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Author Topic: Insulation : Stuck at the first hurdle!  (Read 3197 times)

bexcunn

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Insulation : Stuck at the first hurdle!
« on: December 03, 2017, 07:24:18 PM »
So we've brought our van which were are hoping to convert into a camper. The catch is we have 11 dogs which are racing huskies.

We are looking at converting the rear of the van for the dogs with fitted dog crates. i'd like the walls in this section to be covered in something like altro flooring.

the middle section of the van will be sleeping quatres for us humans.

The van will be used mostly in the winter so needs to be warm, we will also be fitting a night heater.

My question is what do I use to insulate?

I've been told all differnt things and now i'm really confused. I was told to use the bubble foil insulation, but then told this wasn't thick enough and then told to use the closed cell foam, but told you can't mold that into shape, was told to use the wool but then told this holds moisture?

my main problem there will be loads of moisture because of teh amount of dogs breathing in the back!

please please help

Bex

Camper_Dan

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Re: Insulation : Stuck at the first hurdle!
« Reply #1 on: December 03, 2017, 11:09:56 PM »
Greetings &  Welcome!

The ~ONLY~ solution for moisture problems is ventilation.  Proper ventilation totally negates any positive effect of insulation other than to seal up drafts, and for sound deadening purposes.

Only having enough heating and cooling power to defeat, overcome, and compensate for the needed ventilation, will keep you comfortable.

Dry heating & cooling methods work the best, meaning no unvented propane appliances that also add a ton of moisture to the air.

Your bubble wrap will effectively seal up any drafts in places you don't want them, and it will more easily conform to the curved surfaces without taking up extra interior space.  Having both high and low ventilation will make it all automatic without the need for fans...

Good Luck & keep us posted!

chuffstix

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Re: Insulation : Stuck at the first hurdle!
« Reply #2 on: December 07, 2017, 10:24:47 PM »
Greetings &  Welcome!

The ~ONLY~ solution for moisture problems is ventilation.  Proper ventilation totally negates any positive effect of insulation other than to seal up drafts, and for sound deadening purposes.

Only having enough heating and cooling power to defeat, overcome, and compensate for the needed ventilation, will keep you comfortable.

Dry heating & cooling methods work the best, meaning no unvented propane appliances that also add a ton of moisture to the air.

I'm about to start a conversion myself and am completely baffled by the amount of conflicting opinion out there about best practice. What you say makes sense but surely decent insulation + adequate ventilation would use less energy to maintain temperature than minimal insulation + ventilation?
Seems to me that there should by now be consensus on the best way to do this, what with science and evidence and all that.

chris Fearnley

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Re: Insulation : Stuck at the first hurdle!
« Reply #3 on: December 10, 2017, 11:42:41 PM »
Hi CamperDan,
I'm new here so trying to gain a whole lot of advice before starting my build. I've visited several other self-build forums as well as this one.

From your extensive experience you've evidently built up a lot of clear ideas about what works and what doesn't. But as an engineer with experience in heat transfer I'm puzzled by some of your advice - in particular about insulation and ventilation.

For example, in the post above you say "your insulation and lack of windows will keep the natural heat from the sun out in cold weather, and trap the heat in when it hot weather". Now, I'd agree that if the sun is shining in winter, it can add some heat through windows. But in winter the days are short and (in Europe at least) there's probably only a 25-50% chance at best of  a sunny day in winter. So the sun is only going to help perhaps 10% of the time at most - and never at night when a van is going to be at its coldest. Whereas all your windows (you seem to recommend minibus vans over panel/cargo vans) are going to be losing a huge amount of heat during the (coldest) 90% of the time.

As for trapping in the heat in hot weather, how can that problem be attributed to insulation? Hot sun will heat up bare metal to a high temperature; without any insulation that heat will be radiated straight into the van. Same with too many windows; the van becomes a greenhouse. Insulation will reflect much of it back, the opposite of trapping it. Yes, in hot weather you need plenty of ventilation, so you need to open windows or roof panels. But adequate insulation keeps as much of the heat out as possible; ventilation will try to remove whatever heat does get in.

