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After a 4+ month wait, I should be taking delivery of my 136 LR next Monday! I purchased Thinsulate from Hein for the main insulation material. After reading and rereading all the posts on insulation, radiant materials, vapor barriers, etc., one final question remains.

First, just some quick info on what I am using the van for.... In addition to being my daily driver, I will be using it to transport my dogs to events, but I will also be leaving some of them in the van for a few hours at a time, in a variety of weather conditions. I am having a generator installed to run a roof mounted A/C unit and will also have a Maxx or Fantastic fan installed. I will be using the van for an occasional overnight venture on a road trip to a dog event, or to visit family.

My main concern is the comfort and safety of my dogs. I am way more concerned about insulating for protection against the heat, and less worried about the cold. In many cases, I will be parked in the direct sun.

It is my understanding that the reflective materials do not provide thermal protection unless they are installed with an air gap. But, would they provide any protection to reflect against the heat/sun, if I installed something like LowE or Reflectix against the van skin prior to installing the Thinsulate? Would it make a bigger difference if I did that on the ceiling as it likely takes the brunt of the direct sun?

Or, would applying a reflective material after installing the Thinsulate have any effect on keeping it cooler in the van... if it doesn't provide a benefit, I would likely use the Thinsulate alone.

I really appreciate all the info I've obtained from everyone on this forum. The level of knowledge is impressive. I'm pretty handy in general, but I'm really a fish out of water regarding conversions, or most things automotive.

Thank you again,

Susan
 

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With no air gap you get R 1.1. I installed Reflectix as a first layer with double sided tape on the roof so there is somewhat of a air gap in the channels on the roof. I am adding 10mm Aerogel then 3mm Thinsulate over that. If anything, it will reflect heat back in on cold days. Doesn't hurt to add as a first layer, light and thin and can act as a vapor barrier.
 

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I have something in my little brain. How does a reflective material reflect when it is in
the wall?
Works great in the windows.
 

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Don't understand?
An aluminum rad transfers the heat as fast as the old brass ones?
How does this work?
Example, Put aluminum wrap on a potato and throw it in the barbeque.
Just asking.
 

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Look under your van, you will find reflective heat barriers of all types around your exhaust system. You wrap a potato or corn to reflect the high heat from burning the outside so it will bake instead, remove the aluminum and it will cook faster and burn the outside. Heat barriers and insulation only slow down the rate of heat transfer, the more insulation, the less the heater or AC will have to run or work to maintain temperature.
 

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You all are talking different kinds of heat. Reflective foil reflects the radiant heat from the sun or any source. Having it against the skin or inside with just an air gap will help in keeping the van cool in bright sun. That is, it reflects heat back out. Think of the type of heat produced by so called radiant heaters.

Basic insulation is trapped air so air movement does not carry heat from the hot side to the cold side. Many materials stop movement well and all of them have similar R values per inch. If a thin bubble foil material is used alone space it an inch or so from the metal skin. The trapped air, however, has some movement to transfer non radiant heat. Better is to put the foil against the skin with conventional insulation backing it up. This provides the reflection and well trapped air. I think that this is best for hot summer.

Radiant heat is also produced in less intense and smaller quantities from other sources even our bodies. For cold climates a reflective barrier in a floor and walls helps keep internal heat in.
 

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An additional thought. Aluminum is an excellent conductor of thermal heat as opposed to being a reflector of radiant heat. That's why you wrap the potato to bake as the foil gets heat in while protecting the potato on the grill.

Most DIY campers are used in both hot and cold climates so it is all a balancing act.
 

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Hi,
I suppose this may be hard to do, but the best place for a reflective coating for rejecting summer heat would be on the outside of your van. If the van is white, that helps as its highly reflective in visible light, but it absorbs well in the IR and sunlight has a lot of IR. Something like aluminum reflects well across visible and IR.

The other very effective thing you can do is to provide some form of effective shading. Maybe some kind of external shade that could be hung on the outside of the van on the sunny side? This would be like parking in the shade of a tree, only you bring your own tree.

