Beating humidity

[Andy[_10_]]

Last year for the first time since I bought my gilder I discovered
what cold, humid, Northern California winter air can do to the
untreated steel parts on my glider. This year I was determined to
keep corrosion at bay and bought a dehumidifier to put in the
trailer. I also bought one of those radio-remote temperature and
humidity sensors to put inside the trailer to keep track of the
effectiveness of my efforts.

My Cobra trailer is pretty well sealed except for a gap between the
tailgate and the fiberglass top. I positioned the dehumidifier on the
trailer floor between the tailboom and the wing and sealed the air
gap. I checked after the first week and discovered the dehumidifier's
water receptacle was about 1/3 full. The past couple of days have been
rainy and cool - low 50s and 77% humidity this morning. Inside the
trailer it's a few degrees warmer and the really good news is the
humidity is 22%.

I'll probably do a couple of experiments in the coming weeks to see
how long it takes to get the humidity down and how long it takes to
drift back up to ambient levels with the dehumidifier of. I know that
not everyone keeps their trailer near 110v power outlets and my
dehumidifier is 330 watts, so batteries with an inverter and/or solar
cells are not an option for continuous operation, but maybe it would
work if you could get things dry in a burst and let the trailer sit
for a period of time before giving it another burst.

Here's the dehumidifier I bought:

http://www.amazon.com/gp/product/B00009RAVO/ref=oss_product

9B

[John Cochrane[_2_]]

On Dec 11, 3:42*pm, Andy > wrote:
> Last year for the first time since I bought my gilder I discovered
> what cold, humid, Northern California winter air can do to the
> untreated steel parts on my glider. *This year I was determined to
> keep corrosion at bay and bought a dehumidifier to put in the
> trailer. *I also bought one of those radio-remote temperature and
> humidity sensors to put inside the trailer to keep track of the
> effectiveness of my efforts.
>
> My Cobra trailer is pretty well sealed except for a gap between the
> tailgate and the fiberglass top. I positioned the dehumidifier on the
> trailer floor between the tailboom and the wing and sealed the air
> gap. I checked after the first week and discovered the dehumidifier's
> water receptacle was about 1/3 full. The past couple of days have been
> rainy and cool - low 50s and 77% humidity this morning. Inside the
> trailer it's a few degrees warmer and the really good news is the
> humidity is 22%.
>
> I'll probably do a couple of experiments in the coming weeks to see
> how long it takes to get the humidity down and how long it takes to
> drift back up to ambient levels with the dehumidifier of. I know that
> not everyone keeps their trailer near 110v power outlets and my
> dehumidifier is 330 watts, so batteries with an inverter and/or solar
> cells are not an option for continuous operation, but maybe it would
> work if you could get things dry in a burst and let the trailer sit
> for a period of time before giving it another burst.
>
> Here's the dehumidifier I bought:
>
> http://www.amazon.com/gp/product/B00009RAVO/ref=oss_product
>
> 9B

I did some similar experiments a while ago. The big issue is the daily
condensation cycle. All our gliders are sopping wet inside the
trailers many mornings. I saw daily 100% humidities. Inside a hangar
can be worse than outside, since the solar vent no longer works. Also
hangars here in the midwest often have a very cold concrete floor.
Then, you get warm humid spring days, and it's just a moisture
magnet.

I found the "mighty dry" dehumidifier and cut a hole in the bottom of
the trailer to release the water. It worked great while I had a 110V
supply. Alas, I now have to park away from power.

A dehumidifier isn't a great idea where in freezes in the winter. You
can also put a 40 w bulb in, or better (what I use) a bilge heater
from your local boat store. This is a 40w heater designed to address
similar humidity problems in boats. It keeps the glider just slightly
warmer than ambient and seems to help a lot with the condensation
issue.

The world is still waiting for a good humidity solution for trailers
parked away from power.