I don't know which of your '3 types' of people I fit; I don't have first hand experience of campervan conversion (yet); I do have very relevant experience of keeping heat and cold in the right places; but I'm not out to make a buck. I'm retired  :)

Camper_Dan

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Re: Insulation : Stuck at the first hurdle!
« Reply #4 on: December 11, 2017, 10:31:52 AM »
Greetings & Welcome Chris!

I'm in the USA, and during the winter we get at least 8 hours of daylight I think.  Many if not most of the coldest days are sunny, or at least partially sunny.  Enough to normally contribute a noticeable amount of free heat, especially if the ventilation is shut off.  It was 32f today outside with 40mph winds, but it stayed between 68f-70f inside my van with no heat running for the better part of 6 hours.

The loss of heat when running a heater is pretty inconsequential, since we need to have ventilation when running the heater anyway.  The needed ventilation will pretty much defeat any positive effects of  insulation.  Insulation requires a sealed area with a heat source to be effective.  Since unvented heaters, or cooking inside require ventilation, the sealed area part is not possible.  We also need the ventilation to combat moisture problems. 

With or without insulation, but with the proper ventilation, we need enough heat to keep us warm.  A good insulation job is likely to cost upwards of $1,000.  My annual heating & cooking costs are well under $100 in a window van with no added insulation.  Even if I could save the full amount of my heating/cooking costs, which we know isn't going to happen, but if it did, that insulation would take over 10 years to pay for itself.  Even if it saved me half of my heating costs, which is still highly doubtful, it would take over 20 years to pay for itself.  Since I am totally warm and comfortable without any insulation, the under $100 yearly plan just makes better sense...

In a vehicle, insulation in and of itself can not keep us comfortable either all day, or all night, because we don't have enough room to have enough insulation to accomplish it.  In the summer, by mid day, even with 3 inches of insulation all the way around, your van will be an oven inside.  The ventilation won't help, because the insulation will have become saturated with the heat, and will continue to radiate that heat long into the night.  Even airing out the van after sun down, won't stop that insulation from radiating the heat it has absorbed for many hours.  On a really cold night that could potentially be a good thing, but  on warm nights, it is miserable.

An uninsulated van can be cooled off to outside temperatures rather quickly with ventilation and a fan.  Many hours quicker than an insulated van.  If we want the inside temperature to be lower than the outside temperature, this can only be accomplished by added cooling features.  In the summer, shade works better than any amount of insulation.

Any experienced camper will tell you that it is much harder to keep cool than it is to stay warm, yet insulation works better in the winter than it does in the summer.  Insulation can also trap moisture, which can lead to mold and rust problems.

You fit into the experienced crowd, just not of the camper van variety.  You're intelligent enough to ask questions, rather than jump in blindly, and I fully appreciate that.  Camper vans are a totally different environment than a normal building.  Not only does a van have a metal skin, but it has an enormous amount of outside walls compared to a very small interior space.  A camper van is also only normally heated or cooled when it is occupied, and needs ventilation even in the winter.  All these things combined change the rules of what we normally know about house insulation.    In the words of one old timer, "If your van keeps you out of the weather, and gets you where you're going, then it's doing it's job.".  No added insulation is needed to accomplish that.

When all else fails, use the cost vs. benefit analysis.  If the benefits you believe you will get outweigh the costs, then you have your answer.  If your interior is portable, rather than permanently built in, then adding insulation later if you're not happy, should be a pretty easy task.  You can't unspend the cost if it's paid for in advance.

Cheers!

chris Fearnley

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Re: Insulation : Stuck at the first hurdle!
« Reply #5 on: December 11, 2017, 11:21:37 AM »
An uninsulated van can be cooled off to outside temperatures rather quickly with ventilation and a fan.  Many hours quicker than an insulated van.
This cannot be correct. All insulation materials are designed on the basis of being mostly air, and/or very thin AL foil. The heat capacity of these materials is very low  compared with all the other stuff in a van (furniture, cooker, fridge, everything else). Sure, it's insulation, so the heat will take along time to seep out of it. But the amount of heat it contains is minuscule. So please tell us what it is (in an insulated van) that makes it longer to get cool?

