Fleece as soft-side insulation?

[MarkBC]

ski3pin's post today on his home-made arctic-pack thread got me thinking about this subject again.
I think I'm going to try yet another approach to insulating the pop-up soft-sides of my FWC Hawk -- my third approach in as many winters.

Two years ago I bought closed-cell foam (polyethylene) and cut it to length/width to fit the sides. I used adhesive strips of Velcro to attach it to the stock strip of loops at the top of the wall. This worked OK, but there were a couple of problems/drawbacks to this approach:

• The foam makes a big, bulky roll(s) when removed from the wall.
• Because the foam is relatively rigid, if the wind blows and causes the soft-side to flex then the foam buckles and pulls away from the bottom of the wall -- it doesn't seal well -- and cold air spills down/out from behind the foam. I guess I could establish another set of Velcro strips along the bottom of the foam, and I'd have to attach Velcro to the top of the hard-side to mate....
• Adhesive Velcro doesn't stick well to polyethylene (almost nothing does), and the strips were peeling off the foam on my first trip. I guess I could sew/staple the Velcro to the foam...

Last winter I got Reflectix and it worked OK -- I still used it on my trip last month, but -- for me, anyway -- it still has issue 2) from above, and it has issue 1), but the rolls are smaller than the foam so not as bad.

I considered using fleece before I tried Reflectix, but I figured I'd have to use really thick/heavy fleece to equal the insulation/R-value of the closed-cell foam or the Reflectix. But now that I understand that the commercial Arctic-Pack works by trapping a simple, unbaffled layer of air against the soft-side and seems to have little/no insulation of its own I see that even standard/light-weight fleece should work.
And since fleece has intrinsic insulating value -- as well as the ability to trap air between it and the soft-side -- it might be better than the Arctic Pack approach.
Upsides vs my two previous approaches:

• Soft/flexible so it can be folded/stuffed into any shape for storage
• Soft/flexible so it can flex when/if the soft-side does and maintain a better seal against the top of the hard-side...though, a set of Velcro across the bottom would still be a good thing.

Potential downside vs Arctic Pack and/or my two previous approaches:

• It's porous, so it could absorb stuff (water, grease, dirt). But it's machine-washable, and water dries fast from fleece.
• I'll have to sew or staple Velcro strips to the fleece since adhesive surely won't work.

Has anyone tried fleece as soft-side insulation?

 

[pods8]

Off hand it might be too soft/droopy to maintain the airgap verse sluffing against the side. Also fleece will adsorb more water which might make it harder to air out.

That said it'd be interesting to hear the results.

 

[MarkBC]

Off hand it might be too soft/droopy to maintain the airgap verse sluffing against the side. Also fleece will adsorb more water which might make it harder to air out.

I bet that the Artic Pack doesn't keep a constant-thickness layer of air either. If it was rigid enough to do that it wouldn't be flexible enough to be kept in place when the top is lowered...and the advantage of fleece is that it actually has an intrinsic R-value itself (aside from the layer of trapped air).

I will have to air it out after a trip...but one of the features of fleece is that it doesn't retain much water -- that's why it's such a popular insulator in outdoor-wear. When I machine-wash fleece clothing it air-dries fast.

Assuming I actually go through with this

...I'll definitely report the results here -- good and/or bad.

I'm sure I'll go on a week+ trip between Xmas and New Years in central/eastern Nevada, as I usually do, so I want to do this before then. Since the simplest version of this approach -- buy fleece and cut to length/width then staple Velcro to it -- is very simple I'll probably pull it off.

 

[Mark W. Ingalls]

I suggest a cost comparison...

 

[pods8]

I bet that the Artic Pack doesn't keep a constant-thickness layer of air either.


Not constant by any means but if you look at the pictures in ski3pin's thread the fabric looks to be somewhat rigid/self supporting when hanging off the edge of a table or such where as fleece would tend to fold over the corner far more easily. I'm just partially concerned that fleece may stag into the outer wall easier, not sure if that would be negated by a taunt installation or not (or if it would stretch). I'm just throwing out a concern that crossed my mind for your consideration.

 

[Lighthawk]

Funny, it must be the time of year for insulation mods
I just cut out reflectix inserts for my FWC windows and door in prep for Thanksgiving trip to the East Side (12F last year!) and probably DV at Christmas.

Mark, I think the issue #2 with the reflectix/arctic pack not adhering at the bottom can be remedied with more velcro. Our tabs are spaced about 32" o.c. Fleece does trap air, which I think is it's insulation value, as does closed cell foam or reflectix. In addition reflectix (steal from Amazon): Reflects Up To 97% Of The Radiant Heat With An R-Value Of Up To 14.3 Depending On Application I wouldn't give it R14, but the radiant effect is immediately noticeable when you put it up.