John Cochrane BB

[[email protected]]

I insulated the inner walls of my older all metal trailer with 1/8"
inch thick foam. Type used underneath automobile headliners. Worked
wonders with condensation issues I had. Delays the cooling at night
and moderates the heat in the daytime. I open it in the morning and
have no moisure to speak of on my glider. It may still sometimes occur
but it has greatly helped. Before, with the bare metal, it was
terrible, like a glass of iced tea in the summer, dripping wet walls.
I am down in Florida though so your milage my vary. Humid for sure,
but not as cold although our low will be in the upper 20's tomorrow
night.
In addition to this foam liner I only have a solar powered vent fan.
Craig

[Andy[_10_]]

On Dec 11, 1:57*pm, John Cochrane >
wrote:
> On Dec 11, 3:42*pm, Andy > wrote:
>
>
>
>
>
> > Last year for the first time since I bought my gilder I discovered
> > what cold, humid, Northern California winter air can do to the
> > untreated steel parts on my glider. *This year I was determined to
> > keep corrosion at bay and bought a dehumidifier to put in the
> > trailer. *I also bought one of those radio-remote temperature and
> > humidity sensors to put inside the trailer to keep track of the
> > effectiveness of my efforts.
>
> > My Cobra trailer is pretty well sealed except for a gap between the
> > tailgate and the fiberglass top. I positioned the dehumidifier on the
> > trailer floor between the tailboom and the wing and sealed the air
> > gap. I checked after the first week and discovered the dehumidifier's
> > water receptacle was about 1/3 full. The past couple of days have been
> > rainy and cool - low 50s and 77% humidity this morning. Inside the
> > trailer it's a few degrees warmer and the really good news is the
> > humidity is 22%.
>
> > I'll probably do a couple of experiments in the coming weeks to see
> > how long it takes to get the humidity down and how long it takes to
> > drift back up to ambient levels with the dehumidifier of. I know that
> > not everyone keeps their trailer near 110v power outlets and my
> > dehumidifier is 330 watts, so batteries with an inverter and/or solar
> > cells are not an option for continuous operation, but maybe it would
> > work if you could get things dry in a burst and let the trailer sit
> > for a period of time before giving it another burst.
>
> > Here's the dehumidifier I bought:
>
> >http://www.amazon.com/gp/product/B00009RAVO/ref=oss_product
>
> > 9B
>
> I did some similar experiments a while ago. The big issue is the daily
> condensation cycle. All our gliders are sopping wet inside the
> trailers many mornings. I saw daily 100% humidities. Inside a hangar
> can be worse than outside, since the solar vent no longer works. Also
> hangars here in the midwest often have a very cold concrete floor.
> Then, you get warm humid spring days, and it's just a moisture
> magnet.
>
> I found the "mighty dry" dehumidifier and cut a hole in the bottom of
> the trailer to release the water. It worked great while I had a 110V
> supply. Alas, I now have to park away from power.
>
> A dehumidifier isn't a great idea where in freezes in the winter. You
> can also put a 40 w bulb in, or better (what I use) a bilge heater
> from your local boat store. This is a 40w heater designed to address
> similar humidity problems in boats. It keeps the glider just slightly
> warmer than ambient and seems to help a lot with the condensation
> issue.
>
> The world is still waiting for a good humidity solution for trailers
> parked away from power.
>
> John Cochrane BB

I may not understand enough about the condensation cycle. But I would
think if you can get the absolute amount of water vapor inside the
trailer down low enough you'd have a decent chance of keeping it from
condensing through a reasonably wide temperature swing. Fortunately
where I live the swing is usually only 20-25 degrees. If you have to
heat your glider trailer, well that's a whole different set of issues
I guess.

