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Mark Radius (24.247.233.200)

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Posted on Sunday, March 31, 2002 - 9:52 pm:   

Has anyone had any experience with a LP fueled getset on their coach? Any feedback appreciated, including good manufacturers, or units to stay away from!

Thanks... MR
slc (4.17.253.97)

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Posted on Monday, April 01, 2002 - 12:44 am:   

A propane genset is reliable, usually quiet and dependable. If you will NOT use the genset for many hours each day, perhaps for just charging batteries or food prep, it may be a good choice.

HOWEVER, a propane genset will burn up a tank of fuel quickly, having a removeable propane tank for the genset would be a really good idea so you do not have to move your coach when you need gas. The gas burns up quickly since it has a lower btu rating (I think) when compared to Diesel or gasoline. But then again, Propane fuel is cleaner, easier to handle and most coaches carry a propane anyway.

Onan has a unit, i believe HONDA also has some in there RV line. There are others, however I can't think of the names. good luck
Scott Whitney (24.205.239.4)

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Posted on Monday, April 01, 2002 - 1:07 am:   

I have an Onan 6.3 KW Emerald propane unit. What is it you would like to know?

I can tell you a few things off hand:

1) Burns very clean with only a slight smell of propane.
2) Burns so clean, my oil always looks brand new.
3) Burns lots of fuel & that = $.
4) Fairly quiet when in a sound box.

I chose propane because I did not have space in my transit for a diesel genset (nor the money) and did not want to introduce a third fuel. (gas)

I intend (in theory) to run the genset only to recharge batteries, at 130 amp max charge rate, from about 50% to 80% every other day or so. I use propane for all heating, cooking and hot water so the genny is really only for battery charging or if I need to run a serious load like my welder. I would not, for example, burn propane running the gennie, to run the AC all day long as that would get spendy - not to mention empty the tank in short order.

Scott
Lin (65.184.0.189)

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Posted on Monday, April 01, 2002 - 1:47 am:   

I thought about a propane generator. The diesel units are too expensive and too big for where I want it to keep it. Also my needs are only about 6kw to run two AC's. Most of the time a 4kw unit would be fine. I also considered the nuisance of having three fuels to deal with, but finally decided that of the 3 fuels, gas is an easy one to deal with. All you need is a gas can in a pinch.
Phil (204.89.170.3)

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Posted on Monday, April 01, 2002 - 7:49 am:   

Having had LPG gen in my old RV and now having an Onan 7.5 Quiet Diesel, I would never go back. Having said that, I also must say that I dry camp quite a bit in hot weather so I run both AC units and in hot weather the furnace. Also the sat. dish, TV, convection oven, etc. Running off the inverter quickly runs down the house bats. Even with these loads I still only put 200 or so hours a year on the gen. I find I am willing to run it more although my fellow campers might prefer I didn't. I try to be considerate with how I park (where the exhaust is) and when I run it.

Propane: Too expensive to run and too inconvienient to get fuel but the cost difference to go to diesel will never be made up for in fuel costs. Clean and fairly quiet, minimal odor.

Diesel: Very expensive to buy and will not "pay for itself" in its lifetime. Maintenance is fairly expensive on my Onan due to the price of filters. Will last a long time. The Onan QD is very quiet and has some exhaust smell but not bad.

Gas: Least expensive to buy but need a third fuel. Quiet, least inexpensive to operate, little odor. If I were buying a gen for installation I would put in the third tanK!!!

All that being said, I still love my diesel!!
Geoff (64.1.0.9)

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Posted on Monday, April 01, 2002 - 8:52 am:   

Diesel gensets don't have to be that expensive-- I picked up an 7kW Isuzu water cooled 1800 rpm unit for $3295. Of course I had to build a sound box for it which added to the cost somewhat, but my little diesel is pretty quiet (at least not obnoxious) and just purrs along running fuel off the main fuel tank.

--Geoff
'82 RTS CA
Bruce Finlayson (209.53.87.189)

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Posted on Monday, April 01, 2002 - 11:29 am:   

I have a 4.0kw Kohler on propane ----quiet and trouble free. Propane in Canada ( and Mexico) is much more available than in the States. I have a 100 lb. fixed tank and a 40lb. portable tank so supply is no problem.

Bruce MC2
FAST FRED (209.26.87.32)

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Posted on Monday, April 01, 2002 - 4:13 pm:   

The basics have all ben laid out for you.

