Insulation question

[robins]

Excellento, that`s a great discussion and Rich has finally got to the crux of the matter in that last post. If you leave them stock they may last longer, if you change anything there will be repercussions, some good some bad. Most of what has been said above ^^^ is pretty accurate. So leave them stock and in a nice warm garage and they might last another fifty years or change them a little or a lot to how you want them to work. I`m stock engine because the journey is part of or most of the fun of these, I`m a tiny bit lower so it fits in the garage and I`ve managed to stay away from the heady concoction that is ``slammed`` or the addictive drug of more ponies. I have however fallen under the influence of fidgeting and fiddling and that`s mostly inside (mostly) I`ve insulated the fibreglass pop top with 25mm of celotex and 3mm of foamex and the difference is very good insulation wise. I`m about to do the same in the cab area and the rear area and am a little concerned about getting total contact to the roof structure to avoid a space for condensation to form. I know that the smaller the space the less the condensation etc etc etc but I`m working on it and I think I have a decent solution but as with everything else it needs proving. As with comparisons with buildings, that is not valid unless we are talking about the same materials and I will be interested in this block of flats thing because your man has the same dilemma with the steel part of the construction, he`ll have to get the insulation to encase the steel but as that is almost impossible to get it 100% then the steel will have to be coated first then layered to final insulation level. The big problem with steel is it`s waterproof but thermally conductive as in it will transfer the heat / cold all along it`s length like an rsj or a van panel and the outside temperature needs a barrier between it and us because you can`t heat up the county with your propex but you might heat your van if you can stop the heat escaping a bit. Cavity walls are a different proposition in that they are not waterproof generally and water from rain etc will run down the inside of the outerskin but it keeps the weather off the inner skin and the insulation if it`s not waterproof like fibre batts etc, plus it would need a little air circulation but just a little to stop it stinking up the place. Other insulants are indeed waterproof and can happily touch the outer skin like poly styrene or kingspan celotex carbon coated balls even but the big big big difference is that the outer skin usually is not thermally conductive. They also do commercial outer skins that have insulation formed on them even though they are metal,,, that`s interesting.

Ozziedog,,,,,,,,,,,,,Loving this one :mrgreen:

:lol: love you buddy just what I wanted to say but I'm a bit thicker.".....You need a gap what ever the drain holes as wigg pointed out would act as a vent like in a building the trickle vents ...timber frame more so....what are we on about here vans or buildings :roll:

 

[Myvanway]

Low-E
https://youtu.be/8aOaXtx-bt8



We have started using a product at work called Low-E Insulation on our Park Homes. (Where I work)
Its like a thin bubble foam, a lot of peeps are using this stuff to insulate vans/mobile homes etc.
Ive put a link up....... if it works!?!? Lol.

Im going to be replacing the fibre glass that I fitted a few years back with this stuff, and also try it out as thermo window thingys like what you can buy from just campers...... £70 qid i fink..... :shock: gotta be worth a try!!
Ive already used it all over the roof of my carport to stop the damp with amazing results..... its stopped the condensation! 8)

Ive only used Dynamat in certain areas to stop panels vibrating, as a sound proofer and not as an insulating material.

Each to there own....



Not Low-E, but the same as....

https://youtu.be/HDxQwWX7YPE





Carport inside roof:

 

[kempy]

I used Armaflex sheets to insulate my van. I sound proofed first and then fitted the sheets on top.
I did this over two years ago and would highly recommend.

http://www.armacell.co.uk/WWW/armacell/INETArmacell.nsf/standard/2029CACAD1BB23AD802576CE003E61EE

 

[Robcod]

When I go camping being cold is part of it, the worst bit is the condensation and just laying there watching it drip down the windows and rusting the bottoms of them from the inside. Putting up thermal window sheets makes a noticeable difference, as does having an insulated pop top but only when it's down and canvas not exposed. I think having a heater resolves the coldness, removes the damaging condensation and makes probably a healthier environment to sleep in. In the morning you don't have to mop everywhere and you are good to go straight away. The same is true if you park up for the day in winter and want to sit in the van looking out and cooking /talking etc as it soon gets damp inside. Which is why I'm saving for a propex heater. I use a plug in heater the rest of the time. I will be fitting dynamat to reduce panel reverb only. so there we are ....heater equals comfort, warmth, no damaging condensation and ready to go straight away. So put your insulation money into a heater instead. This is before we even get into the environmental issues but we don't worry about poop like that.

 

[ozziedog]

OOOooohhhhh, I like the look of this Armorflex and this Low E, that will be a lot easier to get total contact with our surface area. I`ll look at where to get these and I`m thinking they have a similar technology base. The better the insulationcan only go so far with technology, it has also to consider size and mass of the insulant. Heat transfer and energy transfer are unstoppable processes we know this.
Interesting that Rich throws in about drainage in these areas and that is something I`ve been talking about with my mate Nick at CJ Motors, where we have drainage holes at the bottom of our panels, the later bays had a lot more drainage all through the cills etc. As Nick replaces a lot of panels on old motors, now days he also pops in some extra drainage holes too , going on the theory that if it`s rusted through once or twice, it may need a little help with drainage to stop the rust forming.

