Artistry of the Pea Pod

[joggerjohn]

A bag of dead wet leaves? Now that sounds like organic insulation. I will have to try that with my pea pod.

[MacEntyre]

Ed, about moisture in the PeaPod...

I've noticed that when I use the Speer Top Blanket, the part of the PeaPod that closes over me falls gently onto the Top Blanket, leaving only an air space from my shouders up. I open a small hole in the velcro at the bottom of this air space, and another near the top. So far, there has not been much moisture inside the PeaPod when I awaken.

I think a key to good performance is to fill the PeaPod, or at least to fill the middle. (I'm sure there is another air space at the foot end.) What do you think?

- MacEntyre

[joggerjohn]

I have never had a problem with moisture with my pea pod. I sometimes use a pad and a space blanket underneath my hammock and the bottom of the pea pod. I want to experiment with bags of leaves next. Maybe it works better than it sounds. If mastered it sure sounds like an easy way to combat the cold.

[Pastorus]

A bag of dead wet leaves? Now that sounds like organic insulation. I will have to try that with my pea pod.

Dead wet leaves as organic insulation might also give you some of that composting heat, and if you stay there long enough you'll have some pretty good soil for your garden.

[NotToWorry]

Ed, about moisture in the PeaPod...

I've noticed that when I use the Speer Top Blanket, the part of the PeaPod that closes over me falls gently onto the Top Blanket, leaving only an air space from my shouders up. I open a small hole in the velcro at the bottom of this air space, and another near the top. So far, there has not been much moisture inside the PeaPod when I awaken.

I think a key to good performance is to fill the PeaPod, or at least to fill the middle. (I'm sure there is another air space at the foot end.) What do you think?

- MacEntyre

Mac, I've noticed the same thing, so there must be something to what you found. Arranging two chimney breather holes at different elevations can remove significant moist air & thus greatly reduce accumulated condensation in the PP. I'll also trapped significant expelled breath moisture by using 1) a cotton bandana over my mouth & nose; or 2) one of those heat exchanger/moisterizer breath masks that traps heat from your outgoing breath & then heats your incoming breath---forgot the brand name. The heat exchanger is designed for extremely cold conditions but also works inside the PP since it traps a lot of the moisture in your expelled breath in the mask itsef.

Different people also produce different amounts of body moisture, so what is a problem for some might not be a problem for others. In addition, different outside air humidity on different nights, changing humidity during a single night, and wind can greatly effect how much moisture ends up inside the PP. To be safe on extended multi-night trips, I generally sleep with a stocking cap or balaclava & keep a 10-inch or so breather hole above my head. But if I'm still cold, I'll close the sucker up totally. Karen has been experimenting with our 18-lb dog sleeping in the hammock with her, so there's two bodies producing moisture--so far there's been no problems, but she's not completely closed the PP yet.

All this discussion of body moisture brings up a similar problem---that's moisture on the outside of the PP. I'll put my thoughts in my next post.

[MacEntyre]

... moisture on the outside of the PP. I'll put my thoughts in my next post.

My first night in the PeaPod was a howling sou'wester with rain and fog, on a mountaintop. I managed to find a hollow, but the next day the PaePod was covered with blown rain and condensation. It did not appear to have soaked into the down. I left it hanging, and by lunchtime it was dry. At first I thought the outer shell must be DWR, but your web site says it is not.

...eagerly awaiting your next post!

[NotToWorry]

Cold weather hammocking often means dealing with moisture buildup.
Moisture that collects on the outside of a sleeping bag is often as concerning as moisture trapped inside. Here in the humid southeast, we often get a heavy dew on our PPs, especially on cold windless nights when we camp in the open & don't use a tarp (like on our back deck). This moisture comes from two sources: 1) the outside air; & 2) our body moisture that has been driven thru the insulation & thru the outer PP shell fabric. If the temps dropped below freezing, this dew is frozen by morning. The frost is easily brushed or knocked off, but unfrozen dew beads up on the outer PP fabric & should be removed before re-packing the PP. A cotton bandanna, small shammy cloth, or pack towel works well--in a pinch, even a dirty sock will do!

Remember that the dew point is dependent on humidity & temperature; so dew often collects first on the highest objects above the ground. Setting up below trees, &/or using traps often results in less dew on your hammock.

Here's an interesting experiment---measure the weight of your PP (or any sleeping bag) before & after a nights use. There will be a weight increase due to accumulation of your body moisture. This increase can be something like 2-8 ozs depending on many variables. Breathable shell fabrics are a must as they allow your body heat to set up a convection that drives some, if not most of the moisture thru the insulation & to the outside where it beads up as dew, freezes &/or evaporates. Even in camp, give your PP (or any sleeping bag) lots of time outside the stuff sack so it can breath & dry as much as possible.

If you use a vapor barrier, such as a ground sheet or sleeping pad (which work great BTY), as a liner inside the PP, be aware that it can stop or greatly reduce the moisture-driving convection that is otherwise set up by your body heat. In other words, be very careful that a vapor barrier that adds warmth to the hammock bottom doesn't result in excessive build up of body moisture inside the PP insulation. A bottom vapor barrier provides warmth by partially blocking the upward escape of warm air & by blocking the bottom ingress of cold outside air.