Perhaps it's because you won't allow roof vents for cooling, because they 'always leak'. This can't be true either, there are tens of thousands of vans out there with roof vents. Nearly all VW campers have lifting roofs which are effectively very large roof vents. VW campers wouldn't still be in business after 50 years if all the roofs leaked. And it's far easier to seal a small vent window than a big lifting roof section.

Tell me, does your kerosene heater (that costs 100$ a year to run) vent straight into the van, rather than using blown air and a heat exchanger with exhaust gases vented correctly to outside? Sounds like it does, since you say (in other posts) that it produces less water vapour than gas. If so, isn't that the basis of all your historical problems with condensation / damp / mould / rust?

Camper_Dan

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Re: Insulation : Stuck at the first hurdle!
« Reply #6 on: December 12, 2017, 08:15:39 AM »
> This cannot be correct. All insulation materials are designed on the basis of being mostly air, and/or very thin AL foil.
> The heat capacity of these materials is very low  compared with all the other stuff in a van (furniture, cooker, fridge,
> everything else). Sure, it's insulation, so the heat will take along time to seep out of it. But the amount of heat it
> contains is minuscule. So please tell us what it is (in an insulated van) that makes it longer to get cool?

There are many factors at play here.  If you're somewhere where it's 75f-80f at night, a heavily insulated cargo van, with both side & rear doors open, and two roof vents open, it will remain 10f-15f warmer inside than outside until 3am-4am.  This is real world experience by many many people.  Now if it cooled off more at night, that could obviously change things.  If it cooled off to 60f outside, and the van remained 10f-15f warmer, it would still be comfortable.

> Perhaps it's because you won't allow roof vents for cooling, because they 'always leak'. This can't be true either,
> there are tens of thousands of vans out there with roof vents. Nearly all VW campers have lifting roofs which are
> effectively very large roof vents. VW campers wouldn't still be in business after 50 years if all the roofs leaked.
> And it's far easier to seal a small vent window than a big lifting roof section.

Roof vents and pop tops are two different things.  Pop tops typically have a good  rubber seal, and the design for how they fit on the roof is also totally different.  In addition, they have side walls to keep the rain out.  Roof vents use sealant, which goes bad all too often.  Additionally roof vents frequently get left open in the rain by accident.  Both of my Fantastic Fans had rain sensors, and both of them failed within 2 years.  If you leave a roof vent open when you're away from your van, you're rolling the dice as to whether you will return to a soaked van or not.  There are some vent designs, and vent covers that are more rain proof.   If you remove and reseal a roof vent yearly, like the RV shops recommend, then MAYBE they would never leak, but realistically this rarely happens.

> Tell me, does your kerosene heater (that costs 100$ a year to run) vent straight into the van, rather than using blown
> air and a heat exchanger with exhaust gases vented correctly to outside? Sounds like it does, since you say (in other posts)
> that it produces less water vapour than gas. If so, isn't that the basis of all your historical problems with
> condensation / damp / mould / rust?

Both my kerosene heater, and my kerosene cooktop are portable.  The moisture problems were in a heavily insulated cargo van, with 2 Fantastic roof vents, using a propane "Buddy" type heater, and a propane cooktop.  That van was always too cold in the winter, and too hot in the summer.  I upgraded to a window van, with no added insulation, no roof vents, and switched to kerosene from propane.  This van has pop out at the bottom windows all the way around, and unless you're in gale force winds, no rain will come in them when open.  I have never had a moisture problem since switching vans, and switching to kerosene.  This window van is warmer in the winter and cooler in the summer than the cargo van was.  In full disclosure though, my kerosene heater puts out at least double the heat than the "Buddy" heater did.

~IF~ I would have had the kerosene heater in the cargo van, it ~MIGHT~ have kept me comfortable.  It would not have solved the biggest moisture problems though, because the moisture was coming from condensation on the inside of the metal skin, and the insulation trapped it so it couldn't be evaporated out.