Ozziedog,,,,,,,,,,,,, Best thread for ages,,,, Love you too Rich :lol:

 

[MisterListerSir]

Removed all my insulation when i brought the van and sprayed waxoyl in every cavity using a compressor and a undercoating gun, yes its a bit noisy and chilly at night but after the work I did on the van I dont want any more rust. plus I can quickly remove panels and make sure its dry and rust free, if its full of insulation I don't think people will check

 

[Bundy]

I used that Armacell stuff too. Managed to get foil backed on on side and was available with self adhesive backing the other but cost a lot more so just used an impact adhesive to glue them all on. Struggled to find it last year when I wanted some for the Beetle, so thanks for that link above! Used to get it from an industrial air con installer/spares place.
Really easy to cut and very light weight too.
I find condensation forms on the outside of the van where I've insulated the inside of that panel...can see where its not been done on a cold morning!
Very good soundproofing at the same time!!
Was thinking of lining the inside of the pop-top with a thin layer...maybe one day...

 

[Bajalegend]

Does anybody use moisture absorbers/silica gel packs etc in thier bus? Just wondering if that would prevent the moisture problem

 

[Raggles]

basic rap on insulation ....

Warm air can hold a lot of moisture. When warm air comes into contact with colder air it cools and can no longer hold the moisture - so condensation occurs.

Normal condition in van when cold. Inside is warm air ... air comes into contact with metal/glass cold from the outside temp, cools and condensation forms.

Insulation slows down cooling of air ... so on front face of insulation it is warm (no condensation) on rear of insulation it is cold so condensation forms. If you use open wool/quilt style of insulation that allows air through, then warm air will pass through cooling as it goes and at the critical point condensation will occur - which may be in the middle of the insulation.

If you want to stop condensation then you need to keep the inside face of the room/van warm to stop the air cooling and you need to keep the air from passing through/behind/beyond this face. Normally this is done with a vapour barrier (polythene sheet) wrapping the whole interior (can be integral to the insulation).

On a van I would avoid any kind of insulation that can absorb moisture ... that will retain moisture where you don't want it. If you place insulation spaced off the walls of the van, then the situation will be worse than if you had no insulation from a condensation standpoint. This is because the interior will be warmer because of the insulation, hence it can carry more moisture, so there is more to condense on the cold body work. If you bond the insulation direct to the metal excluding all air, then I suspect the situation condensation ways will be no worse and may be slightly improved on the stock van. This is because no condensation should form where the insulation is bonded as the air can't reach the cold outer service due to the seal. However the air will be warmer, thus containing more moisture, and so condensing more on the remaining cold surfaces of the van (rest of the bare metal/glass)

The only way to address the condensation issue totally is to ensure that all the voids are fully filled with insulation to avoid any cold bridges and then fully seal to make sure no air can penetrate around the sides to the back (not sure if this would be possible). Then the condensation would be concentrated on all the visible metal/glass within the van.

In buildings you tend to try and wrap the outside in insulation to get as much thermal mass as possible internally which will absorb and retain either heat in winter of cold in summer to mediate the temperature throughout the day and night. Normally a vapour barrier is wrapped around the building (this can be the insulation itself depending on type) prior to the insulation layer to avoid condensation within the fabric. If the insulation is placed halfway through the wall build up, then the vapour check is still on the inside of the insulation, and a vented cavity is provided to aid in the evaporation of any condensation that does form ... the outside face is normally then wrapped in a breather membrane to allow the evaporation but prevent any water coming in.

My view is that you will always get condensation in a van in cold weather. Local insulation say in the pop top would be very effective at stopping condensation drips. Otherwise, you pay your money and take your choice ... still using lots of waxoyl to prevent the worst of any side effects.

Hope that helps

 

[Moseley]

Good post above.

As well as the additional warmth inside our vans, we also have to remember that when sleeping inside it, every breath exhaled is full of moisture, so after a night's kip with a few bodies in the van, the air is very humid and condensation on cold parts will be high.

Personally, I feel that taking into account what other's have suggested on this thread, that fully lining (where possible) the van with a sound-deadening type material and then using closed cell foam where space allows, will be the best for avoiding moisture build-up, and trapping long term. Dynamat or similar, is bitumen based which when applied correctly, is a great moisture seal - it is used on pond liners to keep the water in.

However, that being said, my personal preference is no insulation - at least it is easy to inspect and catch any potential problems early!


