Choosing the BEST SEALANT

[danman81]

Hi everyone!  I love this forum so much that I decided to finally join    

Just to provide some background, i plan on the most epicest most amazingest &%#! van build evarr...  haha.. basically what I mean is I am looking for a best of breeds approach using the latest and greatest technology that is available on the market, and that includes insulation.  As everyone knows, insulation is very very important because we spend so much effort on solar/power and HVAC systems, which i think should be the heart of any van build unless you have the option of always traveling toward better weather (something i don't have - and i anticipate anything between very hot to freezing temps).  So, the conclusion I came to for using on my 2016 Ford Transit was using custom sized Vamum Insulated Panels on the side and the ceiling, and Aerogel Spaceloft fabric (which is now available on EBAY) material layered and folded up to fill in the gaps between panels and as an additional layer of insulation over everything.  Within any crevices, such as within the hollow support beams, I plan on first spraying Flex Seal to act as a vapor barrier and to fill in as much of the crevice as possible.  On top of that, I plan to use 100% silicone caulk, which will help dampen vibrations (i.e., noise) but mainly for its thermal properties.  On top of the still uncured silicone, I would like to stuff in pieces aerogel whever I see any remaining space, and then an adhesive vapor barrier lining on top of that to cover any exposed areas once the silicone has cured.  I also plan on using the silicone to fill in any gaps I can find between the VIPs and the Spaceloft.  Now, I've never done anything like this before, so I have a few questions about the silicone sealant:

1.  Is the performance of silicone sealant recommendable, as opposed to a something like a polyeurathane-based sealant, or 3M 5200, or maybe something like Green Glue, in terms of thermal properties and noise dampening properties, and longevity because I don't ever plan on ripping out the insulation.  One thing that I noticed is that silicone sealant is used by the factory on many areas in cars, so it must be a good choice.

2.  Do i need to worry about the silicone not bonding with or breaking down the chemical properties of Aerogel Spaceloft?  If I don't need to worry, then wouldn't it also be okay to use silicone sealant to layer sheets of spaceloft?

3.  Is silicone sealant going to adhere well to the paint job?  If it was bare metal of course I wouldn't worry about this...

Thank you!  I love this forum ohhh yea babyyyyy!!!!!!!!

 

[highdesertranger]

it depends what you are doing with it.

silicone comes in many, many variations. the main problem with it is nothing sticks to it including more silicone. it's also a pain to remove. once silicone is applied, it better work or you will have problems. Permetex Ultra line of silicone is great for use on engines.

I like 3M 5200 if you need both an adhesive and a sealer.

I like Dicor for a self leveling sealer on flat roofs.

so a lot depends on the use. highdesertranger

 

[JT646]

  So, the conclusion I came to for using on my 2016 Ford Transit was using custom sized Vamum Insulated Panels on the side and the ceiling, and Aerogel Spaceloft fabric (which is now available on EBAY) material layered and folded up to fill in the gaps between panels and as an additional layer of insulation over everything.  

Danman welcome  to the forums.  I assume you meant Vacuum Insulated Panels (?).  I was wondering when someone would be creative enough to try something like this--along with the Aerogel fabric.   It's too bad there is not a world wide push to make these cheaper and more common-- like is currently being done with LEDs, EV's and battery technology.  Imagine the energy (and $$$) savings if Aerogel was used in refrigerators alone--I'm sure a much smaller compressor would be needed.
Sorry if I got off track but this stuff could be life changing for the planet one day.  Please keep us posted (with pictures if possible) on this first-of-kind (?) project.

 

[BradKW]

Hi danman, welcome to the forum! You will find a lot of great information in the archives here...one of the first things I learned about planning my build is that my "plan" changes rather fluidly...I feel very fortunate that I didn't jump in and build right away, I would have done things I regretted later.

I can appreciate your desire to use "the best" ingredients when making your build, especially when you're doing foundation work that you hope won't need to be disturbed or re-done for the life of your build. In this case, with what you're looking at for insulation, I have a feeling that taking it a bit too far. If it was simply a matter of "I can afford the best and want it", I'd say sure, why not. However I can see a few possible problems with those materials.

First tho, look at the bigger picture...you can't easily get around some of the built-in flaws in vehicle construction, namely glass, door seals/panels, and structural supports. Vehicles leak R-value, heater and AC units have no problem doing their thing even in moderately insulated vehicles, so is it really worth spending thousands on space-age materials? I looked up pricing on VIPs and Spaceloft... I don't believe that thousands is an exaggeration? Spaceloft looks to be about $5 sq/ft ...amazing R-value of 10+ per inch.