If you live where 2 air cond is the norm 24/7, the diesel would be best choice.

If you only need some battery charging or a couple of days of air cond , once in a while the propane is the least hassle.

Not only do the engines last at least as long as most tiny diesels , the maint cost is also much lower.

Best of all , if your like me , and only need a gen set on rare occasions ,(air cond) the propane is far superior to anything else.

The "carb" evaporates the fuel cleanly at the end of a run , no varnish created after a couple of months of inactivity, so they start and operate with great tollerance for lack of use.

Good starting in the below zero temps too.

Additonally the campers downwind are not being poisoned , or given cancer as a result of breathing the Propane exhaust.

There so benign Uncle Ossha lets them run inside a building.

The old ONHO are very reliable and if the set will ONLY be used on propane the compression ratio can be raised ( mill the heads , like your 41 Plymouth}.

Diesel has about 160,000btu per gal gasolene about 125,000 btu and propane only 95,000 .

Must propane use that is more than 10% over gas is caused by the carb being way too rich.

The proper adjusting procedure is in Da Book .

Two fuels diesel for the DD and propane for everything else makes the coach the easiest to boondock , for months if necessary , so its MY Choice too.

FAST FRED
Gary Carter (216.17.71.35)

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Posted on Monday, April 01, 2002 - 11:35 pm:   

I have a 7KW Kohler propane genset. But then I bought it used with less than 100 hours for $1400 including an 80 gallon tank. I will not burn enough propane in my life to make up the difference. Plus I do not find propane hard to get and usage is not all that bad.
Scott Whitney (24.205.239.4)

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Posted on Tuesday, April 02, 2002 - 12:05 am:   

FAST FRED,

Can you elaborate on what the benefits would be of milling the heads on a propane genset? (Like an OHNO Emerald 6.3Kw) Increased efficiency?

Also, curious about the BTU figures. I had always thought gasoline was a lot more volatile than diesel. Is it not so, or is that not related to the amount of BTUs/gal. they hold.

Thanks,
Scott
FAST FRED (209.26.87.21)

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Posted on Tuesday, April 02, 2002 - 5:27 am:   

Although Propane doesnt have a high BTU per gal count , it IS about 115 octane!

Therefore the engine can be run with a higher compresson with no knocking or ping.And slightly more efficency.

Volatility , the ability to evaporate , and be lit at a low temp (propane its about -40F}and diesel you can toss a lit cigarette into might have a relationship to BTU per gal , but I dont know what it is.

Although it seems that heavier fuel is harder to light.

Heavier fuel DOES have more BTU per gal , cause there is more fuel there.

Arent you glad we dont use #6 Heavy in our DD'S?

Needs to be heated just to flow thru a pipe!

FAST FRED
C. Ray Powell (Raypowell) (152.163.197.186)

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Posted on Tuesday, April 02, 2002 - 8:21 am:   

We went with a Wrico Diesel gen set. Building a sound box & running exhaust thru roof.
C Ray
Tom Caffrey (Pvcces) (12.146.33.21)

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Posted on Tuesday, April 02, 2002 - 10:33 pm:   

Fast Fred, I've always worked with 140,000 btu per gallon for diesel. I just looked it up in "Pocket Ref" by Thomas J. Glover and he says 143,000 btu per gallon.

I know there are heavy and light grades of diesel and that no two batches are identical because of the mix of hydrocarbons involved, but I doubt that it would be diesel if it was 160,000 btu per gallon.

For weight, I've used 7 1/6 lbs. per gallon for diesel and 6 1/6 lbs. per gallon for gasoline. Also, 4 1/4 lbs. per gallon for propane liquid.

I recently saw a brochure from Cat on one of their engines and they listed fuel weight of 7.001 lbs. per gallon in their specs.

The Pocket Ref lists 2.53 million btu per 1000 cubic feet for propane, but I never found out how to translate liquid propane to gaseous propane.

Tom Caffrey PD4106-2576
Mark Radius (24.247.233.200)

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Posted on Thursday, April 04, 2002 - 9:19 pm:   

Wow! What a wealth of information! Thanks everyone.

