What is the internal temp boost on a tarp with doors?

[burtonator]

I was looking at getting a tarp like this:

http://zpacks.com/images/shelter/ham...s_closed_l.jpg

specifically to block out the wind while I sleep as it wakes me up.

Tents usually have an internal temperature boost of 5-10 degrees.

While the doors weigh more, I think the internal temp boost would outweigh the weight.

that and a steady temp the whole night with protection from severe wind would be really nice.

IF there is a temp differential it might be a function of how high you are off the ground.

Flush with the ground is probably the best. The next best is probably something like a few inches.

Does anyone have any idea what the temperature boosts would be? I'd like to avoid doing lots of trial and error myself.

[Jcavenagh]

I have the HammockGear version of the cuben tarp w/ doors. I think there is some heat retention, but not as much as a tent. However, I also don't have the condensation issue anywhere near as bad as in a tent. By pitching the tarp low to the ground you will get significant wind blockage. That, in and of itself, will make you feel warmer.

[FlyingFox]

I have a Tenth Wonder storm tarp, although it doesn't have doors, it has Velcro part way down for added protection.
That plus the mosquito net, blocking any draft makes my hang very comfy, I haven't measured the temp difference, all I know is I sleep well.

Plus I haven't got the added weight of the doors.

[Acer]

This summer was hanging out in front of the house with no shade,,and fried a cuben tarp..separation of material as cuben is laminated. And the separation occurred at the tightest points where you tie the RL to, in this hang,,my 6' x 6's in the wide open. At the time,,day before in the sun in the summer,,I was getting as much as 15 degrees of addtitional heat testing if silnylon vs. cuben was hotter. Both tarps were hung side by side,amount of heat measured was the same silnylon vs cuben,,no difference in temps at all,and sides were 2' off the ground with ends open. After frying the tarp,,and getting it replaced by another HG cuben tarp,,,I also purchased a Tadpole. 3 days ago,,it was about 82 midday outside with Tadpole in porch mode on both sides..temp was 26 degrees hotter than normal outside temp with no wind...very hot and wide open with temp gage hanging in middle under tarp. Also,,one day in a rain storm,,took silnylon poncho,,and enclosed one side of Tadpole to break wind and blowing rain. Temp shot up 15 degrees as soon as the clouds broke from storm passing thru. Didn't take 30 minutes for temps to shoot up with tarp sides about 18 inches off ground and end closed. I plan on testing more this winter as I am curious to know especially on my 2 cuben tarps,,how hot its going to get as .51 will separate in too much heat and sun as I had hung mine only for a couple of days straight in the hot sun prior to frying it, but had hung it maybe a half doz. other days also this summer out in the sun with no shade. In the shade,,yu won't develop the higher severe changes in heat under a tarp but you still will trap heat. I have found,,you will equilize your temps at nite, when hanging over the time during the nite. When you wake up in the morning,,your temp under the tarp will be the same as temp outside the tarp by daybreak, if the doors are closed,,maybe just a few degrees if any, above outside ambient temps. So you will lose heat overnite. I have also found,,if you have fog,,and tarp is wet on the inside, as well as outside,,water will absorb your heat, and create heatloss. Lots of variables to consider. I might add,,I use a bridge hammock,,a RR,,so its hard for me to get the tarp all the way to the ground. I would think,,like a tent,,sides of tarp against the ground will give you less heat loss, but haven't tested on those accounts. Next cuben I get also,,will be made of .74 slightly heavier material,,but that is just my call as I am rough on my equipment and have a tendancy to abuse it moreso.

[nothermark]

Think it through. Aside from the sealing issues the surface area of a tarp is significantly larger than a pod or backpacking tent. How much can you warm up a 12x14 wall tent with one body? How about a 3x7 ft dome section? Big difference in volume and surface area.

[Acer]

You will retain more heat using a hammock with a sock, or a top cover and UQP on the bottom in the winter. Too many cubic feet of air space in a tarp..Northermark is dead on nails on his statement.

[burtonator]

Hey Acer. That's an interesting experiment but I think not valid for use at night and at cooler temperatures.

The severe impact of the sun would have profound implications for a tarp during the day.

The main question is will your body temp increase the tent's internal temp at night.

With open sides (no doors) my bet is no... that it won't.