Vacuum Panels (VIPs) are interesting, however they rely completely on maintaining that vacuum to work...and you cannot cut or shape VIPs to fit. So even if you got them installed, any modification later would ruin it...mounting panels, fans, exhaust vents, re-wiring, etc etc. Not only that, but this from the wiki page: " Aerogels are more difficult to manufacture than polyurethane foams or mineral wools, and strict quality control of manufacture of the membranes and sealing joins is important if a panel is to maintain its vacuum over a long period of time. Air will gradually enter the panel, and as the pressure of the panel normalizes with its surrounding air its R-value deteriorates. Conventional insulation does not depend on the evacuation of air for its thermal performance, and is therefore not susceptible to this form of deterioration."

Spaceloft is described as "dusty" and "Hydrophobic Yet Breathable, repels liquid water but allows vapor to pass through". Which tells me two things: 1) its not a vapor barrier and 2) I could certainly anticipate adhesion issues with some products, silicone being one of them.

Lots of factors to consider and options to look at...I kinda hope you do it anyway, as it will probably be a first in the DIY RV world

 

[danman81]

Danman welcome  to the forums.  I assume you meant Vacuum Insulated Panels (?).  I was wondering when someone would be creative enough to try something like this--along with the Aerogel fabric.   It's too bad there is not a world wide push to make these cheaper and more common-- like is currently being done with LEDs, EV's and battery technology.  Imagine the energy (and $$$) savings if Aerogel was used in refrigerators alone--I'm sure a much smaller compressor would be needed.
Sorry if I got off track but this stuff could be life changing for the planet one day.  Please keep us posted (with pictures if possible) on this first-of-kind (?) project.

Thanks for the response!  Yes, i meant Vacuum Insulated Panels, or VIPs for short.  I just think VIPs are a great idea (not sure why someone didn't think of it sooner) and you get the best performance (by far) compared to any material material out there.  Even if VIPs only perform at half their advertised R-value, it's still going to perform much better than any type of foam panels.  People who make DIY/custom refrigerators/freezers are now using VIPs as well as Aerogel, and I would think are plenty of specialty applications for these modern insulation technologies, for example in the scientific world and boats and yachts (lots of millionaires and even some billionaires there), and of course RVs.   The price is too high for large applications like housing and building (although it has been done), so I'm not sure if we're going to see a big push for it everywhere (i.e., home depot) until the cost comes down more, but I figure a van (mine is a low roof, short wheel base) is not so large that it would be too cost prohibitive (but not cheap by any means).  Plus, space is already limited in a van, so getting better insulation and losing less space at the same time is a win-win for me, and at 10mm thin for Spaceloft, I could easily have multiple layers (assuming I find the right adhesive).  The van itself is still on order with ford (should be arriving this month) and I'm still in the design phases right now, but i will be sure to post pictures and everything once I get the van and start insulating!

 

[danman81]

it depends what you are doing with it.

silicone comes in many, many variations.  the main problem with it is nothing sticks to it including more silicone.  it's also a pain to remove.  once silicone is applied, it better work or you will have problems.  Permetex Ultra line of silicone is great for use on engines.

I like 3M 5200 if you need both an adhesive and a sealer.

I like Dicor for a self leveling sealer on flat roofs.

so a lot depends on the use.  highdesertranger

Thanks for the response!!!  I am indeed trying to find the best possible sealant I can find -- As you say, it looks like silicone won't stick to things the best, so i'm thinking of looking for a separate adhesive (maybe green glue?) for attaching sheets of spaceloft and attaching other things like panel insulation.  Now, I'm thinking silicone would best be used as a gap filler -- for example in between insulation panels and I'm thinking primarily inside the hollow support beams and basically just any crevices I can find because heat leaks out of gaps as you already know..  What made me interested in silicone is that it's itself insulating -- e.g., silicone pot holders.  Plus, silicone seems long lasting (i.e, permanent or semi-permanent) and stays flexible which I think would help it absorb noise (but not on the level of green glue).  Would you recommend the Permetex Ultra over the popular GE Silicone II?  

I've heard good things about 3M 5200 as an adhesive/sealer, but I'm currently leaning toward silicone because it has better thermal properties and is more flexible (i.e., noise dampening, but I could be wrong about that), and I think if you called what i'm using it for, "gap filling", that would probably be the most accurate.  However, it would be in direct contact with the aerogel spaceloft, so I want to make sure there are no contradictions with any solvents and things like that.  Now, especially for the insulation, there is only so much I can plan, and at some point I will just have to order the material and start insulating, so I do expect a little bit of improvisation at least.  For example, I would like to basically stuff strips of aerogel down the hollow support beams, but there would still be air gaps, so I'm thinking of just pouring the silicone down in there all around the aerogel, i mean why not?  (although, curing it is going to a long time i would think but that's okay)  I was thinking of using a foaming sealant, but it expands too much and wouldn't last as long.  Another thing I liked about silicone is that it doesn't use solvents like a lot of the newer sealants out there so there's less contradictions with different plastics and things like that, although I could be wrong about aerogel.  There's just no documentation on this I could find on this.  Looking more into it, the closest thing I find is the following patent that describes a "binder layer comprising a silicon-containing organic material" that is bonded to aerogel, but that's it:

http://www.google.com/patents/US20060263587

Of course, silicone is inorganic, but here is at least a case where it was used in conjunction with aerogel.   The Dicor stuff looks interesting as well and I will be looking more into it!!