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[Raggles]

As well as the additional warmth inside our vans, we also have to remember that when sleeping inside it, every breath exhaled is full of moisture, so after a night's kip with a few bodies in the van, the air is very humid and condensation on cold parts will be high.
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Don't forget, changing the air is a good way of avoiding humid air. An open window to allow some venting will help massively. Again, in modern building construction, all rooms have built in trickle ventilation to change the air within the fabric for this very reason. In the passive haus mentioned above this is done using a heat exchanger to prevent any heat loss.

Myself I keep a window slightly open when sleeping and this deals with most of the condensation ... good sleeping bag/bedding essential in colder weather!

 

[Moseley]

As well as the additional warmth inside our vans, we also have to remember that when sleeping inside it, every breath exhaled is full of moisture, so after a night's kip with a few bodies in the van, the air is very humid and condensation on cold parts will be high.
Sent from my iPad using Tapatalk

Don't forget, changing the air is a good way of avoiding humid air. An open window to allow some venting will help massively. Again, in modern building construction, all rooms have built in trickle ventilation to change the air within the fabric for this very reason. In the passive haus mentioned above this is done using a heat exchanger to prevent any heat loss.

Myself I keep a window slightly open when sleeping and this deals with most of the condensation ... good sleeping bag/bedding essential in colder weather!

Absolutely. We only use ours in the spring / summer so although it probably gets full of moisture over night, it's then normally left with doors / windows open all day in the sun, so should be more than adequate in getting the panels roasting hot and dried out. We're clearly not hardcore enough, even in the summer nights, we wouldn't dream of having any windows open - it's cold enough getting up for an early morning wee!


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[Guest]

a cheap option is closed cell foil faced sleeping mats they are designed to keep you dry in your sleeping bag so work well for insulation. light weight compact (12mm thick) and £4 a roll from Lidl (60cm x 180cm)

tesco were seilling them as well

 

[ozziedog]

Does anybody use moisture absorbers/silica gel packs etc in thier bus? Just wondering if that would prevent the moisture problem

I use a moisture absorber from Unibond but I only use it when the bus is in the garage through the winter, I take it out when I`m driving and for the summer. I got mine from B&Q for a bout a tenner and its about the size somewhere between a tennis ball and a football. Comes with a weirdo type replaceable block that attracts the moisture. Got one in my old car too.

Ozziedog,,,,,,,,,,,,,, We call it fun too :mrgreen:

 

[Seamus1982]

The reason you shouldn't leave a gap between the insulation and the outerskin of the van, is that the condensation will essentially collect on the surface where warm meets cold, so the outside of insulation (if the insulant is continuous with no gaps). In ordinary building, this would need to be ventilated (in regard to a roof), but in cavity construction, the condensation will run down the face of insulant into the cavity at the bottom and direct out towards the outer skin, however, this still requires a minimum air void between insulant and external face of wall where a PIR or similar rigid insulant is used. Basically, if the insulant isn't fully adhered to skin of the van, you need to ventilate behind it to remove the moisture, which of course won't work logistically. You can get spray applied insulation which are designed to deal with the issue of moisture and ventilation gaps, which could possibly work on a van. Like most have said, unless you fully insulate the whole of the van you will get condensation, spray applied to me would be the only way around this.

 

[Seamus1982]

Even with spray applied systems, there is a vapour control layer internally, to dramatically reduce the moisture in the air leaving a building (or structure) so you would also need to try and line the van for this.

 

[Bluesnailman]

I've recently taken my trim panels off for some painting, and looked at the sheeps wool insulation i put in there 5 years ago. I glued it in place and fully filled the spaces/cavities between the panels and the trim, no polythene in place.

Without exception there was no sign that the wool was or had been damp, no signs of water in any cavity. in my view these panels only need to be better insulated than the widows to avoid being full of moisture. laws of physics mean that condensation will form at the weakest thermal point - so in insulating the panels I making sure it forms on the windows first.

(put triple glazing in an old stone cottage and you'll get mould on the walls type theory)

 

[Raggles]

I've recently taken my trim panels off for some painting, and looked at the sheeps wool insulation i put in there 5 years ago. I glued it in place and fully filled the spaces/cavities between the panels and the trim, no polythene in place.

Without exception there was no sign that the wool was or had been damp, no signs of water in any cavity. in my view these panels only need to be better insulated than the widows to avoid being full of moisture. laws of physics mean that condensation will form at the weakest thermal point - so in insulating the panels I making sure it forms on the windows first.

(put triple glazing in an old stone cottage and you'll get mould on the walls type theory)

Metal behind wool insulation will be cold due to the insulation. If any internal air finds its way through the trim panels and wool it will condense on the metal. The air itself does not seek out colder surfaces ... it simply dumps the moisture it contains when it comes up against them. If you have no sign of damp then either the warm air is finding it difficult to get through to the cold surface, or the void is sufficiently breathable to allow any damp to dissipate as the outside environment warms. If the van is generally only used in the warmer months, then the likelihood is that any overnight condensation gets dissipated during the day.