A friend has a 70's era surfer van.  3 years ago we renovated the interior.  It originally had 3" of open cell foam on the floor, walls, and ceiling, covered by carpet.  When we removed the original interior, it was mold and rust free.  We put new foam in, and covered it with crushed velvet.  This allows the moisture to be wicked to the interior to be evaporated out.  He still has no moisture problems. 

When I removed a section of my insulation in my cargo van, the wall behind it was solid rust, and the back of the insulation was covered in black mold.  Before being insulated, the van had no rust or mold.  You can't stop or prevent the moisture from condensation from occurring on the inside skin.  There are only 2 known ways to deal with it, you either need venting clear to the outside skin, or you need to wick the moisture away from the skin and to the interior.  Passenger vans use both methods.

Keep in mind that I work vacation relief, which means the coldest areas in the winter, and the hottest areas in the summer.  The people pushing insulation are the same people who follow the good weather.  The extreme weather campers will tell you to invest in better heating and cooling options instead.

I've learned from my mistakes, at great financial costs, and huge comfort costs.  I'm just trying to prevent others from making the same mistakes.  Too many people have learned the same things I have, but they're too ashamed or proud to admit to them.  I have seen so many insulated vans at gatherings full of rust and mold that it isn't even funny, and many of these people tear it all out, clean it all up, and make the same mistakes all over again.  A year or two later, they are right back doing it all over again, and somehow believe the results will be different.  Go to a rally, and ask anybody with years of experience (they'll be in a window van, guaranteed), and look at the vans, they'll be 10:1 window vans with no added insulation.  You mentioned the iconic and sought after VW campers, they were all window vans, and none of them rolled out of the factory with any added insulation.  (I've had 6 of them ranging from 1961 to 1989...  3 of them I bought brand new)  I got suckered into a cargo van because of all the hype, and that was just what is was, all hype.  If you've never had better, maybe you don't know the difference, but if you've had better, they don't even  come close to measuring up.  BTW, except for a few of the very early westfalias that had a trap door on top, none of them had roof vents.  The splitty's did have a roof vent, but the outside part was above the windshield and facing downwards.  Now those were great leak proof roof vents.  The bay window & vanagons had their fresh air vents under the windshield.

Cheers!


Vantwat

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Re: Insulation : Stuck at the first hurdle!
« Reply #7 on: December 12, 2017, 09:21:07 AM »
Just to add something from my limited experience,my first van was a converted minibus with windows and was bloody freezing.My second van was an LDV the same as mikes,I built it quickly and as a builder I had a small amount of celotex insulation which I put on one wall only,after the winter there was mould on the walls and ceiling that didn’t have insulation.
Onto the van I’m using now,a mwb high top transit with no windows,I’ve put bubble wrap everywhere and put tgv cladding every where,I filled the cavity between the bubble wrap and the cladding completely with rock wool.ive no windows at the moment but I’m planning to put a 450 skylight and possibly a small window behind the gas hob,I plan on getting a 12v fan .The heating I’m using is a webasto diesel heater.
Sooo what I’ve found is in the hottest week of the summer I was lucky enough to be staying in the van in Cornwall and I didn’t lose a minutes sleep from being too hot which was lovely and must have been due to the insulation as I’ve struggled in the past when it’s hot in my previous vans without insulation.This weekend which was the coldest by far at about -5 I had the webasto on for about an hour and that was enough for the night.
Hope this helps . Peace and plants
« Last Edit: December 12, 2017, 09:22:39 AM by Vantwat »

Camper_Dan

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Re: Insulation : Stuck at the first hurdle!
« Reply #8 on: December 13, 2017, 12:40:24 AM »
Greetings Vantwat!

> Just to add something from my limited experience,my first van was a converted minibus with windows and
> was bloody freezing.My second van was an LDV the same as mikes,I built it quickly and as a builder I had a
> small amount of celotex insulation which I put on one wall only, after the winter there was mould on the
> walls and ceiling that didnít have insulation.

You didn't happen to mention whether you had heat, or how much heat, in your minibus...  That is a very important factor.

On your LDV, you also didn't mention heat or ventilation, or what was behind that insulation, if you know.

