Need to really start thinking about insulation and climate control

waldenbound · Oct 24, 2016

Ok, so if I can find my Prince Charming van in the next couple of months, I will have all next year to build it out.
I really need to think about the insulation/floor/walls ect so I can explain it to someone with carpentry skills that I will be paying to do the work. I don't have good carpentry skills, the homemade bed I built looks like a complete amateur job and the materials cost about $500! Most of that was in paint but still......

Initial thoughts on building materials.

Ok, I've had it whittled down to Reflectix, polyiso, spray foam for cracks, 3/4 plywood for flooring, very thin plywood for walls.
I also need some wall studs so I can install hooks to hang gear (daypack, ice axe, climbing rope, ect.) I could also go for that Ultratouch recycled denim.

Conditions I plan on being in

I plan on traveling throughout the west mostly, to the southeast occasionally. Some times in hot weather, sometimes in the Blue Ridge Mountains, sometimes on the Northern California/Oregon coast if I get plain sick of hot weather. Winter in the southern Arizona desert definitely.

I have read Bob's blog post on "Understanding Insulation In Your Van." He recommends insulating for cold climates, and maybe skipping insulation in warm climates. In the comments someone asked spending the majority of their time in Phoenix.

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"I suggest using 1 inch of Polyiso foam board insulation. It’s the highest R-value and still relatively cheap. However, if you are going to be in heat a lot, insulation can work against you. 2 of the 9 months (Dec. Jan)you will be in cold in Phoenix, 2 of them will be cool (November and February of them will be cool and the other 5 months it will be hot.

I think I would skip insulating if I were you. I might jut use Reflectix on the walls with an air gap. That will help both keep it cool in the summer and warm in the winter." Bob

Someone asked "On the walls or in the walls?"

Bob replied "Dave, putting it between the walls will save you space inside the van, but be harder to cut and fit. Having it on top of the ribs will also insulate better because you won’t have thermal gaps where heat can travel out through the ribs.

But i’s a matter of priorities do you want to save the installation time and get better insulation or would you rather have the extra space inside the van? You have to decide for yourself."

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Ok, but every YouTube video I've seen on insulating a van shows them putting Relfectix right over the skin of the van, carefully smoothing it out and taping it down. So, where's the air gap?

About the on or in the walls question, how do you put Relectix on the walls? Can you put a wall stud over the ribs along the side and then put the Reflectix on the stud, then put the plywood over that?

I apologize if this is a nightmare to read and figure out what I'm asking. I just need to get this right and be able to hire someone to do it right.

Almost There · Oct 24, 2016

waldenbound said:
Ok, I've had it whittled down to Reflectix, polyiso, spray foam for cracks, 3/4 plywood for flooring, very thin plywood for walls.
I also need some wall studs so I can install hooks to hang gear (daypack, ice axe, climbing rope, ect.)

Skip the spray foam for the cracks...please!!

Conditions I plan on being in

I plan on traveling throughout the west mostly, to the southeast occasionally. Some times in hot weather, sometimes in the Blue Ridge Mountains, sometimes on the Northern California/Oregon coast if I get plain sick of hot weather. Winter in the southern Arizona desert definitely.

If you're not planning on being in cold winter weather then a lot of insulation doesn't make any sense.

Ok, but every YouTube video I've seen on insulating a van shows them putting Relfectix right over the skin of the van, carefully smoothing it out and taping it down. So, where's the air gap?

Just because you see it on YouTube doesn't make it gospel...

About the on or in the walls question, how do you put Relectix on the walls? Can you put a wall stud over the ribs along the side and then put the Reflectix on the stud, then put the plywood over that?

You could but I think there's a better way.

I apologize if this is a nightmare to read and figure out what I'm asking. I just need to get this right and be able to hire someone to do it right.

The blue typing is mine!

I cut a lot out so that those using phones and pads to read don't curse me. :angel:

I did exactly what you're looking for. Traveling with the seasons and only occasionally having to deal with cooler (not northern cold winters!) means that I'm more concerned with keeping excess heat OUT of the van than keeping heat in from a heater.

You can see the build I did here:

https://vanlivingforum.com/Thread-Building-Arabella

Basically, it goes as follows:

cut reflectix to fit between ribs, bubble wrap glued to the correct side of the reflectix, attach reflectix/bubble wrap panel to ribs with aluminum tape, attach horizontal strapping to walls of van, attach vertical strapping where needed to support cabinets/wall panel edges etc. install wall panels of choice, build cabinets/bed etc.

