PVs and PBs and VBs and HHSSs

[BillyBob58]

So I tried to smash Shug's record and missed by about 46*! Oh well!


I'm hesitant to start this thread because during this Polar Vertex(PV) there are so many personal bests(PBs) being set, and many of them are at much colder temps than my own. Still, I was surprised at how well I did with what I was using. And I'm not sure I am sure of the reasons why.


First, with record lows being forecast I had to decide what to test. And whatever I tested, I was for the 1st time going to add VB clothing to the mix.


I was really tempted to just do it with my PeaPod and added Vbs and insulation. But I knew in my heart I could get er done with that, so no challenge. This was only going to be at most 5F below my previous PB with that, and I did not even use VB clothing. Same with my JRB bridge hammocks and and MW4 UQ, no challenge and I had already been warm within 5F of the forecast without Vbs.


So, it ended up being my HH Super Shelter. For one thing it was already hanging outside since I had just taken it off an older HH to put it on a new HH. And 2: I have never taken and HHSS below about freezing without adding insulation underneath the pad, and for the most part also using the HH kidney/torso pads. Usually both together if anything below 20 was expected. And 3: no matter how much I have added, I have never taken this system below 14 F. So, HHSS it is!

[BillyBob58]

So when I went to bed at about 1045, it was already 11 or 12 F. So already a record for me with the HHSS. Plus I was settling in with somewhat less than I had ever attempted before. When I set my previous PB with this system, I started out inside a 5F Polarguard bag, although I later became confident enough to switch to quilt mode. But this time I was using my Golight TQ, which when I got it was rated at 20 F. But many people debated if this quilt was really that warm, and seems like most people called it more like 25 or even 35F quilt. Indeed, I think the company now calls it a 40 F quilt, and the 20F quilts are several ounces heavier.




But 2 things were new. First time ever to try and sleep with the over cover(OC) on the HHSS. Probably most important, 1st time ever attempting to sleep in vapor barrier(VB) clothing.


Gear: HH Explorer UL zip hammock with HHSS using 1 pad and space blanket and OC. After 45 mins I was still having just a slight coolness at my butt and back of thighs and a little calf pressure, so I decided to add the HH kidney/torso pads(~ 3 oz) and a cut down blue WM pad in the hammock under my legs. This solved all issues.


Clothing:
head: balaclava and JRB down hood
torso: Stephenson's Warmlite(SWL) Fuzzy stuff VB shirt and thin polyester pull over and 1 heavy fleece LL Bean jacket.
Legs: thin Merino wool as liner, TNF Hydrovent WPB hopefully functioning as VB, with 8 oz PG pants over that
Feet: SWL VB socks, wool socks and Polarguard booties.
Hands: VB and fleece gloves, not used.
Back up: foot section of JRB convertible MW3 for under the pad when I got cold. Also original plan for torso sized WN blue pad was to see how it would work under HH OCF pad, but never used either.

[BillyBob58]

As reported in another thread, I was very warm top and bottom and feet. I never tried just the added HH kidney/torso pads with out additional insulation (clothing) under the pad when under 20F. I guess I did not believe it would be enough, but it was tonight. My question is: how much, if any, of this warmth was due to the VB shirt? Considering that a normal part of my HHSS is a space blanket(SB)/VB? Two Vbs are not warmer than one, are they? But maybe the SB being under my hammock is an imperfect VB compared to a tightly closed up VB shirt?


On top, the help from the VB would be more apparent. I was toasty warm at 6-8F with only a 40F(maybe 30F) TQ and fleece jacket. But I'm pretty sure the HH OC also helped with this. I had a fleece frost blocker hanging from my RL, tucked into the neck collar of my TQ. It got quite wet, but was not frozen. I was expecting a lot of frost, and had none or any other condensation that I could tell, except for the wet- but not frosty- fleece frost blocker. Is it possible that the HH OC added 24-26F to the ambient temp, by retaining body heat, to keep that fleece bib from freezing? Seems unlikely, but I have no other explanation.

And did the breathable OC plus it's big vent hole plus the VB clothing really keep the condensation at bay? Apparently so. Again, I am very surprised. Humidity when I got in was 85%. Every thing was dry. I weighed the TQ and it had not gained any moisture and had full loft. In the past I have found a few drops on the SB after really cold nights, but not this time, due to the Vbs. My feet were way too warm, at 6 or 7F!


