Our biggest concern about sleeping in a van during ski season was staying warm, specifically keeping the kids warm.
We considered propane heaters, both portable ones (like a Mr Buddy heater) and permanently installing one in the wall of the van. We also found one that runs on the car’s gasoline. However we were very concerned about carbon monoxide poisoning, especially if the car gets covered in snow.
We looked at electric blankets hooked up to a big battery, but it seemed that it might not last all night and we’d be constantly recharging the battery. And we couldn’t recharge it in one day from a small solar panel on the roof.
In the end we just decided to see how warm we could stay without extra heat during the night. We figured we could ease into the ski season by starting when it was still warmer weather and if we found the weather getting too cold we could drive 45 min down the mountain to where it’s warmer and sleep there overnight.
Our plan was to have everyone sleep in sleeping bags. We heated up the car as much as possible before bed (after inspecting the exhaust pipe to confirm it wasn’t blocked). We bought a carbon monoxide detector just in case and attached it to the inside of the van. In the morning if it was too cold we could make sure there was no new snow and then turn the car on to warm it up before getting the kids out of bed.
The sleeping bags we used were all 10 to 17F (-12 to -8C) bags in good condition, except one 20F (-7C) bag in poor condition which was for an adult who claims not to get cold easily. We also insulated all the windows. We bought a Weather Tech windshield cover. We made custom covers for all the other windows using Reflectix that was cut to fit the window. Then we covered one side of each piece with black Gorilla tape. This makes one side good for hot weather (reflecting the sun) and one good for cold weather (absorbing the heat) and also makes the pieces stiffer so they fit in the window easier and last longer. Also when the black side is facing out it makes it less obvious that someone is sleeping there. We usually parked the van between other cars in a sheltered location, to minimize the impact of windchill.
The result was that we were usually about 15F (9C) warmer inside the van in the morning than it was outside, so we ended up staying pretty warm. We believe that this is in large part due to good insulation in the van walls, along with the window insulation, and also because of the small space with 4 people in it. We have been comfortable down to 10F (-12C) in the van. The coldest night we have spent in the Van was -19F (-28C) outside -5F (-20C) inside, and we decided that was way too cold.
Interestingly, we did spend one night without the kids and found the temperature difference from outside to inside was only a few degrees F (1C) so the kids are important to keeping the van warm.
I started playing with temperature loggers to document the temperatures we are seeing. Here’s a graph of outside vs inside the van overnight:
The one other backup we bought but haven’t used much are some electric hand warmers. They are nice in the sleeping bag if you put them in a sock so you don’t get burned. Unfortunately the -19F (-28C) night we didn’t have them with us and they definitely would have been nice to have.
Next up, how we store all of our gear in the van, both for driving mode and sleeping mode.
Details on the sleeping bags we use:
Two Silicon Valley engineers who have had a love of the outdoors since childhood. Parents of two small kids, spending our free time exploring the outdoors with them.