9B

[John Cochrane[_2_]]

>
> I may not understand enough about the condensation cycle. But I would
> think if you can get the absolute amount of water vapor inside the
> trailer down low enough you'd have a decent chance of keeping it from
> condensing through a reasonably wide temperature swing. Fortunately
> where I live the swing is usually only 20-25 degrees. *If you have to
> heat your glider trailer, well that's a whole different set of issues
> I guess.
>
> 9B

That's a thought that has occurred to me. Seal the thing up tight,
spread drying crystals all over the place. However, then it would get
really super hot in the middle of the day which I'm not so sure is a
good idea.

John Cochrane

[Darryl Ramm]

On Dec 11, 1:42*pm, Andy > wrote:
> Last year for the first time since I bought my gilder I discovered
> what cold, humid, Northern California winter air can do to the
> untreated steel parts on my glider. *This year I was determined to
> keep corrosion at bay and bought a dehumidifier to put in the
> trailer. *I also bought one of those radio-remote temperature and
> humidity sensors to put inside the trailer to keep track of the
> effectiveness of my efforts.
>
> My Cobra trailer is pretty well sealed except for a gap between the
> tailgate and the fiberglass top. I positioned the dehumidifier on the
> trailer floor between the tailboom and the wing and sealed the air
> gap. I checked after the first week and discovered the dehumidifier's
> water receptacle was about 1/3 full. The past couple of days have been
> rainy and cool - low 50s and 77% humidity this morning. Inside the
> trailer it's a few degrees warmer and the really good news is the
> humidity is 22%.
>
> I'll probably do a couple of experiments in the coming weeks to see
> how long it takes to get the humidity down and how long it takes to
> drift back up to ambient levels with the dehumidifier of. I know that
> not everyone keeps their trailer near 110v power outlets and my
> dehumidifier is 330 watts, so batteries with an inverter and/or solar
> cells are not an option for continuous operation, but maybe it would
> work if you could get things dry in a burst and let the trailer sit
> for a period of time before giving it another burst.
>
> Here's the dehumidifier I bought:
>
> http://www.amazon.com/gp/product/B00009RAVO/ref=oss_product
>
> 9B


I think Andy is goign about this right. I face rust issues on
machinery in my woodwork shop and use a DeLonghi Dehumidifier, as well
as special covers and waxing on exposed die cast surfaces etc. to keep
rust issues down. The exact humidifier I uses is no longer
manufactured, its a fairly large one designed for basements etc, with
a built in pump to get the caught water outside. If I had my trailer
at home I would probalby have a similar dehumidifier in the front,
turn it down to a pretty low humidity and let it run. All it needs is
for the temperature to get warm enough and it kick on an scrub out the
moisture (where Andy lives near me this is not a problem). In colder
weather I'd think about insulation and lightbulbs/heaters as well.

Andy I hope you have a fiberglass trailer top or some way of putting
the antenna of the sensor outside? Are you logging this to a computer?
The results would be interesting.

With a dehumidier like this inside you want to seal the trailer really
well. You can go around the trailer carefully sealing up obvious holes/
vents etc. but as a warning I've also noticed on my 18m Cobra trailer
at least that the gas struts deform the side of the lid enough that it
is a poor seal along the sides near where the gas struts attach to the
lid. Somethign I've not tried to fix and not sure if there is an easy
fix for. So I wonder about this happening on a 15m trailer as well.
You want to do some playing inside the trailer and see if it seals
well for you.

I remain skeptical of some of the solar vents as being that useful and
maybe contribute themselves to problems. I'd like to see actual
humidity and air and surface temperature measurements inside trailers
and started to build a system to do this but never finished it.


