118 replies to this topic

[alano]

We also used Insul-Bright to make our thermal liner as my wife is also a quilter and has made whimsical oven mitts as gifts so she was familiar with the product. I kept meaning to post about it, but never really got around to it. Can't compare it to other solutions of course, but it seems to work for us. We noticed a difference in insulation and condensation control. Generally we are about ten degrees warmer than outside without using the heater based on my occasional sampling. At colder temps we run the heater so I don't really know if that ten degrees is constant over a wide temp range. When it gets down to mid-thirties or below, we still had condensation issues. I believe condensation control is more an art than a science as every night is different so it is impossible to do any controlled studies.

 

Alan

[exmx_racer]

Has anyone thought about using ready-made thermal curtain panels available at Lowe's cut to fit & velcro added as necessary. Not sure about insulating properties but this is from Lowe's description:

Room darkening and noise reducing
Reduces energy costs by preventing up to 25% of heat loss
Blocks up to 99% of outside light
Blocks outside noise

I think this might be less expensive especially if you have a 29" pop-up like our Fleet. Evolution fabric not wide enough to get 2 lengths out of the 55" width.

[ckent323]

Thinking about cold, insulation and condensation in the camper.

 

Seems to me that the best way to minimize condensation inside is to have a wrap on the outside so that the camper inside wall is the warm side of the insulating wall rather than the cold side.

 

I can imagine a continuous length of insulation wrapping around the camper with perhaps plastic windows in the right places. Heck I can even imagine a custom fit insulating blanket for the top as well.

 

I could further imagine panels for each side that attach to each other and the camper with velcro and perhaps bungies to make installation and removal easier.  Having it on the outside would allow greater insulation thickness if desired.

 

I am having trouble thinking about how the side insulation could be left in place and still allow the camper top to be lowered and latched.  It seems that this probably is more of a hassle than most want to deal with but perhaps it would be better performing for those who really need it (condensation issues and colder places.

 

I am not sure I want that hassle but maybe there is another way to go about insulation and minimizing condensation.

[MarkBC]

Seems to me that the best way to minimize condensation inside is to have a wrap on the outside so that the camper inside wall is the warm side of the insulating wall rather than the cold side.

 

.....

 

I think external insulation is a good approach, and RicoV actually did this very thing -- he posted about it here a couple of years ago. Here's one of his photos from that post:

 

 

I had a similar idea with the same rationale -- outside insulation to make the vinyl warm so that condensation doesn't form.  My concept was based on using 1/2" thick closed cell foam on the outside...but it remained in the concept stage -- I never did it...kinda like my "fleece as soft-side insulation" concept. 

[Casa Escarlata Robles Too]

IMO these campers were designed to be simple,and things that change that approach seem to be not worth it.

Frank

[ckent323]

MarkBC,

 

Thanks for the link.  I left RicoV some questions.  I just looked up refectix and it only has an R value of around 1.7 (horizontal) or less depending on orientation.  My degree is in Physics and I work with reflective mylar blanketing material all the time in my job (Space Based Earth Resources and Weather Instruments).

 

While I am not a Thermodynamacist I believe that in general there are three forms of heat transfer, radiative, convective and conductive. Heat transfer is most efficient by convection, then by conduction; radiation is the least efficient and slowest means of heat transfer.

 

A vacuum inhibits both convection and conduction and so is a good insulator.  In vacuum, radiation is the dominant heat transfer mechanism and that is why we use reflective blankets made of metallized mylar on spacecraft (sometimes many layers thick since the radiation path is layer to layer and the vacuum between layers helps the insulation efficiency).

 

Metal is a great heat conductor and in an Earth ambient (non-vacuum) environment both conduction and convection far and away dominate over radiation. Therefore, the low R value for Reflectix does not surprise me and I think it is not a very good insulation material.  Further the Refectix metallized metal surface may actually be helping the heat transfer via conduction into and through the material.

 

What is needed is a good convection and conduction insulator.  Again, in an Earth Ambient environment that means dead air space, trapped volumes of air to minimize convection, between low conductive materials.  This is why closed cell foam has such a good R rating as compared to fiberglass batts and why thicker is better (as we all know).

 

So I think your path to a different material is appropriate.  Bubble wrap is a natural thought but there are conductive paths at the edges of all the bubble cells where it has been heat sealed to trap air.  To be sure it is better than nothing just not very efficient.

 

I think some kind of open cell very flexible foam or even a very flexible but thin layer, say 1/2" to 3/4" of closed cell foam that is flexible (if such a thing exists) that is enclosed between two layers of some durable material say polyurethane would be far superior to fleece.  Oh wait, I just described a thermarest type mattress (they use open cell foam).  Open cell is better considering transport because, unlike closed cell foam, the air can be squeezed out of it.

 

So I think a superior approach here is something equivalent to a large thermarest mattress that can be wrapped around and attached to the camper sides (even the top) using velcro and/or bungies. When it is removed it can be compressed, as it is rolled up, to squeeze out the air to make it less bulky for carrying and storage just like a backpacking mattress.

