Warmer inside a tent? yeah right!

[John H Swanson]

Okay, be forewarned that I'm ranting.

It amazes me that people think it is warmer (higher temperature) inside a tent in winter. I often see quotes saying things like: it was -22 outside, but really only -15 because we were inside the tent.

Is it just me or are there any other engineers out there that find this conclusion ludicrous?

I really doubt the metabolic rate of two sleeping humans could generate enough intrinsic heat to raise the inside temperature of a tent by 5F. Granted, you have the dead air space between the inner and outer wall, but there's no insulation in the walls!

I'll believe it if someone shows me the data. Has anyone ever measure this?

Don't get me wrong, your heat loss while camping inside a tent is much less. You don't have radiational losses from the clear skies. You don't have as much convective losses because of the wind protection. So it may feel warmer (less heat loss) but this doesn't mean it's warmer inside your tent.

 

[Warren]

On several occasions I've measured it- once on Hallcott Mnt. It was in the low teens outside, we got it up to near 20 inside. A candle lantern helps, as does staying outside your sleeping bag.

 

[SherpaKroto]

Believe it. I would much rather sleep in a tent than in a lean-to in winter. I'm convinced that it is warmer (at least 5 to 10 degrees), but have no proof. I'm sure someone can provide measured evidence to back this up.

 

[Paul_Bear]

If you can believe the little thermometers that attach to a zipper pull, then it's been my experience that it's 5 to 10 degrees warmer inside a tent versus the outside temperature.

Certainly the lack of wind helps a lot also.

 

[Mongoose]

It is warmer in a tent. I've measured it a few times. Your body heats up the air and the tent helps prevent the warmer air from blowing away.

As for sleeping in a lean-to, one of the things that makes shelters and tent playforms very cold in winter is that there is a big air space under it and wind can blow through it. It's actually warmer to sleep directly on the snow than on a tent platform.

 

[Peakbagr]

John,

Sorry I gotta disagree with you. In my experience, it is quite a bit warmer in a tent than outside.
First, there is no breeze inside the tent unless its a howling gale outside. The excaping body heat plus respiration = warmer ambient temps.
A tent allows a much more comfortable evening and is way more comfortable for multiple nights out.
This is completely without the added warmth that a candle lantern provides.

PB

 

[Mike BIRD Mammy]

warmer in a tent

Its a hell of a lot warmer in a tent, esp if you have a cutie girlfriend and one of those double zip up sleeping bags.
I think one time I measured the inside air at about 85 degrees (damn near tropical) when it was a mere 20 outside

Mike Mammy


BirdHead Studios

 

[dave.m]

Since the heat output of stoves, candles and flashlights is pretty negligible, I've always thought the one and only heat source of any concern in winter camping was your body. If this is true, then doesn't it follow that minimizing heat loss IS warmth. I mean, that's why I pull a big poofy parka out of my pack when I stop, right?

The tent is just a parka of sorts. Sure, with no bodies in it (heat sources) it will soon be the same temp as the outside. Same is true with sleeping bags. But put some bodies in it and it retains (body) heat.

I'd say you can feel free to experiment yourself, but if you're camping with me, I want your body heat in the tent. Well.... depending on what you ate that night and all that!!

 

[NYBRAD]

I may not be an engineer, but I've done plenty of winter camping over the last 15 years. And I can tell you that when you open the tent door in the morning when it's -10 to -30f, you can easily feel the difference in temperature outside.
Also, if there were no difference in temperature, condensation wouldn't be as much of a issue in summer or winter.
Sorry to disagree with you, but that's my experience.

 

[Rick]

Surely there are other things more woirthwhile to rant about,

But John - Do the experiment and let us know your findings.

Many years of winter camping under my belt tells me that it is ALWAYS a little warmer in a tent or closed shelter of any kind.

why is it in the morning, when I open my tent door, I am greeted with cold air - even when the air is still, it is colder?

Certainly other factors come into play- wind, number of folks in the tent, tent design and such, but speaking in generalities, I would agree with a 5d difference.

