Generator Powered Heat Sources

[tbro16]

Headed out for a late fall, cold weather hunt in mid November. Going to be a “camp at the truck” type of deal. There will be 3 of us. We plan to camp in my insulated ice fishing hub shelter. Ideally avoiding propane heat sources. I’ve got a generator that I’d like to use to power a safer, drier heat. Google recommends “oil filled radiator heaters” , which appear to be nothing more than a heater you’d plug in to the wall in your home. Any experience using them camping? Or any other ideas?

 

[R boar]

No experience camping with electric heaters, but just keep this in mind. All of them are exactly the same efficiency. The only way you'll get any more efficiency is with a heat pump. So spending more money on a fancier heater won't get you any more heat than the cheapest little blower style or whatever.

 

[NRA4LIFE]

I got a small 500W heater I can power with my super quiet 1000W generator. Little generator will run for about 8 hours on a tank of gas. Does well in small enclosures. If you take a larger generator, I'd go up to a 1000W heater.

 

[GSPHUNTER]

Why can't you use an electric Radient heater. not the oil filled type? I have used them in my work shop.

 

[taskswap]

No experience camping with electric heaters, but just keep this in mind. All of them are exactly the same efficiency. The only way you'll get any more efficiency is with a heat pump. So spending more money on a fancier heater won't get you any more heat than the cheapest little blower style or whatever.

This. Put in technical terms, what makes you warm is BTU's/hr. Say you need 20,000 BTU's/hr to heat some arbitrary camper space. Propane contains ~21,500 BTU per pound. Assuming no efficiency loss (and there always is), a 20lb cylinder will heat that space for 21.5hrs (21500*20 / 20000, the math just happens to work out neatly here that's all).

Now consider electric. 1 watt is 3.41 BTU, so you would need to produce ~5900 watts to run an electric heater to produce the same heat. And it's actually far worse because a gas generator -> its AC output -> the heater will have more losses - most generators are only around 20% efficient, so multiply that by 5 and suddenly you need a 25kW generator just to get by. It doesn't matter whether you have a direct radiant electric heater or an oil-filled one. The oil filled ones just store some heat so after they're shut off they keep warming a room. The heat that went into the oil still came from the same source - it doesn't put out MORE heat, it just stores some for later.

Electric is just about the worst way to heat any space unless it's literally your only option or you have a special case (like in-floor radiant, which still isn't that great). It's not that the heaters are actually all that bad - they're pretty close to 100% efficient, actually, because literally all they're doing is converting angry pixies to heat. What they lose goes to making the filament red which is why they glow. They're just crappy light bulbs.

If you want something efficient and simple, stick with a Mr Buddy or anything in propane land. If moisture is your main concern, look into diesel heaters. They're incredibly efficient, sip fuel, and put out very dry air because of how they're designed. They're cheap, too. They do take power but just to run their fans and glow plugs while starting, so even a modest sized 12V car battery can run one for a week or more. No generator required.

Anyone else camped near you will thank you.

 

[CorbLand]

The little Amazon diesel heaters? Use the generator to charge a battery. Run the heater off your battery.

 

[taskswap]

Yeah those diesel heaters are great. I got one on a whim and used it for what might be a surprising use case. We had our cistern freeze over last winter because I had opened it to do some maintenance but got sick before I could complete it, and didn't get it closed before a cold snap. We had about 1.5" of ice and in a 4'x8' tank that's a lot of ice to melt. You don't let sunshine into cisterns unless you want bacteria/algae to grow so it was going to be months until warmer weather before outside air alone would handle it, and even a 1500W stock tank deicer barely made a dent.

I rigged up one of those little backpack-size diesel heaters on the ground next to it and fired it up, then run a 3" flex hose into the cistern's top port. Cranked it to max and in about 6 hours the cistern was ice free. I ran the whole thing off a small Harbor Freight battery, the 10Ah model I think. Needless to say I'm a big fan of them now. I'm thinking of converting my camper furnace over because even though it already has a propane unit, the diesel heater is actually smaller and since my truck runs on diesel I always have that fuel around. They're insanely efficient - I doubt I used more than a pint defrosting my cistern...

The only thing I would say for a camping scenario is their "installation" is a little heavy on parts count. Most kits come with all kinds of stuff you have to bolt on like fresh air intakes, exhaust/muffler setups, the heat vent pipe, battery, etc. You're expected to handle that yourself with these things. I plan to build a small box for mine to live in so I can make it more of a finished unit that I can move around all as one piece.