Optimistic Paranoid · Oct 24, 2016

waldenbound said:
Ok, but every YouTube video I've seen on insulating a van shows them putting Relfectix right over the skin of the van, carefully smoothing it out and taping it down. So, where's the air gap?

You have no particular reason to trust me, but the fact is that every single YouTube video you've seen on taping Reflectix right to the skin has been wrong.

Heat transfers in three different ways: by radiation, by conduction, and by convection.

Reflectix has no real conventional insulating value (R value) and doesn't stop conduction or convection.

It's purpose is to REFLECT radiation heat back, and it can't do that if it's in contact with the hot radiating surface - the metal van skin. The skin just makes IT hot by conduction. It then radiates the heat further inward.

From the above info, it should be fairly obvious that Reflectix is only really useful in hot climates. It doesn't help hold heat in in cold climates.

As far as polyiso foam goes, it prevents heat transfer by both conduction and convection, and is the ideal insulation for cold weather, where you are trying to retain heat.

Rather than 1" poly, I would recommend 1/2" poly. It will bend easier wherever the walls or roof are not perfectly straight, and you can put another layer on top to build it up to 1" equivalent. If there's room, maybe even build it up to 1 1/2" equivalent.

As for using it in hot climates, there's a school of thought that, since insulation doesn't STOP heat transfer, it only slows it way way down, by the end of the day the inside of the van will be hot, and the insulation will help HOLD the heat in overnight.

Personally, I think if you have enough windows to open, and a powered rooftop fan to exhaust the hot air and suck the cooler air in from outside, you'll be fine. However, if you are talking about a stealth cargo van without windows, I could see where it might be an issue. Some people run two powered rooftop vents at opposite ends, one to blow air in and one to suck air out. But that can cut into solar panel space.

Hope this gives you a few things to think about.

Oh, and spray foam causes the steel under it to rust!

waldenbound · Oct 24, 2016

Almost There said:
Basically, it goes as follows:

cut reflectix to fit between ribs, bubble wrap glued to the correct side of the reflectix, attach reflectix/bubble wrap panel to ribs with aluminum tape, attach horizontal strapping to walls of van, attach vertical strapping where needed to support cabinets/wall panel edges etc. install wall panels of choice, build cabinets/bed etc.

I've heard about the bubble wrap a number of times while browsing threads. Bubble wrap against metal getting pounded by the Arizona sun, wouldn't it melt?

But I hear you on the rest. I'm going to refer back to your build often.

Almost There · Oct 24, 2016

Well, to be honest the heat in AZ was nothing compared to the heat up here in Ontario in July but by then I was parking in the shade as much as possible.

Everyone seems to be fixated on 'heat in AZ' - in December through to January...it wasn't THAT hot, heck most mornings started with me in a fall jacket. February was really comfortable...shorts/sandals by 10 AM, the hot springs in the afternoon. By March we were moving uphill to places like Cottonwood (3,000 ft) and leaving the sea level areas behind. By end of April it was time to head for 7,000 feet for some, I had to head northeast then.

I haven't taken a wall apart to see how the bubble wrap has fared. But so far the system seems to be working well and I haven't heard any noise of bubbles breaking...that would freak me out....

The inside of the van was cooler than the outside even when closed up when parked in the sun.

waldenbound · Oct 24, 2016

Optimistic Paranoid said:
You have no particular reason to trust me, but the fact is that every single YouTube video you've seen on taping Reflectix right to the skin has been wrong.
Oh, I trust you alright. You are the one on the road and I'm sitting in my condo.

Heat transfers in three different ways: by radiation, by conduction, and by convection.

Reflectix has no real conventional insulating value (R value) and doesn't stop conduction or convection.

It's purpose is to REFLECT radiation heat back, and it can't do that if it's in contact with the hot radiating surface - the metal van skin. The skin just makes IT hot by conduction. It then radiates the heat further inward.

From the above info, it should be fairly obvious that Reflectix is only really useful in hot climates. It doesn't help hold heat in in cold climates.

I know Reflectix doesn't insulate. I just need that heat out of my van as much as possible. I will be taking two cats and possibly getting a dog. Climate control is of utmost importance. I need that air gap. I hope bubble wrap doesn't melt when it's hotter than Hades outside.

As far as polyiso foam goes, it prevents heat transfer by both conduction and convection, and is the ideal insulation for cold weather, where you are trying to retain heat.