We went the reflectix route you may recall (Cost $45 ). I like something that can't absorb water/dirt and never needs to be washed (ok, well maybe wipe with a paper towel ) The rolls were 24" wide, which is conveniently exactly the height of the sideliner. Although the top velcro attached easily I had no extra width to attach velcro on the bottom edge. I made flaps by folding duct tape onto itself and the reflectix. Result: a 2" long tab with velcro to connect the lower edge. We find deploying or stowing the two rolls (one roll per side) of reflectix to be an easy one person job as you unfurl or re-roll. I would be concerned about the floppy-ness of fleece and difficulty in folding it into a smallish bundle. Both our rolls fit behind the couch standing upright, so storage is pretty good. Our reflectix is only a year old and there's minor wear & tear. I do see a little bit of air leakage at the bottom, but it doesn't bother us. If I want better sealing, I can always add more velcro tabs.

I do like the idea of stapling through the velcro to secure it. I don't trust the self-adhesive tabs much, but they do adhere to the reflectix. I guess the main downside compared to Ski3pin's arrangement is that we have to remove the reflectix to drop the top (and put it up when we pop the top). To each their own solution! That's what makes this board great.

 

[MarkBC]

Not constant by any means but if you look at the pictures in ski3pin's thread the fabric looks to be somewhat rigid/self supporting when hanging off the edge of a table or such where as fleece would tend to fold over the corner far more easily. I'm just partially concerned that fleece may stag into the outer wall easier, not sure if that would be negated by a taunt installation or not (or if it would stretch). I'm just throwing out a concern that crossed my mind for your consideration.

I understand and you could be right.
BUT: I think the possibility that the fleece might touch the wall more than arctic pack is ok, because the fleece has an intrinsic insulating value and the arctic pack fabric does not, and that's a big plus for fleece.
An unbaffled layer of air -- which is what the arctic pack provides -- is better insulation than nothing at all -- as proven by the reports that the arctic pack approach is warmer than the bare wall. But unbaffled air is not a good insulator compared to other possible insulators. For example, a traditional "air mattress" -- the kind that kids float around on and people used to sleep on -- are not good insulation against the ground because unbaffled air develops convection currents that transports heat, and not transporting heat is what an insulator is supposed to do. Another example: Thinsulate can provide the same insulation as thicker forms of synthetic because the fibers are thinner with smaller spaces between them, so it's harder for air to move through it and carry heat from one side to the other. So, having no fibers to restrict the movement of heat-convecting air -- e.g., arctic pack -- is not ideal.

I don't doubt that the arctic pack approach makes the camper significantly warmer...but I think that most of the effect is because the soft-side is no insulation at all, so even a simple layer of air as insulation is a big improvement. I just think I can improve on the "simple layer of air" approach. We'll see.

As for the cost, I don't think the difference -- if any -- will matter. The cost will be trivial compared to what I spend for truck-fuel for even one interstate camping trip, and the value will be received for years -- not just one trip. All that matters in this case is what provides the best net function.

Lighthawk: You're right -- a strip of Velcro across the bottom could address Issue 2). And as I said, I'm still using the Reflectix, so I'm not anti-Reflectix at all.

And if my usual procrastination applies, I still may be using Reflectix this winter, too.

 

[pods8]

Give it a go and report back, should be interesting to hear the results. By no means was I trying to discourage, just voicing thoughts to make sure they were considered. You have and don't take issue with them so get sewing!

 

[busboy66]

Sounds like a good test. I think the arctic pak may be more air impermeable than fleece, but as mentioned, the fleece may have better R value. The better R, plus airspace may even be better than arctic pak.

 

[Lighthawk]

Hmmm . . . procrastinate or get sewing!
It's your call, Mark.

 

[MarkBC]

Hmmm . . . procrastinate or get sewing!
It's your call, Mark.

Or I may opt for stapling, instead of sewing...

 

[Casa Escarlata Robles Too]

Great show and tell,Ski.I don't feel we need a "cold pack" so much as a dead air space to keep the condensation off the liner.Manily in the bed area.I find that since we sleep crosswise our heads are to one side and there seems to be condensation from the front corner to the area between the windows.On our Denali/Yukon trip this year when I started noticing the problem, I have thought that a fabric like the fleece would create a dead air space,keeping the moist air from coming into contact with the liner.I am anxious to hear how Marc's cold pack works out.

What luck have owners had with the purchased cold pack?

Frank

 

[Alley-Kat]

What luck have owners had with the purchased cold pack?

Frank



I put my impressions in the original "Building an Artic - Cold Weather Pack" thread, message #5. I did a feeble attempt at duplicating the writing style of ski3pin's trip reports. He has his report summary in message #17, same thread.

 

[Gerdo]

A nice thing about fleece is that it'll dry fast.

Have you thought about a windstop fleece?

Or neoprene?

The nice thing about fleece and neoprene is that it can be cut and doesn't unravel.

 

[MarkBC]

Have you thought about a windstop fleece?
Or neoprene?