Anyway, warm and toasty for me at a new all time low of 6-7F, new record by about 5F. And probably warmer than with those higher temps, and with less bulk on top and below.
New PB in any form of augmented HHSS, by about 4 or 5F.
PB in HHSS with no clothing added to UC shattered by about 25F, and warmer than I ever was at 30F!
No hot water bottle, frequently used before when below 20F. No tarp(only OC) and no pillow for insulation. I am really surprised at how warm and dry I was. My only problem was my face, as I could not find my neck gator, and had a cold nose. But I bet it would have been a lot colder without that HH OC!

[Cali]

Go BillyBob, go!!!!!

[BillyBob58]

Go BillyBob, go!!!!!

Thanks, Cali! When I look back to some of my earlier threads years ago, trying to see how far I could push a base stock SS ( as opposed to kwpapke's approach by adding sleeping bags etc below for minus 26), I see that I was just barely warm enough right at freezing. And I remember putting it something like this: for back warmth, I call it not warm and not cold. Just kind of neutral, but OK.

So by adding a mere 3 oz worth of HH kidney/torso pads, plus using the sit pad/emergency go to ground pad I always carry anyway for a leg pad, I have dropped that by a good 25F. But the only thing counting for back and butt are the small, extra HH pads. Thus the additional 25F seems rather incredible to me, for such little added on. But as surprising as it seems to me, it is really much more than just adding 25F,because this wasn't just barely OK/good enough to get by. Rather, I was WARM! IOW, I for sure could have gone lower if nature had cooperated even more. So that is a truly big difference.

But of course, there was one additional factor, though not necessarily added weight because it can replace other clothing: my VB shirt and clothing. I would love to hear opinions about if that could have added to the bottom warmth considering a bottom VB(the space blanket) has always been part of the system.

The other thing I would love comments on is why I was so dry in the HH over cover, and how the condensation I got on my fleece frost bib was liquid, not frost. And everything else(net/OC) dry! I was really expecting a lot of frost and condensation inside that OC. And it must have added at least 27F or else I would have had frost, right? I am again surprised it added that much.

[OldRagFreeze]

Very interesting test, for sure. The only thing I can really comment on from personal experience is the frost bib being wet but not frozen. I slept out the same night, with temps just a couple degrees below yours, and found that my breath slightly wet my SB (next time I'll use a bib like you did) in front of my face... But it did not freeze. Even more oddly, in the morning I noticed that a small amount of frost did form right along a seam that was folded over and thus protected from my breath a bit.

I'm thinking that consistent exhaling creates and maintains a bubble of warmth which prevents freezing even well below freezing temps. To support this, I can say that my thermometer which hung on my ridge line would rise steadily each time I would pull it towards my head to read it, then fall when I pushed it down the RL closer to me waist.

This is surprising considering I felt a steady breeze through the tarp (compared to strong gusts outside my tarp) most of the night. My guess is that since we exhale at such regular intervals we maintain the 'bubble' regardless of air movement.

[OutandBack]

BB, If you are wearing VB clothing, socks, pants, shirt.
I would think a spaceblanket, first layer of the HHSS system, would not be required.
For me eliminating anything extra is a big plus in the cold.
Your thoughts...

[BillyBob58]

Very interesting test, for sure. The only thing I can really comment on from personal experience is the frost bib being wet but not frozen. I slept out the same night, with temps just a couple degrees below yours, and found that my breath slightly wet my SB (next time I'll use a bib like you did) in front of my face... But it did not freeze. Even more oddly, in the morning I noticed that a small amount of frost did form right along a seam that was folded over and thus protected from my breath a bit.

I'm thinking that consistent exhaling creates and maintains a bubble of warmth which prevents freezing even well below freezing temps. To support this, I can say that my thermometer which hung on my ridge line would rise steadily each time I would pull it towards my head to read it, then fall when I pushed it down the RL closer to me waist.

This is surprising considering I felt a steady breeze through the tarp (compared to strong gusts outside my tarp) most of the night. My guess is that since we exhale at such regular intervals we maintain the 'bubble' regardless of air movement.