 

[danman81]

Hi danman, welcome to the forum! You will find a lot of great information in the archives here...one of the first things I learned about planning my build is that my "plan" changes rather fluidly...I feel very fortunate that I didn't jump in and build right away, I would have done things I regretted later.

I can appreciate your desire to use "the best" ingredients when making your build, especially when you're doing foundation work that you hope won't need to be disturbed or re-done for the life of your build. In this case, with what you're looking at for insulation, I have a feeling that taking it a bit too far. If it was simply a matter of "I can afford the best and want it", I'd say sure, why not. However I can see a few possible problems with those materials.

First tho, look at the bigger picture...you can't easily get around some of the built-in flaws in vehicle construction, namely glass, door seals/panels, and structural supports. Vehicles leak R-value, heater and AC units have no problem doing their thing even in moderately insulated vehicles, so is it really worth spending thousands on space-age materials? I looked up pricing on VIPs and Spaceloft... I don't believe that thousands is an exaggeration? Spaceloft looks to be about $5 sq/ft ...amazing R-value of 10+ per inch.

Vacuum Panels (VIPs) are interesting, however they rely completely on maintaining that vacuum to work...and you cannot cut or shape VIPs to fit. So even if you got them installed, any modification later would ruin it...mounting panels, fans, exhaust vents, re-wiring, etc etc. Not only that, but this from the wiki page: "  Aerogels are more difficult to manufacture than polyurethane foams or mineral wools, and strict quality control of manufacture of the membranes and sealing joins is important if a panel is to maintain its vacuum over a long period of time. Air will gradually enter the panel, and as the pressure of the panel normalizes with its surrounding air its R-value deteriorates. Conventional insulation does not depend on the evacuation of air for its thermal performance, and is therefore not susceptible to this form of deterioration."

Spaceloft is described as "dusty" and "Hydrophobic Yet Breathable, repels liquid water but allows vapor to pass through". Which tells me two things: 1) its not a vapor barrier and 2) I could certainly anticipate adhesion issues with some products, silicone being one of them.

Lots of factors to consider and options to look at...I kinda hope you do it anyway, as it will probably be a first in the DIY RV world  

Wow, thanks for the amazing response from everyone -- I love this forum!!!  You are very correct that I am looking for a best-of-breeds approach -- I'm not trying to brag or anything, but I'm not the type of person that wants to live in a van to save money or because I "need" to and I know a lot of people dont, and actually i think there's somewhat of a surge happening now with people who are thinking more outside the box, especially as technology is improving and products are just becoming more and more efficient as a result.  People (like the amazing people on this amazing forum) are realizing that you don't have to live in a single family home with 2.5 bathrooms and a white picket fence and perfectly trimmed lawns and all that stuff and with garages and closets full of crap no one even needs.  For me, there's just no reason to live in a $0.5M or $0.6M home that I don't even have time to live in when I can spend 1/10th of that on the most modern, technologically advanced RV van build there is and have the freedom to go anywhere, anytime.  If you think about it, at that price you don't even have to sell your home and you can just rent it out or something. You might say, oh well 2, 3, or even 4K is too much to spend on insulation, but if you take into account how much you could put into today's solar system (e.g., a single LiFePo lithium battery bank can easily cost 4K alone or more), it seems like a waste to just let all that effort dissipate out the van, right through the walls.  Plus, being stuck in a cold van in freezing weather after a series of cloudy days is something I'm scarred of, even if I have a Chihuahua and blankets to keep me warm.  I just feel like with today's technology there is just no need to live like that.  Also, hehe, mentioning my dog, and having a full time job, I get worried about leaving him in the van 8 hours at a time in the winter or summer.  The solar system, HVAC system, insulation system must be efficient enough that I can keep it running 24/7, and with the refrigerator (although those can now be very efficient too).  Yes, I do want to be comfortable anywhere I travel to and anytime of the year but i'm probably more worried about my dog than anything else to tell you the truth. You are right that housands of dollars on insulation alone is a lot and it's not for everybody that's for sure, but the reason i'm doing this is to have freedom and live my life to the fullest and has nothing to do with saving money even though I will be -- and it is a great way to save for anyone else out there "on the fringe".

Haha, anyways, sorry i hope that wasn't too off-topic.  You are right that there's lot of room for leakage in a van and that was a huge concern for me and heat travels through them like water.  I won't have windows because this is a white cargo van (stealth ohh baby baby!), and I will be putting in a metal partition behind the front seats that will also be insulated so that the front cabin acts like a barrier zone much like in an earth ship home.  Thermal leakage is also another reason why I'm trying to find the perfect sealant so i can be sure to plug up any holes that I can, while still being able to open the doors and things like that.  I decided on a low-roof, short wheel base van on a number of reasons (a little out of scope again, hehe), but having less space to climate control and increasing HVAC efficiency was one of them.   You mention the structural supports which is something I am worried about, and I would definitely like to fill them with threaded strips of fabric insulation and/or sealant with insulating properties (e.g., silicone).  I've also thought of getting it insulated professionally with spray foam, but foam has longevity issues, meaning it doesn't absorb vibrations well.  I also thought about professional installations like for reefer vans but it's so thick there wouldn't be enough space to live and would cost more too.  

