Ideas for adding low bulk, low weight insulation to tent

[Anonymous]

Hi Colin,

Thanks for all the info and feedback, and based on direct experience nonetheless! That’s interesting about down vs aerogel.  I had assumed that next to vacuum insulation, that aerogel was the most efficient insulation per weight.  To be honest, I didn’t do any exact calculations based on knowing that the material is almost 99% air.

My main concern with using down is not knowing what the moisture management situation would be like.  I’m “thinking” of using loose microfiber polypropylene fibers to give the two air gaps plus space blanket a little boost.  The fiber is usually sold for concrete reinforcement.  I know it will loose it’s spring fairly quick with stuffing, but it doesn’t really have to loft per se since the foam skeleton is providing the “loft”. The foam is an open cell, low density foam that is sold for air conditioning gaps (it would have been a bit cheaper, and definitely more convenient to buy a large sheet of foam of a specific thickness).

Would 2.5 Apex be an acceptable replacement do you think?  The current method requires a lot of time. If using Apex, would the space blanket still reflect IR?

I’ve commenced making it.  Here’s a couple pics:

 

 

[Anonymous]

I should have mentioned that I’ve decided to not velcro this to a cuben tent anymore. It will be a tent of and on it’s own.

[Anonymous]

The dimensions… If it looks a little short for a panel, it’s because it is.  I’m trying to keep it as small as possible, with as little sewing as possible. I did some calculations and figured that with my shorter than average height, I can sleep diagonal in a pyramid type tent and have enough length–about 78 inches (almost a foot more than my height).

The less space, the less weight and greater the thermal efficiency in general and especially when using a candle.

I have some experiments to do with soy wax/coconut oil blends and using carbon felt as a large surface area wick.

[Colin Krusor]

I’m interested in your project, Edward. I’ll keep an eye out for the thread. UHMWPE is often the articular surface in replaced hip joints, so you can boast that you upgraded to Dyneema hips when you’re back on the trail.

Justin, your project is a good opportunity for a lot of interesting thought experiments. A gap between film layers in many IR blankets is achieved with just scrim. It seems to me that the material in the gap should ideally be thin, and it should have small openings. The foam chamber idea seems to be the opposite of that.

[Colin Krusor]

Candidly, I think an insulated tent seems like a big puffy insulated camp chair. Its a wonderful luxury, but it’s a bunch of insulation that you can’t easily use if temps dip unexpectedly. What I mean is that an insulated tent uses insulation inefficiently, and you can’t easily pull it down on you, or wear it around, if you get cold. An oversized quilt that you string up would (If designed for it) work as well as a dedicated insulated tent wall, it can be used as a very warm and versatile quilt, it can be dried easily, it can be draped over a row of shoulders watching a sunset, etc. If you want an IR barrier, just add some Velcro tabs in your shelter so you can stick a Heatsheet up on the walls. Then, as for the quilt, you can use it in the insulated tent configuration or for other things (like wrapped around you).

[Anonymous]

Hi Colin,

I wasn’t finished making the baffles and was going to combine it with loose PP microfiber to help boost insulation.

In any case,  as also mentioned, because of the tediousness of doing the foam and other issues, I’m thinking of just going with Apex.

Not sure if you saw my earlier question or not, but do you think that most IR will be reflected if Apex is on the back and/or front of space blanket?  I’m thinking of shaving a sort of largish grid pattern in the Apex to help with same, or is that unnecessary?  You seem to know more about IR and it’s properties than most here.

 

 

[Colin Krusor]

Also, I like using a Heatsheet that way because the shiny side can face in on the West wall to make the tent into a little solar sauna on cold winter mornings. When the tent warms up, the Heatsheet gets moved to the East wall, about the time that West light becomes bright enough to make breakfast. A dedicated insulated tent with IR barrier walls is always dark.

[Anonymous]

If we’re talking about conserving body heat alone, I would likely agree with you.

But if we’re talking combining body heat, plus the heat of a couple candles–a small, insulated tent for more extreme cold starts to make more sense.

It’s a matter of figuring out what works best and is most efficient.  I’m still in that process which is why I started this thread to begin with, for various ideas, feedback, etc.  As I think about it more, I’m figuring it out a little better here and there.

 

[Colin Krusor]

The person who could answer all of your questions and explain any mistakes in my comments is Richard Nisley.

[Anonymous]

“A dedicated insulated tent with IR barrier walls is always dark.”

There will be a removeable insulation panel for the front door that will not have IR reflecting material in it, and will be highly breathable.  Also one near the peak. Should allow sufficient light to see.

Candles will be used as heat and light source when not sleeping.  Much of the concept of this tent revolves around more extreme cold and use of modified candles + body heat. Just need some light and not much extra warmth, use a regular beeswax candle.  Need some more serious warmth, use a tin filled with soy wax/coconut oil blend and a large surface area carbon fiber wick.

