Hi all,i am after a bit of advice about my sleep mat(exped 7.5 airmat)if i think the temp will drop i will take my army bivi on a wild camp and use it inside my Tiger Paws tent along with my Snugpak Chrysalis and my mat,well as my back/knees/neck are showing wear and tear i want to trim my kit down to a more comfortable weight(sub 2 tonnes).I know my mat has rubbish insulation from the ground that is why i place it inside my bivi,the question is has anyone used a sol emergency bivvy to help insulate,i was thinking about putting my mat inside or lay my mat ontop,any thoughts about the merits of doing this.
Upgrading exped 7.5 airmat
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I have thought about using an emergency survial blanket on the bottom of bedding or between bedding to reflect heat, dont know if anyones tryed it on here??
the emergency bivvy in a sleeping bag to sleep in might make you sweat to much? dont know really never tryed it with it .
the emergency bivvy in a sleeping bag to sleep in might make you sweat to much? dont know really never tryed it with it .
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it was an impulse buy,never going to climb inside it and use like a bivi unless i want to be boil in the bag,my first thought was to put my mat inside the bivi but then i read on another site the bivi being so close won't work as well,so the theory was to put the bivi under the mat,but which way round silver outside or inside,tres confusing
I dont think that the foil is handed and you can use it inside or out
Only thing to do is try it out and let us know how you get on
Just found this, might help
http://adventure.howstuffworks.com/survival/gear/space-blanket1.htm
". Excessive heat loss leads to hypothermia, an extremely dangerous condition. Space blankets stop both evaporative and convective heat loss.
Evaporation is the process of water changing from a liquid to a gas. In the case of a person, the liquid can be sweat or wet clothing. Evaporation uses a lot of energy and lowers the body temperature. This is why you need to be careful not to get too sweaty in cold weather. Your body temperature will drop quickly once you stop exerting yourself -- and the evaporation of sweat will make you even colder. To prevent evaporative heat loss, you should try to stay as dry as possible. A space blanket helps slow down the process of evaporative heat loss by increasing the humidity of the air next to the skin.
Convection is a lot like conduction. Conduction is the transfer of heat or cold between two objects. For example, if you sit down on a pile of snow, your backside will get colder, and the snow will get warmer. With convective heat loss, however, the cold object is moving -- like a cold wind. The wind takes the warmth away from whatever it touches. The faster the object is traveling, the colder you'll get. You can help reduce convective heat loss by wearing layers of clothing as insulation. A space blanket forms a barrier between the wearer and the wind, providing insulation.
Lastly, we also lose body heat through radiation -- it simply radiates off our body. The reflective agent on space blankets -- usually silver or gold -- reflects about 80 percent of our body heat back to us"
Only thing to do is try it out and let us know how you get on
Just found this, might help
http://adventure.howstuffworks.com/survival/gear/space-blanket1.htm
". Excessive heat loss leads to hypothermia, an extremely dangerous condition. Space blankets stop both evaporative and convective heat loss.
Evaporation is the process of water changing from a liquid to a gas. In the case of a person, the liquid can be sweat or wet clothing. Evaporation uses a lot of energy and lowers the body temperature. This is why you need to be careful not to get too sweaty in cold weather. Your body temperature will drop quickly once you stop exerting yourself -- and the evaporation of sweat will make you even colder. To prevent evaporative heat loss, you should try to stay as dry as possible. A space blanket helps slow down the process of evaporative heat loss by increasing the humidity of the air next to the skin.
Convection is a lot like conduction. Conduction is the transfer of heat or cold between two objects. For example, if you sit down on a pile of snow, your backside will get colder, and the snow will get warmer. With convective heat loss, however, the cold object is moving -- like a cold wind. The wind takes the warmth away from whatever it touches. The faster the object is traveling, the colder you'll get. You can help reduce convective heat loss by wearing layers of clothing as insulation. A space blanket forms a barrier between the wearer and the wind, providing insulation.
Lastly, we also lose body heat through radiation -- it simply radiates off our body. The reflective agent on space blankets -- usually silver or gold -- reflects about 80 percent of our body heat back to us"
The bivvy won't add much in the way of insulation from below, it'll help trap air around your sleeping bag though and that will make you feel warmer. I'd get another section of mat just long enough to cover your torso and thighs, fold it in half and slip it down the back of your pack.
I think the army bivi bags are around 900g, you can get better insulation for a quarter or third of that. No need for the bivi inside the tent if you ask me.
I think the army bivi bags are around 900g, you can get better insulation for a quarter or third of that. No need for the bivi inside the tent if you ask me.
Dirty Ben, your right about another mat - the Exped 7.5 (according to the blurb I've just read) is 'ideal for summer camping or tropical climes' with an R rating of 0.75 and a temp rating of +10c. No wonder your cold! The emergency bivi is a good idea to carry, but its not designed to add insulation to a mat.
For £40 you can get the Alpkit Numo, which is lighter, but has an R value of 2.5 (more a summer thing though). The Airo has the same R value, and is 439g all in http://www.alpkit.com/sleeping-mats/compare - for £40 you can't go wrong. You can always put a cheap closed cell mat underneath the self inflating mat so that it insulates you from the ground. If your in a tent, you don't need the bivi, but remember that the Snugpak isn't always as warm as they say it is (long-time owner of an Osprey), so a fleece liner might be an idea.
There is always the Downmat/Synmat - fantastic reviews (R 4.5 for Synmat), but expect to pay about a ton for the Downmat, and about £80 for the Synmat.
For £40 you can get the Alpkit Numo, which is lighter, but has an R value of 2.5 (more a summer thing though). The Airo has the same R value, and is 439g all in http://www.alpkit.com/sleeping-mats/compare - for £40 you can't go wrong. You can always put a cheap closed cell mat underneath the self inflating mat so that it insulates you from the ground. If your in a tent, you don't need the bivi, but remember that the Snugpak isn't always as warm as they say it is (long-time owner of an Osprey), so a fleece liner might be an idea.
There is always the Downmat/Synmat - fantastic reviews (R 4.5 for Synmat), but expect to pay about a ton for the Downmat, and about £80 for the Synmat.
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