Hey, you may be on to something there! It might have been quite a bit cooler throughout the rest of the OC ( HH OC + UC= sort of a sock more or less) but my breath might have added enough warmth, as you say, to keep it from frosting. In fact, I need to look up my old thread testing the JRM MW4/BMBH combo at ~ 10F. I started off with this very same quilt, but with more layers on me, and I remember when I got a bit cool on top middle of the night, I also noticed that the neck area of my UQ was quite wet, making me swap it out for an old 5F PG bag. But now I'm wondering if that was frozen or not, because I did not have any over cover. If I can find if that was liquid, rather than frost even with no OC, then I think you have nailed it.

I have read about so many instances of frost and condensation inside socks and such. Even with the above explanation for the area near my face, I am still surprised at my lack of condensation of any kind in the rest of the covered hammock.

BB, If you are wearing VB clothing, socks, pants, shirt.
I would think a spaceblanket, first layer of the HHSS system, would not be required.
For me eliminating anything extra is a big plus in the cold.
Your thoughts...

Yes, I have often wondered the same thing. For sure VB clothing could totally replace, even outperform, the VB functions of the SB. But I did not yet put that to the test yet for a couple of reasons:
1: I did not have true VBs on my legs, rather so called WPB pants with my 8 oz pair of insulated pants over that. Stephensons claim WPB will function as a VB, and a couple of VB testers here have used WPB as a VB with at least some apparent success. But it has always been hard for me to believe because wearing WPB clothing feels dramatically different than VB clothing to me. So I did not fully trust this approach, and did not want a wet OCF HH pad on the coldest night ever for me to test. So the SB stayed in.
2: Is there anything to the radiant function of the SB, or is it all just VB? Unknown to me. But again since I was going for my all time PB and trying it with less than I normally used at previous PBs, I thought I would play it safe. However, as far as VB function alone goes, I think total VB clothing would out perform the space blanket, so if it's effect is actually all from VB, it should be left behind. In fact, I am still trying to figure out if being so warm at 6-7F was all due to just the added HH kidney/torso pads, or did I get some noticeable help from a superior VB effect being zipped inside a shirt?

Actually warm at 6F seems a bit of a stretch to me with that small amount of back side insulation. But RamblinRev was at least OK- and maybe actually warm? - at 12F so maybe it is not a stretch.

Wouldn't Y'all have expected a lot of condensation inside that OC/UC at 6F with 85% humidity(before I went to bed anyway) ?

[OutandBack]

snip...
2: Is there anything to the radiant function of the SB, or is it all just VB? Unknown to me.

But again since I was going for my all time PB and trying it with less than I normally used at previous PBs, I thought I would play it safe. However, as far as VB function alone goes, I think total VB clothing would out perform the space blanket, so if it's effect is actually all from VB, it should be left behind. In fact, I am still trying to figure out if being so warm at 6-7F was all due to just the added HH kidney/torso pads, or did I get some noticeable help from a superior VB effect being zipped inside a shirt?

Actually warm at 6F seems a bit of a stretch to me with that small amount of back side insulation. But RamblinRev was at least OK- and maybe actually warm? - at 12F so maybe it is not a stretch.

Here's my take on spaceblankets.
I have a bit of history with these types of materials.
In my old job at Lockheed I work on and tested solar blankets used on satellites.

If you build a fire and put a SB behind you your back will be almost as warm as your front.
The radiant heat will be reflected back at you.

Now take that same SB and lay it out in the snow.
Then lay on it with no shirt and do to mylar having no insulative properties thru conduction
the snow will adsorb more heat than you can possibly radiate. So if you have nothing
below your SB to store heat you can never really warm up.
The cold air below you will continue to adsorb your heat thru conduction until you can't generate anymore.

It is my guess any piece of plastic sheeting will work like a VB just like the SB in the SS
and the tiny amount of radiant heat you are generating is so small you would not feel the
difference between the two.

Wouldn't Y'all have expected a lot of condensation inside that OC/UC at 6F with 85% humidity(before I went to bed anyway) ?

Only if you reached the dewpoint would you see water vapor(high humidity) condense into water droplets.

Loving your tests hope you will keep it up.
I bought some neoprene sock from Cabelas to try as VBers even though I no they are not true VB
if you taked to the VB guys. Baby steps for me.