 

[Peakbagr]

One more and I'll shut up (maybe). I've slept out lots in the last 25 years. In my experience, the difference is a LOT more than 5 degrees in the average 2 or 3 person tent.

 

[sli74]

I won't repeat what has already been said BUT I also find that my 4 season tent keeps heat inside better than my 3 season tent, must be something to do with the fabric and the less mesh areas on the 4 season.

sli74

 

[Wanderer1]

I know that a double wall tent provides insulation. A couple of years ago while camping in the Adirondacks I actually took some measurements. I was camping solo in a Mountain Hardwear Trango Tent. I was camping in a sheltered area out of the wind and in the shelter of trees. I sure this helped some too. I was using a miniature Camping Gaz lantern. (it uses the small LP canisters) The outside temperature was close to -20F. I don't remember how long it took but it wasn't to long that it was quite comfortable. On the floor it was 20 some F. I could see my breath if I lied down. It was noticably warmer if I propped myself up on my elbow. (about 35F). The temperature near the peak of the tent was 52F. When I sat up it was very comfortable. What I needed was a ceiling fan. I know. You aren't suppose to use these devices in a tent but I ventilated and didn't lie down or sleep with it going. It was comfortable to sit and read having just my lower body in the sleeping bag. When it's dark by 5:00pm and that cold out it was really nice to have it. Now if I had used it outside I would have felt zero heat from it plus it wouldn't have even lit since LP doesn't evaporate that low. I warmed the canister before I used it in the tent and with the heat it generated in the tent kept it warm enough to work fine. It was hanging by it's chain so about a foot below the peak.
I have even noticed when it was nowhere near that cold (say 35F) and I get up in the morning that it is much warmer in the tent. When I unzip the door you can definetly feel the difference.
Another example that a tent traps heat is to set in one in the bright sun with it all zipped up and see how hot it gets. It can get too warm.

 

[peak_bgr]

I agree with all. It's an unmistakable difference.

 

[Buddur]

Wanna Bet!

Moist air holds much more heat energy than cold air does, and a 4-season tent does not let a breeze occur inside the shelter. So theoretically it would make sense that an occupied fully-enclosed tent in the winter would be warmer than outside because of the heat energy built up by the occupants and their moist air, and that heat energy would remain inside the shelter because of limited air circulation.

Frankly, regardless of theoretical mumbo jumbo, from my experience I believe my tent is warmer than outside temps even if I cannot prove it directly.

 

[pedxing]

I agree with those who find that the air is significantly warmer in the tent.

I assume that human activity is the main reason for this, but another factor not yet mentioned is that the temperature drops over night. To the extent that the tent walls slow the cooling of the air inside the tent, the air in the tent will be warmer in the early morning.

 

[spencer]

okay, okay....

John gets the picture. let's not beat a dead horse.

spencer

 

[Mark_151]

I know a few years ago I was in a group that did the Owl's Head bushwack. We brought 2 VE25's and siamesed them with a tarp to make one giant tent for 4 people. It was better than -25F outside that night -- inside it was pretty much shirtsleeve, and my -20 Western Mountaineering Puma bag was a misery to sleep in.

 

[Jaytrek57]

It's warmer in a dead horse. Well a recently dead horse anyways.
Worked for Han Solo anyways.

I don't know the answer...I have slept in shelters and tents and found it to be cold outside my sleeping bag either way.

 

[oldfogie]

The human body produces heat. The radiant heat from the skin gets stored in the sleeping bag where it stays for a while depending on how well insulated it is and that's what keeps you warm.

But consider that your lungs are a big pump. Each exhalation puts a few gallons every minute of HEATED air into the environment around you where it will stay for a while. As long as you're not dead, the pump keeps doing this all though the night. Not a bad deal actually!

Pack about 20 people into a 2-man tent and see if I'm not right.

Maybe you were keeping the door or window open to minimize condensation. Personally, I'll live with a little snow flurries inside my tent for the extra heat.

One trick I use is (if the snow is fluffy and your tent is strong) pile up as much snow on the outside walls of the tent. That will give you a few more degrees.