts -- 4 kWhrs per hour of
running time, which, at net NY rates, is about $1. If you could recoup 1/4
of that, you're earning 25c an hour.
--
EA

On Thu, 14 Jan 2010 23:31:00 -0500, Existential Angst wrote:

Could make a J tube of sorts, to catch any condensate.

I think the suggestion about using more ducting was good. It's perty cheap,
and you can just run it around all the floor or ceiling corners, or some
kind of serpentine config.

It takes very little additional ducting to destroy a dryers performance.
Add 10' and perhaps a bend or two and you'll be looking at two hour
dry times.

Nate Nagel wrote:
Has anyone tried to use a heat exchanger of any kind on their dryer
vent, or better yet, is there any commercially available product to do
this? I have a gas dryer so simply venting indoors likely isn't a
good option, as welcome as the extra humidity may be the few months
out of the year that I'd actually want to do this.

I realize that it's probably inconsequential in the grand scheme of
things, but it does seem wasteful to heat all that air and then just
blow it outdoors when it's 20 degrees out.

I tried to do a quick online search, but all I saw was a little
discussion and not much in the way of actual plans, products, or
results.

Google for "dryer+vent+valve"

Here's one:
http://www.amazon.com/Dundas-Jafine-.../dp/B001KPPOZU

When you start the dryer, you flip a lever and the dryer exhaust enters the
room instead of being wasted outside. This has two advantages: You get the
heat, you get the humidity.

On the down side, you'll have to put up with all the folks who will say
"You're gonna die a horrible death, covered with fungating pustules and
dripping sores!", particulrly if you have a gas dryer.

As for being inconsequential, not so. Thirty minutes of drying time will
turn your utility room and anything nearby into a plenty-toasty territority,
plus you'll be helping to save the planet.

"AZ Nomad" wrote in message
...
On Thu, 14 Jan 2010 23:31:00 -0500, Existential Angst
wrote:

Could make a J tube of sorts, to catch any condensate.

I think the suggestion about using more ducting was good. It's perty
cheap,
and you can just run it around all the floor or ceiling corners, or some
kind of serpentine config.

It takes very little additional ducting to destroy a dryers performance.
Add 10' and perhaps a bend or two and you'll be looking at two hour
dry times.

Duct booster?
Heh, starting to get complicated already....
--
EA

HeyBub wrote:
Nate Nagel wrote:
Has anyone tried to use a heat exchanger of any kind on their dryer
vent, or better yet, is there any commercially available product to do
this? I have a gas dryer so simply venting indoors likely isn't a
good option, as welcome as the extra humidity may be the few months
out of the year that I'd actually want to do this.

I realize that it's probably inconsequential in the grand scheme of
things, but it does seem wasteful to heat all that air and then just
blow it outdoors when it's 20 degrees out.

I tried to do a quick online search, but all I saw was a little
discussion and not much in the way of actual plans, products, or
results.

Google for "dryer+vent+valve"

Here's one:
http://www.amazon.com/Dundas-Jafine-.../dp/B001KPPOZU

When you start the dryer, you flip a lever and the dryer exhaust enters the
room instead of being wasted outside. This has two advantages: You get the
heat, you get the humidity.

On the down side, you'll have to put up with all the folks who will say
"You're gonna die a horrible death, covered with fungating pustules and
dripping sores!", particulrly if you have a gas dryer.

As for being inconsequential, not so. Thirty minutes of drying time will
turn your utility room and anything nearby into a plenty-toasty territority,
plus you'll be helping to save the planet.


Been doing this for 30 years with an
electric dryer. The heat and humidity
are welcome. The lint is another story.
In the basement it was not a problem.
However, in a home with the dryer in the
living quarters, you might want to
do as this person says, filter the air
to remove lint. But, you have to clean it
after every use, just like the filter in
the dryer itself.

On Jan 15, 8:41*am, Van Chocstraw
wrote:
On 01/14/2010 09:52 PM, Nate Nagel wrote: Has anyone tried to use a heat exchanger of any kind on their dryer
vent, or better yet, is there any commercially available product to do
this? *I have a gas dryer so simply venting indoors likely isn't a good
option, as welcome as the extra humidity may be the few months out of
the year that I'd actually want to do this.

I realize that it's probably inconsequential in the grand scheme of
things, but it does seem wasteful to heat all that air and then just
blow it outdoors when it's 20 degrees out.

I tried to do a quick online search, but all I saw was a little
discussion and not much in the way of actual plans, products, or results.

nate

I have seen a commercial dryer heat exchanger in the past. I don't know
if *they still make them.

