Propane generators

Topic: Propane generators (Read 1244 times) previous topic - next topic

Propane generators

February 04, 2012, 03:55:28 pm

As I review the literature on the older coaches that might be of interest to us some day, it seems that they all have propane generators. Most other brands have diesel generators. Is there some advantage to propane over diesel? The other brands are generally 3-4 years newer. On the other hand, every Wanderlodge I've seen advertised has a diesel generator if the engine is diesel, and the ones I've looked at are several years older than the Foretravels.

Re: Propane generators

Reply #1 – February 04, 2012, 04:29:13 pm

I think the diesel generator is a very big plus as sometimes it is difficult to find a place to buy propane. Many of the unihomes of u280 and u300 have diesel generators but the u225 and u240 and the straight grandvillas had the propane generators due to mounting space. Also the diesel generators use less fuel FWIW

Re: Propane generators

Reply #2 – February 04, 2012, 04:36:03 pm

I called up the specs on a 94 U-280, and it shows a 6.5 KW slideout generator, LP fuel.

Re: Propane generators

Reply #3 – February 04, 2012, 04:42:55 pm

Yes, most prefer a diesel generator.

But, you asked the advantages of a propane generator, so here goes:

Less than half the weight of a diesel generator.

Air cooled, so FAR less complex in terms of cooling issues.

Propane is a clean fuel, with no gumming up of the carburetor.

LONG oil change intervals because it is a clean burning fuel.

Yes, I would rather have a diesel generator, but in the lighter coaches (U225 and U240) the diesel generator was too large and too heavy to reasonably fit.

Brett

Re: Propane generators

Reply #4 – February 04, 2012, 05:59:45 pm

Couple of other advantages I can think of. They start easily in really cold weather, generally vibrate a little less, usually less noisy and don't smoke or smell as much, especially at high altitude and during the morning start up. A real plus in a crowded National Park campground. They also fit into smaller spaces so more room for storage. An Onan Emerald 7000 could have been mounted in the nose of my U300 leaving another compartment free. Harder to work on in that location but they are pretty reliable.

Propane can be up to $2/gal less expensive so the increased fuel consumption is offset a bit IF you have an inexpensive source.

Still do like my diesel generator but I could live with a Onan.

Pierce

Re: Propane generators

Reply #5 – February 04, 2012, 07:51:49 pm

The question becomes then how big are the propane tanks in a MH and how long would it take to empty the tank if you were boondocking.

I have a fixed site propane gen set ( 13 KW ) at my house and the recent snowstorm in Oct that brought down all the electricity wires in CT because the trees were so heavy with leaves and snow left many w/o power for 11 days.

I used 78 gals of propane in 7 days operating the gen set about 75% of a day. I have 300 gallons of capacity.

I think in a M/H you would want a diesel gen set as you have more fuel supply available from your main fuel tank.

Re: Propane generators

Reply #6 – February 04, 2012, 09:28:16 pm

That's what I'm concerned about. I printed the spec sheet for a 94 U-280 just as an example, and it has a propane generator with a 270 pound tank.

How long will that tank run the generator, stove, hot water heater, etc. when boondocking? Yes, we'll cut way down on dish washing and showers, but unless the temperature is very cooperative, we'll need either the heat or a/c at least once in a while.

Re: Propane generators

Reply #7 – February 04, 2012, 09:40:54 pm

That seems like a very big tank for a motorhome, how many gallons is it ?

Re: Propane generators

Reply #8 – February 04, 2012, 09:44:53 pm

That's what the sheet says. I've noticed that some manufacturers list the tanks by weight and some by volume. According to one site I just checked, propane is 4.11 or 4.2 pounds per gallon. That would say the Foretravel tank is about 65 gallons. Does that sound better?

Re: Propane generators

Reply #9 – February 04, 2012, 10:12:42 pm

Quote

According to one site I just checked, propane is 4.11 or 4.2 pounds per gallon. That would say the Foretravel tank is about 65 gallons. Does that sound better?

David,

Actually, the propane tank in that U-280 is an 80 gallon; however, understand that a "full" tank of propane only holds approx. 80% propane. Thus, a full tank holds about 65 gallons or 273 lbs. There may be a few U-280's from '92 on that have propane generators in them, but not very many. I have inspected nearly a dozen 280's between '92- and '95 and not a one had a propane generator. There are owners on this forum who have been stranded in cold weather and had to use their propane generators nearly 24hrs/day. As I recall, they had to refill in less than a week. When you include the two propane furnaces, hot water heater and oven, even the 80 gallon tank won't last long. The specs on my coach stated 267 lbs capacity for the 80 gallon tank.

I have the big propane tank, but the 7.5KW Onan diesel generator. The propane is just for the furnaces, water heater and stove.

Re: Propane generators

Reply #10 – February 04, 2012, 10:42:36 pm

I suppose there might have been, but I've yet to see a propane gennie on a U280/U300.

Re: Propane generators

Reply #11 – February 04, 2012, 10:47:33 pm

My 93 had the Powertech 10KW with Kubota 4 cyl. That was the standard generator for 280/300/320 for 'several' years. Rock solid generator.