In terms of VIPs, you are correct that they cannot be shaped or cut, and even with custom-size VIPs, you're not going to get a closer size than cutting it yourself with rounded corners and things like that, and that is definetley something I worry about.  You also have to be careful not to puncture it with screws or anything like that, but I think I'm going to have a layer of plywood over all the insulation so I'm not too worried about damaging it.  One thing that cannot be avoided with VIPs is that the performance will deteriorate over time as air seeps in as you say.  But then, I thought, you are going from "R-40" all the way down to the regular insulation value of the foam or whatever they use in there in the case it gets completely punctured, so it's really not that much worse than a conventional foam panel in the end, or even a "high performance foam panel" with an R value of max 6 or 7 maybe.  More expensive, yes, but I don't see it as worse performing in the long run, but please anyone correct me if anyone sees otherwise.  I'm trying to learn and plan and improve my plan as much as I can before I start building.  Anyways, here's a link to some of the "more afforabally" priced VIPs I'm talking about:

http://www.rparts.com/index.php?cPath=84_32

If anyone finds a better value, I would love to know!  

In terms of spaceloft, you are correct that you would want a vapor barrier.  That company actually sells another version of spaceloft that has an attached foil vapor barrier for cold applications like freezers.  I would use an adhesive (haven't decided on which one) to attach the spaceloft, and then seal it all in with an adhesive backed vapor barrier on top of that (sealed at the edges), and then probably repeat like that.  In addition, I'm not too fond of breathing in aerogel dust (no matter how "non-toxic" it is, because I'm sure it still is), so I'm hoping a vapor barrier will minimize dust issues.  

My backup choice for spaceloft would probably be thinsulate if I see too many problems, but used in the same way pretty much.  I've also considered blue jean denim insulation becuase there's no dust to worry about, but it absorbs moisture.

 

[danman81]

Hey Everyone -- Just wanted to say thanks for the overwhelming responses -- I think this might be the best single forum for this kind of stuff!  I didn't want you to get bored by my responses cause I'm realizing they are pretty long, just wanted to summarize some conclusions and go back to the original thread:

Silicone sealant sounds like the best gap filler.  It lasts a long time, vibration dampening (i.e., dries rubbery), and is thermally insulating (which is the most important).  It sounds like silicone is going play well with other plastics since there are no solvents (which also means silicone doesn't shrink from what I understand), and i'm hoping it won't conflict with aerogel spaceloft.  From an adhesive standpoint, silicone is not the strongest thing, so I still need to decide on a good adhesive.  I'm thinking maybe a spray-type adhesive for sticking on the spaceloft (not sure what kind yet tho) and perhaps Green Glue for more "structural" adhesive because of sound dampening properties (e.g., behind the final plywood layer).  

So much to plan and i can't wait to get started on this build, but i'm covering as much groundwork as possible before i start!  i will post pictures!!  thanks everyone!!!   :heart: :heart: :heart:

 

[GotSmart]

I have been building things since the 1960's.  One piece of advice.

D. O. T.   Don't Overthink Things.   

With what you are proposing I do not see much possibility of it happening.  24/7 AC? Using a regular cargo van you would have almost no living room building it to R~40 specs. (11 inches) 

I have a layer of thinsulate on my floor with Advantec and carpets over that.  That works out perfectly.  

As for sealant, go to any hardware store, and read the cover tags on the bins.  As long as you seal the hole, most modern products only differ in moisture resistance or paintability.

 

[Canine]

The vacuum insulated panels are awesome that's for sure. I have a thing against thermal breaks, though. I place more value over having a complete sheet of insulation rather than have the best insulation possible, but having gaps or breaks in the insulation.

 

[danman81]

I have been building things since the 1960's.  One piece of advice.

D. O. T.   Don't Overthink Things.   

With what you are proposing I do not see much possibility of it happening.  24/7 AC? Using a regular cargo van you would have almost no living room building it to R~40 specs. (11 inches) 

I have a layer of thinsulate on my floor with Advantec and carpets over that.  That works out perfectly.  

As for sealant, go to any hardware store, and read the cover tags on the bins.  As long as you seal the hole, most modern products only differ in moisture resistance or paintability.