Some long-term polar explorers have reported sleeping bag weight increases of as much as 60 lbs---but they were still warm even though their body moisture was freezing inside their sleeping bag insulation each night & never had the chance to evaporate. Yes they were weaning a lot of other clothes to sleep in! In our more moderate conditions here in the US, body moisture trapped in the insulation would not normally be frozen, but instead there is a small risk that it could result in loss of down loft (ie warmth) due to wetting, especially on long multi-night outdoor winter trips. Down is an extremely versatile insulation & can take an incredible amount of water moisture before it loses loft, so this shouldn't be a problem for the attentive camper. I used my PP for 5,000 miles of AT hiking & never had a problem--OK, most of that was summer time!

Most often a balance is set up where your body heat drives moisture out of the PP each night at the same rate that new body moisture is accumulating---as long as vapor barriers such as ground sheets, sleeping pads, or ice don't get in the way. I use bottom vapor barriers in cold weather because they add greath warmth for very little weight & bulk--I also pay closer attention to what is happening inside my PP's insulation.

Be safe & always practise, test & become comfortable with your cold weather hammock system first in a convenient bail-out place (back yard, car camping, etc) before heading to the remote back country. Remember each person is different & the setup that works for one person might not be sufficient for someone else. The good news is the PP is highly versitile & can be adapted for use at most any temperature.

[Wentworth]

I've never noticed moisture buildup in the peapod even when fully closed. Of course this doesn't mean it can't happen, just that I haven't experienced it. It is definitely my favorite way to keep warm.

[BillyBob58]

......................
If you use a vapor barrier, such as a ground sheet or sleeping pad (which work great BTY), as a liner inside the PP, be aware that it can stop or greatly reduce the moisture-driving convection that is otherwise set up by your body heat. In other words, be very careful that a vapor barrier that adds warmth to the hammock bottom doesn't result in excessive build up of body moisture inside the PP insulation. A bottom vapor barrier provides warmth by partially blocking the upward escape of warm air & by blocking the bottom ingress of cold outside air............................. Remember each person is different & the setup that works for one person might not be sufficient for someone else. The good news is the PP is highly versitile & can be adapted for use at most any temperature.

Thanks Ed for all the comments and info! Just in time as there seems to have been a recent jump in p.Pod use.

(If you find time for more comments)In your comments above about VBs in the Pea Pod: If the vapor barrier under the hammock prevents(hopefully) body moisture from getting into the down under the hammock, then why would it possibly " result in excessive build up of body moisture inside the PP insulation"? I ask this more from just seeking an explanation than from neccesarily disagreeing with the premise. Since I have learned while trying to talk some folks through HH Super Shelter use that VBs can be tricky and may not work for one person in the same way as they do another.

But if in theory at least, we assume that the VB between hammock bottom and Pea Pod blocks all moisture from getting from my back below into the down, then are you maybe saying that this blocked moisture ends up going some where and thus might rise and end up condensing in the upper layers of down in the pod or TQ? Or are you referring to someting else?

Just trying to pick your brain. There are not many folks who can report on 5 months straight of Pea Pod use! I do love the versatility of the Pea Pod, though. It is definitely one of my favorite pieces of gear.

Oft told story repeat for any new folks: On a week long trip to the Rockies Sept a year ago, with lows from mid-hi 20s to 30s, with rain, wind, hail and snow, I got by fine with the 20* model Pod and NO top quilt. I managed to just use the warm clothing I would have had with me any way, which I needed for sitting around camp at night and even in the day time. A light top quilt would have been far more luxurious, but still I managed to stay warm. I think some think the PPod works great but is a bit big and heavy. But I thought that was pretty darn good weight efficiency, considering two long quilts ( a TQ and UQ) good to 20 or so plus a hood would weigh at least as much as the Pea Pod.

[NotToWorry]

Yeah BB that's it. Maybe I should explain what I meant a little better. A bottom VB between the hammock & the PP does prevent body moisture from reaching the bottom insulation of the PP. But excessive body moisture might still accumulate in the upper portions of the PP.

The PP is made with breathable fabric shells, so without a bottom VB, heat from your body rises & creates a convection current that continuously carries warm air (& body moisture) upward to escape thru the upper PP, while cooler (or cold) outside air enters thru the bottom of the PP, only to be warmed in turn by your body heat & then rise upward to escape back to the outside. It is this convection current that keeps the accumulation of your own body moisture from completely wetting you, the hammock & the PP. However, this convection is constantly robbing you of body heat, so a happy balance is necessary to stay warm & comfortably dry overnight. It's a battle between warm & wet or cold & dry! The PP's breathable shells help tilt the balance in your favor.

Using a full-body VB is recommended by some people for extremely cold conditions, but I much prefer the dryer alternative of a partial VB---such as a bottom VB sheet or sleeping pad between the PP & the hammock. The bottom VB will almost stop, or significantly reduce, the natural convection cycle mentioned above---and thus retained heat can accumulate around your body, although at the risk of increased moisture buildup around & above your body. Without the ability of escaping, it can be this buildup of body moisture that results in excessive wetting of you, the hammock & the insulation above you. I've found that wearing wicking long johns adds comfort by helping keep any accumulated wetness away from my skin.

As you can imagine, there are so many variables at play here that it's camper beware. One can easily get into serious trouble here, such as frostbite &/or spending a cold, wet miserable night. Understanding the gear combination that works for you in all conditions is crucial before heading to the remote outdoors. I've spent years in the backyard & even now still use my backyard for frequent tests. Our forecast is about 15F tonight w/ light wind---Karen & I will be out there yet again!