Official Test Results: Five Ways to Heat a Tent

[MattJ]

I know this is a thread topic that is on an endless loop, but I was so fascinated by all of the suggestions that I decided to test them myself in the field! So hopefully this thread provides some additional details and ideas to the conversations.

I have a Tepui roof top tent (Autana Sky) and annex. I tested the following products:

Electric blankets
Electric mattress warmer
Propane tank heating blanket
Mr. Heater Buddy catalytic heater
UCO 3-candle lantern
Propex portable heater kit

And what did I learn? Well, Nd4SpdSe said it best:

My notes on each product are in the posts below. Thanks to everyone who has contributed to this topic over the various threads! Let the endless loop continue . . .

 

[MattJ]

First I tested a propane tank heater, since I had trouble getting my catalytic heater to light when I left a 20lb tank outside in 20F temperatures overnight. I think the real problem was the extension hose, not the tank itself, but it doesn't really matter now. The blanket did keep the tank warm, but the inverter shut down after six hours when the voltage dropped below 11.5 volts. I was running the blanket off of my Optima yellow top deep-cycle battery.

Summary - using battery power to heat a propane tank is inefficient and a futile idea. But worth a try.

 

[MattJ]

Next I tested two electric blankets. I plugged them in to my Optima yellow top and left them in my Jeep overnight. In the morning, they didn't feel particularly warm and the battery voltage had dropped to 11.5 volts. Maybe if the blankets were inside a tent or inside a sleeping bag, they would have provided more warmth. But ultimately I decided they just weren't warm enough and were very inefficient at converting battery power into heat.

Plus, electric blankets obviously only heat themselves, not the air in the tent. So those cold minutes outside the sleeping bag before bed and after waking up would still be cold.

 

[MattJ]

Next I tried an electric mattress heating pad. These are used by long-haul truckers (I think). They are meant to be used with normal sheets and a mattress, not a sleeping bag. I have a 3-inch foam mattress in my Tepui tent, so I figured I could pin the heating pad to the mattress and sleep on it with a flat sheet and unzipped sleeping bag as a blanket. But I never tested this approach. Similar to the electric blankets, the mattress heating pad didn't seem to get very warm overnight and drained my Optima yellow top. I think this heating solution was probably a workable one, but I was pretty convinced that battery power wasn't going to be the best way to heat a tent. So I gave up before actually sleep-testing the mattress pad.

 

[MattJ]

In the field, I tested the Mr. Heater Buddy catalytic heater. What everyone says is true: it generates a LOT of heat, uses a LOT of propane, and generates moist air. Of all the things I learned in the field tests, perhaps the most important was that my Tepui annex is BIG. Lots of space, which makes it easy to move around and comfortable for three people to lounge in, but VERY hard to keep warm! The catalytic heater was great at warming that large space in hurry. I used a small USB fan to circulate the heat, so it didn't simply rise and heat the ceiling of the annex (the floor of the tent). I was using 1lb tanks, and the heater consumed them at a rate of one per 3 or 4 hours. In the future, I will plan to use a 5lb tank.

This solution is good for morning and evening warm-up sessions, but I didn't really like it as an overnight option. Even with the window flap open, a battery operated CO monitor, a low-oxygen shut-off feature and tip-over shut-off feature, I didn't want to deal with the risks of burns (or worse). Plus, even at the low setting, this heater puts out a LOT of heat. It's a cheap solution (until you add the cost of 1lb tanks), but has some shortcomings.

 

[MattJ]

I also tested the UCO 3-candle lantern. My field testing of this product wasn't really fair, since I tested it in the massive annex. I didn't even leave it lit long enough to take pictures. I should have tested it in the tent, where it probably would have been much more effective. In the annex, it really didn't generate much heat. But in the tent, I bet it would have heated and dried the air quite well. I also have a single-candle lantern. I will plan to test these in the tent on another trip. You can use the 3-candle lantern for light AND warming up small containers of food or liquid on the top of the lantern (which gets very hot).

 

[MattJ]

Finally, I tested a Propex portable heater system that cost a pile of money and took quite a bit of tinkering to set up. You can see in the photos that I tried various positions for setting up the heater that would keep it out of the weather (we got rain, snow and freezing rain during my trek).

The real challenge of the Propex heater is ensuring that you get the warm air into the tent through a very insulated hose and then circulate the same warm air back to the heater with another insulated hose. Unfortunately, the kit is shipped with just a single 5-foot hose, so I spent a lot of time and money making extension hoses. Plus, I had to make a high-temperature exhaust hose to route the CO away from the tent.

You can see in the photos that I decided the best place to put the heater was on some portable quick-shelves that I hang from my Sunseeker tarp. This allowed me to pump the warm air into the tent across a short distance. With this configuration, the Propex system worked VERY well. The thermostat was extremely accurate, allowing me to set the exact temperature and run cycle for the heater from inside the tent.