This is interesting: * *http://www.youtube.com/watch?v=hilZKO-29VM

Gas vs Electric dryers are two different stories. Electrics can vent
indoors with only the lint problem, we have been doing this for the 51
years we have been married. But gas presents a problem with the fumes
and humidity combined. If it were my situation, I would just place a
fan near the exhaust piping and blow air over the piping and recover a
little bit of heat that way, but at a negligible cost.

On Jan 15, 10:33*am, "hr(bob) "
wrote:
On Jan 15, 8:41*am, Van Chocstraw
wrote:





On 01/14/2010 09:52 PM, Nate Nagel wrote: Has anyone tried to use a heat exchanger of any kind on their dryer
vent, or better yet, is there any commercially available product to do
this? *I have a gas dryer so simply venting indoors likely isn't a good
option, as welcome as the extra humidity may be the few months out of
the year that I'd actually want to do this.

I realize that it's probably inconsequential in the grand scheme of
things, but it does seem wasteful to heat all that air and then just
blow it outdoors when it's 20 degrees out.

I tried to do a quick online search, but all I saw was a little
discussion and not much in the way of actual plans, products, or results.

nate

I have seen a commercial dryer heat exchanger in the past. I don't know
if *they still make them.

This is interesting: * *http://www.youtube.com/watch?v=hilZKO-29VM

Gas vs Electric dryers are two different stories. *Electrics can vent
indoors with only the lint problem, we have been doing this for the 51
years we have been married. *But gas presents a problem with the fumes
and humidity combined. *If it were my situation, I would just place a
fan near the exhaust piping and blow air over the piping and recover a
little bit of heat that way, but at a negligible cost.- Hide quoted text -

- Show quoted text -

Our electric dryer vents into the greenhouse during the winter, saving
some of the heating costs.

Paul

On Fri, 15 Jan 2010 00:12:25 -0600, AZ Nomad wrote:

On Thu, 14 Jan 2010 23:31:00 -0500, Existential Angst wrote:

Could make a J tube of sorts, to catch any condensate.

I think the suggestion about using more ducting was good. It's perty cheap,
and you can just run it around all the floor or ceiling corners, or some
kind of serpentine config.

It takes very little additional ducting to destroy a dryers performance.
Add 10' and perhaps a bend or two and you'll be looking at two hour
dry times.

I'm running about 8' and a couple of 90-degree elbows and it's not bad
- about an hour for a full load (electric dryer). No condensate issues,
either (I sited it in the basement right next to where the sump pump will
be going, just in case).

One thing that is worth doing is dismantling the dryer every couple of
years; they really plug up after a while, even if the airflow coming out
still seems good. Sometime I'll get a wild hair and make a proper access
panel for the back of ours (the whole back has to be removed right now,
plus it extends underneath the machine so the whole lot has to be turned
over to get inside)

I've thought about recovering heat from ours in the past, too (as recently
as a week ago, actually) - but I'm just not sure that it's worth it, at
least not for anything that uses power to do the recovery. We run the
dryer for around an hour a day, and given the 23 hours it's not running,
I'm probably better off insulating the heck out of the pipe to reduce heat
loss from the house, and save more money that way.

cheers

Jules

On Fri, 15 Jan 2010 10:36:01 -0600, Jules wrote:
On Fri, 15 Jan 2010 00:12:25 -0600, AZ Nomad wrote:

On Thu, 14 Jan 2010 23:31:00 -0500, Existential Angst wrote:

Could make a J tube of sorts, to catch any condensate.

I think the suggestion about using more ducting was good. It's perty cheap,
and you can just run it around all the floor or ceiling corners, or some
kind of serpentine config.

It takes very little additional ducting to destroy a dryers performance.
Add 10' and perhaps a bend or two and you'll be looking at two hour
dry times.

I'm running about 8' and a couple of 90-degree elbows and it's not bad
- about an hour for a full load (electric dryer). No condensate issues,
either (I sited it in the basement right next to where the sump pump will
be going, just in case).

One thing that is worth doing is dismantling the dryer every couple of
years; they really plug up after a while, even if the airflow coming out
still seems good. Sometime I'll get a wild hair and make a proper access
panel for the back of ours (the whole back has to be removed right now,
plus it extends underneath the machine so the whole lot has to be turned
over to get inside)

The previous poster was suggesting more than 8' and a couple of 90 degree
turns. He'd be lucky if he managed to dry a load of clothing in under
5 hours and if the dryer didn't shut down due to overheating.