Darryl

[Andy[_10_]]

On Dec 11, 4:50*pm, Darryl Ramm > wrote:
> On Dec 11, 1:42*pm, Andy > wrote:
>
>
>
>
>
> > Last year for the first time since I bought my gilder I discovered
> > what cold, humid, Northern California winter air can do to the
> > untreated steel parts on my glider. *This year I was determined to
> > keep corrosion at bay and bought a dehumidifier to put in the
> > trailer. *I also bought one of those radio-remote temperature and
> > humidity sensors to put inside the trailer to keep track of the
> > effectiveness of my efforts.
>
> > My Cobra trailer is pretty well sealed except for a gap between the
> > tailgate and the fiberglass top. I positioned the dehumidifier on the
> > trailer floor between the tailboom and the wing and sealed the air
> > gap. I checked after the first week and discovered the dehumidifier's
> > water receptacle was about 1/3 full. The past couple of days have been
> > rainy and cool - low 50s and 77% humidity this morning. Inside the
> > trailer it's a few degrees warmer and the really good news is the
> > humidity is 22%.
>
> > I'll probably do a couple of experiments in the coming weeks to see
> > how long it takes to get the humidity down and how long it takes to
> > drift back up to ambient levels with the dehumidifier of. I know that
> > not everyone keeps their trailer near 110v power outlets and my
> > dehumidifier is 330 watts, so batteries with an inverter and/or solar
> > cells are not an option for continuous operation, but maybe it would
> > work if you could get things dry in a burst and let the trailer sit
> > for a period of time before giving it another burst.
>
> > Here's the dehumidifier I bought:
>
> >http://www.amazon.com/gp/product/B00009RAVO/ref=oss_product
>
> > 9B
>
> I think Andy is goign about this right. I face rust issues on
> machinery in my woodwork shop and use a DeLonghi Dehumidifier, as well
> as special covers and waxing on exposed die cast surfaces etc. to keep
> rust issues down. The exact humidifier I uses is no longer
> manufactured, its a fairly large one designed for basements etc, with
> a built in pump to get the caught water outside. If I had my trailer
> at home I would probalby have a similar dehumidifier in the front,
> turn it down to a pretty low humidity and let it run. All it needs is
> for the temperature to get warm enough and it kick on an scrub out the
> moisture (where Andy lives near me this is not a problem). In colder
> weather I'd think about insulation and lightbulbs/heaters as well.
>
> Andy I hope you have a fiberglass trailer top or some way of putting
> the antenna of the sensor outside? Are you logging this to a computer?
> The results would be interesting.
>
> With a dehumidier like this inside you want to seal the trailer really
> well. You can go around the trailer carefully sealing up obvious holes/
> vents etc. *but as a warning I've also noticed on my 18m Cobra trailer
> at least that the gas struts deform the side of the lid enough that it
> is a poor seal along the sides near where the gas struts attach to the
> lid. Somethign I've not tried to fix and not sure if there is an easy
> fix for. So I wonder about this happening on a 15m trailer as well.
> You want to do some playing inside the trailer and see if it seals
> well for you.
>
> I remain skeptical of some of the solar vents as being that useful and
> maybe contribute themselves to problems. I'd like to see actual
> humidity and air and surface temperature measurements inside trailers
> and started to build a system to do this but never finished it.
>
> Darryl

Yeah, I've got the glass top trailer, which has no venting that I can
find. The side rails seem to seat pretty well with the rubber seal on
the sidewall sill. The tailgate sits pretty low vs the top so I
stuffed the gap with a little bathroom rug to at least keep the air
from circulating between inside and outside.

The humidity sensor is one of those cheap Honeywell units you use
around the house. It has a range of maybe 75 feet. No computer
logging. If I could get a logging unit cheap I'd take more systematic
measurements. I also made a suspended tarp "carport" next to my
garage for the trailer to sit under partly to keep the sun off but
mostly so I don't have to spend hours buffing out the stains from tree
sap and bird poop that find the top. So far it works great and I don't
have to worry about temperature extremes.

It was easier when I kept the trailer in a hanger in the high desert,
but I think I've got the new situation under control finally.