Re: Propane generators

Reply #12 – February 04, 2012, 10:49:33 pm

Like I said I used 78 gallons in 7 days at about 75% use a day.

65 gallons in a motor home is not much capacity for a propane gen set.

Re: Propane generators

Reply #13 – February 04, 2012, 10:58:01 pm

How about a little shocker / fact of life. Average RV load demand on average generator.
A generator on LP Gas will average 24 gal day, running non stop.

The exact same load using a diesel will burn 10 gal fuel in 24 hours, non stop.

Cut/slice it any way you like. Facts are facts, have run both types gensets in the MCI for thousands of hours, and kept clear records, why I went the diesel route, Real clear & simple fact.

Dave M

Re: Propane generators

Reply #14 – February 04, 2012, 11:23:14 pm

According to charts I found on line:

#2 Fuel Oil: 138,500 BTU/gal 7.15 lb/gal
propane: 92,000 BTU/gal 4.23 lb/gal

Values will vary a bit with temperature and specifics of the product. In any case, diesel fuel is much more dense than propane. It is also much more expensive than propane, but it is easier to fill a diesel tank than a propane tank.

In the two 1997 model coaches I have owned: SOB had 6.5KW Onan propane generator; FT has 10KW Powertech/Kubota diesel generator. The 1997 FT cost about double the cost of 1997 SOB in 2010. <OPINION>I like the diesel generator WAY better. I like the FT WAY better.</OPINION>

Your experience, preferences, and budget may lead you on a different path.

Re: Propane generators

Reply #15 – February 05, 2012, 12:23:56 am

I know there are a lot of thoughts here and perhaps this one is superfluous.
My previous motorhome had a propane generator and diesel pusher. The generator was quiet, ran great never gave me a problem with starting, running whatever. The thoughts on being a cheaper fuel is spot on (can't say I did not like that). The generator runs quieter, and the emissions are less objectionable (but not safer). Here are the hitches, not every place you may get fuel has propane. When you stop to fill up, you have to fill up twice, diesel for the motorhome and propane for the generator. This usually takes about 3 times as long as you have to run down some guy to pump the propane for you (as you can not pump it yourself). My previous motorhome had too small of a tank (FT is larger propane tank) and this necessitated me having to fill on a way too regular basis. I do not full time, use my motorhome weekends and vacations. Now, if I was looking for a FT and saw one with a propane genset in great shape with the right price, I would consider it. However my FT (present motorhome) has the diesel generator and I can say that it has been a good one. And I like the convenience of having only one fuel to deal with at truck stops. Yes, the diesel has some drawbacks but I really prefer it because of the pluses. Final thought is I would consider a motorhome with a propane generator but prefer the diesel.
I hope this is helpful.

Re: Propane generators

Reply #16 – February 05, 2012, 08:48:50 am

An observation from my reading and researching - the generator fuel type seems to be dictated by the power being generated. The propane powered Onans run from 5KW to about 7KW; the smallest diesels I've seen run from 10KW on up. In general, it would appear that larger coaches = more KW needed = diesel genset.

Diesel has more BTUs per pound of fuel than propane, so yes - you'll burn more fuel per hour of operation, but as the propane gensets have smaller engines producing less power, it becomes a somewhat blurred picture in terms of direct comparison. Pluses and minuses whichever type you have. Output vs efficiency vs maintenance vs repair costs vs complexity vs weight and space, etc.

I seriously considered a bus conversion at one point; wanting to power everything from diesel. Diesel furnace, gennie, hot water, etc. I even found a diesel stovetop, although these are only available in Europe right now.

Dealing with a second fuel source is a hassle, but propane powered equipment seems to be simple, reliable, and not terribly expensive to replace (well, the gennie will set you back).

Steve

Re: Propane generators

Reply #17 – February 05, 2012, 11:00:24 am

We have never had a generator of any sort on an RV so we're pretty happy with the propane 6.5kw gennie on our U225. We have to buy propane anyway for the stove (and refrigerator if we're off the grid) and for the furnace and water heater regardless. So the dual fuel is not an issue for us. The propane generator seems nice and quiet (especially inside the coach). I suspect we could get by with a 2.5kw generator actually.

I'm a big fan of diesel (I've had diesel cars and trucks since the 1980s) but I just don't see it as much of an issue with the generator. We will probably never run our generator more than 2 hours at a time anyway.

All-in-all, I prefer solar panels and a decent inverter.

Craig

Re: Propane generators

Reply #18 – February 05, 2012, 02:23:53 pm

A big plus for the diesel generator owners is the partial load fuel consumption. Sure, diesel has about 40% more energy per gallon but where it really shines is at partial load. This is when you are charging batteries, have one roof air on, etc. A gasoline/propane fueled generator operates at about 14.7 parts air to 1 part fuel (both numbers reflect mass) all the time. So if at idle, part load or full load, it still needs about a 14.7 ratio to run. (OK, new Honda stratified engines run 22 to 1)

A diesel on the other hand will operate on air/fuel ratios from about 15 to 1 at full throttle to 120 to 1 at idle, so at partial load, the diesel really shines. At idle, all it needs to do is inject (spray) enough diesel to overcome internal friction plus a tiny bit more, for example to idle all night waiting for taxi passengers outside a train station.