There are people in 30 to 40 foot uninsulated school buses, that stay warm well below freezing with one or two big kerosene heaters.  Heat is what keeps you warm, not the insulation.  Insulation only slightly slows the heat loss, and with adequate ventilation, it's debatable whether it even does that.  Both dry heat, and ventilation are needed to keep moisture in check.

We can gather around a campfire outside in the open air and stay warm on even the chilliest of nights.  Any tent or structure will hold that heat in better than outside with a campfire.  These are both simple facts, and insulation doesn't play a role in either of them.  Insulation can't improve your comfort without that heat source, but  more heat can improve your comfort without the insulation.  Insulation only slows the heating or cooling process, but does not provide either.

I have been the route of a heavily insulated cargo van, and an under powered heater.  It was miserable at best.  Today, in an uninsulated window van, but with a bigger heater, I am totally comfortable.  It is so cheap to heat, that the cost of insulation would be foolish, regardless of whether it worked or not.

Shade in the summer works far better than any amount of insulation.  Even with heavy insulation, without shade, and sunny, by mid morning your rig will be heating up big time.  A fan and good ventilation can keep the heat at bay longer than insulation alone, and can keep it no warmer than outside temperatures until probably at least noon.  By then, if you're in the sun, or the temperatures are too warm, the only thing that is going to save you is some sort of air conditioning.

For many years I used a non-evaporative swamp cooler with no complaints, and I still have it because the jury is still out on a different model I picked up.  The new model is a combination evaporative and non-evaporative swamp cooler.  The evaporative part draws in outside air, and exhausts it back outside.  The object is to keep the water in the reservoir cold.  That cold water is then circulated through a small radiator with a fan, that circulates only inside air through it.  It worked great in a dry environment last summer, but I haven't had the opportunity to test it in a humid environment yet.  It draws under 3 amps @ 12 volts, and is supposed to circulate up to 420 CFM.  A vendor at a campout was making and selling these, and I wanted to help him out if nothing else.  It actually works better than I had expected so far.  He said he was also going to be working on a heating option for it too.  I'm hoping I'll run into the fellow again.

Cheers!



Vantwat

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Re: Insulation : Stuck at the first hurdle!
« Reply #9 on: December 13, 2017, 09:04:30 AM »
Hello mate, in the minibus the only heat I had was from the hob which was in front of a window that was open while cooking.As regards the LDV the wall that was insulated was done with 25mm celotex and held partially in place with expanding foam,so there was gaps as the foam was sporadic,like I said the only difference was that wall didnít get any mould,and yet again I had no heating other than the hob when I was cooking.Also as I said with my latest van when we had the hottest week it was a comfortable temperature in the van and i didnít have windows open as I havenít got any yet.Its still a work in progress but itíll be there soon.

Camper_Dan

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Re: Insulation : Stuck at the first hurdle!
« Reply #10 on: December 15, 2017, 02:00:58 AM »
> Hello mate, in the minibus the only heat I had was from the hob which was
> in front of a window that was open while cooking.

More people heat with their cook stove ( hob ) than any other method.  You would open a window farthest from the stove to retain the heat inside.



>As regards the LDV the wall that was insulated was done with 25mm celotex
> and held partially in place with expanding foam,so there was gaps as the
> foam was sporadic,like I said the only difference was that wall didnít get any
> mould,and yet again I had no heating other than the hob when I was cooking.

You can't stop condensation, insulation can only hide it or trap it, unless it is specifically designed to wick that moisture to the inteior where it can be evaporated out.

> Sooo what Iíve found is in the hottest week of the summer I was lucky enough
> to be staying in the van in Cornwall and I didnít lose a minutes sleep from being
> too hot which was lovely and must have been due to the insulation as Iíve
> struggled in the past when itís hot in my previous vans without insulation.
> This weekend which was the coldest by far at about -5 I had the webasto on
> for about an hour and that was enough for the night.

> Also as I said with my latest van when we had the hottest week it was a
> comfortable temperature in the van and i didnít have windows open as
> I havenít got any yet.Its still a work in progress but itíll be there soon.