9B

[Darryl Ramm]

On Dec 11, 5:21*pm, Andy > wrote:
> On Dec 11, 4:50*pm, Darryl Ramm > wrote:
>
>
>
> > On Dec 11, 1:42*pm, Andy > wrote:
>
> > > Last year for the first time since I bought my gilder I discovered
> > > what cold, humid, Northern California winter air can do to the
> > > untreated steel parts on my glider. *This year I was determined to
> > > keep corrosion at bay and bought a dehumidifier to put in the
> > > trailer. *I also bought one of those radio-remote temperature and
> > > humidity sensors to put inside the trailer to keep track of the
> > > effectiveness of my efforts.
>
> > > My Cobra trailer is pretty well sealed except for a gap between the
> > > tailgate and the fiberglass top. I positioned the dehumidifier on the
> > > trailer floor between the tailboom and the wing and sealed the air
> > > gap. I checked after the first week and discovered the dehumidifier's
> > > water receptacle was about 1/3 full. The past couple of days have been
> > > rainy and cool - low 50s and 77% humidity this morning. Inside the
> > > trailer it's a few degrees warmer and the really good news is the
> > > humidity is 22%.
>
> > > I'll probably do a couple of experiments in the coming weeks to see
> > > how long it takes to get the humidity down and how long it takes to
> > > drift back up to ambient levels with the dehumidifier of. I know that
> > > not everyone keeps their trailer near 110v power outlets and my
> > > dehumidifier is 330 watts, so batteries with an inverter and/or solar
> > > cells are not an option for continuous operation, but maybe it would
> > > work if you could get things dry in a burst and let the trailer sit
> > > for a period of time before giving it another burst.
>
> > > Here's the dehumidifier I bought:
>
> > >http://www.amazon.com/gp/product/B00009RAVO/ref=oss_product
>
> > > 9B
>
> > I think Andy is goign about this right. I face rust issues on
> > machinery in my woodwork shop and use a DeLonghi Dehumidifier, as well
> > as special covers and waxing on exposed die cast surfaces etc. to keep
> > rust issues down. The exact humidifier I uses is no longer
> > manufactured, its a fairly large one designed for basements etc, with
> > a built in pump to get the caught water outside. If I had my trailer
> > at home I would probalby have a similar dehumidifier in the front,
> > turn it down to a pretty low humidity and let it run. All it needs is
> > for the temperature to get warm enough and it kick on an scrub out the
> > moisture (where Andy lives near me this is not a problem). In colder
> > weather I'd think about insulation and lightbulbs/heaters as well.
>
> > Andy I hope you have a fiberglass trailer top or some way of putting
> > the antenna of the sensor outside? Are you logging this to a computer?
> > The results would be interesting.
>
> > With a dehumidier like this inside you want to seal the trailer really
> > well. You can go around the trailer carefully sealing up obvious holes/
> > vents etc. *but as a warning I've also noticed on my 18m Cobra trailer
> > at least that the gas struts deform the side of the lid enough that it
> > is a poor seal along the sides near where the gas struts attach to the
> > lid. Somethign I've not tried to fix and not sure if there is an easy
> > fix for. So I wonder about this happening on a 15m trailer as well.
> > You want to do some playing inside the trailer and see if it seals
> > well for you.
>
> > I remain skeptical of some of the solar vents as being that useful and
> > maybe contribute themselves to problems. I'd like to see actual
> > humidity and air and surface temperature measurements inside trailers
> > and started to build a system to do this but never finished it.
>
> > Darryl
>
> Yeah, I've got the glass top trailer, which has no venting that I can
> find. The side rails seem to seat pretty well with the rubber seal on
> the sidewall sill. The tailgate sits pretty low vs the top so I
> stuffed the gap with a little bathroom rug to at least keep the air
> from circulating between inside and outside.
>
> The humidity sensor is one of those cheap Honeywell units you use
> around the house. It has a range of maybe 75 feet. No computer
> logging. If I could get a logging unit cheap I'd take more systematic
> measurements. *I also made a suspended tarp "carport" next to my
> garage for the trailer to sit under partly to keep the sun off but
> mostly so I don't have to spend hours buffing out the stains from tree
> sap and bird poop that find the top. So far it works great and I don't
> have to worry about temperature extremes.
>
> It was easier when I kept the trailer in a hanger in the high desert,
> but I think I've got the new situation under control finally.
>
> 9B