Thanks @GotSmart for your response!!!  You guys are soo funny and that's why i love forum so much!   And definitely, I respect your experience and I'm sure there are a lot of things that you know that I don't know, but look..  I'm a young guy and I'm a technologist.  In the world we are living in today, I believe that technology, when applied correctly, is supposed to push the envelope.  That's the whole purpose of technology in our modern world.  A guy like me is always going to try and find a way to make it better, faster, more efficient, smaller, simpler, etc..  I dunno, it's just in my blood -- thats what i do.  And if i fail, I fail, but i will try, at least in theory.  Now, if ideas prove me wrong, I am all for giving up and just doing it "the way i'm supposed to do it" or "the way it's been done", but i have to at least know why, or basically i'm not going to be able to sleep at night hahah.  Anyways, I'm 100% sure what you tried in the past works, for sure -- I'm not putting it down -- and anything "new fangled" that we come up with only builds on top of what people like you have already accomplished.  So, just wanna say thanks for your comments, without going too much off subject hehehe, and thank you for being a pioneer in this life style~!

So, let me explain some of my numbers just a little bit, and these are not perfect exact numbers, but a rough estimation so feel free to call something out if you need to.  Here is a portable 12v air conditioner that was released pretty recently, that puts out 3250 BTU and 36 amps:

http://www.indelb.com/products/parking_air_cooler/sleeping_well/sw_cube

I estimate that the cargo area of a van loses roughly 6000 BTU without insulation, but insulated, lets just say this unit can keep the temperature stable without connecting it to a thermostat or anything and just keeping it on when not driving (My can van cool the rear with it's own AC system when I am driving for getting to the desired initial temperature).  I plan on having a 600 watt solar system generating about 200 amps per day and roughly 450 amps per day from a dedicated 250 amp alternator if I drive for 2 hours a day, which is what I'm estimating conservatively in terms of driving.  In 22 hours of not driving, i would be able to consume 792 ah a day for AC alone.  So, you are correct that 24/7 AC will not be possible.  I will have to turn the AC off at night or use a thermostat or run the AC on a lower setting, or drive more on hot days, or not use the computer, or something, or I would be approx. 142 ah over budget.  I do see myself trying to drive toward better weather whenever I can and I don't really mind driving a little more than usual (since i would be living on the road anyway) when it's hot or trying to find shorepower for a little while, but this does show the importance of insulation.  I do not anticipate having R-40 all the way around, and I think it would be almost impossible without doing something to seal the doors or something like that, but the VIP panels I posted the link for above are rated for R-40 and they are 1 inch thick.  This is another reason why I need to find the right sealant to fill the gaps, like I think silicone is.  I'm absolutely sure you can find a sealant that will do the job and plug holes as you say, but they will only seal the gap in terms of air, not thermally.  

As per the thinsulate, yes, I think thinsulate looks great, and I would def. use it if aerogel was not available, but you can find it on ebay now.  I haven't ruled out thinsulate, but the performance of aerogel is higher.  Maybe I will be a first to do this as it was pointed out, or one of the first, but I will always lean on the side of technology if I can find a way!  And that dosen't always necessarily mean more expensive either, because as systems like insulation become more efficient, you have less complexity and overall costs and energy requirements go down, like solar systems and AC systems.  Of course, not to mention that solar systems and HVAC systems have to constantly run, perhaps repaired, battery banks have to be replaced, etc..  The insulation just has to sit there basically, and it goes both ways keeping you warm in winter and cool in summer so it's like a 2 for 1 deal in a way -- oh baby baby

Anyways, trying to keep my posts short, here's a link to some info on high-tech insulation materials, and there's probably more ideas I'm not even thinking about:

http://inspectapedia.com/Energy/Super_High_R_Value_Insulation.php

thank you again for your response!

 

[GotSmart]

Thanks @GotSmart for your response!!!  You guys are soo funny and that's why i love forum so much!   And definitely, I respect your experience and I'm sure there are a lot of things that you know that I don't know, but look..  I'm a young guy and I'm a technologist.  In the world we are living in today, I believe that technology, when applied correctly, is supposed to push the envelope.  That's the whole purpose of technology in our modern world.  A guy like me is always going to try and find a way to make it better, faster, more efficient, smaller, simpler, etc..  I dunno, it's just in my blood -- thats what i do.  And if i fail, I fail, but i will try, at least in theory.  Now, if ideas prove me wrong, I am all for giving up and just doing it "the way i'm supposed to do it" or "the way it's been done", but i have to at least know why, or basically i'm not going to be able to sleep at night hahah.  Anyways, I'm 100% sure what you tried in the past works, for sure -- I'm not putting it down -- and anything "new fangled" that we come up with only builds on top of what people like you have already accomplished.  So, just wanna say thanks for your comments, without going too much off subject hehehe, and thank you for being a pioneer in this life style~!

