'sweating' of aluminum frames...
Tarmagost
its cold out and the inside is heated? My sister says the sales people tell
her this...and that it sweats on the inside of the wall (??). Any comments?
Tim, Denver
gle...@attglobal.net
when it's real cold outside and you run the heater and keep the windows
closed, all RV's "sweat". The walls are cold and your breath and the
furnace air contain a lot of moisture. It's not just aluminum. It's
the nature of the beast.
Glenn
John Irwin
a bit more when cooking or showering. Warm, moist air rises and even a very
small ceiling vent opening can keep the inside humidity down quite a bit.
Breath and cooking are the big culprits. Furnace air will contain exactly
the same amount of moisture as the room air in general. It is merely room
air recirculated.
I have kept quite warm and dry down to 26 degrees.
<gle...@attglobal.net> wrote in message
news:38946175...@attglobal.net...
Janet Wilder
aluminum frame when there is a big change in temperature like the warm days
and cold nights in the desert. Wood frames do not have this problem. Some
maunfacturers of alum. framed iuhnits put in a *vapor barrier* to prevent this
happening.
In article <38946175...@attglobal.net>, gle...@attglobal.net writes:
>Tim,
>when it's real cold outside and you run the heater and keep the windows
>closed, all RV's "sweat". The walls are cold and your breath and the
>furnace air contain a lot of moisture. It's not just aluminum. It's
>the nature of the beast.
>Glenn
>
>Tarmagost wrote:
>>
>> Any truth to the rumor that aluminum frame TTs 'sweat' (condense moisture)
>when
>> its cold out and the inside is heated? My sister says the sales people
>tell
>> her this...and that it sweats on the inside of the wall (??). Any
>comments?
>>
Janet Wilder
"The Road Princess"
Residentially Challenged
Janet Wilder
(Tarmagost) writes:
>Any truth to the rumor that aluminum frame TTs 'sweat' (condense moisture)
>when
>its cold out and the inside is heated? My sister says the sales people tell
>her this...and that it sweats on the inside of the wall (??). Any comments?
>
Yes it is true. It also happens when the days are warm and nights are cold.
There are some manufacturers who install a vapor barrier to prevent sweating.
BigKen97
>
>Keep a ceiling vent open a crack and it will minimize condesation. Open it
>a bit more when cooking or showering. Warm, moist air rises and even a very
>small ceiling vent opening can keep the inside humidity down quite a bit.
>
>Breath and cooking are the big culprits. Furnace air will contain exactly
>the same amount of moisture as the room air in general. It is merely room
>air recirculated.
>
>I have kept quite warm and dry down to 26 degrees.
As I understand it, my furnance draws in outside air, heats it and blows it
through the ducts.
RV'n Ken in Las Vegas... Winter is almost over.... Planing summer trip.
John Irwin
Every RV furnace I've seen exclusively recirculates air from the interior of
the RV. The two openings on the exterior of the trailer are the intake and
exhaust air for the burner, which you had better hope is isolated from the
trailer interior.
BigKen97 <bigk...@aol.comNOSPAM> wrote in message
news:20000202030452...@ng-fm1.aol.com...
Stanley P. Miller
with an inch or so thickness of the blue foam insulation panel.
On Thu, 10 Feb 2000 03:22:19 GMT, D Craft <david...@my-deja.com>
wrote:
>The aluminum conducts better than wood. Therefore in laminates with
>aluminum frames, the condensation will form inside where the metal
>makes contact with paneling. Some models do have a paper/foam layer,
>however, this is prone to delamination. I think aluminum is still a
>good way to go...the venting mentioned earlier is a good deterant.
> D Craft
>
>
>Sent via Deja.com http://www.deja.com/
>Before you buy.
Stanley P. Miller ka...@primenet.com -- Automated Commercial E-Mail
Proofreading Service -- Please review the terms & fees for processing
unsolicited commercial e-mail before submitting your e-mail for
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D Craft
aluminum frames, the condensation will form inside where the metal
makes contact with paneling. Some models do have a paper/foam layer,
however, this is prone to delamination. I think aluminum is still a
good way to go...the venting mentioned earlier is a good deterant.
D Craft
tarm...@aol.com (Tarmagost) wrote:
> Any truth to the rumor that aluminum frame TTs 'sweat' (condense
moisture) when
> its cold out and the inside is heated? My sister says the sales
people tell
> her this...and that it sweats on the inside of the wall (??). Any
comments?
>
Ronald Stitt
sweat. I am right now in south texas where the temp get 90+ and the humidity
is something else. No sweating...last spring was in southern Utah with the
temp in the 20s and snow on the ground...No sweating. I sorta believe that
some of the stuff about aluminum frames is put out by people who sell
trailers that don't have them. Still using wood.
Ron
Charles C.
"Ronald Stitt" <rons...@worldnet.att.net> wrote in message
news:zx3q4.10019$LC4.2...@bgtnsc04-news.ops.worldnet.att.net...
Of all types of metal, aluminum is least likely to sweat. It dissipates heat
and cold so quickly, there is little temperature differential to generate
sweat.
Mike Niemela
This in regards to condensation forming when heat transfer is involved.
The fact that aluminum transfers heat efficiently is exactly what causes
condensate to form on it easily.
When warm, moist air contacts any cool surface the heat is drawn from
the air causing it to loose volume. This, in effect, is much like
squeezing a sodden sponge making the water run out of it. The cooled
air looses moisture when it reaches its dew point and this moisture is
deposited on the cool surface.