 

[rayporter]

listen to taskswap
dont be fooled.
a 2k diesel should put out 6700 btus and a 5k should be about 16000 btus.

 

[OkayestHNTR]

Thread 'Diesel heater suggestion'

Sep 7, 2025

I’m looking for a backup heating solution for my 10x15 wall tent. I usually use a wood stove, but with the fire ban likely lasting deep into October this year, I need an alternative.


I recently purchased a cheap Vevor 8kW diesel heater, and so far, I’m not impressed. The exhaust smokes heavily, and I’ve already had to replace the low-quality fuel lines.


Does anyone have recommendations for a mid-tier option? I’m not looking to spend $2,000 on a high-end unit since I might only use it occasionally. That said, if I find a unit that works well, I could see myself transitioning to a diesel...

• aaron600rr
• Replies: 79
• Forum: General Discussion Forum

 

[taskswap]

I can't speak for the Vevor, but "smokes heavily" sounds like a bad unit worthy of a warranty return. Mine was this HCalory 8kW version: https://www.amazon.com/dp/B0B42TG6FQ. It's no longer made because they have a new case for it with a bit of a nicer display here: https://www.amazon.com/8KW-Diesel-Heater-Air-10-Temperature/dp/B0F83ZZQC8. I do not own the new version so I can't speak for it. But mine doesn't emit ANY visible smoke even while starting up. I'm not saying the unit I bought is the best option but hopefully it's at least a helpful data point.

I can share a negative for those evaluating these seriously. These "suitcase" format units are all fairly narrow. They're heavy enough to still be pretty stable, but I worried a lot about mine tipping over so I screwed mine to a piece of plywood as a footer, and the case has screw holes to do just that. I'm on a few RV/camper forums as well and these are popular for the van-life crowd and people replacing RV furnaces, and most of those folks ditch the case entirely. The actual heater inside the case is a lot more compact than you'd think - there's some unused space plus room for the fuel tank. So if you take it apart and you're a DIYer you can re-organize it any way you want.

I stole an imagine online to show what I mean (this is not mine):


Here you can see somebody used a Pelican (or whatever brand) box to make a setup that worked better for them. I suspect it's because these heaters aren't new at all. They're just repurposing a product that's been sold to semi-truck drivers for years now as cab heaters so they don't need to idle their engines when they're resting. That core unit is the "real" heater and they're all just copying the same design. Heck I bet 80% are made by the same company, and all these different "8kW diesel heater" makers on Amazon are just making the case and display, and throwing stuff inside any which way. There's no magic in there.

 

[fatbacks]

Those diesel heaters are money. I use one up in Alaska for late season Haul Road hunts and actually use this to heat our cabin the winter. Hook it to any battery or generator and they are good to go for a long time. Sips the diesel as well .

 

[hikenhunt]

This. Put in technical terms, what makes you warm is BTU's/hr. Say you need 20,000 BTU's/hr to heat some arbitrary camper space. Propane contains ~21,500 BTU per pound. Assuming no efficiency loss (and there always is), a 20lb cylinder will heat that space for 21.5hrs (21500*20 / 20000, the math just happens to work out neatly here that's all).

Now consider electric. 1 watt is 3.41 BTU, so you would need to produce ~5900 watts to run an electric heater to produce the same heat. And it's actually far worse because a gas generator -> its AC output -> the heater will have more losses - most generators are only around 20% efficient, so multiply that by 5 and suddenly you need a 25kW generator just to get by. It doesn't matter whether you have a direct radiant electric heater or an oil-filled one. The oil filled ones just store some heat so after they're shut off they keep warming a room. The heat that went into the oil still came from the same source - it doesn't put out MORE heat, it just stores some for later.

Electric is just about the worst way to heat any space unless it's literally your only option or you have a special case (like in-floor radiant, which still isn't that great). It's not that the heaters are actually all that bad - they're pretty close to 100% efficient, actually, because literally all they're doing is converting angry pixies to heat. What they lose goes to making the filament red which is why they glow. They're just crappy light bulbs.