So, let me explain some of my numbers just a little bit, and these are not perfect exact numbers, but a rough estimation so feel free to call something out if you need to.  Here is a portable 12v air conditioner that was released pretty recently, that puts out 3250 BTU and 36 amps:

http://www.indelb.com/products/parking_air_cooler/sleeping_well/sw_cube

I estimate that the cargo area of a van loses roughly 6000 BTU without insulation, but insulated, lets just say this unit can keep the temperature stable without connecting it to a thermostat or anything and just keeping it on when not driving (My can van cool the rear with it's own AC system when I am driving for getting to the desired initial temperature).  I plan on having a 600 watt solar system generating about 200 amps per day and roughly 450 amps per day from a dedicated 250 amp alternator if I drive for 2 hours a day, which is what I'm estimating conservatively in terms of driving.  In 22 hours of not driving, i would be able to consume 792 ah a day for AC alone.  So, you are correct that 24/7 AC will not be possible.  I will have to turn the AC off at night or use a thermostat or run the AC on a lower setting, or drive more on hot days, or not use the computer, or something, or I would be approx. 142 ah over budget.  I do see myself trying to drive toward better weather whenever I can and I don't really mind driving a little more than usual (since i would be living on the road anyway) when it's hot or trying to find shorepower for a little while, but this does show the importance of insulation.  I do not anticipate having R-40 all the way around, and I think it would be almost impossible without doing something to seal the doors or something like that, but the VIP panels I posted the link for above are rated for R-40 and they are 1 inch thick.  This is another reason why I need to find the right sealant to fill the gaps, like I think silicone is.  I'm absolutely sure you can find a sealant that will do the job and plug holes as you say, but they will only seal the gap in terms of air, not thermally.  

As per the thinsulate, yes, I think thinsulate looks great, and I would def. use it if aerogel was not available, but you can find it on ebay now.  I haven't ruled out thinsulate, but the performance of aerogel is higher.  Maybe I will be a first to do this as it was pointed out, or one of the first, but I will always lean on the side of technology if I can find a way!  And that dosen't always necessarily mean more expensive either, because as systems like insulation become more efficient, you have less complexity and overall costs and energy requirements go down, like solar systems and AC systems.  Of course, not to mention that solar systems and HVAC systems have to constantly run, perhaps repaired, battery banks have to be replaced, etc..  The insulation just has to sit there basically, and it goes both ways keeping you warm in winter and cool in summer so it's like a 2 for 1 deal in a way -- oh baby baby

Anyways, trying to keep my posts short, here's a link to some info on high-tech insulation materials, and there's probably more ideas I'm not even thinking about:

http://inspectapedia.com/Energy/Super_High_R_Value_Insulation.php

thank you again for your response!

thank you again for your response!   :s  I think I have been called a relic!  

OK you young go getter.

More power to your and your fancy expensive specialty insulation. 

The Italian AC that is expensive, and requires a lot of power.  

Someone has to go first.    

Post pictures you Dreamer.

 

[BradKW]

So, let me explain some of my numbers just a little bit, and these are not perfect exact numbers, but a rough estimation so feel free to call something out if you need to.  Here is a portable 12v air conditioner that was released pretty recently, that puts out 3250 BTU and 36 amps:

http://www.indelb.com/products/parking_air_cooler/sleeping_well/sw_cube

I estimate that the cargo area of a van loses roughly 6000 BTU without insulation, but insulated, lets just say this unit can keep the temperature stable without connecting it to a thermostat or anything and just keeping it on when not driving (My can van cool the rear with it's own AC system when I am driving for getting to the desired initial temperature).  I plan on having a 600 watt solar system generating about 200 amps per day and roughly 450 amps per day from a dedicated 250 amp alternator if I drive for 2 hours a day, which is what I'm estimating conservatively in terms of driving.  In 22 hours of not driving, i would be able to consume 792 ah a day for AC alone.  So, you are correct that 24/7 AC will not be possible.  I will have to turn the AC off at night or use a thermostat or run the AC on a lower setting, or drive more on hot days, or not use the computer, or something, or I would be approx. 142 ah over budget.  I do see myself trying to drive toward better weather whenever I can and I don't really mind driving a little more than usual (since i would be living on the road anyway) when it's hot or trying to find shorepower for a little while, 

That's a nice little AC unit... Jostelli over on the Sprinter forum has one, but I haven't seen him post an update recently with his experiences. I'm fairly sure that he is using LiP04 batteries, and given you're usage stated above, I believe you would need to do so as well. Lithium can easily handle 80-90% capacity usage daily without harm, and can recharge much faster. Here's a US based supplier of the U-go: https://www.unmannedsystemssource.com/shop/u-go-portable-air-conditioner/

Until Tesla's Power Wall becomes available to the DIY market (2017 maybeee?) I'd say your looking at a startup cost of $8,000 to run 3250btu cooling from DC for 12hrs a day? Be interested in seeing your numbers...DC AC is something I'd kinda written off for the time being.

 

[danman81]

The vacuum insulated panels are awesome that's for sure. I have a thing against thermal breaks, though. I place more value over having a complete sheet of insulation rather than have the best insulation possible, but having gaps or breaks in the insulation.