On Jan 14, 9:52*pm, Nate Nagel wrote:
Has anyone tried to use a heat exchanger of any kind on their dryer
vent, or better yet, is there any commercially available product to do
this? *I have a gas dryer so simply venting indoors likely isn't a good
option, as welcome as the extra humidity may be the few months out of
the year that I'd actually want to do this.

I realize that it's probably inconsequential in the grand scheme of
things, but it does seem wasteful to heat all that air and then just
blow it outdoors when it's 20 degrees out.

I tried to do a quick online search, but all I saw was a little
discussion and not much in the way of actual plans, products, or results.

nate

--
replace "roosters" with "cox" to reply.http://members.cox.net/njnagel

On Jan 14, 9:52*pm, Nate Nagel wrote:
Has anyone tried to use a heat exchanger of any kind on their dryer
vent, or better yet, is there any commercially available product to do
this? *I have a gas dryer so simply venting indoors likely isn't a good
option, as welcome as the extra humidity may be the few months out of
the year that I'd actually want to do this.

I realize that it's probably inconsequential in the grand scheme of
things, but it does seem wasteful to heat all that air and then just
blow it outdoors when it's 20 degrees out.

I tried to do a quick online search, but all I saw was a little
discussion and not much in the way of actual plans, products, or results.

nate

--
replace "roosters" with "cox" to reply.http://members.cox.net/njnagel

One of my DIYer friends down in Ga. mounted a gutted out service panel
on the wall above his dryer. Normally the air flows from the bottom
back of the box through an HVAC filter to the front of the box and out
the top to the vent.To dump the warm humid air into the house he just
opens the door on it. I don't know if or how he provided for keeping
the cold air from coming down the vent.

Jimmie

On Jan 14, 11:32*pm, Linda Hungerford
wrote:
On Jan 14, 10:28*pm, "Pete C." wrote:

Nate Nagel wrote:
It's one of those things that has been contemplated for eons. The reason
that there is not a product for the purpose is that there are too many
issues to overcome, like humidity, condensate, corrosion, back pressure,
lint buildup, etc. and too little to gain, something like 15,000 BTU for
30 min.

Once in a while, I will vent the dryer into the house. *I try to keep
the lint dust down by covering the far end of the dryer hose with a
knee high nylon hose.
hth....
Linda H.

I usually do it when the humidity is really low. Sometimes, like the
last couple of weeks, the humidifier just cant keep up.

Jimmie

Jules wrote:
On Fri, 15 Jan 2010 00:12:25 -0600, AZ Nomad wrote:

On Thu, 14 Jan 2010 23:31:00 -0500, Existential Angst
wrote:

Could make a J tube of sorts, to catch any condensate.

I think the suggestion about using more ducting was good. It's
perty cheap, and you can just run it around all the floor or
ceiling corners, or some kind of serpentine config.

It takes very little additional ducting to destroy a dryers
performance.
Add 10' and perhaps a bend or two and you'll be looking at two hour
dry times.

I'm running about 8' and a couple of 90-degree elbows and it's not bad
- about an hour for a full load (electric dryer). No condensate
issues, either (I sited it in the basement right next to where the
sump pump will be going, just in case).

One thing that is worth doing is dismantling the dryer every couple of
years; they really plug up after a while, even if the airflow coming
out still seems good.

I have "restored" a couple of "non-working" dryers by taking outside, and
blasting out all the air passages with a large blaster nozzle on my air
compressor hose. You'll be amazed at the crud that comes out. After that, they
worked fine.

O.P. If you add duct to extract more heat, use a larger size duct so you don't
restrict the dryers air flow.. This will also give it more heat exchange area.
Just make sure you clean out the inside regularly, or it will become insulated
with lint, and become a fire hazard.

HeyBub wrote:
Nate Nagel wrote:
Has anyone tried to use a heat exchanger of any kind on their dryer
vent, or better yet, is there any commercially available product to
do this? I have a gas dryer so simply venting indoors likely isn't a
good option, as welcome as the extra humidity may be the few months
out of the year that I'd actually want to do this.

I realize that it's probably inconsequential in the grand scheme of
things, but it does seem wasteful to heat all that air and then just
blow it outdoors when it's 20 degrees out.

I tried to do a quick online search, but all I saw was a little
discussion and not much in the way of actual plans, products, or
results.

Google for "dryer+vent+valve"

Here's one:
http://www.amazon.com/Dundas-Jafine-.../dp/B001KPPOZU

When you start the dryer, you flip a lever and the dryer exhaust
enters the room instead of being wasted outside. This has two
advantages: You get the heat, you get the humidity.