Don't know what your climate is like, but if its dry, then evaporative coolers are quite effective and there are some made for vans. They could probably be run on batteries without a generator. Here is a DIY one: http://www.builditsolar.com/Projects/Cooling/RVSwampCooler/RVSwampCooler.htm and a commercial one: http://www.turbokool.com/



Gary
 

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ST111 use both. In my opinion the Thinsulate would be best.

There is no reason to have a reflective material in a hidden wall, it just so happens
that it is what it is made out of. Still works fine as that is what my first layer is.

You can use plastic as a muffler heat shield but there is one problem ,It would melt and catch
on fire.So aluminum is a choice product because of weight ,fire resistant and cost.

AHHH the bake potato . Aluminum distributes the heat more evenly.
 

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Heat is transferred in three ways: by Conduction, Convection and Radiation. To insulate your van well reduce the movement of heat in our out by providing barriers to all three. Most thermal barriers also are sound barriers so you may accomplish both jobs with a careful selection of insulators.

To stop heat movement by conduction place materials against the conducting material (the metal frame and surface of the van) to prevent heat being carried by the metal as steel is a good conductor and moves heat along fairly well. Hold a nail in a flame and notice it takes some time but the end in your hand will get hot and stay hot as the flame's heat moves along the several inches of the nail in a few moments. The distance the heat needs to move through the vans surface happens in seconds. Wrap the nail in dry cloth to prevent the conduction of heat from the hot nail to your hand. Place even a 1/4 inch piece of foam backed fabric, to nearly stop the conduction of the vans skin to yours.

To stop heat by convection in a fluid (air) the air must be trapped so it cannot convect (rise) carrying the heat along. Trap that air with sealed surfaced materials like the reflexix or a sealed layer of rigid insulation. Glass fibers in normal house insulation are not good at stoping convection unless it is sealed on all sides, something most installers and contractors do not do. Many folks have attics with open insulation laying between rafters or joists. it does little there and the same stuff will trap moisture in your van wall rusting it out.... bad.

To stop heat transfer by radiation introduce a material that slows the radiant transfer. An inch simple wood introduces a reduction of 1. Think of radiant insulation values as inches of wood R6 is similiar to 6 inches of wood. 1 inch of Thermax "tuff R" is equal to R6 or 6 inches of wood and has a reflective surface which if next to a dead air space adds an additional 1 to 3 inches of wood equivalence. It is a simplification of course but convenient to think about.

Lastly think about the conditions in the space between the walls and the van's interior. Some foam insulations begin to fail and sag at 160 degrees F. Hein has posted about thinsulate which is a material designed to take this heat. Many clear plastics cannot withstand such heat and will become brittle so vibration will destroy them.
I am now stepping down from the soapbox......
 

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I am now stepping down from the soapbox......
What is soapbox? some kinda a show people watch when they are at home?

What is your advice for the OP?
A van is opposite to a house . The out side is sealed where as a house is not.
 

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I am now stepping down from the soapbox......
What is soapbox? some kinda a show people watch when they are at home?

What is your advice for the OP?
A van is opposite to a house . The out side is sealed where as a house is not.
soap·box
ˈsōpˌbäks
noun
a box or crate used as a makeshift stand by a public speaker.
"a soapbox orator"
a thing that provides an opportunity for someone to air their views publicly.
"fanzines are soapboxes for critical sports fans"
I did mention two products that will solve the OP's issue.
The question was not about sealing or condensation so I did not volunteer anything on that.
I don't have a TV but there may very well be a "Soapbox" reality show

I keep seeing questions about insulation that might be answered by a general explanation not a specific one. I was attempting to do both. If that was inappropriate....Mea Culpa
 

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Thanks! Did not know how to take soapbox.
I did not think that was inapproriate. Was totally slow on the soap box thing.

If condensation is there ,we need the van to breath. I went with something like reflex ( can
not remember what it is called) It has the tiny bubbles. Then on top of that (ceiling) insulated
ceiling tile. Peel off the decorative top layer. It is rigid and easy to cut and glue,(spray adhesive).
The walls are Roxul but it is terrible to work with.
Would of used Thinsulate but did not find out about it until after I had finished.
 

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So, REFLECTING on this thread, here's what I have ABSORBED...

