4 season camper project

[Gentleman]

Question about insulation

I am building a camper housing unit (early planning stage). I am bit of a newbie.

What kind of a insulation do I need? Or what kind of insulation have you used in similar conditions?

My first guess would be 50mm (2 inch) thick:

http://www.isover.fi/tuotteet/rakenn...3/isover-kl-37 finnish page - info pdf link in english.

heat conductivity: 0,037 W/mK

My planned housing unit would have perhaps 20 M3 of heated space (rough guess). Sleeping space is on top so that helps. There will be some heat leakage from tiny gaps as there will be non-fixed joints.

Temperature conditions:
Cold is my enemy. I would say -10 to -15 C would be common in winter times. -22 would be rare. -30 C would be once in seven years and -35 would be ones in twentyfive years.

Survival is not the issue. I will have sleeping bag and clothing to keep me going with just a tent. I would like to have reasonably comfortable temperature in my housing unit say 11 to 14 C (? what would be realistic with reasonable heating in -15 C?).

Windows and such will be the biggest cold spots. I plan to build option to replace such things with equipment designed for winter conditions (insulation top priority)

Weight is an issue so I aim for moderate price and light weight.

How would you grade my first proposal to isolation? (acceptable; good; bad - consider XX instead)
What have you used when you have build?
Any pointers?
Am I overkilling with insulation?
Are my expectations unrealistic?
What solutions people use for windows in cold conditions? (should I look for something specific?)

With kind regards and hoping to hear from you,
Janne

PS I am in so early stages that I am reluctant to post my drafts yet since there are so many things that I will redraw as I ponder the basic questions. Perhaps once I am reasonably confident in my design.

I would specially like to hear experiences on no water toilet like http://www.natureshead.net/
and
http://motorhome.webasto.co.uk/cooki...oker-x100.html (with intention to make do without gas in my camper. this would require aggregate or fuel-cell to generate electricity for fridge etc. - any experience on such ? )

PPS thank you Iain for your thread about your project!

[Bike_Mech]

Janne,

I also am in the middle of planing a camper that I will be using frequently in cold weather. Here is a thread I started a few months back, and got some good feedback from our fellow Expo'ers.

-Chris

[Gentleman]

Thank you for the link. good info ther!

my project:
1) Frame of the box. welding it myself is not an option. (My sister has a farm but firework is not allowed within facility -- no facility as we speak). Only option I can see is to order one made to my specifications. This would mean better quality and more expenses.

2) Insulation. I found out few leads on compound insulation so I guess that will be the road to go. atleast now I have contact & rough price/performance info.

Power source: wondering should I have Gas installed or go for Disel cooking plat & heating and fuel cell / agrigate to power electricity.

gas -- extra space & weight
-- one more component

Disel -- some electricity needed that could be gotten away with gas.
-- smell?
-- harder to tune in for heating ??
-- slower

Which way to go? my options as I see them:

My current car is Dacia logan MVC.
1) go with current one. take tent aboard on travels and use it / sleep within the car on platform made for it.
++ little extra cost / effort, other paths still open
2) go with dacia and upgrade with roof tent & shover option.
-- this combination will loose some of the parking stealth. better storage volume for car (++), shover (++)
3) go for 3,5t truck & custom made (self made?) box for it
4) go for max 7,5 ton truck. as 3) + I need to upgrade my divers license.

As the resolving & designing 3) and 4) will take time I will go with 1) and do lowcost upgrades where I find them possible.

Big question mark:

regarding the frame of the box.
Assuming max weight of 1.5 ton for box.
Assuming that there is three Iron/steal beams across the bead of the truck to carry the total 1.5 ton load.
how strudy must the beams be?

if total weight is 1,5 ton that is 500kg load / beam = 250kg load per one end of a beam (stable)

Now the bead is two I beams so max leverage for the 250kg load is 0.7m

Considering the momentum of the box lets assume max load of 350kg per end of a beam. (no extream feats expected from chasis.

How to resolve what is sufficient material thickness / configuration for this type of expected force? or what would you reccomend for material in lowes level of the frame?

