Official Test Results: Five Ways to Heat a Tent

[Alloy]

Some more upgrades this weekend. I found some flexible exhaust ducting that is leak-proof. And it only cost $40 instead of the $80 that I spent on the electrical conduit material. I did have to twist a short length of conduit onto the exhaust ducting so that it fit tightly in my coupler. But the end product works great, and is completely air-tight.

I also installed rivnuts and thumb screws to hold the intake and output hoses in place, so I won't have to fight with the circular clamps anymore.

We use a Proflex to heat our 35' (280sqft) trailer. With jus the Proflex it takes about 4-5 hour to bring the temp from 32F up to 60F. Exhaust gas temp of the Propex is +/- 150F while the RV furnace is over 250F which means the Proflex is more efficient.

For maximum efficiency I kept the exhaust to 48" and the heating duct is 36" of 4" steel duct. There is no intake ducting

A concentric vent I made with 1" and 2" aluminum pipe exhausts through the side of the trailer.




Some ideas.

For the exhaust Home Depot has Home-Flex stainless gas pipe. TracPipe and Gastite also make it.


Some quick release hose clamps

 

[Borrego60]

Been running a Propex heater for years and never looked back. Price was not a consideration in keeping warm,KEEPING WARM WAS!

 

[kalieaire]

I know that propane tends to burn "cleaner" than diesel and gasoline. When internal combustion engines are run on propane, they don't have quite as many carbon deposits as gas or diesel engines.

I have an eberspacher gasoline fired air heater in an old VW that I have used for years. It tends to get quite a bit of carbon buildup fairly quickly. It has a funny glowplug/sparkplug igniter (seriously, it's both) that builds up carbon after a couple hundred hours. This might be because it's a 45 year old design or it might be because it wasn't supposed to be used with unleaded fuel. But, I do need to clean it fairly often. I just spray it down with oven cleaner and it's back up and running again. The new gasoline heaters might be better but I have a feeling propane will be even less likely to carbon up.

Carbon build up from Gasoline and Diesel heaters is due to a couple of things.

• The lubricating nature of Diesel makes it prone to deposits
• Running too cold (meaning setting it low) makes it difficult to achieve complete combustion
• Gasoline, opposite of diesel, has a lot of additives to reduce knock is prone to carbon

So that low setting might be saving you fuel, but not from grief. Run it on high more often before turning it off to burn off the excess so your glow plug doesn't have to work as hard. Running 1K Kerosene will give you a nearly spotless combustion chamber because it's highly refined, almost sulfur free, and burns completely at lower temperatures. White gas will burn more completely at lower temperatures as well.

If you've ever distilled gasoline to produce white gas (gasoline free of additives), you'd see how much is in there.

After a good bit of Googling, it seems that the Diesel and Gas heaters are finicky about elevation (over 5000) and maintenance (carbon buildup).

Run kerosene or white gas to reduce carbon issues. Likewise, with certain diesel heater models, you can actually adjust the fuel output of the pump to get a more stoichiometric air/fuel ratio.

Been running a Propex heater for years and never looked back. Price was not a consideration in keeping warm,KEEPING WARM WAS!

This is the right attitude in my opinion. One and done!

 

[Ark]

Carbon build up from Gasoline and Diesel heaters is due to a couple of things.

• The lubricating nature of Diesel makes it prone to deposits
• Running too cold (meaning setting it low) makes it difficult to achieve complete combustion
• Gasoline, opposite of diesel, has a lot of additives to reduce knock is prone to carbon

So that low setting might be saving you fuel, but not from grief. Run it on high more often before turning it off to burn off the excess so your glow plug doesn't have to work as hard. Running 1K Kerosene will give you a nearly spotless combustion chamber because it's highly refined, almost sulfur free, and burns completely at lower temperatures. White gas will burn more completely at lower temperatures as well.

If you've ever distilled gasoline to produce white gas (gasoline free of additives), you'd see how much is in there.




Run kerosene or white gas to reduce carbon issues. Likewise, with certain diesel heater models, you can actually adjust the fuel output of the pump to get a more stoichiometric air/fuel ratio.



This is the right attitude in my opinion. One and done!