 

My guess is that an R-value for such an insulating wrap might be 3 or greater.  That is about 2 times what reflectix can provide (BTW: as the Reflectix web site says, just doubling up Reflectix doesn't help much.

 

 

I have no idea how difficult or costly it would be to make such a thing but i'll bet there is a good reason that a thermarest type mattress costs $60 - $200 depending on size and thickness.  Scaling to a camper I'm guessing that would be the equivalent of 6 to 8 mattresses so a price of $800 or more would not surprise me.  Maybe a bit cheaper if there were say only four panels.

 

For those of us who camp in places that get very warm or very cold $800 or so may not be too much to pay for more comfort.

 

I will try to engage one of my thermodynamic colleagues on this question and see what he/she thinks about it.

 

Regards,

Craig

[thepartyhound]

I figured that I would add my two cents to this thread.   I'm a budget minded individual...some may even call me cheap!  I have a 1994 Viking brand pop-up slide in camper in the back of my 2013 tacoma...and I got it cheap!  And I love it! It is in nearly new condition and I got it for $1100.   I modified it to how I wanted it and the one last thing that I wanted to change was how quickly it would cool down after the [loud] heater shut off.  I guess that I hadn't even looked on here to see what everyone else was doing to insulate their canvas sides for cold weather camping.  I went my own route.

My girlfriend had recently got a sewing machine and has been making quilts.  Because of this I found myself in quilting/craft shops with her while she looked around.  In one of these shope I came across a thermal batting that has a foil thermal barrier infused into what I think is a polyester material.  It is the stuff that is used for the insulating material in hot pads and oven mitts. Here is the link to what material I'm talking about.

We bought some old, clean, king sized bed sheets from a thrift store for 50 cents each, cut the sheets and insulating material to fit the canvas portion of the pop-up camper, and sewed a layer of the sheet on each side of the insulating material.  We added a few windows, sewed velcro to the top and bottom, used sticky back adhesive velcro on hard surfaces at the top and bottom of the canvas portion of the pop-up, then put everything in place.  I have to admit, I have not yet fully field tested this thermal liner.  That will be done in 3 days time out elk hunting.  However, there is a definate cold layer of air in the space between the canvas and the thermal liner.  I can raise and lower the top with this liner in place.  It looks nice and adds a warm feel to the inside of the camper.  And it was pretty inexpensive...maybe even cheap!  Besides time, it cost about $65 shipped for the insulating material and about $45 for the 70' of velcro I needed to have a continious strip of velcro on both the top and bottom of the insulating barrier and to seal the windows that we build into it.  The bed sheets and thread were all bought from a thrift store and the total cost there was under $5.  So, all together it was about $115.  When I see on the FWC site the cost of their thermal liner for their smilar-to-my-camper-size Eagle model camper is $475, I think I did pretty dang good!  I'll give a more thorough report in the future as I have quite a bit of winter camping planned over the next couple of months, but I suspect excellent performance!

 

Update!

 

During the month of November my girlfriend and I camped out in this camper for 3 weeks with this insulating liner in place.  We were at or above 7000 feet nearly all of that time and saw an average high of about 30*F, an average low of 0*F,  and 3 days of -10*F temps.  I did this exact same trip last year without the insulating liner.  The difference was profound!  The heater had to run much less often to keep the inside temps comfortable. 

There were still some condensation issues, however it was much less of an issue with the liner there to absorb the moisture instead of my pillow or blankets.  In all honesty, I barely even noticed the condensation this year as opposed to last year without the liner in place and there should have been plenty of moisture in the air inside the camper with 2 of us staying in there, cooking, coming out of the hot springs with our damp robes and towels and then placed in front of the heater to dry.  It was easy enough to just pull the thermal liner out when we got home and run it through the laundry.

What I really like about this solution is that it stays in place.  It is not something that I have to install each and every time I raise the top for the night and then take down and fold/roll up in the morning before lowering the top and driving away.  Perhaps there are better solutions out there.  However, in my opinion this solves the problem of the heater running too often, condensation forming on the inside of the walls and leaking down onto my bed, and keeping the tempratures inside the camper comfortable and stable.

 

One thing I will add to this post in regards to condensation is that there were a few nights, about 5 in all, that I would run an electric heater.  I don't know for sure, but it seems to me that electric heaters that have the red-hot heating elements may serve to dry out the air.  I knew ahead of time that there would be a few nights in which I would camp out next to power just to top off my batteries and keep them in good shape, so I brought a thermostat controlled electric heater with me to run on those nights.  I figured that since I'm already paying for the use of the power I may as well not be paying for the propane on those nights as well.  The electric heater may very well have served to dry out the inside walls of the camper on the nights we used it...an unintended although desireable effect.

[craig333]

Yes, electric heat is very dry. Thanks Ckent323. Now I have another excuse for not having a polar pack. Its not my lack of sewing skills, money or general laziness, I'm just waiting for the latest research and development before I commit!

[deethe]

wouldn't the solution to condensation best be handled by making the popup canvas from a breathable fabric like reinforced wader fabric? ... maybe a simple covering over the window screens for the two cabover bedroom windows ?

Edited by deethe, 10 January 2015 - 04:06 PM.