Engine vs. Propane for cold weather heat.

[CUP]

Probably asked and answered many times. If its cold enough to run the furnace in a gas class A, not hooked to shore power, what is the down side to letting the engine run (over night) providing dash heat which also provides heat in the rear via the Motor Aide system (heat exchanger under the bed) as opposed to running the generator using approx. 1/2 gal per hour and using your propane? Which is more efficient?

[Teamfoxy]

The propane furnace usually operates on DC (battery) power and will run without being plugged into shore power or running the generator. The blower is a significant drain on the batteries and they will need to be recharged sooner.

[BobC]

Running the engine overnight is going to be much more dangerous due to the risk of carbon monoxide seeping into the coach from the exhaust. I wouldn't do it myself.

You might want to check out some of the LPG powered catalytic heaters that are safe for indoor use, like the Olympian Wave heaters or, for occasional use, a Mister Heater Little or Big Buddy.

[Morich]

Very hard on engines to idle for long periods. Can be done but most manuals for vehicles do have a separate schedule for engines which are required to idle for long periods, so it can be a penny saved but cost a dollar? Also there is a good chance that the heat will not get to the bedroom in nearly as good a fashion as from the furnace.
Noisy, costly, and not very much fun?

[KTM251ss]

If the propane furnace isn't keeping up and you are not on shore power your most efficient and safest choice (IMHO) would be to run the generator and plug in a oil filled radiant heater in the bedroom. Running the Chassis engine at idle for hours on end isn't what it is designed to do and can cause a failure, lack of air flow on radiators, excessive heat trapped in engine compartment causing certain parts to fail from heat. It's just not designed for it.

[747Driver]

We do a lot of dry camping and some of it in colder wx. We run generator up to quiet hours, getting RV up to toasty temps using heat pump, if warm enough, to mid 70's. Then run thermostat down to 63 F, set for gas heat, with extra blankets ready. We then close the sliding doors to the bedroom. Our model has two zones, the front zone is the one it uses for gas heat. Keeping the front at 63, we are around 67 in the bedroom.

We have a ceramic heater for those situations, where it is too cold for the heat pump.

You will need to get the generator up and running to get batteries charged in the AM. The gas heater does run the batteries down and will tell you how strong your batteries are.

[Pianotuna]

Do not use an unvented combustion heater.


If running the engine--it should be on "high idle".


I won't run a generator while sleeping, much less the engine.

[Jim_HiTek]

I'm with PianoTuna somewhat. I wouldn't run the generator without using an above the roof exhaust system for it. They make them or you can make your own.

[Frederick]

Because I am a mechanic I can say with confidence that long idling periods on the engine are not good. It’s not going to cause any immediate catastrophic damage, but it’s not a good practice long term. Like others have said the propane furnace should run on DC power. Having said that the control board on my furnace went on the blitz last month at the boondocking site at the Petrified Forest Natonal Park with overnight lows of 18 degrees. I let the V10 idle overnight and used the cab heater for the night until I could get a replacement control board. It’s good to know that in an emergency the can heater will do the job. But, I wouldn’t recommend as a consistent practice.

[GTobey]

Originally Posted by CUP

Probably asked and answered many times. If its cold enough to run the furnace in a gas class A, not hooked to shore power, what is the down side to letting the engine run (over night) providing dash heat which also provides heat in the rear via the Motor Aide system (heat exchanger under the bed) as opposed to running the generator using approx. 1/2 gal per hour and using your propane? Which is more efficient?

It's not good to operate an engine unloaded, and not at it's peak operating temperatures. Running the main engine at idle or partially above leads to oil contamination from incomplete combustion in the cylinders, fuel dilution of the oil, carbon build up in the cylinders, extra wear to all moving components from engine oil contamination, etc. Generator engines are sized to the exact power requirements of the generator head. They are made to run at that power factor for that rpm whether 1800rpm or 3600rpm. Run the generator as needed to properly power your accessories in the RV. You may have to fill up with propane more often, but that is the nature of cold temps. Your coach engine is for transporting the RV, not for keeping warm with.

[Journey39n]

Usually, the propane furnace is sized to provide sufficient heat in the RV for reasonable cold temps, say above 10 degrees. And it does run off the 12v system in the coach, but you will have to run the generator in the morning, to bring those coach batteries back up to proper voltage.

That being said, if temps are below freezing for long periods of time, what measures are you taking to keep your water systems from freezing. Using the propane heat for the water heater will keep that area warm, but what about other areas? Some RV's are not equipped to handle really cold temps.

You just have to learn what works for your RV. Starting our full time adventure, first day on the road, was in the winter, driving through 30 degree temps, rain and snow, heading south of course, finally parked at 10:30pm, in a casino lot, quiet hour time. We set the thermostat at 55, and curled up in bed. Next morning, even though the propane furnace had kicked on several times during the 15 degree night, the coach was at 55 inside. We still had enough juice to easily start the generator, and charge up the batteries. Setting the thermostat at 65, the propane furnace got us toasty warm in short order. Our adventure was on its way !

