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Matt Herron Jr.
September 26th 10, 03:17 AM
Is there an easy way to check that my solar powered vent on top of the
Cobra trailer is functioning properly? I haven't heard it running
lately, but don't really know what triggers it to run (besides light
of course...)

Thanks,

Matt

JS
September 26th 10, 05:53 AM
If it's the Intersolar vent as delivered from Cobra, it's likely
"D.E.D."
The 4" Nicro Day/Night vent with C-cell NiMH battery works very
well. You'll just need to drill 3 new mounting holes and plug the old
ones if replacing an Intersolar vent.
If the battery is completely dead, the Nicro may not work. If the
push-button switch inside (not everyone knows it's there) is in the
OFF position, it won't do much either.
The Nicro is available from most gliding suppliers or marine
suppliers.
Jim

Matt Herron Jr.
September 26th 10, 06:13 AM
So these things are designed to run continuously? They don't kick on
when the temp is above a set point?

brianDG303[_2_]
September 26th 10, 02:35 PM
On Sep 25, 10:13*pm, "Matt Herron Jr." > wrote:
> So these things are designed to run continuously? *They don't kick on
> when the temp is above a set point?

Nope. They just run whenever there is power (sun or battery)
available, as long as the push-button switch (which some don't have)
is ON.

John Cochrane[_2_]
September 26th 10, 04:42 PM
On Sep 26, 8:35*am, brianDG303 > wrote:
> On Sep 25, 10:13*pm, "Matt Herron Jr." > wrote:
>
> > So these things are designed to run continuously? *They don't kick on
> > when the temp is above a set point?
>
> Nope. They just run whenever there is power (sun or battery)
> available, as long as the push-button switch (which some don't have)
> is ON.

Now, with winter coming, is a great time to hear the assembled wisdom
(and random opinions!) of r.a.s. on the trailer vent issue. It's been
nagging me for years.

Most trailers are left outside. Go look at your glider at 6 am. It's
covered with condensation. Bad. The sun comes out, the condensation
dries, and the vent sucks it all out. Well, that's better than no
vent, in which case it would stay dripping all day and the gel coat
would peel off in your hands after a few months. I bought a little
recording hygrometer to test all this, and the result is frightening
-- 100% relative humidity for the early morning hours.

So, I got a battery powered vent that sucks all night too. But am I
doing any good? I'm just sucking in more humid air. I stack the thing
with drying crystals, but who knows if that is helping. Sure, they
soak up a lot of moisture, but since I'm also venting perhaps they are
just drying air that I then promptly pump outside.

The right answer is to hook it up to power and throw in a
dehumidifier. This works like a charm... but there is no power at my
trailer. A small heater works well too, and I use one over the winter.
But there is no power at my trailer. An even better answer of course
is to store it inside in a humidity controlled environment. Note: The
average hangar can be worse than outside. They leak, the solar vent no
longer works, and that huge concrete slab below you is a humidity
magnet in the springtime; it also keeps the glider from warming up and
drying out.

Sooo. Does anyone have hard data or anything other than obvious
opinions on what works best? Vents were solution 1.0 to this problem.
Are battery powered vents better or worse? What's solution 2.0? Some
solar powered heating or dehumidifier system seems to be the way to
go, but it has to cost less than a hangar.

John Cochrane

mattm[_2_]
September 26th 10, 08:22 PM
On Sep 26, 11:42*am, John Cochrane >
wrote:
> On Sep 26, 8:35*am, brianDG303 > wrote:
>
> > On Sep 25, 10:13*pm, "Matt Herron Jr." > wrote:
>
> > > So these things are designed to run continuously? *They don't kick on
> > > when the temp is above a set point?
>
> > Nope. They just run whenever there is power (sun or battery)
> > available, as long as the push-button switch (which some don't have)
> > is ON.
>
> Now, with winter coming, is a great time to hear the assembled wisdom
> (and random opinions!) of r.a.s. on the trailer vent issue. It's been
> nagging me for years.
>
> Most trailers are left outside. Go look at your glider at 6 am. It's
> covered with condensation. Bad. The sun comes out, the condensation
> dries, and the vent sucks it all out. Well, that's better than no
> vent, in which case it would stay dripping all day and the gel coat
> would peel off in your hands after a few months. I bought a little
> recording hygrometer to test all this, and the result is frightening
> -- 100% relative humidity for the early morning hours.
>
> So, I got a battery powered vent that sucks all night too. But am I
> doing any good? I'm just sucking in more humid air. I stack the thing
> with drying crystals, but who knows if that is helping. Sure, they
> soak up a lot of moisture, but since I'm also venting perhaps they are
> just drying air that I then promptly pump outside.
>
> The right answer is to hook it up to power and throw in a
> dehumidifier. This works like a charm... but there is no power at my
> trailer. A small heater works well too, and I use one over the winter.
> But there is no power at my trailer. An even better answer of course
> is to store it inside in a humidity controlled environment. Note: The
> average hangar can be worse than outside. They leak, the solar vent no
> longer works, and that huge concrete slab below you is a humidity
> magnet in the springtime; it also keeps the glider from warming up and
> drying out.
>
> Sooo. Does anyone have hard data or anything other than obvious
> opinions on what works best? *Vents were solution 1.0 to this problem.
> Are battery powered vents better or worse? What's solution 2.0? Some
> solar powered heating or dehumidifier system seems to be the way to
> go, but it has to cost less than a hangar.
>
> John Cochrane