Rather than 1" poly, I would recommend 1/2" poly. It will bend easier wherever the walls or roof are not perfectly straight, and you can put another layer on top to build it up to 1" equivalent. If there's room, maybe even build it up to 1 1/2" equivalent.

As for using it in hot climates, there's a school of thought that, since insulation doesn't STOP heat transfer, it only slows it way way down, by the end of the day the inside of the van will be hot, and the insulation will help HOLD the heat in overnight.

I'm seriously thinking of skipping the polyiso since I don't plan on being in a cold climate. But with only 1/2 inch, that will help with cold mornings right? Gets cold in the desert. Fantastic Fans will be moving the hot air out of the vehicle.

Personally, I think if you have enough windows to open, and a powered rooftop fan to exhaust the hot air and suck the cooler air in from outside, you'll be fine. However, if you are talking about a stealth cargo van without windows, I could see where it might be an issue. Some people run two powered rooftop vents at opposite ends, one to blow air in and one to suck air out. But that can cut into solar panel space.

I plan on getting two Fantastic Fans, one fore and one aft, with reverse switches. The middle of the roof is for solar, hopefully one 300 watt panel.

Hope this gives you a few things to think about.

Ok, here's my best Joan Crawford imitation:

No spray foam everrrrrrrrrr!!!!!
No Reflectix against the van's metal skin everrrrrrrrrrr!!!!!!!

GotSmart · Oct 24, 2016

I only use Reflectix as a windshield sun shade. I cut two pieces to overlap in the mirror area, with a slit to go past the mirror. It worked real well in the desert.

DrJean · Oct 24, 2016

Prodex is another option Prodex

I will be using it instead for a few reasons, one is initial cost, two is that I don't have to spend money on spray 3M90 to make it stick, three because it doesn't stick directly to the metal except in double taped areas. The insulating factor, from what I've read, is all about the size of the air gap between the layers and whether you have them vapor barriered or not?

I still haven't cleared it in my mind how something touted as REFLECTIVE uses SPRAY GLUE which ruins reflectivity... hmmm

While I'm at it... I've seen car windows break because of highly reflective windshield screens reflecting the sun back on very hot sunny days. I think I will cover my prodex window coverings with cloth? IDK.

Good wishes!

TrainChaser · Oct 24, 2016

Yes, the guys above are right about the Reflectix. It is only effective when it is DIRECTLY reflecting heat, meaning the First Surface the heat hits (other than glass). In a van, that would be when you have it covering the windows to REFLECT the sun's rays, and when used inside the van as the TOP LAYER, when it would be REFLECTing your body heat and containing it inside the van. If you're using the polyiso with the aluminum surface facing inward, it should do the same thing w/o the added cost of the Reflectix. For vans and Reflectix, you're really talking covering windows only, and that is the only place that needs the air space.

I spent several months living in a stealth-type van: a schoolbus yellow Ford cargo type w/no extra windows. It was well insulated. It had a roof vent, but no fan. I went from desert heat to mountain freezing (but not much below 30F) and slept fine.

I have also traveled in a white unvented, uninsulated Dodge van. There was no comparison. The very first thing that van got was a roof vent. I did it myself with a power Dremel tool and quite a few cutting blades. To make sure I wasn't cutting over a rib, I marked where the vent was going from INSIDE the van, and drilled four marker holes, then worked from the top. The next thing it got was insulation covered with a colorful upholstery fabric. That also really cut down on the shake/rattle/roll noises -- it was like driving inside a microphone w/o insulation.

Some people blow off insulating at all "because they'll be in the desert". Maybe I'm just more sensitive to heat, but as far as I could tell, every single mile on the open road under that SW summer sun baked that van like a potato. Open windows and the wide-open vent didn't force the hot air out, and the A/C struggled to cool the front end. I thought about the American pioneers in their covered wagons a LOT, telling myself that it could be worse at 2 mph.

Now, about those wall studs for hanging stuff that you want. I've spent quite a while trying to figure out the best way to do this AND insulate the van. I've looked online, and either the people doing this kind of work have NEVER, EVER measured the distance from the van skin to the innermost surface of the van ribs, OR every single van is different. :dodgy:

One problem is that if you cover the ribs with insulation, you're usually hiding them from being usable. If you don't cover the ribs, cold and heat will migrate through them to the inside.