But with closed doors... I think it will but by how much.

And would a bottom under the tarp further boost the temperature.

This summer was hanging out in front of the house with no shade,,and fried a cuben tarp..separation of material as cuben is laminated. And the separation occurred at the tightest points where you tie the RL to, in this hang,,my 6' x 6's in the wide open. At the time,,day before in the sun in the summer,,I was getting as much as 15 degrees of addtitional heat testing if silnylon vs. cuben was hotter. Both tarps were hung side by side,amount of heat measured was the same silnylon vs cuben,,no difference in temps at all,and sides were 2' off the ground with ends open. After frying the tarp,,and getting it replaced by another HG cuben tarp,,,I also purchased a Tadpole. 3 days ago,,it was about 82 midday outside with Tadpole in porch mode on both sides..temp was 26 degrees hotter than normal outside temp with no wind...very hot and wide open with temp gage hanging in middle under tarp. Also,,one day in a rain storm,,took silnylon poncho,,and enclosed one side of Tadpole to break wind and blowing rain. Temp shot up 15 degrees as soon as the clouds broke from storm passing thru. Didn't take 30 minutes for temps to shoot up with tarp sides about 18 inches off ground and end closed. I plan on testing more this winter as I am curious to know especially on my 2 cuben tarps,,how hot its going to get as .51 will separate in too much heat and sun as I had hung mine only for a couple of days straight in the hot sun prior to frying it, but had hung it maybe a half doz. other days also this summer out in the sun with no shade. In the shade,,yu won't develop the higher severe changes in heat under a tarp but you still will trap heat. I have found,,you will equilize your temps at nite, when hanging over the time during the nite. When you wake up in the morning,,your temp under the tarp will be the same as temp outside the tarp by daybreak, if the doors are closed,,maybe just a few degrees if any, above outside ambient temps. So you will lose heat overnite. I have also found,,if you have fog,,and tarp is wet on the inside, as well as outside,,water will absorb your heat, and create heatloss. Lots of variables to consider. I might add,,I use a bridge hammock,,a RR,,so its hard for me to get the tarp all the way to the ground. I would think,,like a tent,,sides of tarp against the ground will give you less heat loss, but haven't tested on those accounts. Next cuben I get also,,will be made of .74 slightly heavier material,,but that is just my call as I am rough on my equipment and have a tendancy to abuse it moreso.

[burtonator]

If you have a tight pitch, you're going to have ABOUT the same volume as a single person tent and a single person can boost the internal temp from 5-10 degrees in this situation.

but you're right.. the more interior volume, the less of a temp boost you're going to see.

Think it through. Aside from the sealing issues the surface area of a tarp is significantly larger than a pod or backpacking tent. How much can you warm up a 12x14 wall tent with one body? How about a 3x7 ft dome section? Big difference in volume and surface area.

[pgibson]

In my experience your not going to see much if any temp change for a trap with doors. There is just so much surface area and so many small gaps, even pitch tight to the ground there is still gaps at the suspension exit points, along the lower edges where the cat cuts are. They are just not the same as a tent that tend to be more sealed up. Personally I don't think that's a bad thing...I always hated a hot stuffy tent, add a dog or two and it was miserable in there.

Even in very cold weather you will find many of us pitching our tarps in Porch mode....I do it with a winter tarp too...be it for the view, ventilation or just cause it looks cool for the pictures.

[burtonator]

The other issue I'm going for is to drop a lot of weight because I can use a WW micro or other UL hammock and then use the tarp to encase my hammock 360 degrees.

I think one thing I could do is to use some tarp pullouts to mock it up.

Four would be located around the main area of the tarp to pull it away from my body. Then (in the mockup) I could use some tape to pull the extra fabric together UNDER the tarp to close out the wind.

This would mean I could use stock / generic tarps and just make a few modifications. It would be similar to a sock in that it would be TIGHT around my body but I could also expand the tarp easily to expand it for a more traditional setup during the day.

One of my main concerns with a sock, without a tarp, is what do you do when it rains.

Ideally i would not be stuck within it but could expand the tarp from within so that I can get out and get changed without getting my tarp wet.

You will retain more heat using a hammock with a sock, or a top cover and UQP on the bottom in the winter. Too many cubic feet of air space in a tarp..Northermark is dead on nails on his statement.