The opinion we have at our airport (and that's all it is, I'm afraid),
is that
the purely solar powered vents are best. When the weather is warm and
dry
and sunny they pull air through your trailer and dry it out. When the
weather
is damp and cloudy they leave well enough alone.

My plane sat parked in its trailer for 6 years before I bought it. It
didn't have
a solar vent. The condensation would collect on the wings and
fuselage,
run down to the low point (leading edge of the wings), and gradually
rot
the gelcoat. It had to have a partial refinish of the leading edges
before
I bought it.

I got a solar vent and installed it early this year to improve the
circulation.
In my case the passive vents were in the front of the trailer, so I
put mine
on top of the doghouse.

-- Matt

Bastoune
September 26th 10, 09:11 PM
Could someone please explain the condensation cycle inside a trailer?

I understand that, at night, the relative humidity increases all
around. I assume that the air inside the trailer cools slower than the
air outside, as thus, becomes warmer relative to the outside. Does the
relatively warm air inside the trailer then condensate against the
cold inner skin of the trailer? Is it then fair to assume that the
water we find on the glider is the result of the condensation dripping
on the glider, and not air condensating on the glider itself?

Thanks.

Darryl Ramm
September 26th 10, 09:57 PM
On Sep 26, 1:11*pm, Bastoune > wrote:
> Could someone please explain the condensation cycle inside a trailer?
>
> I understand that, at night, the relative humidity increases all
> around. I assume that the air inside the trailer cools slower than the
> air outside, as thus, becomes warmer relative to the outside. Does the
> relatively warm air inside the trailer then condensate against the
> cold inner skin of the trailer? Is it then fair to assume that the
> water we find on the glider is the result of the condensation dripping
> on the glider, and not air condensating on the glider itself?
>
> Thanks.

And once the morning warming cycle starts and the surfaces of the
trailer warm up before the high thermal mass parts of the glider the
water may cycle back in the air and condense on the glider. Open some
damp trailers in the early morning and you'll see condensation clearly
on the glider. Once the glider surfaces fall below the dew point
moisture could also condense there, so its not exclusively going to be
on the outer surfaces.

I also would like to see some study of humidity in trailers, all the
folklore and different ideas about fiberglass or aluminum top
trailers, insulated trailer tops, different types of vents and fans
etc. would be interesting to explore. I started to build a data logger
that could capture the humidity and air and surface temps but got
sidetracked and never got it finished. I am concerned that some of the
fans may such in moist air in the morning that condenses and then
takes a while to vent out. Maybe by the time the solar fans really
kick in the glider has warmed enough, but who knows.

The very worst thing probably just a leak either of rain or
condensation on the outside of the trailer. Worth double checking that
any water on the floor of the trailer is not simply from a leak. I've
had both my cobra aluminum top trailers one brand new, one near new)
leak rainwater around the tail fin vent and was a simple matter of
removing and reinstalling with fresh silicone sealant. Worth playing
with a hose and checking out if they leak.

Darryl

Andy[_10_]
September 27th 10, 12:18 AM
On Sep 26, 8:42*am, John Cochrane >
wrote:
> On Sep 26, 8:35*am, brianDG303 > wrote:
>
> > On Sep 25, 10:13*pm, "Matt Herron Jr." > wrote:
>
> > > So these things are designed to run continuously? *They don't kick on
> > > when the temp is above a set point?
>
> > Nope. They just run whenever there is power (sun or battery)
> > available, as long as the push-button switch (which some don't have)
> > is ON.
>
> Now, with winter coming, is a great time to hear the assembled wisdom
> (and random opinions!) of r.a.s. on the trailer vent issue. It's been
> nagging me for years.
>
> Most trailers are left outside. Go look at your glider at 6 am. It's
> covered with condensation. Bad. The sun comes out, the condensation
> dries, and the vent sucks it all out. Well, that's better than no
> vent, in which case it would stay dripping all day and the gel coat
> would peel off in your hands after a few months. I bought a little
> recording hygrometer to test all this, and the result is frightening
> -- 100% relative humidity for the early morning hours.
>
> So, I got a battery powered vent that sucks all night too. But am I
> doing any good? I'm just sucking in more humid air. I stack the thing
> with drying crystals, but who knows if that is helping. Sure, they
> soak up a lot of moisture, but since I'm also venting perhaps they are
> just drying air that I then promptly pump outside.
>
> The right answer is to hook it up to power and throw in a
> dehumidifier. This works like a charm... but there is no power at my
> trailer. A small heater works well too, and I use one over the winter.
> But there is no power at my trailer. An even better answer of course
> is to store it inside in a humidity controlled environment. Note: The
> average hangar can be worse than outside. They leak, the solar vent no
> longer works, and that huge concrete slab below you is a humidity
> magnet in the springtime; it also keeps the glider from warming up and
> drying out.
>
> Sooo. Does anyone have hard data or anything other than obvious
> opinions on what works best? *Vents were solution 1.0 to this problem.
> Are battery powered vents better or worse? What's solution 2.0? Some
> solar powered heating or dehumidifier system seems to be the way to
> go, but it has to cost less than a hangar.
>
> John Cochrane