[Billincamo]

Buy a small honda eu2200 gas generator. The best purchase you will ever make for boon docking. It will run the furnace, TV, and lights all night long without worrying about running your batteries down. I have had mine for 8 years and love it. Very quiet and sips gas.

[UncleGoat]

Billincamo,
Stupid question here. I'm new to the whole RV living, and generator using. So, how do you hook the EU2200 up to run the systems? Is it sitting outside the RV or does it need to be inside, and you just crack a few windows? I know that sounds like an absurd question, because, if not mistaken most generators have exhaust, no? That being said, maybe with modern technology, there's something of which I am unaware.

[WinnieView]

Originally Posted by UncleGoat

Billincamo,
Stupid question here. I'm new to the whole RV living, and generator using. So, how do you hook the EU2200 up to run the systems? Is it sitting outside the RV or does it need to be inside, and you just crack a few windows? I know that sounds like an absurd question, because, if not mistaken most generators have exhaust, no? That being said, maybe with modern technology, there's something of which I am unaware.

There's nothing new and generators should be placed outside and always vented outdoors.
Some owners will erect a small shelter if needed to protect it from the elements.

[Teamfoxy]

Originally Posted by UncleGoat

Billincamo,
Stupid question here. I'm new to the whole RV living, and generator using. So, how do you hook the EU2200 up to run the systems? Is it sitting outside the RV or does it need to be inside, and you just crack a few windows? I know that sounds like an absurd question, because, if not mistaken most generators have exhaust, no? That being said, maybe with modern technology, there's something of which I am unaware.

Any portable generator needs to be run outside the RV and you need to plug the shore power cord into it. An adapter is usually needed. If you are concerned about theft, then use a cable or chain lock to something hard to move.

I personally would not use any heater that gets its combustion air from and vents it to the RV. We either use the furnace, which has a heat exchanger, or we use a small electric (cube) heater.

[Phil G.]

Originally Posted by CUP

Probably asked and answered many times. If its cold enough to run the furnace in a gas class A, not hooked to shore power, what is the down side to letting the engine run (over night) providing dash heat which also provides heat in the rear via the Motor Aide system (heat exchanger under the bed) as opposed to running the generator using approx. 1/2 gal per hour and using your propane? Which is more efficient?

I'm confused about your situation. You apparently have a Class A with it's built-in generator?

Then why not run your generator all night to keep warm and use no propane at all while consuming only 1/2 gal. per hour of main engine fuel?

Keep warm by running the generator to power one or two electric heaters. This is a safe solution ... and two of them should keep the interior comfortable enough to get by in fairly cold temperatures. The only problem might be how do you use the electric heating to also keep the fresh/grey/black water plumbing systems from freezing, which sometimes RV propane furnace ducting systems are designed to take care of along with keeping the interior warm.

We have a small Class C motorhome, but it's 4000 watt built-in generator will of course easily power a couple of electric heaters.

We keep all built-in generator fumes out of the interior while it runs for air conditioning any other purpose by maintaining a slight air pressure inside the interior ... this prevents fumes from entering any small cracks, or openings ... including a slightly open window. This technique keeps the interior fume-free at all times while using the built-in generator.

[Pianotuna]

keep any generator 50 feet from the RV when it is being run.

[4x4van]

Originally Posted by CUP

Probably asked and answered many times. If its cold enough to run the furnace in a gas class A, not hooked to shore power, what is the down side to letting the engine run (over night) providing dash heat which also provides heat in the rear via the Motor Aide system (heat exchanger under the bed) as opposed to running the generator using approx. 1/2 gal per hour and using your propane? Which is more efficient?

There is no reason to run a generator in order to use the LPG furnace; it operates off of 12vdc, not 120VAC. As long as your batteries are in good condition/SOC, you can easily get 1 or even 2 nights worth of furnace use. Been doing it for 30 years, with 3 different RVs.

[SarahW]

Originally Posted by Phil G.

We keep all built-in generator fumes out of the interior while it runs for air conditioning any other purpose by maintaining a slight air pressure inside the interior ... this prevents fumes from entering any small cracks, or openings ... including a slightly open window. This technique keeps the interior fume-free at all times while using the built-in generator.

And how do you maintain a slight air pressure inside? Are you operating the vent fans?

[Diesel-Lover]

One of the best things you can do is not idle an engine, as at idle the processes are not generally optimal, besides why have all those horses in a slow treadmill when they are tuned to at the least cantor or mosey at a nice gait, and at best galloping down the road! The dangers from CO are also very bad and in most cases the tail pipe is right under the bedroom! Generator could be cycled on partway through the night to recharge the battery, sad the RV industry is sleeping and not realizing that a liq cooled generator could double duty as a heat source too! THey are snoring louder than the generator sounds and totally ignoring fuel cells which produce some heat, and co2 as byproduct while running quietly and generating a hush about like a fan running! There are some tiny heaters that run via combustion of diesel or even gasoline (blue air, espar etc etc), they have much lower fuel and battery drain and can heat the section you want heated via a thermostat at a given temp level! unlike your dash heat unless you are in a RV that borrowed from automobile industry dash heat regulation system after what a decade or more of ignoring temperature settings on dash heat and AC !