On the down side, you'll have to put up with all the folks who will
say "You're gonna die a horrible death, covered with fungating
pustules and dripping sores!", particulrly if you have a gas dryer.

As for being inconsequential, not so. Thirty minutes of drying time
will turn your utility room and anything nearby into a plenty-toasty
territority, plus you'll be helping to save the planet.

And all your tools in the room will rust out.

Bob F wrote:
HeyBub wrote:
Nate Nagel wrote:
Has anyone tried to use a heat exchanger of any kind on their dryer
vent, or better yet, is there any commercially available product to
do this? I have a gas dryer so simply venting indoors likely isn't
a good option, as welcome as the extra humidity may be the few
months out of the year that I'd actually want to do this.

I realize that it's probably inconsequential in the grand scheme of
things, but it does seem wasteful to heat all that air and then just
blow it outdoors when it's 20 degrees out.

I tried to do a quick online search, but all I saw was a little
discussion and not much in the way of actual plans, products, or
results.

Google for "dryer+vent+valve"

Here's one:
http://www.amazon.com/Dundas-Jafine-.../dp/B001KPPOZU

When you start the dryer, you flip a lever and the dryer exhaust
enters the room instead of being wasted outside. This has two
advantages: You get the heat, you get the humidity.

On the down side, you'll have to put up with all the folks who will
say "You're gonna die a horrible death, covered with fungating
pustules and dripping sores!", particulrly if you have a gas dryer.

As for being inconsequential, not so. Thirty minutes of drying time
will turn your utility room and anything nearby into a plenty-toasty
territority, plus you'll be helping to save the planet.

And all your tools in the room will rust out.

Ah, right. I should have said "fungating pustules, dripping sores, and
rust."

Thanks for the correction.

hr(bob) wrote:

I have seen a commercial dryer heat exchanger in the past. I don't
know
if they still make them.

This is interesting: http://www.youtube.com/watch?v=hilZKO-29VM

Gas vs Electric dryers are two different stories. Electrics can vent
indoors with only the lint problem, we have been doing this for the 51
years we have been married. But gas presents a problem with the fumes
and humidity combined.

What "fumes?"

What's the difference between the output of a gas dryer and a natural gas
space heater?

JIMMIE wrote:

One of my DIYer friends down in Ga. mounted a gutted out service panel
on the wall above his dryer. Normally the air flows from the bottom
back of the box through an HVAC filter to the front of the box and out
the top to the vent.To dump the warm humid air into the house he just
opens the door on it. I don't know if or how he provided for keeping
the cold air from coming down the vent.


Assuming he keeps the dryer door closed when not in use, where's the cold
air going to go?

Bob F wrote:
....

O.P. If you add duct to extract more heat, use a larger size duct so you don't
restrict the dryers air flow.. This will also give it more heat exchange area.
Just make sure you clean out the inside regularly, or it will become insulated
with lint, and become a fire hazard.

Somebody else mentioned a fan to move air over the existing duct -- I'
think a combination of a larger piece of duct around the existing w/ an
airflow down the resulting annulus would create a counterflow exchanger
w/o having to worry about filtering lint nor the possibly excessive
humidity.

$0.01, etc., etc., etc., ...

--

On Fri, 15 Jan 2010 16:55:11 -0600, dpb wrote:
Bob F wrote:
...

O.P. If you add duct to extract more heat, use a larger size duct so you don't
restrict the dryers air flow.. This will also give it more heat exchange area.
Just make sure you clean out the inside regularly, or it will become insulated
with lint, and become a fire hazard.

Somebody else mentioned a fan to move air over the existing duct -- I'
think a combination of a larger piece of duct around the existing w/ an
airflow down the resulting annulus would create a counterflow exchanger
w/o having to worry about filtering lint nor the possibly excessive
humidity.

$0.01, etc., etc., etc., ...

I love it when everybody has such a fountain of advice that they've
never actually tried. The anal vapor is overpowering.

On Fri, 15 Jan 2010 17:34:52 -0600, AZ Nomad
wrote:

On Fri, 15 Jan 2010 16:55:11 -0600, dpb wrote:
Bob F wrote:
...

O.P. If you add duct to extract more heat, use a larger size duct so you don't
restrict the dryers air flow.. This will also give it more heat exchange area.
Just make sure you clean out the inside regularly, or it will become insulated
with lint, and become a fire hazard.