The fiberglass top trailers or maybe just being 15m may be different.
On my 18m aluminum top trailer there was dust inside on windy days and
that lead to investigation and you could see dusty areas on top of the
lower rubber seal on the trailer where the dust had been blowing
through a gap and crawling around inside with the lid closed you can
see where the small gaps where the lid is bowing.

Darryl

[brianDG303[_2_]]

On Dec 11, 5:27*pm, Darryl Ramm > wrote:
> On Dec 11, 5:21*pm, Andy > wrote:
>
>
>
> > On Dec 11, 4:50*pm, Darryl Ramm > wrote:
>
> > > On Dec 11, 1:42*pm, Andy > wrote:
>
> > > > Last year for the first time since I bought my gilder I discovered
> > > > what cold, humid, Northern California winter air can do to the
> > > > untreated steel parts on my glider. *This year I was determined to
> > > > keep corrosion at bay and bought a dehumidifier to put in the
> > > > trailer. *I also bought one of those radio-remote temperature and
> > > > humidity sensors to put inside the trailer to keep track of the
> > > > effectiveness of my efforts.
>
> > > > My Cobra trailer is pretty well sealed except for a gap between the
> > > > tailgate and the fiberglass top. I positioned the dehumidifier on the
> > > > trailer floor between the tailboom and the wing and sealed the air
> > > > gap. I checked after the first week and discovered the dehumidifier's
> > > > water receptacle was about 1/3 full. The past couple of days have been
> > > > rainy and cool - low 50s and 77% humidity this morning. Inside the
> > > > trailer it's a few degrees warmer and the really good news is the
> > > > humidity is 22%.
>
> > > > I'll probably do a couple of experiments in the coming weeks to see
> > > > how long it takes to get the humidity down and how long it takes to
> > > > drift back up to ambient levels with the dehumidifier of. I know that
> > > > not everyone keeps their trailer near 110v power outlets and my
> > > > dehumidifier is 330 watts, so batteries with an inverter and/or solar
> > > > cells are not an option for continuous operation, but maybe it would
> > > > work if you could get things dry in a burst and let the trailer sit
> > > > for a period of time before giving it another burst.
>
> > > > Here's the dehumidifier I bought:
>
> > > >http://www.amazon.com/gp/product/B00009RAVO/ref=oss_product
>
> > > > 9B
>
> > > I think Andy is goign about this right. I face rust issues on
> > > machinery in my woodwork shop and use a DeLonghi Dehumidifier, as well
> > > as special covers and waxing on exposed die cast surfaces etc. to keep
> > > rust issues down. The exact humidifier I uses is no longer
> > > manufactured, its a fairly large one designed for basements etc, with
> > > a built in pump to get the caught water outside. If I had my trailer
> > > at home I would probalby have a similar dehumidifier in the front,
> > > turn it down to a pretty low humidity and let it run. All it needs is
> > > for the temperature to get warm enough and it kick on an scrub out the
> > > moisture (where Andy lives near me this is not a problem). In colder
> > > weather I'd think about insulation and lightbulbs/heaters as well.
>
> > > Andy I hope you have a fiberglass trailer top or some way of putting
> > > the antenna of the sensor outside? Are you logging this to a computer?
> > > The results would be interesting.
>
> > > With a dehumidier like this inside you want to seal the trailer really
> > > well. You can go around the trailer carefully sealing up obvious holes/
> > > vents etc. *but as a warning I've also noticed on my 18m Cobra trailer
> > > at least that the gas struts deform the side of the lid enough that it
> > > is a poor seal along the sides near where the gas struts attach to the
> > > lid. Somethign I've not tried to fix and not sure if there is an easy
> > > fix for. So I wonder about this happening on a 15m trailer as well.
> > > You want to do some playing inside the trailer and see if it seals
> > > well for you.
>
> > > I remain skeptical of some of the solar vents as being that useful and
> > > maybe contribute themselves to problems. I'd like to see actual
> > > humidity and air and surface temperature measurements inside trailers
> > > and started to build a system to do this but never finished it.
>
> > > Darryl
>
> > Yeah, I've got the glass top trailer, which has no venting that I can
> > find. The side rails seem to seat pretty well with the rubber seal on
> > the sidewall sill. The tailgate sits pretty low vs the top so I
> > stuffed the gap with a little bathroom rug to at least keep the air
> > from circulating between inside and outside.
>
> > The humidity sensor is one of those cheap Honeywell units you use
> > around the house. It has a range of maybe 75 feet. No computer
> > logging. If I could get a logging unit cheap I'd take more systematic
> > measurements. *I also made a suspended tarp "carport" next to my
> > garage for the trailer to sit under partly to keep the sun off but
> > mostly so I don't have to spend hours buffing out the stains from tree
> > sap and bird poop that find the top. So far it works great and I don't
> > have to worry about temperature extremes.
>
> > It was easier when I kept the trailer in a hanger in the high desert,
> > but I think I've got the new situation under control finally.
>
> > 9B
>
> The fiberglass top trailers or maybe just being 15m may be different.
> On my 18m aluminum top trailer there was dust inside on windy days and
> that lead to investigation and you could see dusty areas on top of the
> lower rubber seal on the trailer where the dust had been blowing
> through a gap and crawling around inside with the lid closed you can
> see where the small gaps where the lid is bowing.
>
> Darryl