I don't know about the new gas or diesel heaters but the original Eberspacher furnaces don't have a "low" setting. They cycle on and off to control the cabin temperature but when they're on the flame is fully on. There's also no way to adjust the fuel pump output. Most of these "parking" heaters pull fuel from vehicle's fuel tank so no white gas option either.

The gasoline heaters take a little bit of maintenance but it hasn't been too difficult to keep my 45 year old furnace running. Propane would definitely be a little less finicky though. You are right, there are a whole lot of additives in modern gasoline. I am sure it works great in a modern, high compression engine but it does tend to build carbon up on my 1970's furnace after 50-100 hours. But, after a couple squirts of oven cleaner I'm back in business!

 

[kalieaire]

I don't know about the new gas or diesel heaters but the original Eberspacher furnaces don't have a "low" setting. They cycle on and off to control the cabin temperature but when they're on the flame is fully on. There's also no way to adjust the fuel pump output. Most of these "parking" heaters pull fuel from vehicle's fuel tank so no white gas option either.

Ya, the Chinese models allow for low, medium, high settings. The low setting requires the glow plug to be engaged because there's not enough fuel/air to maintain a clean burn, but it works, however, it's probably at the expense of glow plug life. The more sophisticated controllers also allow for altitude compensation.

The nice bit about the Chinese ones is ~$200 bucks you can have a unit with a remote control you can keep around my neck.

• Turn it on for 15-20 minutes before you jump into bed.
• Turn it on for 15-20 minutes when you wake up.

As for using fuel from a different tank, that's always been an option, you just have to install a secondary tank. I just wouldn't for gasoline models since they're highly combustible. Diesel and Kerosene models are much safer since the fumes won't cause an explosion or death if there's a leak.

 

[MattJ]

I wanted to post a quick edit to one of the designs I added to this thread. In the field this week, I realized that I needed to reverse the mount for the 12v fan so that it is further away from the heat generated by the Mr Heater unit. Photos below.

 

[Bobzdar]

Not

The exhaust chugs out at a constant rate but without much pressure, so I just need to give it some help getting away from the tent. The conduit solution fits very tight and snug, plus it is 100% metal. I've learned the hard way that even high-heat silicone and ducting can melt due to the extreme heat of the exhaust. I'm not sure if the conduit is waterproof, airtight or pressure-capable, but I don't think it needs to be any of those. Just needs to get the monoxide a few feet away and not melt. I've learned there is some condensation that builds up in the exhaust pipe too, so it's important that it runs downhill. But thanks for your question and observation!




Yeah, I know. But I got obsessed with figuring out how to design the perfect insulation system for the air intake, heat output and exhaust. All the failed attempts just made me more determined to figure it out. And I convinced myself that a durable, portable, well-made heating kit with extension hoses might come in handy someday for other uses. Such as heating a sleep-in trailer or ice fishing hut or Tentipi or a Hilleberg expedition tent or . . .

Anyway, I did a test-run in the driveway today. Everything worked great. I made a carrying case that doubles as a rain-proof cover. I couldn't fit the largest hose into the case, but at least it fits on top of the case on my Jeep cargo rack.

I went with an electric start “quiet” generator with efficiency mode - it’s around $500 at harbor freight and will run 20 hours on a fill up of 4 gallons running at 1500W (5k btu) which is about the limit of a 110 electric heater. With that you can run electric heat or a/c. Footprint is about the same as that tote - mine slides in my Jeep next to the slide, weighs 120lbs. The fans running are usually as loud as the generator inside the tent so it’s not intrusive. Outside noise is higher but it’s 1/3 the cost, safer and, well, a lot easier. The generator can also be used for a lot of other stuff.

The only time I’ve needed more than 1500W was when it dropped below 15f, and then I added a 2nd heater as the generator has enough capacity, though it uses more fuel. Usually it cycles to idle (efficiency mode) with a thermostatically controlled heater and will get more than 20 hours on a fill as the heater isn’t running the whole time so the generator can drop to idle. I had to use it 24/7 for 4 days on a trip due to needing a/c for a diabetic guest and it worked well needing about one fill up per day - we had 2 5 gallon jerry cans we had to leave and fill up once (brought them filled). For me it just gets used when sleeping for the most part so will go 3 days+ with just the gas in it. An additional 5 gallon jerry can will get close to a week depending on the temps.