Somebody else mentioned a fan to move air over the existing duct -- I'
think a combination of a larger piece of duct around the existing w/ an
airflow down the resulting annulus would create a counterflow exchanger
w/o having to worry about filtering lint nor the possibly excessive
humidity.

$0.01, etc., etc., etc., ...

I love it when everybody has such a fountain of advice that they've
never actually tried. The anal vapor is overpowering.


Well, this last suggestion is actually something that IS used, very
often, in another application.
It is used on almost all certified light aircraft and many
experimental aircraft to extract heat from the exhaust to warm the
cabin and also provide carburetor heat.

Wrap a couple coil springs (like screen door springs) around the vent
pipe, then wrap a sheet of aluminum around that to make a larger duct
over top of the spring. Cut a hole in the middle of the outer skin and
force air in or draw air out and the air will be heated by transfer
from the inner "skin" to the spring and the outer "skin", and from all
3 to the air passing over.

On Fri, 15 Jan 2010 21:28:26 -0500, wrote:
On Fri, 15 Jan 2010 17:34:52 -0600, AZ Nomad
wrote:

On Fri, 15 Jan 2010 16:55:11 -0600, dpb wrote:
Bob F wrote:
...

O.P. If you add duct to extract more heat, use a larger size duct so you don't
restrict the dryers air flow.. This will also give it more heat exchange area.
Just make sure you clean out the inside regularly, or it will become insulated
with lint, and become a fire hazard.

Somebody else mentioned a fan to move air over the existing duct -- I'
think a combination of a larger piece of duct around the existing w/ an
airflow down the resulting annulus would create a counterflow exchanger
w/o having to worry about filtering lint nor the possibly excessive
humidity.

$0.01, etc., etc., etc., ...

I love it when everybody has such a fountain of advice that they've
never actually tried. The anal vapor is overpowering.


Well, this last suggestion is actually something that IS used, very
often, in another application.

sure. name one instalation.

On Jan 15, 8:40*pm, AZ Nomad wrote:
On Fri, 15 Jan 2010 21:28:26 -0500, wrote:
On Fri, 15 Jan 2010 17:34:52 -0600, AZ Nomad
wrote:
On Fri, 15 Jan 2010 16:55:11 -0600, dpb wrote:
Bob F wrote:
...

O.P. If you add duct to extract more heat, use a larger size duct so you don't
restrict the dryers air flow.. This will also give it more heat exchange area.
Just make sure you clean out the inside regularly, or it will become insulated
with lint, and become a fire hazard.

Somebody else mentioned a fan to move air over the existing duct -- I'
think a combination of a larger piece of duct around the existing w/ an
airflow down the resulting annulus would create a counterflow exchanger
w/o having to worry about filtering lint nor the possibly excessive
humidity.

$0.01, etc., etc., etc., ...

I love it when everybody has such a fountain of advice that they've
never actually tried. *The anal vapor is overpowering.
Well, this last suggestion is actually something that IS used, very
often, in another application.

sure. *name one instalation.- Hide quoted text -

- Show quoted text -

He just did!

AZ Nomad wrote:
....


Well, this last suggestion is actually something that IS used, very
often, in another application.

sure. name one instalation.

Never heard of reheat cycle I take it????

Just postulated a very simple implementation of concept.

"The Brayton Cycle with Regeneration, Intercooling, & Reheating
Section 8.9-10
By: Denise Lane
ME 372 Thermodynamics
....
The Brayton Cycle with Regeneration

In gas-turbine engines, the temperature of the exhaust gas leaving the
turbine is often considerably higher than the temperature of the air
leaving the compressor. Therefore, the high-pressure air leaving the
compressor can be heated by transferring heat to it from the hot exhaust
gases in a counter-flow heat exchanger, which is also known as a
regenerator or recuperator."

--

On Sat, 16 Jan 2010 00:52:54 -0500, Existential Angst wrote:
"hr(bob) " wrote in message
...
On Jan 15, 8:40 pm, AZ Nomad wrote:
On Fri, 15 Jan 2010 21:28:26 -0500,
wrote:
On Fri, 15 Jan 2010 17:34:52 -0600, AZ Nomad
wrote:
On Fri, 15 Jan 2010 16:55:11 -0600, dpb wrote:
Bob F wrote:
...

O.P. If you add duct to extract more heat, use a larger size duct so
you don't
restrict the dryers air flow.. This will also give it more heat
exchange area.
Just make sure you clean out the inside regularly, or it will become
insulated
with lint, and become a fire hazard.