Just as a discussion, I have had some experience trying to make even
quite small containers (art exhibit display cases) dust tight with a
notable lack of success, both by me and others I have observed. As
you seal the container, you don't actually change the amount of air
circulation, I suspect; you just change the velocity of the air at the
inlet points you can't close up. I am sure there is some benefit to
sealing, but to make a display case dust tight you seal up what you
can, then provide positive pressure through a lot of filters, or in
less critical situation just provide a lot of filter surface area to
lower the resistance of the filtered air. The problem is that
temperature differences inside to outside create air pressure
differences that push the air in and out. Perhaps a solution is to
seal up the trailer really well and then provide a source of inlet air
that is drawn across a long desiccant tray or something.

Brian

[Eric Greenwell[_4_]]

On 12/11/2010 9:07 PM, brianDG303 wrote:
>
> Just as a discussion, I have had some experience trying to make even
> quite small containers (art exhibit display cases) dust tight with a
> notable lack of success, both by me and others I have observed. As
> you seal the container, you don't actually change the amount of air
> circulation, I suspect; you just change the velocity of the air at the
> inlet points you can't close up. I am sure there is some benefit to
> sealing, but to make a display case dust tight you seal up what you
> can, then provide positive pressure through a lot of filters, or in
> less critical situation just provide a lot of filter surface area to
> lower the resistance of the filtered air. The problem is that
> temperature differences inside to outside create air pressure
> differences that push the air in and out. Perhaps a solution is to
> seal up the trailer really well and then provide a source of inlet air
> that is drawn across a long desiccant tray or something.

Maybe you need "ballast". Make the trailer airtight, but run a vent tube
from it to a plastic garbage bag half full of air: when the trailer
"breathes" it just moves air in and out of the garbage bag, and soon the
dehumidifier has all the trailer air (and bag air) dry, dry, dry!