Anyone watching LeMans on TV has seen the Audi and Peugeot diesels almost celebrate yellow flag laps where they can run all the slower laps at very high air/fuel ratios compared to their gasoline fueled competition.

Also why our motorhomes get such good fuel mileage when you cruise at lower speeds with less fuel lost fighting wind resistance. At 55, the throttle is only slightly depressed. My neighbors pickup truck actually uses more gallons of fuel going to San Francisco than I do with the U300.

Pierce

Re: Propane generators

Reply #19 – February 05, 2012, 04:15:57 pm

To distill it down, if you run your generator a lot, go diesel.

If you use the generator some, but rarely 24 hours at a time day after day, a propane generator is just fine (and a LOT less hassle than a gasoline generator).

Brett

Re: Propane generators

Reply #20 – February 05, 2012, 04:54:36 pm

Thanks for all of the helpful comments. It sounds like, all other factors being equal, we ought to pick the coach with the diesel generator. A propane one is not necessarily a deal-breaker, but certainly would be a bit of a negative. Is that a fair assessment?

We're starting to think that we may do more boondocking that we originally thought, so perhaps the generator would run more. Also, any motor home headed into the sun will heat up fairly quickly, thanks to the large windshield, and running the house A/C would probably make sense.

I'm using a 94 U-280 that MOT has listed as an example for all of this. We are NOT buying a coach now (much as I'd like to), but that is one that seems to fit many of our wants and needs. It may be for sale again when we're ready to buy, or it may not. I'm just using it as an example. I went back and looked at the information on it, and it is listed as a 10 KW Powertech, which I assume is a diesel. The spec sheet doesn't list that, so maybe it was an option? Nice to know that most will have the diesel generator, as that's what I think I'd prefer.

Re: Propane generators

Reply #21 – February 05, 2012, 04:55:53 pm

Yup, I love the LP Gas / Natural Gas generators, we sell a lot of them up to 250 kw on Nat Gas. about 140 of LP, We do not sell gasoline generators, too much hassle, bad fuel, water in fuel, set too long, gasoline dried up leaving crud & problems, etc etc & etc.. no win. If your gonna use gasoline, use the high test, it lasts much longer before causing issues.
Dave M

Re: Propane generators

Reply #22 – February 06, 2012, 06:32:36 pm

I have a 10KW diesel genset in my 1996 U320 and am thinking seriously about selling it and I have been living in my U320 since early November (except 2 weeks in Canada at christmas) and last ran the genset on Dec 2nd to exercise it. I am due to run it again soon, but do not need the power.
Solar, LED lights throughout, and power management results in not needing the generator.
Any one interested in a 1995 10KW diesel genset with 1400 hours which runs perfectly?

Re: Propane generators

Reply #23 – January 08, 2014, 02:09:54 pm

Reminds me of when I first looked at the specs of my 94 U280:

Seems the Propane Genset was the Standard, and the Diesel (Mine is 10KW with Kubota 4cyl), along with an upgraded heart Inverter (3kw, I think) was the Upgrade:

What I have seen since this is most of the rigs had, and it does make more sense;

I can last for several months on the Propane without genset usage; Also have a 'Gentlemens' 2kw quiet genny for use at MWRs, or boondocking when need to be quiet.

Reid

Re: Propane generators

Reply #24 – January 08, 2014, 07:36:24 pm

Grand Villa Propane tank,

I am going full solar, and small Swap and Go Tanks,

With the front curtains shut, and all the awnings out, Face the front of the Coach to the east,
In 38 + Celcius,
My coach had a cool breeze blowing through it,
It handles the heat with no A/C going,
-4 Celcius, It was still warm inside the Coach,
But your cold is a different story, You need heat in your Coachs, Or parked for the winter,

The one on the left is Ian's. The one on the right is mine, They are Big Tanks, and very heavy,

My tractor was struggling to lift it. Plus it was almost full of gas,

Gas here is half the price of fuel, So if you can run gas, Do it,

LPG, Diesel, Petrol, All come out of the same Bowser, And you pump the lot of it,

Swap and Go Bottles, come in a precharged bottle, You put yours down and pick up the full ones, There is no waiting for your tank to get filled,

Pump Gas is every where here, Remote area's. You might have only one servo selling gas in that town,, But they do have it,
Swap and Go tanks, are everywhere, Local shop sells them, Well almost, Hahahaha,

I do love the truck pumps, It fills it fast, and the G/V handles the high volume easily,

I have an Onan powered petrol mobile welder, Same size motor almost as my Coach, Its very heavy on fuel, and it ate a litre of oil per day, Since new,
They literally self destruct if they run out of oil, Ive seen it a few times on other people welders,

The white Tank in Ian's piccy is a Swap and Go Tank,

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