Somebody else mentioned a fan to move air over the existing duct -- I'
think a combination of a larger piece of duct around the existing w/ an
airflow down the resulting annulus would create a counterflow exchanger
w/o having to worry about filtering lint nor the possibly excessive
humidity.

$0.01, etc., etc., etc., ...

I love it when everybody has such a fountain of advice that they've
never actually tried. The anal vapor is overpowering.
Well, this last suggestion is actually something that IS used, very
often, in another application.

sure. name one instalation.- Hide quoted text -

- Show quoted text -

He just did!

No he didn't. He pulled out of his ass a bunch of bull****.

On Fri, 15 Jan 2010 20:40:34 -0600, AZ Nomad
wrote:

On Fri, 15 Jan 2010 21:28:26 -0500, wrote:
On Fri, 15 Jan 2010 17:34:52 -0600, AZ Nomad
wrote:

On Fri, 15 Jan 2010 16:55:11 -0600, dpb wrote:
Bob F wrote:
...

O.P. If you add duct to extract more heat, use a larger size duct so you don't
restrict the dryers air flow.. This will also give it more heat exchange area.
Just make sure you clean out the inside regularly, or it will become insulated
with lint, and become a fire hazard.

Somebody else mentioned a fan to move air over the existing duct -- I'
think a combination of a larger piece of duct around the existing w/ an
airflow down the resulting annulus would create a counterflow exchanger
w/o having to worry about filtering lint nor the possibly excessive
humidity.

$0.01, etc., etc., etc., ...

I love it when everybody has such a fountain of advice that they've
never actually tried. The anal vapor is overpowering.


Well, this last suggestion is actually something that IS used, very
often, in another application.

sure. name one instalation.
I gave you TWO very common uses of the "technology"

On Sat, 16 Jan 2010 12:35:26 -0600, AZ Nomad
wrote:

On Sat, 16 Jan 2010 00:52:54 -0500, Existential Angst wrote:
"hr(bob) " wrote in message
...
On Jan 15, 8:40 pm, AZ Nomad wrote:
On Fri, 15 Jan 2010 21:28:26 -0500,
wrote:
On Fri, 15 Jan 2010 17:34:52 -0600, AZ Nomad
wrote:
On Fri, 15 Jan 2010 16:55:11 -0600, dpb wrote:
Bob F wrote:
...

O.P. If you add duct to extract more heat, use a larger size duct so
you don't
restrict the dryers air flow.. This will also give it more heat
exchange area.
Just make sure you clean out the inside regularly, or it will become
insulated
with lint, and become a fire hazard.

Somebody else mentioned a fan to move air over the existing duct -- I'
think a combination of a larger piece of duct around the existing w/ an
airflow down the resulting annulus would create a counterflow exchanger
w/o having to worry about filtering lint nor the possibly excessive
humidity.

$0.01, etc., etc., etc., ...

I love it when everybody has such a fountain of advice that they've
never actually tried. The anal vapor is overpowering.
Well, this last suggestion is actually something that IS used, very
often, in another application.

sure. name one instalation.- Hide quoted text -

- Show quoted text -

He just did!

No he didn't. He pulled out of his ass a bunch of bull****.
Go back to the desert you old Arizona Hippy.

On Jan 14, 9:52*pm, Nate Nagel wrote:
Has anyone tried to use a heat exchanger of any kind on their dryer
vent, or better yet, is there any commercially available product to do
this? *I have a gas dryer so simply venting indoors likely isn't a good
option, as welcome as the extra humidity may be the few months out of
the year that I'd actually want to do this.

I realize that it's probably inconsequential in the grand scheme of
things, but it does seem wasteful to heat all that air and then just
blow it outdoors when it's 20 degrees out.

I tried to do a quick online search, but all I saw was a little
discussion and not much in the way of actual plans, products, or results.

nate

--
replace "roosters" with "cox" to reply.http://members.cox.net/njnagel

Try putting on the clothes as soon as they come out of the dryer. The
house may not be any warmer but you will be for a few seconds.

HeyBub wrote:
hr(bob) wrote:

I have seen a commercial dryer heat exchanger in the past. I don't
know
if they still make them.

This is interesting: http://www.youtube.com/watch?v=hilZKO-29VM

Gas vs Electric dryers are two different stories. Electrics can vent
indoors with only the lint problem, we have been doing this for the
51 years we have been married. But gas presents a problem with the
fumes and humidity combined.

What "fumes?"

What's the difference between the output of a gas dryer and a natural
gas space heater?

One is designed to exhaust outside? The other may or may not be.