--
Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
email me)

[Mike the Strike]

On Dec 11, 10:15*pm, Eric Greenwell > wrote:
> On 12/11/2010 9:07 PM, brianDG303 wrote:
>
>
>
> > Just as a discussion, I have had some experience trying to make even
> > quite small containers (art exhibit display cases) dust tight with a
> > notable lack of success, both by me and others I have observed. *As
> > you seal the container, you don't actually change the amount of air
> > circulation, I suspect; you just change the velocity of the air at the
> > inlet points you can't close up. *I am sure there is some benefit to
> > sealing, but to make a display case dust tight you seal up what you
> > can, then provide positive pressure through a lot of filters, or in
> > less critical situation just provide a lot of filter surface area to
> > lower the resistance of the filtered air. *The problem is that
> > temperature differences inside to outside create air pressure
> > differences that push the air in and out. *Perhaps a solution is to
> > seal up the trailer really well and then provide a source of inlet air
> > that is drawn across a long desiccant tray or something.
>
> Maybe you need "ballast". Make the trailer airtight, but run a vent tube
> from it to a plastic garbage bag half full of air: when the trailer
> "breathes" it just moves air in and out of the garbage bag, and soon the
> dehumidifier has all the trailer air (and bag air) dry, dry, dry!
>
> --
> Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
> email me)

Andy, a few years ago, you were reputed to be moving to Arizona.
Maybe it's time to reconsider where you live? I can confirm that you
are very unlikely to have severe condensation issues here.

However, if we can't talk you into moving to a more sensible climatic
zone, I had to solve a similar situation many years ago when I needed
to maintain a dry atmosphere inside an outside 4'x4' metal cabinet
with sensitive electronic equipment. We ran two 60-watt light bulbs
in series - worked great! About six to ten 60-watt bulbs operated at
60 V should do the trick.

Mike

[Andy[_10_]]

On Dec 12, 5:05*pm, Mike the Strike > wrote:
> On Dec 11, 10:15*pm, Eric Greenwell > wrote:
>
>
>
>
>
> > On 12/11/2010 9:07 PM, brianDG303 wrote:
>
> > > Just as a discussion, I have had some experience trying to make even
> > > quite small containers (art exhibit display cases) dust tight with a
> > > notable lack of success, both by me and others I have observed. *As
> > > you seal the container, you don't actually change the amount of air
> > > circulation, I suspect; you just change the velocity of the air at the
> > > inlet points you can't close up. *I am sure there is some benefit to
> > > sealing, but to make a display case dust tight you seal up what you
> > > can, then provide positive pressure through a lot of filters, or in
> > > less critical situation just provide a lot of filter surface area to
> > > lower the resistance of the filtered air. *The problem is that
> > > temperature differences inside to outside create air pressure
> > > differences that push the air in and out. *Perhaps a solution is to
> > > seal up the trailer really well and then provide a source of inlet air
> > > that is drawn across a long desiccant tray or something.
>
> > Maybe you need "ballast". Make the trailer airtight, but run a vent tube
> > from it to a plastic garbage bag half full of air: when the trailer
> > "breathes" it just moves air in and out of the garbage bag, and soon the
> > dehumidifier has all the trailer air (and bag air) dry, dry, dry!
>
> > --
> > Eric Greenwell - Washington State, USA (change ".netto" to ".us" to
> > email me)
>
> Andy, a few years ago, you were reputed to be moving to Arizona.
> Maybe it's time to reconsider where you live? *I can confirm that you
> are very unlikely to have severe condensation issues here.
>
> However, if we can't talk you into moving to a more sensible climatic
> zone, I had to solve a similar situation many years ago when I needed
> to maintain a dry atmosphere inside an outside 4'x4' metal cabinet
> with sensitive electronic equipment. *We ran two 60-watt light bulbs
> in series - worked great! *About six to ten 60-watt bulbs operated at
> 60 V should do the trick.
>
> Mike

Yeah, my move was...uh...delayed.

For now the dehumidifier is working. I don't see a lot of reason why
there would be tons of air movement in and out. There isn't much
temperature differential or change thereto over time. I guess
lightbulbs could help too.

9B