Is it colder to sleep in a car or a tent?

OK – so I slept in our people carrier on Saturday. (Merida, not kicked out of house)

Had a duvet and stuff, but woke up totally freezing (there was a frost on the ground)

Spoke to some people later, and a couple said “Oh, you’d have been warmer in a tent”

Firstly, is this actually true, and if so – why!?

Better insulated.

Depends. If you were in the same sleeping bag on the same sleeping mat, then there would have been no real difference

Have two windows slightly open- gets rid of the condensation

I would have thought the car was better insulated. However, a tent is more breathable. It could be you were a bit damp from condensation (from breathing) so felt colder.

Frozen in your own morning breath – eeuw!

do not ever sleep in a ford transit.
ever!!!!.

Have two windows slightly open Aye that’ll make things warmer 🙄

Done quite a bit of camping and never been freezing cold and our sleeping bags aren’t particularly fancy. Never slept in a car but I would imagine it would get cold, all that metal and all.

Proper campers have insulation in the body panles, but even those with a high percentage of glass coverage will get cold. A proper double skinned tent is far far far better insulated to the ambient temperature than something made out of glass and metal.

If the vehicle is carpetted and you have a sleeping mat, put a sheet up inside, to make a little tent in the car. Toasty.

Slept in both cars and tents, sometimes in the same weekend. I’d say the car was warmer but more uncomfy – there’s simply a lot more insulation in a car despite the metal and glass outer skin – I still suggest this is better than a fabric skin as this never “holds” the air. If you sleep on the floor of a van you’re likely to be colder as the metal conducts heat away more rapidly, but with a like-for-like carry-mat or seat as a base to lie on, the method of heat transport away is through you heating the air (convection). In a car the convection is free convection to a pseudo-sealed volume of air. In the tent your air is a free-flowing fluid passing through the tent, extracting the heat faster (forced convection is better at heat removal) and its not a closed system meaning the air effectively never gets warmer unless its a very still night and your tent has few vents.

A tent in thick snow is lovely, all vents get covered, the snow piles up a lovely insulating layer and its pretty damn warm on the inside!

Cars are bigger than tents so it takes more of your body heat to warm them up?

Cars don’t have any heating insulation at all, they’re designed to get the heat from the engine to warm the car. Insulation would just be unecessary weight. I guess the sound insualtion might trap some heat though?
I think the main problem is that the metal outer of a car is a very good conductor of heat. I/e. it conducts the heat out of the car.

A double skin tent will be warmer. Your body will heat up the inner tent (smaller is better) and the layer of air betwixt inner and outer acts as an insulator.

A decent quality mountain tent will always be warmer – you get a nice 2-4 inch layer of air between the inner and outer to act as insulation. I have slept in my tent when it was well below freezing outside and it was many degrees warmer inside. A single candle burning in the tent adds appreciable warmth. The vents are adjustable so you can keep the airflow to a minimum – the outer has no gaps to let air out other than between the outer and the ground and even those are very small and lower than the mudwalling on the groundsheet. With hot air rising you gt a bubble of warm air in the tent

Less volume of air and more insulation = warmer. I suspect those who find cars warmer have not been using decent quality tents

Tent ^ for the reasons TJ says.

surely with any wind, the air between the two tent layers is continually changing?

Good quality tents here thanks, two of (Vango and Khyam), and relatively expensive sleeping bags and thermarests. My larger tent is actually the better at keeping warmer as it has less mesh material on the inner so lets the air pass through less well. I just find wind whips away any insulating layer of air almost instantly. You’re fine if your inner is fairly tight-knit as this maintains a bubble of warm air inside the inner, but the gap between inner and outer is pointless for anything other than avoiding condensation. Tent fabric has virtuatlly no thermal resistance (much like glass) so the heat is not held in by the gap between skins, it just passes through the fabrics to ambient.

Having spent the last 3 nights in just such a situation on the west coast I can conclusively say I’d rather have been in my car. I’ve never had my car interior reach -ves despite me leaving it out in -10 winters (always leave a small bottle of water in boot), whereas a similar volume of water in a bottle inside my tent has frozen in the past in as little as -2 with 2 people in it (the tent not the water).

I’ve never had my car interior reach -ves despite me leaving it out in -10 winters

It must depend on the car to some degree, I had a bottle of water freeze inside my car this winter whilst it was parked on my driveway, in Nottingham – not anywhere particularly cold, think they said it had been -8 that night.

True, much as it probably depends on your tent type too. Though “My car” would be select any a tin-box pug 1990 205 to a slightly warmer and comfier toyota from the same era, or my 2001 pug 306 estate!

I’ve never had my car interior reach -ves despite me leaving it out in -10 winters

Same as ebygomm – I had frozen water in my car on a couple of occasions over the winter

Right.

Someone put up a tent in their garden tonight and leave thermometers in the tent and their car.

Thread closed.

*re-opens thread*

You forgot about a heat source. D’oh!

Tent is warmer everytime, I’ve slept in cars even in summer and still been cold.

I’m genuinely willing to do this if I can find a heat source that wont burn down my tent and will last all night and be close to the output of a human asleep. Any suggestions?

I’m still swearign it is down to air movement immediately around the heat source – this is vastly higher in a tent.

I’d rather be in a tent any time – I’ve spent many nights in a Transit & it’s even cold in the summer

OK so I need 100w of heat output, spread over an area and not exceeding the surface temp of a human – anyone donate lots of reptile heater pads?

100W??? I think you use a bit less when asleep…

There is no air movement in my tent when its all buttoned down – it gets really stuffy

I’ve never had my car interior reach -ves despite me leaving it out in -10 winters (always leave a small bottle of water in boot)

Would you sleep in the boot?

On several occasions I’ve woken to frozen condensation on the inside of the windscreen. A decent tent and thermarest is definitely warmer.

I’ve slept in quite a few vans and never been cold, admittedly in summer and using a 4 season sleeping bag and thermarest. Main advantage is not having to fight with zips when you wake up in the middle of the night still drunk and bursting for a pee.

Am I the only one on here with any brains? Leave the engine running …..

🙂

you can have a fire in a car though without worrying about it, like you would in a tent.

In my experience tents really don’t burn as well as some would like you to believe!

SST – Member

Am I the only one on here with any brains? Leave the engine running …..

And run a hose from the exhaust to the interior for additional heat *

[*] *awaits a rollicking from some demented forumite because their father/wife/dog committed suicide by this means…..[/*]

its warmer in a bivvy bag than the car FFS ….only time the car wins is when the midges are about but i use my -20 bag in my bivvy bag in the car even in summer ….out doors in the same weather ill use a +5 bag …..after waking up freezing in the car once at a dh race

AndyP – Member

you can have a fire in a car though without worrying about it, like you would in a tent.

😀 Go on – find that thread Andy….

?

Another good thing about sleeping in cars is that when you wake up hungover you can just press the electric windows button, hark out of the window, then shut it again. No need to even move your head in the slightest. No faffing with zips and the like.

Reading festival 1992 Sunday night slept in mates metro, second coldest nights ‘sleep’ ever. Coldest was stone bench in Weston super mud on bonfire night (beach race weekend) in the late 80s.

The only time Ive tried to sleep in my car is after a night out partying, with just my sweat covered clothes for insulation, so not really fair, but Ive been freezing every time!

AndyP – apologies. I thought you were making a humorous reference to this thread