 

[MattJ]

I've spent a couple weekends trying to come up with a method for burning anthracite coal in a wood stove for my tipi tent. Anyone out there have experience with this? Anthracite burns hot and long, but my early tests indicate it requires a lot of airflow from below. Here is a photo of the wood stove in the tent, and some photos of the experiments with anthracite on my back patio.

I'm still undecided as to whether this might be a great way to get a nice 24-hour burn or a complete waste of time because it simply will never work. I would appreciate input from any experts out there!

 

[kalieaire]

Not

I went with an electric start “quiet” generator with efficiency mode - it’s around $500 at harbor freight and will run 20 hours on a fill up of 4 gallons running at 1500W (5k btu) which is about the limit of a 110 electric heater. With that you can run electric heat or a/c. Footprint is about the same as that tote - mine slides in my Jeep next to the slide, weighs 120lbs. The fans running are usually as loud as the generator inside the tent so it’s not intrusive. Outside noise is higher but it’s 1/3 the cost, safer and, well, a lot easier. The generator can also be used for a lot of other stuff.

The only time I’ve needed more than 1500W was when it dropped below 15f, and then I added a 2nd heater as the generator has enough capacity, though it uses more fuel. Usually it cycles to idle (efficiency mode) with a thermostatically controlled heater and will get more than 20 hours on a fill as the heater isn’t running the whole time so the generator can drop to idle. I had to use it 24/7 for 4 days on a trip due to needing a/c for a diabetic guest and it worked well needing about one fill up per day - we had 2 5 gallon jerry cans we had to leave and fill up once (brought them filled). For me it just gets used when sleeping for the most part so will go 3 days+ with just the gas in it. An additional 5 gallon jerry can will get close to a week depending on the temps.

wow. I could run my heater for 126hrs non-stop on 10 gallons.

 

[morerpmfred]

Have used coal winter camping in wall tent. We used gravel on the bottom. Layer of wood then piled the coal on top. Once going turned the dampers down and air intake down. Only ever got 6 hours burn time at -30 below. With damper opened slightly snd intake. At -10 we could get a full 8+ hours burn time. Stove was a larger top loading design.

 

[logan_gibson]

I wanted to post a quick edit to one of the designs I added to this thread. In the field this week, I realized that I needed to reverse the mount for the 12v fan so that it is further away from the heat generated by the Mr Heater unit. Photos below.

What model fan is this? Do you have a link?

 

[MattJ]

What model fan is this? Do you have a link?

For some reason, the "share link" button on Amazon products quit working for me last week. Haven't figured out why. But here's a screenshot:

 

[Redman333]

I added some bungie loops to my 12v fan so I can strap it to the handle of my radiant propane heater. I'm planning to test it in a tipi tent next month.

Where did you get that fan


Sent from my iPhone using Tapatalk

 

[logan_gibson]

For some reason, the "share link" button on Amazon products quit working for me last week. Haven't figured out why. But here's a screenshot:

Thanks, its OOS and wouldn't pull up for me, but I found it eventually.

 

[Heavyopp]

I've spent a couple weekends trying to come up with a method for burning anthracite coal in a wood stove for my tipi tent. Anyone out there have experience with this?

I'm still undecided as to whether this might be a great way to get a nice 24-hour burn or a complete waste of time because it simply will never work. I would appreciate input from any experts out there!

I do have a few years experience burning coal at home in a coal burning stove -- I wouldn't expect you will be able to get a long burn like you want in a stove thats not designed to burn coal

1st off by just looking at the pictures the air intake is wrong -- I have 2 different coal stoves in my house -- both have the air intake below the fire grate - this forces the intake air up, thru the coals making for a good hot fire

You also need a way to separate the coals from the ash -- if you can't separate the ash out of the fire the ash will smother the fire -- all coal stoves I have ever seen have some sort of shaker system to the fire grate -- If you can't sustain a long coal fire in your stove this is probably why

Burning coal is finicky -- disturb it too much and the fire goes out, slowly -- you can't just poke the ash out