Here's my current idea for when I get my van (unless I change my mind a few more times):

1. I'm probably going to use multiple layers of 1/2" polyiso, because that thickness is much more flexible than the thicker ones, and will bend to fit the curves of the van, thus preventing having to make multiple cuts to do the same job. Home Depot prices: $19.25 for the rigid 1" thick, and $11.47 for the 1/2". Using two sheets of 1/2" costs $3.65 more to cover the same area -- I can live with that difference to avoid more work. I plan on building up the polyiso to be level with the ribs.

2. I will probably be using fir 1x3s to cover the ribs. It's R value is only about 1.0, but it's better than raw metal. I'm not expecting perfection. If the weather is good and I have the time and initiative, I may stain the 1x3s so they look like 'day-core'. Or not.

3. Many/most of the van ribs have holes suitable for bolts. Before the wood is put in place, I need to mark the vertical wood strips to show where the holes are. Since I have been known to change my mind

, I will be marking most of the holes so I'll know where they are when I want to add or move the strips, but will only be drilling the holes that I have immediate use for . Then I need to decide where I will want to install the horizontal support strips. These strips will have different things attached to them: cabinets sitting on the floor to hold plastic totes (etc), maybe to hold the platform bed in place so it doesn't shift, maybe hooks on the upper strips or shallow cupboards.

DrJean · Oct 24, 2016

I'm not doing it exactly like this guy, but after watching literally a 100 hours of youtube videos on this, he has it laid out the best and talks to us about moisture and insulation etc. And he does nice work

Best Video I've found on van insulation

waldenbound · Oct 24, 2016

DrJean said:
I'm not doing it exactly like this guy, but after watching literally a 100 hours of youtube videos on this, he has it laid out the best and talks to us about moisture and insulation etc. And he does nice work

Best Video I've found on van insulation

Well hallelujah, someone on YouTube knows about not putting Reflectix directly against the van skin!

He said he uses a thin 1/8 some-kind-of-styrofoam in between the van ribs, then Reflictix on top of that, then 1/2 polyiso to finish filling in the "between the ribs" space. Does that sound like a good combination?

TrainChaser, about those studs. Could you do your materials like the above paragraph, then put the thin plywood over that, then put the wall studs horizontally at the top, middle, and bottom, fastening them where the ribs are? You would be left with external, horizontally placed wall studs, and can put up hooks, and maybe a light-duty 2x4 shelf.

Almost There · Oct 24, 2016

waldenbound said:
Well hallelujah, someone on YouTube knows about not putting Reflectix directly against the van skin!

He said he uses a thin 1/8 some-kind-of-styrofoam in between the van ribs, then Reflictix on top of that, then 1/2 polyiso to finish filling in the "between the ribs" space. Does that sound like a good combination?

I didn't watch the video because I'm already over my data limit for the month and still have a half month to go...sigh!

BUT I'm almost sure that the styrofoam won't give you a dead air space. It's too solid a material IMO. More research required on that one!

And 1/8" is not nearly enough dead air space even if it was effective as dead air.

When I was figuring out how to do my van I went to the Reflectix web site and read every page of technical/how to that I could find. The closest we come in a van is a steel building so I kinda followed that scenario.

I wasn't happy with 1/2" bubble wrap but it was the thickest I could buy here in Ontario and it cost me wayyyy too much $$. I tried my best to not push the bubble wrap/reflectix panel tightly in to the wall when I was taping it, in the hope that I was leaving a bit more air space.

I wanted to do the 1/2" polyiso to fill in the ribs but the thinnest I could find here was 2" because with our northern building codes nobody uses just 1/2" for anything. Since you can get it, it's not a bad idea.

waldenbound · Oct 24, 2016

Boy, this radiant barrier/insulating thing really leads to "analysis paralysis." :huh:

Ok, let's try this. You're standing in a cargo van, looking at the wall. Take a furring strip, fasten it to the ribs, at the top, middle, and bottom. Horizontally. Three strips.

Take the Reflectix, fasten it to the strip. Then add polyiso, then add plywood.

Than, take the top furring strip, and fasten all of the layers together. You're kind of sandwiching the Reflectix, polyiso, and plywood on top of the ribs. That means there is the dead air space in between the ribs, because there is no material there. The furring strips are keeping the Reflectix off the van's skin. Plus, the ribs are covered, the whole wall is covered.

Almost There · Oct 24, 2016

Yes, it would work.

BUT, always a big but around here....

You're losing a lot of interior space that way. I'd guess at a half inch each side for the reflectix plus the depth of whatever polyiso you're putting on there.

By putting the reflectix and the polyiso inside the ribs you're saving yourself upwards of 2" in the finished width of the van.

And trust me, 2" is a whole lot of interior space.