[Iain_U1250]

I listed all the weights on my camper project thread a while ago, and it is heavy - but then it needs to be if you intend on carrying more than 1.5ton of fuel water and stuff. In regards the camper frame - the most important thing is the mounting, the static weight is not the problem, it is the loads put onto the camper frame from the chassis flex.

The cross members on my OEM mog frame are substantial, but probably overkill since the bed frame comes off a U1750 with a 6 ton capacity

[charlieaarons]

I believe your conductivity is off by a factor of 10. My Mog is
0.44 w/sq m-deg K with 55mm foam.

Charlie

[Gentleman]

I believe your conductivity is off by a factor of 10. My Mog is
0.44 w/sq m-deg K with 55mm foam.

Charlie

Hello charlie!

As said .. limited experience on the subject..
I imagine the value "heat conductivity: 0,037 W/mK" is the base value (1000mm = 1m)
To my limited understanding:
0,037 W/mK / 0,055m (thickness) >> 0.67 w/sq m-deg K

which means that foam would be a lot better with 0.44 w/sq m-deg K for same 55mm


Using layered foam sheets as insulation / building elements seems to be the way to go.
1. Layered product is easier to use in building than using separate wall,insulation,innerwall.
2. layered foam has structural strength so building is bit easier
3. foam dose not soak up water.

There are many different layered products.. figuring out what exactly to use can be figured out at later date.

Janne

[Gentleman]

I listed all the weights on my camper project thread a while ago, and it is heavy - but then it needs to be if you intend on carrying more than 1.5ton of fuel water and stuff. In regards the camper frame - the most important thing is the mounting, the static weight is not the problem, it is the loads put onto the camper frame from the chassis flex.

The cross members on my OEM mog frame are substantial, but probably overkill since the bed frame comes off a U1750 with a 6 ton capacity

Hello Iain!

I guess you are referring to "Unimog Hippo" post. Yes, wonderful post, thank you for the detailed info. It quite well underlines the fact that _things add up_ as you pointed out.

Thank you for pointing out the flexing and mounting!! that is definitely something that has to be figured out. I guess some form of 3 point mounting. ( [only?] alternative would be just about fixed mounting and that would restrict vehicle to roads)

Janne

http://www.epicycles.com/Truck%20Blo...2010-01-01.htm is very informative project also. (also this project has a lot less steal in the wall & ceiling than others I have seen in the web)

[Iain_U1250]

Hi Janne, I think if you fixed mounted it, even a few speed bumps would put lots of stress on the camper box, I'm surprised how flexible the chassis is on my Mog, even jacking it up in the workshop makes it twist a bit. Mine has a 4 point mounting system - I can put up photos if you want.

[charlieaarons]

Hello charlie!

As said .. limited experience on the subject..
I imagine the value "heat conductivity: 0,037 W/mK" is the base value (1000mm = 1m)
To my limited understanding:
0,037 W/mK / 0,055m (thickness) >> 0.67 w/sq m-deg K

which means that foam would be a lot better with 0.44 w/sq m-deg K for same 55mm


Using layered foam sheets as insulation / building elements seems to be the way to go.
1. Layered product is easier to use in building than using separate wall,insulation,innerwall.
2. layered foam has structural strength so building is bit easier
3. foam dose not soak up water.

There are many different layered products.. figuring out what exactly to use can be figured out at later date.

Janne

The dimensional part of the formula is square meter area. Thickness is already taken into account in meausring the heat transfer coefficient.
0.037 W/msq-deg K is an impossibly low coefficient of heat transfer, unless the walls are 6-700mm thick!!!!
0.67 is more realistic, should correspond to 35-40mm foam. 55mm should be about 0.44 (mine is).

Charlie

[Gentleman]

Hi Janne, I think if you fixed mounted it, even a few speed bumps would put lots of stress on the camper box, I'm surprised how flexible the chassis is on my Mog, even jacking it up in the workshop makes it twist a bit. Mine has a 4 point mounting system - I can put up photos if you want.

Photos would be great if you would take the effort Iain! No rush, I (hopefully) will be traveling a bit in europe during next 2 months.

With kind regards,
Janne