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I know that a pocket of still air is an excellent insulator.

Would placing a tent inside of another tent provide any substantive benefits to warmth? For a concrete example, consider placing a small two person dome tent inside of a much larger 6 or 8 person family tent.

I'm interested in comparing tent alone / tent with fly / tent in tent.

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  • 10
    Sounds like you've just planned your weekend, all you need are two tents and a thermometer.
    – ShemSeger
    Mar 16, 2016 at 1:25
  • Booom, it sounds like booom tent booom inception +1, I think it would improve a lot, it's gonna be an oven-like tent
    – Kyle
    Mar 16, 2016 at 11:54
  • 5
    While more layers with air gaps will always insulate more, I am struggling to see the application for this. With backpacking weight is too much of a concern and a single tent that does the job would always be lighter. With car camping or expedition trips, any place cold enough to merit this "double tent" hybrid would also bring risk that merits spending the $$ on the proper equipment. Mar 16, 2016 at 13:55
  • I know on one lightweight trans alpine trip, we pitched a tent inside an alpine hut to stay warm. Based on this experience, in extreme conditions it would help. But there are better options.
    – user5330
    Jul 5, 2017 at 23:01
  • 2
    Air gaps are insulation, as the heat needs to traverse the air between layers - the problem is that the air will circulate in the gap, reducing it's effectiveness - a 2mm styrofoam layer would probably already outcompete this gap for heat retention, as it is in effect also an airgap, but compartimentalized into tiny bubbles that allow no convection. depending on the fabrics used, heat retention by reflection of radiation might also play a role, but this would need two fabrics whose thermal radiation/transmission/reflection parameters were designed to work together.
    – bukwyrm
    Oct 15, 2018 at 7:42

7 Answers 7

19

That's essentially how 4 season tents work, the tent is full nylon (no mesh) and the fly is full and basically acts as a second tent, creating that air gap. some 4 season tents even have little foamies on them that help keep the gap, preventing snow from squishing the fly against the tent and eliminating that insulating volume:

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Putting a tent inside another tent would work, but it would work better if the tents were closer in size, then you wouldn't have a large of a volume of air to try and warm.

If you really want to insulate your tent, try putting a blanket or old sleeping bag in between the tent and the fly. In a pinch you can use dry grass or leaves, that's what Siberians do, they make a shelter inside of a shelter and fill the gap in-between with grass.

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    Just a quick note: If the extra insulation between the tent and the fly touches the fly, and if it where to rain, the fly will leak.
    – DudeOnRock
    Mar 16, 2016 at 2:41
  • @DudeOnRock This is true.
    – ShemSeger
    Mar 16, 2016 at 3:02
  • 5
    I'd say that if you put insulation between the outer and inner tent, then you lose ventilation that helps keep condensation at bay and will likely get your insulation wet - unless the insulation is in waterproof compartments and you still leave some space for ventilation between insulation and whichever tent part is not insulated. So yes in principle.. but I think DudeOnRock is right that a better/extra sleeping bag weighs less, assuming you do not want to lounge around in the tent or it is a big base camp tent for many people.
    – nsandersen
    Mar 22, 2016 at 18:47
  • The gap doesn't provide insulation. The gap keep water off the inner.
    – user2766
    Sep 19, 2016 at 9:48
  • @Liam Have you ever slept in one? They are warmer.
    – ShemSeger
    Sep 19, 2016 at 14:16
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I don't know what your situation is exactly, but my advice would be to instead invest in a good down sleeping-bag. Or bring someone to cuddle with. A good sleeping bag will provide that pocket of still air you are looking for and is going to be much more compact and lightweight.

For about a year and a half while at college I lived in a three-season two-person tent which was inside a cloth-teepee. I only had a 20 degree (Fahrenheit) sleeping bag and it got pretty cold (I slept in my boots some winter nights). I perceived the main benefit to be peace of mind that my stuff was protected a little more in case the elements misbehaved while I was gone. It worked for me in my situation, and, without having collected any data to quantify, felt more comfortable than just the two-person tent, but I am not sure you would want to do this where you have to carry both tents.

8

Tent in a tent will not really work.

Firstly the chance of getting two tents that are designed to work this way is essentially nil. You will end up having to find two tents that are compatible - one larger than the other. The smaller tent must still be usable, and the larger one so large that it will not touch the smaller one anywhere.

Secondly you're going to have issues with condensation. If you are looking to create an air-pocket, you will have to zip or close up all the ventilation holes. This will create an environment in which you will have a lot of condensation on the inside tent.

Like others suggested: Use a decent sleeping bag (and liner) to get the warmth you need, and a good-enough tent to keep you dry and out of the wind and free of bugs.

6

A tents job is not insulation. Your tents job is to provide shelter from wind, etc. Heat will (and should) pass though tent membranes very eaily.

Therefore adding a tent inside a tent will add practically no extra insulation and therfore no benefit. The outer tent will protect you from wind/rain and provide shelter. The inner tent is doing nothing.

4

Among the problems with this idea is that pole ends from the inner tent can damage the floor of the outer tent. If you need to be warmer, augment your sleeping gear with an inexpensive blanket or two. Check around at used clothing stores or buy new.

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Yes. I recently spent over a year living off-grid and used a smaller tent inside a larger one to conserve heat in the smaller one. The inner tent was my sleeping area while the extra space inside the outer tent was used for storing non-essential gear and items which needed to be protected from exposure to the elements. For short camping trips, using 2 tents is not very practical, and you'd probably do better to just put a blanket or other insulating cover over a single tent.

You will need to use some sort of barrier between the tent poles and the floor of the larger tent, such as bits of cloth or even styrofoam pressed over the pole tips. I used a tarp with an emergency blanket laid over it and set up on top of the blanket.

The outer tent does not provide a great deal of insulation, but it does reduce air-flow between the outside world and the smaller tent. This can greatly reduce heat loss, especially on a wet or windy day. Since your body puts off heat naturally and the inner tent retains heat more efficiently, it can become toasty inside the inner tent. If you have a camp heater, it can be used in the outer tent to keep temperatures up without making the inner tent stuffy or over-warm.

Another trick for conserving heat is to put a blanket on the floor of the tent (even if you are only using a single tent) to act as a barrier between the ground and your sleeping space.

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Makes a huge difference. I did it this weekend. The inner tent was very comfortable wearing long underwear, even outside the sleeping bag. The outer tent was cold and drafty. Outside was 30 degrees.

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