Thanks, @Canine -- Yes, I agree!  It's one of the main reasons I would like to find the best sealant that's an insulator and not just a sealant, but a thermal gap filler otherwise all that energy just leaks out -- actually with the sealant it will still leak out, but it's minimized at least.  I do think one large panel to cover the entire wall or ceiling is the best option, and I do intend to have a final panel like that consisting of layers of aerogel, a vapor barrier, a layer of mass loaded vinyl (for sound dampening), and finally plywood so that I have something to attach cabinets to.  However, there is still partitioned space underneath that -- for example between support beams on the walls and the ceiling, in the window cutout areas -- places where you usually see people use foam panels.  The way I was looking it was if I'm going to use panels, then I should use the best panels I could obtain within budget.  A low roof short wheel base van only has room for so much insulation anyways.  One problem I am seeing is that even though VIPs are custom cut, they still won't be cut as close to the edge like if you cut them yourself with foam panels from home depot, so you may have a VIP that is R-40, but you lose more insulation on the edge unless you have a really good sealant or other way to fill in the gaps.  Another idea is to use VIPs and then cut your own smaller pieces of foam paneling to fill in the gaps along with sealant.  I'm sure if you took a picture of your heated van with a thermal camera, you would see all the heat escaping out through all those gaps too!  What have you done for your van, or what do you plan on doing for insulation?

 

[danman81]

thank you again for your response!   :s  I think I have been called a relic!  

OK you young go getter.

More power to your and your fancy expensive specialty insulation. 

The Italian AC that is expensive, and requires a lot of power.  

Someone has to go first.    

Post pictures you Dreamer.

Thanks @GotSmart haha I am very truly honored by your blessing!      That AC unit uses 36 amps at 12vdc -- what kind of AC do you use if you use one where you're from?  My goal is to find the most efficient small AC unit available on the market, and one that I don't have to refill with ice all the time, and definitely 12v (all the way baby!).  leaving my Chihuahua alone in there on hot summer days while i'm at work is the single biggest fear I have of living in a van, actually in my whole life -- if I ever lost him because of something stupid i did i would just literally die and you would never hear from me again!  I will probably have to find a way to monitor the temperature through my phone or something, lol.  Smart homes can do it, but i will have to see if it can be done power-efficiently.  My 2nd choice right now would be the Bergstrom NITE Pheonix (spec'd at 25-65 amps @ 12v for 7,500 BTU), but that seems like it would be less efficient than the newer Indel Sleeping Well Cube, which is also cheaper.  I will definitely post pictures for you when I start!!

 

[GotSmart]

Are you even reading the replies?  :huh:

I do not use AC.  I love the heat, and so does my cat.  

By utilizing the Fantastic Fan, and cross breezes, (along with the ice chest and rug) my cat has a cool spot if he wants it.  115 outside, 65 along the side of the ice chest. 

What do you expect to spend on this project?

how many amp hours do you expect to use in the worst case?  (36 x 12 = 432) 

How will you generate it?

How (and where) will you store it?

This is my storage, and I think it is about 1/3 of what you will need.

 

[danman81]

That's a nice little AC unit... Jostelli over on the Sprinter forum has one, but I haven't seen him post an update recently with his experiences. I'm fairly sure that he is using LiP04 batteries, and given you're usage stated above, I believe you would need to do so as well. Lithium can easily handle 80-90% capacity usage daily without harm, and can recharge much faster. Here's a US based supplier of the U-go: https://www.unmannedsystemssource.com/shop/u-go-portable-air-conditioner/

Until Tesla's Power Wall becomes available to the DIY market (2017 maybeee?) I'd say your looking at a startup cost of $8,000 to run 3250btu cooling from DC for 12hrs a day? Be interested in seeing your numbers...DC AC is something I'd kinda written off for the time being.

Thanks @BradKW -- and thanks for the US-version link!!  Yes, I really think this is the perfect AC unit on today's market for simplicity and efficiency -- and all you need are 2 holes for the ducts through the floor for stealth of course.  I really do hope the Power Wall will become available for the DIY market!  Lithium is definitely the way to go too, longer lasting like you said and I really like the fact that they don't have to be constantly topped off -- I can just use power when I need it and charge whenever i can, and more capacity with less weight.  Here is a link to the battery I was looking at, haha I hope i'm not too off topic:

http://www.balqon.com/store-2/#!/12-Volt-9-kWhr/p/34783145/category=12286436

The startup costs you talk about is a reasonable estimate.  For the solar system, my current estimate is about $4.5k for the battery, $1.25k for 5 solar panels, and $5k for everything else including 5 mppt charge controllers, inverter/charger, second alternator, alternator regulator, wiring, etc.., and plus shipping for everything.  You could do it cheaper if you wanted, but i think the efficiency would go down (e.g., less efficient panels, a single charge controller, etc..) or you could do a smaller system (like 400ah) with 2 high quality 6v AGM batteries, which would be cheaper, but not enough power for me.