On my Graphite Grey PM, if I were to cover the roof with POTATOES wrapped in aluminum foil, it would keep the van COOL in the summer by REFLECTING HEAT and INSULATING the van. On the other hand, a bunch of (already baked) potatoes, placed inside the van would probably RADIATE HEAT and keep me warm and toasty all night in the winter! ;)

Now it all makes sense!

I hope this won't lead to a HEATED discussion, and ask that everyone just CHILL out.>:D

Ed

Afterthought: a POTATO cut in half and used as earmuffs would probably help with sound deadening in the van... but that's another thread. :D
 

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I think we will all be fine but we can do better if we know what's going on behind the finish in the camper. Personally I doubt we can avoid condensation in some situations unless we spray foam the cavities. If the moisture has a way to escape down the walls and out the built in drains or by evaporation back into the camper's air it should be ok. Using insulation that lets those happen by avoiding types like chopped denim, spun fiberglass, and cellulose is probably enough. Many of the builds on here have covered the ribs too. I plan to expose them but use headliner fabric (a furry surface with open cell foam backing) to keep moisture from forming. They breathe and are made for the job. Sorry about the long posts but when you get up on that soapbox you just can't stop.
 

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So, REFLECTING on this thread, here's what I have ABSORBED...

On my Graphite Grey PM, if I were to cover the roof with POTATOES wrapped in aluminum foil, it would keep the van COOL in the summer by REFLECTING HEAT and INSULATING the van. On the other hand, a bunch of (already baked) potatoes, placed inside the van would probably RADIATE HEAT and keep me warm and toasty all night in the winter! ;)

Now it all makes sense!

I hope this won't lead to a HEATED discussion, and ask that everyone just CHILL out.>:D

Ed

Afterthought: a POTATO cut in half and used as earmuffs would probably help with sound deadening in the van... but that's another thread. :D
Laugh my brains out and now can not think LOL!

I forgot to mention another little trick, is to put Depends at the bottom of the
walls to adsorb the condensation:D.
When designing the interior make sure that you have access:eek:.
Now I must step down off of the soap box because I am pooped out.:nerd:
 

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I'm loving this thread.

To me, the first rule of insulating is: ”First, do no harm." I made the conscious decision to preserve the built-in ventilation--the ceiling cavity is still connected to the base drain, assuming moisture travels through Thinsulate, which is my understanding. I don't trust any liner, especially plastic, to hold up long-term under a vehicle's harsh conditions.

I have personal experience that the aluminum faces of Reflectix disappear with exposure to condensate: I made some cozies for backpacking and was soon left with see-through pieces of bubble-wrap. I had to make new ones with covers of waterproof fabric.

I strongly urge anyone who hasn't already started to seriously consider Hein's Thinsulate. Put the cost in perspective: about 1% of the cost of the van. I would say the stuff is a joy to work with, except that no insulating job is a joy. Kinda hard to be doing such a tedious task while dreaming of the final product.
 

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Discussion Starter #19 (Edited)
Thanks for the replies...

RDinNHandAZ: I appreciate the time and effort put into your reply, unfortunately, it is just way too much technical information for me. :) I just really couldn't determine what your bottom line answer was.

uncubed, seapro and mojogoat: I'm not sure, but I think your replies indicated it would be worthwhile to use the reflective material in conjunction with the Thinsulate.

GaryBIS: I am in the Chicago area and will be visiting FL occasionally, so the evaporative coolers are not an option. I do appreciate what you are saying about the shade, as I have used an Aluminet tarp over the top of my current small van. It does keep the inside cooler, but not enough on it's own. In conjunction with the A/C unit, I think it would be helpful. The problem I see is that with the fan and A/C unit on top of the PM, there won't be too much room to drape it over the top without interfering with their operation. It is definitely something to consider. Hoisting that thing over the PM will be a job though, considering the size I'd have to get to be effective.

I was just looking for a simple answer-- Would using a reflectix type material against the van skin (or with an air space) be beneficial against the heat of the sun? (using it in conjunction with Thinsulate)....

But I guess there is no simple answer. I'm probably overthinking this, but I just don't want to make a mistake while I've got the chance to do it right.

I really do appreciate the replies :) Thank you

MsNomer: Didn't see your post till I just posted mine! Thanks for the info!
 
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