If this surface is subjected to an ample temperature differential and
transfers heat easily, like an aluminum window frame with no TIM barrier
in it, the condensate will accumulate to a noticeable level. Hence the
surface seems to "sweat".
Materials which transfer heat poorly will, obviously, sweat less than
highly conductive, thermally speaking, materials such as glass and
aluminum.
Best
Mike N
Tom J
Tenc...@webtv.net (Mike Niemela) wrote:
> Charles C. made the statement that "aluminum is least likely to
>sweat".
> This in regards to condensation forming when heat transfer is
>involved.
>
> The fact that aluminum transfers heat efficiently is exactly what
>causes condensate to form on it easily.
>
I have owned aluminum framed trailers since 1967, and the only sweat I
have had is windows, just like all my friends with the wood framed
trailers. This is just one of the sales gimmics for wood framed
trailers that dies hard.
--
tomj...@my-Deja.com
http://homepages.go.com/~tomjanis/
http://homepages.go.com/~aviontravelcade/
Marge & Stan Barnett
little "socks" that came with them to catch the moisture? Aluminum glasses
sweat. I suspect aluminum frames, and aluminum skins, do too.
Mike Niemela wrote:
> Charles C. made the statement that "aluminum is least likely to sweat".
> This in regards to condensation forming when heat transfer is involved.
>
> The fact that aluminum transfers heat efficiently is exactly what causes
> condensate to form on it easily.
>
Ronald Stitt
fulltime.....no sweating! My windows don't sweat either....they are
thermopane....or double.
Ron
"Tom J" <tomj...@my-deja.com> wrote in message
news:88eqdr$krq$1...@nnrp1.deja.com...
> In article <1661-38A...@storefull-165.iap.bryant.webtv.net>,
Mike Niemela
I did not mean to imply that an aluminum framed trailer would
automatically sweat, only attempting to make a simple explanation of the
cause of condinsation formation.
When I was studying vapor barriers, "R" factors, heat transfer and such
the instructor always seemed to be contradicting himself. There are so
many variables that setting guidelines would be problematic at best.
Any RV would be a real nightmare, IMO, to build because of the materials
people want and what is required for durability. Take the question of
vapor barriers for example. If you have more than one barrier in a wall
that is impervious to moisture you will, in nearly all cases, end up
with moisture trapped between them. This causes loss of insulating
ability, mold, rot, rust and a host of other problems. Now with most
RVs we have an outside skin that is waterproof. This means if we put a
vapor barrier against the underside of the inside wall we are going to
trap water inside the wall. On the other hand, if we do not prevent the
moisture from cooking, bathing and such from migrating thru the inside
paneling it will tend to condense on the inside of the outside sheeting.
This will eventually wet the insulation and cause it to be ineffective
and will also allow the framing of the RV to become saturated.
As Chris mentioned it is very possible to have enough insulation to slow
the heat transfer to the point that the dew point is reached somewhere
in the middle of the insulation blanket. In this case the insulation
becomes wet, looses its ability to slow heat transfer, and the situation
deteriorates.
What are the cures? Keep the inside of the RV dry as best you can. Use
proper ventilation, dehumidifiers, heat and good moisture management
practices.
Will an RV with an aluminum frame have more of a sweating problem than a
wood frame RV? IMO, if the two are similar in construction, there will
be little or no difference. The condensate may show up in different
places but the amount formed will be very similar.
Best
Mike N
Tom J
Tenc...@webtv.net (Mike Niemela) wrote:
> that is impervious to moisture you will, in nearly all cases, end up
> with moisture trapped between them. This causes loss of insulating
> ability, mold, rot, rust and a host of other problems. Now with most
> RVs we have an outside skin that is waterproof. This means if we put
>a
> vapor barrier against the underside of the inside wall we are going to
> trap water inside the wall. On the other hand, if we do not prevent
What you say is true in most cases. I happen to have a trailer that
has an aluminum outside skin with aluminum frame, that has been sprayed
almost solid with rigid foam insulation, and then an aluminum skin,
with interior finish applied, for the inside walls. There are
fiberglass inside end caps because of rounded corners, and there is
foam tape between the inside skin anf the frame members. There is no
place for the moisture to go but out the vents, or collect on the
windows. I wished it was still possible to buy such units new, but cost
went through the roof, and nobody builds such a unit anymore, that I am
aware of. I had a 1966 model before I bought my 1986 model, and both
are still in regular use today. A good friend bought the 1966 model
from me, and paid me what it cost new! ;-)
levele...@gmail.com
Hank not George
> I cannot believe that with all of this talk no one has mentioned a dehumidifier. All RVs should really have a small dehumidifier to help prevent condensation. Even if you don’t see condensation it can form inside the walls of any RV. It’s just piece of mind to take the extra precaution and get one. We are full time in a 33’ Toy Hauler, just two people, and a dehumidifier eliminated the condensation for us. I should mention that we also of course vent when we cook and shower. We only saw it when it was below 40 degrees outside while we ran our heater inside. I bought a “Hysure brand 2L electric dehumidifier “ on amazon for about $80 and it’s just the right size and does the trick. Best of luck to everyone!
Hank
Ralph E Lindberg
There are two types of dehumidifiers. The smaller (cheaper) ones like
you bought (I just found it for $65) use a solid state device and fan.
In my testing they could not lower the humidity below 60% running full
time.
The larger (more expensive) units use a compressor (just like an A/C)
and fan, in my testing (same conditions) one of these could lower the
humidity below 40% running full time and 50% running part time.
Living west of Seattle dehumidifiers can be, important.