Most of us fight for every 1/4" we can get.

DrJean · Oct 24, 2016

Yes the reflectix will work, but to work efficiently one needs to do the layering of some type.

Foil layered Bubble wrap is not insulation. It's a radiant barrier but the heat will transfer through the reflectix if you have it against the metal of your van.

By putting that thin foam on the metal and then the foil wrap, you'll prevent that heat transfer. The foam can be bought quite cheaply at craft stores, in rolls, I've even seen it in storage room rental centers for wrapping plates etc.

You can also use stiffer styrofoam up to maybe 1/8 " thick.. but like Almost There shared, the thinner you can go the better on that one.

The reflectix will work as a radiant and vapor barrier both. But you still need maybe a gap of at least 1/2" of air of the polyiso should work ok. Any "R" factor is not on the bubble wrap itself, but the instillation...and I think based upon a 1" air gap?

One important thing is to not leave any gaps in the attachment of the reflextix. If moisture gets into the works, the van can grow mold or even rust, so use the overlaps on the edges of the roll, and use the tape they suggest to seal it up.

I have read really bad things about spray foam...how over time it totally disintegrates. I can attest to this for the uses I have here at the house...just never thought about it succumbing to the elements in a van. So be sure to find all the holes in the inner wall areas, the cubby holes and stuff them with real insulation (after putting the reflectix in if you can reach it.)

(Oh he used 3M 80... holds in high heat...other adhesives may release at certain temperatures.) Like I said I went with the Prodex because of the expense of the Reflectix and also the expense of the 3M 80 to adhere not just it, but the thin foam. I figured I would need nearly $200 worth of the spray! The Prodex has double stick tape for every 2 feet, so it isn't flat against the metal. I'll be putting it on the floor under the rubber form fitted mat too... but might put the thin foam down first for added sound barrier? IDK have to check my notes. I would have been done by now on the first van, been so long I have forgotten how I worked it all out.

I don't know all this myself...but watching the videos I kept seeing things that didn't sit right. I finally went looking for a physicist online to explain things and well, alot of what's online being DIY isn't going to be the best in the long run....

Well something I haven't fully figured out yet is how to keep the firm board/ foam board whatever I use as insulating from squeaking where I butt joint it. :-/ Maybe hammer the ends down and fold it over each other hahahah

Do your best.

waldenbound · Oct 24, 2016

Almost There said:
Yes, it would work.

BUT, always a big but around here....

You're losing a lot of interior space that way. I'd guess at a half inch each side for the reflectix plus the depth of whatever polyiso you're putting on there.

By putting the reflectix and the polyiso inside the ribs you're saving yourself upwards of 2" in the finished width of the van.

And trust me, 2" is a whole lot of interior space.

Most of us fight for every 1/4" we can get.

If that will work, and all it will cost me is 2 inches, then heck with the 2 inches. I'll gladly give it up. When I get the van, I'll measure the heck out of it, and start calculating materials costs. Then hire someone to help me with the work.

DrJean · Oct 24, 2016

Sounds like a plan. Be sure to cover those ribs or you will not have a moisture barrier.

Almost There · Oct 24, 2016

So many people worry about moisture barriers unnecessarily IMO.

With the number of times that our doors are opened each day and the ventilation we all try to get with roof vents and windows that open, seriously, moisture build up to the point of causing a problem is so remote as to not even be a consideration.

The inside of the vans are all well painted and rust only starts where it's bare metal. It takes years of salt and moist air for rust to happen on the outside of our vehicles but that's the outside.

As to mold, I've never seen it except where there was standing water like in pink insulation (which we're not talking about using here). We see mold in RV's where the window seals leaked and were allowed to continue leaking over a long period of time. I saw mold in the van but it was because the PO drilled holes in the fiberglass roof for mounting various objects and used absolutely no sealant of any kind anywhere. The pink fiberglass that he used was so laden with water that I could squeeze it out like a sponge. Where it had laid on wood and on the original van roof, yes there was mold...no where else.

In 40 years of running with a vans I've never seen either be an issue except as mentioned above.

highdesertranger · Oct 24, 2016

am I missing something,

"The adhesive is not for attaching the insulation to a surface - It is for sealing the seams". this is straight from their website. highdesertranger

DrJean · Oct 24, 2016

I think you're talking about the Reflectix site? IDK but I read that as having edges with adhesive so you maintain a barrier...for sealing the edges where they meet, not for sticking it to the metal van. ?

Need to really start thinking about insulation and climate control

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