 

[danman81]

Are you even reading the replies?  :huh:

I do not use AC.  I love the heat, and so does my cat.  

By utilizing the Fantastic Fan, and cross breezes, (along with the ice chest and rug) my cat has a cool spot if he wants it.  115 outside, 65 along the side of the ice chest. 

What do you expect to spend on this project?

how many amp hours do you expect to use in the worst case?  (36 x 12 = 432) 

How will you generate it?

How (and where) will you store it?

This is my storage, and I think it is about 1/3 of what you will need.

Wow those are some cool pics!!  Hehe, and yes, I am reading your replies -- I'm just trying to be nice because you have more experience than i do :  

I plan to generate about 200 ah from solar per day, plus 450 ah from ~2 hours of driving a day from a dedicated 250 amp alternator (200 amps at idle), which is 650ah, which would take up about 85% of a 12v 750ah LiFePO4 battery bank.  For daily use, I plan on charging to full and consuming down to 15% or maybe 20% -- haven't decided yet.  Just posted a link to the battery bank above that I am targeting.  I have heard from some people that it will be hard to obtain being chinese and everything, but the site is up and it says in stock.  One thing for sure is Balqon does not answer emails or phone calls lol.

Also you mentioned ventilation, and I know it's important, but I have not considered it too much because that would impede on stealth in my view. I literally don't want anything to stick out at all on the sides or the roof that's not from the factory. Even my solar panels are flexible. I would have to have anything like that go through the floor, and I'm only guessing right now the AC will have a fan only mode, but that could end up being my only form of a fan. A separate ducted fan might end up being necessary.

 

[Canine]

I have spray in foam insulation with composite studs. I use the composite studs for weight reduction and mitigating thermal breaks.

If I needed 2" of rigid foam board insulation, instead of using 2" sheets, I would use two 1" sheets and overlap the seams to stop the thermal breaks that are created when two sheets of insulation are butted together.

I will be installing AC as well. Here is what I will get. It will be a while because I need to take care of other things first.

https://americancomfort.com/acw-1000-btu-personal-air-cooler.asp

It seems common sense to me, but a unit like that is made for blowing cold air on you not for cooling down a room. A lot of people don't understand that running an AC unit unconnected to a vent will heat a room up. The heat needs to be vented in order for a room to cool down. I have little doubt this will cool down the overhead sleeping area in my camper. As to the rest of the camper? Meh, probably not, but of course I'm going to try. This isn't DC, but a DC unit is crazy expensive. I'll take the small energy loss using an inverter. Another benefit of an AC unit is I'm not required to mount the AC almost on top of the battery bank or use huge wiring to get some distance; I can plug in an extension cord and move it around.

I've looked and looked, but can't find a page I was looking at that discussed insulating the inside of metal pipes and square tubing. Long story short, insulating the inside of tubing does almost nothing. Eliminating the convective heat transfer inside a hollow pipe by filling it with spray foam insulation is a pittance compared to the conductive heat transfer of the metal wall. While you didn't bring this up, I thought it may be of interest.

 

[GotSmart]

Wow those are some cool pics!!  Hehe, and yes, I am reading your replies -- I'm just trying to be nice because you have more experience than i do :  

I plan to generate about 200 ah from solar per day, plus 450 ah from ~2 hours of driving a day from a dedicated 250 amp alternator (200 amps at idle), which is 650ah, which would take up about 85% of a 12v 750ah LiFePO4 battery bank.  For daily use, I plan on charging to full and consuming down to 15% or maybe 20% -- haven't decided yet.  Just posted a link to the battery bank above that I am targeting.  I have heard from some people that it will be hard to obtain being chinese and everything, but the site is up and it says in stock.  One thing for sure is Balqon does not answer emails or phone calls lol.

Also you mentioned ventilation, and I know it's important, but I have not considered it too much because that would impede on stealth in my view.  I literally don't want anything to stick out at all on the sides or the roof that's not from the factory.  Even my solar panels are flexible.  I would have to have anything like that go through the floor, and I'm only guessing right now the AC will have a fan only mode, but that could end up being my only form of a fan.  A separate ducted fan might end up being necessary.

I asked about reading because you seem to be ignoring some crucial details. 

You can run a wire to a battery, but you can not force it to absorb power at a rate is is unable to take.  You can also not deplete a battery to 15%. The one you linked to has this in the specs.  [font=Arial, Helvetica, sans-serif]3,000 Cycle at 80% DOD      [/font]

Do not fully discharge flooded batteries (80% or more). This will damage (or kill) the battery.

Research the battery information on this forum from Sternwake.  

Also, there is no such thing as stealth camping.  In this day and age of electronics, you are seen.  

Now as to solar.  Flex panels are not a product I would trust.  My company pulled out of that market because they do not hold up to the stress of the 130 MPH + wind forces from driving. 

$15,000 just for set up without the cost of the van.  Or anything to make it habitable.  :s

What kind of van?