Basically, I think I can get this to about a similar weight as a large tipi or pyramid plus stove/pipe set up, without the danger, faff and work of same (or if you’re in an area where wood is scarce). That’s the basic concept.

[Colin Krusor]

I think something I wrote might have been unclear. I believe that insulated tents work. I like using them. But if one has a pile of insulation and a handful of candles, making the insulation into a shelter and using the candles inside will always be the coldest option any reasonable person would consider. It’s a very nice option if you don’t mind bringing extra insulation to account for its inefficient use (and I don’t mind), and it’s a nice option with improved safety and versatility of the extra insulation can be removed from the standing shelter to be used for other things.

[Anonymous]

In any case, I appreciate the feedback Colin. It’s good to hear different ideas, counter arguments, etc.

I may have mentioned much earlier, but this is not just for backpacking, but also for a bug out bag too.  So I’m trying to think of various different variables in both the short and long term senses.

If a pulk was being used, and could be relied completely upon (can’t in a survival/preparedness situation unfortunately), then thinnish foam panels would probably be the most weight and convenience efficient, and the bulk would be less of a factor.  But if end up in a situation of needing to carry it around when there is no snow, won’t work as well.

Those polymer aerogel films you mentioned earlier look interesting, but I imagine they are pretty pricey?

I’ve considered Down, and it would be near ideal in all areas except for one–uncertainty re: moisture.  Down between two breathable fabrics directly on top of you, and Down encased between two highly waterproof fabrics might behave differently in relation to moisture?  It’s enough of an unknown, that I’m not sure I want to go there.

[Colin Krusor]

Yeah, commercial polyimide aerogels are very expensive right now, but in a couple of years they will be in every high-end jacket, sleeping pad, and shoe insole, as well as most electronic devices. Silica aerogels were never well suited to apparel and other textile applications like tents or quilts. The Aspen mats, Cabot pillows, and other attempts to use silica aerogels in flexible blankets will soon disappear. Aspen and Cabot overestimated the development time for polymer aerogels. Polymer aerogels (polyimide currently) will be the new nylon.

[Edward John M]

My personal experience is that RFL doesn’t add much to the insulation, I use it for the lighting benefit.

It reflects the light, bounces it back and forth between surfaces and makes efficient use of my old UCO candle lantern

Mind you I have never experimented with multiple separated layers of RFL, layers of RFL with air gaps between may be the most efficient way to go if the delamination  problem can be addressed

[Edward John M]

@Colin Krusor

My next project is going to be anything but ultra light Colin

I’ll be setting up a fixed camp so I can afford to ski as much of the white season as I can. I’m using a very small cotton wall tent [ 6.5ounce Stormpruf japara cotton, 8’6″ * 7′ * 6’6″ and 30′ walls 11 lbs ] simply lined with woollen and synthetic blankets and a very small twig stove made from a stockpot

Covered with an extra large synthetic fly and framed with 55mm commercial awing tube

[Colin Krusor]

That sounds like comfy living. Base camping without strict weight constraints is great. Insulated tents, in any of a variety of materials and designs, are well suited to that kind of camping, I think. I like the versatility of your blanket idea. Cotton is obviously an unorthodox choice of shelter materials these days, but snowy base camping seems like good conditions for it.

[R]

This might be too late for you, but Quest Outfitters carries x-pac VS 75, which is a 1.4osy 20/30d nylon ripstop w/ a silver foil lining.

http://www.questoutfitters.com/Coated_2.htm#SILNYLON 1.1 OZ RIPSTOP (scroll way down)

[Anonymous]

Thank you Rene.  I’ve started a new job, so things have slowed down on projects because of less time.  Could use it on some of it.   Didn’t realize that Quest Outfitters carried this material.

Awhile back, I had gotten a little from Cascade Craftworks, for a VBL liner, but it got lost during a flight.

It’s an interesting material–not noisy like space blankets, and I believe Richard Nisley tested it to be pretty durable as far as the IR reflecting goes, but not durably waterproof enough for tent/tarp use.  Though the latter wouldn’t matter for my application since this would be an inner liner.  Need to think whether the weight and cost is worth it though.

[Edward John M]

I’m coming back to say that I have had a big win with some NOS Thinsulate. My beloved wife and I scored almost a full roll of type “U” 80GSM Thinsulate courtesy of RipCurl in Torquay for $30-

Because the tent for my fixed winter camp is an old fashioned cabin style I don’t see any point in posting a new thread for the build as it is all straight seams and adhesive tape to make the liner.

Talking to somebody who has already made a fully lined wall tent I will be cutting the liner the same size as the tents internal dimensions and then gravity will give that airspace between liner and tent body. The person with whom I have been conversing was using his tent in winter above the Arctic circle and used a waterproof nylon fabric on the inner side. He stressed the need for good ventilation but indicated the efficiency of the insulated liner by noting that his kerosene use in his Coleman heater dropped to a third of the usual consumption.

Also I have had the hip surgery and I am now 2 weeks into recovery and  walking with just a stick

[Author]

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