If you want something efficient and simple, stick with a Mr Buddy or anything in propane land. If moisture is your main concern, look into diesel heaters. They're incredibly efficient, sip fuel, and put out very dry air because of how they're designed. They're cheap, too. They do take power but just to run their fans and glow plugs while starting, so even a modest sized 12V car battery can run one for a week or more. No generator required.

Anyone else camped near you will thank you.

You're math looks correct, but just so everyone knows, 20,000 btu/hr would turn your camper into an oven. You could heat a 2000 sf home with that amount of heat where I live.

 

[Mighty Mouse]

Now consider electric. 1 watt is 3.41 BTU, so you would need to produce ~5900 watts to run an electric heater to produce the same heat. And it's actually far worse because a gas generator -> its AC output -> the heater will have more losses - most generators are only around 20% efficient, so multiply that by 5 and suddenly you need a 25kW generator just to get by.

Your generator math is way off. You absolutely do not need a 25,000 watt generator to run a 5900 watt heater. Generators are rated based on their electric power output. To run a 5900W device, you would need approximately* a 5900W generator. There’s no 80% loss between the generator and the device you’re running.

Also, a 5900W heater is way overkill for the OP’s use case.

*Actually slightly larger to account for minor wiring losses between the generator and device and to have some margin for inrush current at startup.

 

[Hunter26]

I have heated a wall tent for around 20 years now and mostly with propane heaters. You do truly have to be careful of Carbon monoxide poisoning. Early on we made a mistake closing the socks up high on both ends and tried to make sure no air was drifting in the bottom and woke up with a bad headache the next morning. We got lucky so be careful. That said they do a great job of getting heat fast and you can stay warm. They are also pretty reliable. The downside other than killing yourself is the fact you have to have space for them to run because they can and more than likely will burn something if you use one long enough. I have tried a small electric heater in a 17x14 and it didn't stand a chance to actually generate enough heat to be warm. I just bought a little diesel heater and am hopeful that will be the ticket. Probably get a chance to test it out next year at this point. I bought a Jackery 1000 battery bank to run it over the night and plan to charge devices as well. Then when we are in camp in the evening I will run my generator for lights and recharge the Jackery. We will see how it works but I have high hopes. A small propane heater can get you heat inexpensive and they are the easy button.

 

[taskswap]

Your generator math is way off. You absolutely do not need a 25,000 watt generator to run a 5900 watt heater. Generators are rated based on their electric power output. To run a 5900W device, you would need approximately* a 5900W generator. There’s no 80% loss between the generator and the device you’re running.

Also, a 5900W heater is way overkill for the OP’s use case.

*Actually slightly larger to account for minor wiring losses between the generator and device and to have some margin for inrush current at startup.

Whoops you're right, that 20% is fuel efficiency. Shouldn't post 2 bourbons in. What I should have said was you should derate the generator by some amount so you aren't maxing it out (and I do usually use 20% there) so you'd want a 6500W or so) but then on top of that since they're only 20% efficient on their fuel use (that part is true for most standard generators) you're going to need 5x the fuel of a diesel heater (which I stand by). Either way you're taking losses on both sides that IMO make it not the best choice.

The 5000W of heat is just monkey math - OP didn't say anything about the size of their ice shelter, but either way those things have much less insulation than a typical hard-side camper and since a 5000W electric heater is pretty much the mainstream size for a typical compact ceramic element unit, I just did the math around that. You can divide or multiply it as needed and the math still works. It's still bad IMO.

 

[*zap*]

Oil filled radiator is the most efficient.

 

[arctichunting]

Get a two burner propane stove. I leave mine with one burner on low all night, it’s fantastic.


Sent from my iPhone using Tapatalk

 

[Mighty Mouse]

Whoops you're right, that 20% is fuel efficiency. Shouldn't post 2 bourbons in. What I should have said was you should derate the generator by some amount so you aren't maxing it out (and I do usually use 20% there) so you'd want a 6500W or so) but then on top of that since they're only 20% efficient on their fuel use (that part is true for most standard generators) you're going to need 5x the fuel of a diesel heater (which I stand by). Either way you're taking losses on both sides that IMO make it not the best choice.

I agree on the fuel efficiency part. It’s much more efficient to produce heat directly burning the fuel rather than using the fuel to drive an engine that turns a generator that produces electricity that powers a heating element. I could believe a 5x difference in fuel consumption between a diesel heater and a fixed speed (non-inverter) generator running below full load.