Neoprene -- I assume you mean neoprene foam, for its insulating ability -- does sound like a good idea, but two years ago I already tried the closed-cell foam approach, and I've moved on. Now, the thing about neoprene foam -- unlike the polyethylene foam that I tried 2 years ago -- is that it's relatively soft/flexible so it has better "drape" (at least, in thin grades) and maybe would have less tendency to buckle and leak air. But the reason that I didn't use Neoprene foam in my closed-cell-foam experiment is that it's a lot more expensive than the PE foam I used.

Speaking of co$t: I've checked fleece costs online, and it looks like I can get 60-inch wide material for 5 - 7 $/yard, and I think I'll need 4 yards at most, so it'll cost me around $25 for the fleece.
So, I think I can afford this experiment no matter what the outcome. And if it doesn't meet my needs I'll just cut it into cozy shawls for gifts.

It's a win-win situation!

 

[busboy66]

What luck have owners had with the purchased cold pack?


My Eagle has the arctic pak. I haven't found much of a difference in the cold with mine - mainly because I have no heater
It does make a bit of difference with the sun shining on the canvas. Keeps a bit of the heat out.

 

[MarkBC]

My original idea for insulating the soft-sides -- one from several years ago that I've never tried, but I still think makes good sense from a physics standpoint (if nothing else) -- is to attach panels of closed-cell foam to the outside of the softsides.

Yes, I'm serious!

I think what put this idea in my head 3+ years ago was when I noticed the overhanging lip around the edge of the roof of my Hawk -- a lip under/into which a 1/2" foam sheet would fit perfectly. At the time it seemed like the obvious approach, combined with these physics advantages:

• Putting the insulation on the outside of the vinyl means that the soft-side walls will not get cold, so there will be little/no condensation inside of the walls (within reason, I mean...not counting having a pot of water boiling inside, etc.). With any kind of inside insulation the softsides will be in contact with the cold outside, so they'll be cold, so there will be an opportunity for water to condense...unless your inside insulation is also non-porous/impermeable (like a sheet of plastic) and is well-sealed around all its edges.
• Another physics advantage over inside-camper insulation: With outside insulation, the air trapped between the foam and the softside is warm, so it won't have a tendency to "fall" down/out from under the foam since the surrounding air is colder, and the top of the foam is nested into that lip so the warm air can't rise out.

HOWEVER...I started considering the difficulties with this approach:

• Just how do I attach the sheets of foam?
• How do I keep strong winds from blowing under the foam sheets and lifting/tearing them off or at least blowing against and cooling the softside?

A couple of other, more-minor downsides to this approach:

• Because they're on the outside it'll frequently happen that I'll be putting up the insulation in night-time darkness, rather than in the well-lit interior.
• The foam is closed-cell, so it won't soak up water, but when it snows/rains it'll still carry a lot of surface moisture that I'd have to deal with when stowing it for travel.
• It's bulky to store -- the same problem/drawback #1 from my first post.

I just thought I'd publish this idea here...don't know if it's already been patented...
J/K

 

[Gerdo]

Where does the price of windstoper fleece come out?
I think there could be a major benefit to it.

 

[chnlisle]

I could be wrong on this one but I think the whole idea behind the Arctic Pack is to create a dead air space between the inside of the camper and the vinyl liner. I'm not really sure why one would use fleece etc. but I am ready to learn.

 

[MarkBC]

I could be wrong on this one but I think the whole idea behind the Arctic Pack is to create a dead air space between the inside of the camper and the vinyl liner.


Yep, Jay, that's my understanding, too, as I mentioned in Post #1 of this thread (e.g., "commercial Artic-Pack works by trapping a simple, unbaffled layer of air against the soft-side"). And a dead air space is better insulation than nothing. But almost any other type of insulation is better than dead air.

Here's my long-winded explanation -- stop reading when it becomes tedious.

That layer of dead air reduces heat-flow out of the camper, compared to the vinyl alone, because air has lower heat conductivity than vinyl and because it's a thicker layer than vinyl. But besides conductivity/conduction there also convection -- air movement, and when air heats or cools it's density changes and it moves around...and when it moves around it transfers heat -- and transferring heat is NOT what insulation should do. In other words, "dead air" is not dead enough.
For example, fiberglass insulation is put in the walls of houses rather than leaving that space empty, because walls filled with air-and-fibers is better than walls filled with air. The space is still mostly empty air, -- desirable because air has low heat-conductivity -- but the network of fine fibers puts drag on the air and reduces its convection -- movement.
This principle of reducing conduction and convection (and radiation) is behind all insulation. A classic vacuum "Thermos" bottle uses all three: A vacuum is nothing, so it doesn't conduct, and because there's nothing that can move it doesn't permit convection, and the walls of the container are reflective so heat transfer by radiation is reduced.

Why fleece? Because the fine fibers in the fleece fabric create a layer of isolated, non-convecting, air.
The bubbles in Reflectix are another example of isolated, non-convecting air.

--------------------------
Where does the price of windstoper fleece come out?
I think there could be a major benefit to it.

Gerdo, I haven't checked it yet. But I'm not sure I need it... Since there's no wind inside the camper, why would I need insulation with a wind barrier inside the camper?