We're not getting enough information here, because there are many factors at play.  Since it is a high top van, it will take longer to heat up due to the larger volume of air inside.  The orientation of the van in relation to the sun, and/or shade can both make huge differences.  What your sleeping hours were makes a difference too.  If you slept in until 8am or 9am, and didn't lose a minutes sleep, it's because you were up and out before the van heated up.  I work different shifts, so sometimes I'm sleeping in my van during the hottest part of the day.  Times involved, orientation of the van, shade, and ventilation all make considerably more difference than any amout of insulation.

On cold nights, my uninsulated window van, with ventilation open, will stay 10f-20f degrees warmer than outside temperatures.  If it's too cold to be comfortable, I just run my heat all night long.  Last night at -18f degrees outside with a strong wind, I slept on top of the covers because it was 74f degrees inside my van.  There are many ways to keep your van warm in cold weather...  They all require heat,  and not one of them requires insulation.  Insulation can only slightly slow temperature changes, but does not provide either heating or cooling, and can't keep the temperature comfortable either all day or all night, unless no insulation was needed in the first place.

chris Fearnley

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Re: Insulation : Stuck at the first hurdle!
« Reply #11 on: December 18, 2017, 12:07:38 AM »
"Last night at -18f degrees outside with a strong wind, I slept on top of the covers because it was 74f degrees inside my van"
In a standard mid-size uninsulated van this would need about 27k BTU/hr (about 8KW) of heat. I only use 4KW to heat my whole 7-room house during winter. You're either mad or you're lying.

Camper_Dan

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Re: Insulation : Stuck at the first hurdle!
« Reply #12 on: December 18, 2017, 10:57:10 AM »
Actually I have a total of about 60k btu's available between multiple sources. (Big  heater, small heater, cook stove, & lanterns.)

I'll use the big heater (23k BTU's) generally to heat it up quickly, then the small heater on it's lowest setting to maintain the temperature throughout the night.  Probably under 2k BTU's.  It takes vvery little heat to maintain the temperature once it's comfortable, but a lot of heat to heat it up quickly.  Using the smaller heater only, it would take too long to heat the whole van up by 90f degrees.  If it gets down to around -40f, then I'll keep the smaller heater on about medium all night.  If I'm keeping the heat on all night, it's not unusual for me to sleep on top of the covers, because the van will be in the 70's all night long.  I can't really keep it any cooler without shutting the heat off, and then it gets too cold and things might start freezing.  Anything below about 10f, it's just the most comfortable to run the heat all night.  Above that, I'll just start the heat in the morning before I get out of bed.

I don't know how BTU's translates to KW, so I can't comment on that, but most camper vans come with 40k-60k BTU furnaces.  Those furnaces are not nearly as efficient as my kerosene heaters are.  My van is also the extended, not a mid size.  In the winter, I only open the floor vents  in the cab, so the heat stays in very well, even with the ventilation.  If you're using a roof vent for your ventilation, then all the heat is just going up and out the roof vent.  Heat rises, so in the winter you want your ventilation down low.  In the summer, you want both high and low ventilation, so the heat goes up and  out while drawing in the cooler air at the floor.  With that scheme no fan is needed to circulate the air and keep it cooler inside.

My heavily insulated cargo van with roof vents cost 2-3 times more to heat than my uninsulated window van, because the heat was going out the roof vent instead of being trapped inside like it is with my window van.  Once the top 95%+ of the van is sealed, the heat stays in quite well.

> In a standard mid-size uninsulated van this would need about 27k BTU/hr (about 8KW)
> of heat. I only use 4KW to heat my whole 7-room house during winter.

~IF~ your figures for heating your house are correct, you need to keep in mind that it is only to maintain the temperature, not to raise it.  A typical house will have a 100k+ BTU furnace, and even larger in colder climates.  Your heat runs constantly to maintain that temperature.  In a vehicle, unless permanently parked, the heat is only run while the vehicle is occupied.  Additionally in a house, it won't cool off the whole house if you open a door to enter or exit, because of the much larger volume of air  inside to begin with.  In a vehicle, opening a door to enter or exit can drain it of most of it's heat almost instantly.  Houses and vehicles are two totally and very different scenarios.  People tend to believe that somehow the two should be similar, when in fact they're closer to opposites.  Vehicles have been referred to as "rolling steel tents", and that is probably a better comparison than a house.  You likely pay a whole lot more than the $75-$100 a year I pay to heat my van for a year, to heat your house.