You could buy about 100 of these:

http://tinyurl.com/254daal

If your trailer is well sealed maybe you won't have to dry them out on
a regular basis.

I think traditional dehumidifiers draw 3-5 amps - too much for solar
or battery.

9B

Dave Nadler
September 27th 10, 02:08 AM
On Sep 25, 10:17*pm, "Matt Herron Jr." > wrote:
> Is there an easy way to check that my solar powered vent on top of the
> Cobra trailer is functioning properly? *I haven't heard it running
> lately, but don't really know what triggers it to run (besides light
> of course...)
>
> Thanks,
>
> Matt

Lie down next to the fuselage.
Have your significant other close, latch, and lock the trailer.
After a couple of days in there you should have
a pretty good idea of how its working.

See ya, Dave

Andy[_10_]
September 27th 10, 03:57 AM
On Sep 26, 4:18*pm, Andy > wrote:
> On Sep 26, 8:42*am, John Cochrane >
> wrote:
>
>
>
>
>
> > On Sep 26, 8:35*am, brianDG303 > wrote:
>
> > > On Sep 25, 10:13*pm, "Matt Herron Jr." > wrote:
>
> > > > So these things are designed to run continuously? *They don't kick on
> > > > when the temp is above a set point?
>
> > > Nope. They just run whenever there is power (sun or battery)
> > > available, as long as the push-button switch (which some don't have)
> > > is ON.
>
> > Now, with winter coming, is a great time to hear the assembled wisdom
> > (and random opinions!) of r.a.s. on the trailer vent issue. It's been
> > nagging me for years.
>
> > Most trailers are left outside. Go look at your glider at 6 am. It's
> > covered with condensation. Bad. The sun comes out, the condensation
> > dries, and the vent sucks it all out. Well, that's better than no
> > vent, in which case it would stay dripping all day and the gel coat
> > would peel off in your hands after a few months. I bought a little
> > recording hygrometer to test all this, and the result is frightening
> > -- 100% relative humidity for the early morning hours.
>
> > So, I got a battery powered vent that sucks all night too. But am I
> > doing any good? I'm just sucking in more humid air. I stack the thing
> > with drying crystals, but who knows if that is helping. Sure, they
> > soak up a lot of moisture, but since I'm also venting perhaps they are
> > just drying air that I then promptly pump outside.
>
> > The right answer is to hook it up to power and throw in a
> > dehumidifier. This works like a charm... but there is no power at my
> > trailer. A small heater works well too, and I use one over the winter.
> > But there is no power at my trailer. An even better answer of course
> > is to store it inside in a humidity controlled environment. Note: The
> > average hangar can be worse than outside. They leak, the solar vent no
> > longer works, and that huge concrete slab below you is a humidity
> > magnet in the springtime; it also keeps the glider from warming up and
> > drying out.
>
> > Sooo. Does anyone have hard data or anything other than obvious
> > opinions on what works best? *Vents were solution 1.0 to this problem..
> > Are battery powered vents better or worse? What's solution 2.0? Some
> > solar powered heating or dehumidifier system seems to be the way to
> > go, but it has to cost less than a hangar.
>
> > John Cochrane
>
> You could buy about 100 of these:
>
> http://tinyurl.com/254daal
>
> If your trailer is well sealed maybe you won't have to dry them out on
> a regular basis.
>
> I think traditional dehumidifiers draw 3-5 amps - too much for solar
> or battery.
>
> 9B

I take it back apparently these things can absorb up to 8-10 ounces of
water, which is about half the amount of water contained in the air
inside your trailer if it's saturated at 60 degrees F (at least
according to Wikipedia). So it kind of depends how quickly moisture
creeps in through the cracks. Might be worth buying a couple and
seeing if they have any effect - they're only $20 or so.

9B

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