You can see that I also used a reflective space blanket on the roof of the tent, which I think really helped. On my next cold weather trek, I plan to hang a couple of these in the annex and see if that improves the ability of the annex to retain heat. I also want to test different combinations of input and outake for the warm air and recycling hoses on both the tent and the annex.

 

[chet6.7]

:clapsmile

 

[cactusjk]

So what is the recommendation?

 

[john61ct]

The three little-output options will only make a difference in a **very** tight and well insulated space.

Batteries powering a heat source? No.

And even the big propane sources are crazy expensive in an uninsulated tent, I would only use a little while before and after sleeping.

Money better spent on top-notch layered clothing and sleeping bags, suck it up get used to it or head toward the equator.

 

[SoCal Tom]

I’ve been told the electric blanket/mattress warmers are great for preheating the bed. Turn them on about an hour before bed, and the extra warmth makes falling asleep much easier. Turn them off once in bed to save the battery. That would be a test I’d like to see. Heating Jeep seats doesn’t seem like a real test to me. Seems like he e-blankets, coupled with the Mr. buddy would be a nice combo. Warm the bed with the e-blanket, then warm up the place with Mr. buddy in the am.


Sent from my iPad using Tapatalk

 

[krick3tt]

It is very interesting that you actually tried several options and probably heating the bed and using some sort of lofting bedding would be the least dangerous and most efficient. Thanks for your efforts. When I last slept in a RTT in Idaho I found ice hanging from the roof inside in the AM. Not pleasant.
Now when it is really cold I sleep in the back of the Rover and son't use a tent at all.

 

[MattJ]

Thanks everyone for the input and responses. Some additional clarifications:

1) Yes - I didn't mention any of the basic materials and gear that are essential in cold conditions: sleeping bag rated to 0F or better, thermo-reflective sleeping pad, fleece sleeping bag liner, layered clothing (including my favorites, fleece gloves and a balaclava under a wool hat) and a Nalgene bottle full of hot water at the bottom of the sleeping bag. In a smaller tent, the right gear can keep you plenty warm. Maybe add a 1 or 3-candle UCO lantern for the minutes before/after climbing into the sleeping bag? I want to test that.

2) I agree my approach with the electric blankets and mattress heater wasn't set up correctly. After I bought those products, I realized that a) they aren't meant to be used inside or under a sleeping bag, so I would have to use a different bedding system than the one I have (see #1 above), and b) having to run my engine to recharge my auxiliary battery each day did not sound like a good solution. My camping style is to set up a base camp and stay a few days. But I agree that in the right use situations, with the right bedding, those two products could be very helpful. If I can't figure out a way for the Propex heater to warm BOTH the tent and annex at night, an e-heat solution might be the only one that works overnight in the annex.

3) I should have mentioned that the Propex heater was surprisingly efficient with its propane consumption. I was told it had a 60-hour run time on a 20lb tank. After three days in the field, I believe it. And, importantly, those 60 hours are run time, not the actual cycling time that the thermostat controls. In 20F conditions, I would estimate the Propex heater was cycling 2 minutes on / 8 minutes off overnight, and that kept the tent plenty warm. Also, I learned that the efficiency of the heater goes WAY up when you configure a good circulation system with an intake hose that pulls warm air back to the heater. That's why it is frustrating that the kit only comes with a single 5-foot hose. I had to buy parts from the U.K. to replicate the hose that comes with the kit after several failed attempts to make one with local products. That could be a whole separate thread if anyone is interested!

4) A recommendation? Well, it's hard to really compare each of these products since they work in very different ways and span a wide range of cost. The Mr. Heater Buddy is great for creating a wave of very hot, moist air with a bit of an odor. The Propex is great for turning any space into a climate-controlled environment with clean, dry, warm air on a thermostat. I also like that the Propex is very safe since all combustion happens outside the tent. But the Propex is CRAZY expensive when you compare it to the cost of any other camping gear and even the tent itself! By the time you pay for a roof top tent and Propex system you have spent half of the cost of a teardrop trailer that comes with its own heater, I think.

 

[nwoods]

I use one of these. Not wild about the potential of catching the tent on fire, but it heats up the tent very quickly and effectively, allow us to shut it down while we are still awake. Holds one green gas canister in the base:

 

[autarkus]

I had to buy parts from the U.K. to replicate the hose that comes with the kit after several failed attempts to make one with local products. That could be a whole separate thread if anyone is interested!

First, thanks for taking the time to share your efforts. I'd certainly be interested in the parts breakdown, if you're planning to post.

Also considered getting the HS2211, which looks like it's very similar to the HS2000, only designed to be mounted outside.