Until somebody has actually experienced both methods, it might be hard to understand.  I started out with several VW camper vans.  All were window vans, with no added insulation, and were very comfortable.  I got suckered into believing that a heavily insulated cargo van would be much better.  IT WASN'T!  While I had that cargo van, I did 6 months in a live aboard boat.  It had glass from beltline to ceiling all the way around, and was many times more comfortable than my cargo van.  It reminded me of my old VW campers, and how much more comfortable they were, so I switched back to a window van, just not a VW.  Getting rid of that cargo van was one of the best things I have ever done, even if I did lose a ton of money on it.  That cargo van would have never paid for itself.  My current window van, including the interior, paid for itself the very first month, and that was over 10 years ago now.

There are many different factors at play, and many of them can change very abruptly.  Some people travel with the weather, but others stay in place.  Some fight the  heat, others fight the cold, and some of us have to fight both.  Done right it can be a wonderful life, or a wonderful diversion.  Done wrong, we have just paid a fortune to become homeless, and maybe jobless too.  The only time I ever felt homeless, or got treated like I was homeless was in that cargo van. 

Everybody has a choice of how they do things, if you screw up, you can have a do over, and you can remember what I've said and make better choices.  Experience is a great teacher, and once you get enough of it, you'll have proven me right.


chris Fearnley

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Re: Insulation : Stuck at the first hurdle!
« Reply #13 on: December 18, 2017, 08:01:18 PM »
Most of your above post is irrelevant to my point. The  bits which are relevant aren't correct.

The 27k BTU/hour I referred to is the steady-state heating requirement, not what's needed to get the van to heat up in the first place. It's calculated from the spreadsheet you can find here:
http://www.buildagreenrv.com/design-and-build-information-for-camper-vans/heat-loss-calculator-for-camper-van-conversions/ but in fact you'd need more heat than that because it's not allowing for all the heat you'll be losing through all the ventilation you need to get rid of the H20 and CO2 you're generating.
2 k BTU/Hr equates to only half a kilowatt; that's not nearly enough to keep an uninsulated van hot. You're a factor of 10 out. You can put your own temperatures and van areas into the spreadsheet and see for yourself.
BTW you're not even using the correct units in your answer, a rate of heat output is BTU/Hr not just BTU.

"most camper vans come with 40k-60k BTU furnaces" - well, no, they don't. A very common one in the UK is about 2 kW, or about 7k BTU/Hr. You say "those furnaces are not nearly as efficient as my kerosene heaters are" . BTU is an amount of heat; BTU/Hr is an amount of heat getting used per hour. One furnace may be more efficient than another in many ways, some may use more or less fuel to achieve a certain heat output. I'm comparing heat output here; not the fuel or equipment used to obtain it.

Pretty much everything you say in this field goes against not only science and engineering but against every other forum and book on the subject. Your data above proves that you just don't believe science and you can't do the math. I just wish you would stop polluting this site with your c**p advice. I'll say no more.

Camper_Dan

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Re: Insulation : Stuck at the first hurdle!
« Reply #14 on: December 20, 2017, 03:17:57 AM »
I spent some time debunking that ridiculous site you referenced in a reply, but I didn't really want to bash somebody else's site, regardless of how inaccurate  it was.  I then wrote another reply, backing up what I'm trying to teach you, with lots of references to more accurate information.

About that time, my boss showed up to ask me to work another shift.  I inadvertently turned off my computer, and lost both replies.  On the way in, we chatted about our conversation. (He lives in a small Class C RV on the site).   He proceeded to tell me that with age and experience comes wisdom, and that you can't teach fools with a closed mind anything.  He suggested that you should do your own work or fail, and doing the work for you was not my responsibility, and you obviously didn't appreciate it anyway.

My boss is right, so go find your own answers, and when you fail, look in the mirror.  If and when you want to learn, then look me up, or someone else who actually knows what they're talking about, has actual experience, and isn't trying to make money from their advice.