[LynyrdSkynyrd]

Anybody come out and open up the cargo area and see thin Ice on the ceilling. How to stop this, this van has electrical parts and when the ice melts it drips, like a basting top on a dutch oven.

 

[KeepMeMoving]

Before we insulated the roof there would be condensation on it after a night of sleeping in it. After adding insulation the condensation was gone. Adding insulation should keep the ceiling from getting so cold condensation or ice forms.

 

[TedV865]

You also might check for water leaks at the rooftop clearance/marker lights and along the sides where you see plastic clips that hold on the side trim. I thought I saw some posts about leaks in those places.

If you live in an area with high humidity, it's normal. Kind of like a terrarium. Run the AC on recirculation and the air inside the van will be a little less humid. Winter time run AC with heat.

 

[GaryBIS]

Before we insulated the roof there would be condensation on it after a night of sleeping in it. After adding insulation the condensation was gone. Adding insulation should keep the ceiling from getting so cold condensation or ice forms.

Hi,
Adding insulation actually makes the roof sheet metal run colder -- that is, it runs closer to the outside temperature because there is insulation between the roof and the inside of the van.

If the insulation is not permeable to water vapor, then you won't get condensation on the roof metal because the water vapor can't get to the roof. You probably won't get condensation to the inside of the insulation either if the inside of the van temperature stays above the dew point.

If the insulation is permeable to water vapor, then you will still get condensation on the roof metal because the water vapor travels through the insulation and then condenses on the cold roof metal. You may not see the condensation if the insulation absorbs or holds it against the metal.

Gary

 

[medicineman4040]

So Gary, it sounds like the first layer of insulation against the roof metal needs to be impermeable and occlusive with my goal of being to eliminate any and all possible air gaps.

 

[GaryBIS]

So Gary, it sounds like the first layer of insulation against the roof metal needs to be impermeable and occlusive with my goal of being to eliminate any and all possible air gaps.

Hi,
That's the way I feel about it. Make the layer that is against the van skin non-permeable to water vapor and glue/seal it well enough to the van skin that water vapor can't get behind the insulation.

Spray urethane or rigid polyiso sheet glued to the van skin with Great Stuff are two ways to do this. But, neither method can achieve this 100% as its very hard to fill the cavities in the frames completely.

For sure not everyone agrees with this approach.

Gary

 

[KNDLKSTMS]

Lyn Skyd I just live up the road from ya'. Every thing I own is full of water/vapor . I'll be spending all weekend drying out watertite and less than watertite vans , cars , you name it. In between floods I've opened up the PM to fit stuff and it got condensation all over when it's closing time. Non permeable insulation is the ticket but .... . . . . this is the WATER planet and it's going to get in EVERYWHERE !!! When it's drying time make sure the van can breath .

 

[RDinNHandAZ]

So Gary, it sounds like the first layer of insulation against the roof metal needs to be impermeable and occlusive with my goal of being to eliminate any and all possible air gaps.

This is why foil faced polyisocyanurate is so good. Run the strips of great stuff (adhesive) across the van and horizontally on the walls so that water, if it forms, can escape to the rocker panel scuppers. They are there for that reason. I don’t think an adhesive on the whole sheet is a good idea because you are going to trap water against the van ceiling or walls. You will not stop all that condensation, but you can reduce it to almost nil and control the small amount that forms.

 

[KilWerBzz]

You have too much moisture run the A/C to get rid of the moisture it will still heat the van. Or run heat at one of the two defrost settings this will run the A/C.

 

[LynyrdSkynyrd]

Thanks everybody, lots of great info, I also just built shelves out of wood but it has been cold hear so I cant see the wood causing too much of this, if it was hot and it dried out I could see it, but not in the cold we are having at this time.. I do open up all the doors and windows on a sunny day to try and dry it out, but I will have to do the top insulation. I cant have the water droplets landing all over my electrical parts. That was the main reason for the van was to keep all of my metal parts dry and shiny. I do commercial electrical. I dig the van, but i have some bugs to work out. Like today I pulled my soda out of the cup holder on the floor, and I got my soda and the side of the cup holder came up with it.

I only get the wicked condensation on nights that are in the low 30s. And that dose not happen too often.

But as for the condensation, Its funny its like I am inside of self basting Dutch Oven.
You gotta laugh!!!

This forum is great!

 

[166322]

Thanks everybody, lots of great info, I also just built shelves out of wood but it has been cold hear so I cant see the wood causing too much of this, if it was hot and it dried out I could see it, but not in the cold we are having at this time.. I do open up all the doors and windows on a sunny day to try and dry it out, but I will have to do the top insulation. I cant have the water droplets landing all over my electrical parts. That was the main reason for the van was to keep all of my metal parts dry and shiny. I do commercial electrical. I dig the van, but i have some bugs to work out. Like today I pulled my soda out of the cup holder on the floor, and I got my soda and the side of the cup holder came up with it.

I only get the wicked condensation on nights that are in the low 30s. And that dose not happen too often.

But as for the condensation, Its funny its like I am inside of self basting Dutch Oven.
You gotta laugh!!!

This forum is great!

Lynyrd,

Condensation, frozen cargo van walls and ceiling is typical for all makes of steel boxes on wheels world wide. At a minimum add air circulation/venting. Commercial/fleet vehicles are increasingly hip to making sure air is circulating at all times. Consider adding a Flattener http://www.flettner.co.uk or electric vent combined with a floor intake/return air vent. In Europe and now North America passive venting is becoming popular to limit condensation in commercial vehicles.

I have found While working inside my PM in the cold weather that if I turn on my Max fan I can eliminate all condensation and icing. My flattener keeps the van free of condensation while driving. Of corse if you can invests in insulation all the better.

Hope this helps

dave