MR
John G Root Jr (Johnroot) (140.186.114.253)

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Posted on Saturday, April 06, 2002 - 11:03 am:   

This is great, just the topic I need. I originally decided to go all electric, diesel gen, diesel heat, etc. can get it so quiet that all you hear is the air coming in and out. Then I had to agree with Fast Fred about poisening fellow campers as little as possible. Now I will do propane, BUT does that mean if I have a propane fridge I have to put one of those propane fridge vent grill things through the bus side? How big a propane tank would I need to go a week with 2 roof airs going 24/7? Lets say 6.5 cubic ft an hour, the figure given by Generac for the consumption running that load, times 24 times 7 or 1092 cubic ft. Now how many gallons or pounds is that? And how big is that tank? Does anyone know, or know how I can find out?
Thanks
John
Scott Whitney (24.205.239.4)

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Posted on Saturday, April 06, 2002 - 1:42 pm:   

Hi John,

If you are going to use a propane fridge, you'll have to vent it somehow. The roof makes most sense. It actually needs a vent on the side for air in and a vent on the roof for air out. That way you get a good convection. They are wonderfully efficient and I love mine.

If you are thiking of running two ACs 24/7 on a propane genset, I think you better forget about a tank. Get a 1/2" propane pipe plumbed directly to your rig. Just kdding of course, but I don't see running that much AC from a propane genset as being practical.

I have an Onan 6.3 KW Emerald propane (NHE). It specs at 6.6 Lbs/hr running at full load. Running two ACs will put it at full tilt. So. . that puts you at about 158 Lbs of propane a day. That comes out to about 37 gallons of propane per 24 hour period. For a stay of one week, you'll need a propane tank of about 260 gallons. That is one whopping big LP tank. At about $1.50/gal. your propane budget would need to be about $391/week.

I can't imagine running 2 ACs 24/7 on propane. But if you did run the propane genset constantly, you could use those numbers as a basis.

Someone please correct me if my math is off. Sounds like based on your needs, a diesel genny is in your future.

Scott
FAST FRED (209.26.87.58)

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Posted on Saturday, April 06, 2002 - 4:22 pm:   

Although there are lots of places that need air cond 24/7 , not many coaches need that style full blast 24/7.
Even if a coach was painted BLACK the need for AC goes way down after the sun stops being a huge source.

As the fuel consumption follows the power being generated , when an air cond compressor only cycles on 50% of the time , your fuel consumption will only be 1/4 of 2 units goung full blast.

The "Hole" in the top of the coach fridge requirement is best met with a Nicro Fico solar vent.

Instead of a huge hole and prayers that the breeze is in the right direction ect, the $100 or sovent has a motor , solar cell and battery.

These make almost NO noise and need no maint.

One or two will have a fridge happily working , even when the coach is 110 inside with NO air cond.

There does need to be a duct , or shield behind the fridge to help the air go up , but sheet metal , or taped together Fireproof insulating duct works just fine.

Besides the RV fridges there are other brands of Propane freezers and fridges, many very efficent , compared to RV stuff.

Space is claimed to be precious in an RV so many RV fridges suffer from almost no insulation.
AS homes are larger , some home propane units are well insulated.

To me the all propane rig is best at camping for extended periods of time, however a case can be made for a set of solar pannels and a Sun Frost DC fridge , if one lives in sunny somewhere.

For crusing , probably not , but it could work.


The cost of living with propane in anything BUT a long 24/7 operation is vastly lower than a diesel noisemaker , huge batt sets , good charging and monitoring equippment , a big inverter and $100 sams club 120V "bargan" fridge.

FAST FRED
Mark Radius (216.202.132.34)

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Posted on Saturday, April 06, 2002 - 9:25 pm:   

I have a chance to pick up a very nice Honda Gasoline genset (contractor's grade, 6.5 kw) quite reasonably. Can they be converted to run on either gasoline or propane? Or converted to run on just propane?

MR
Gary Stadler (Boogiethecat) (68.7.217.217)

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Posted on Saturday, April 06, 2002 - 9:36 pm:   

This guy sells a nice kit on ebay that will allow the genset to run on either
http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=1718845917
John G Root Jr (Johnroot) (140.186.114.253)

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Posted on Saturday, April 06, 2002 - 10:13 pm:   

You guys are great, now I can proceed with my propane system. First the bus will be well insulated. I am using a foam board 1 1/2 inches thick which claims an R value of 9 and the Tempshield Double Bubble over that for a claimed 15 R value in just under 2 inches!!! We shall see if it works. So the air conditioner will not need to run 24 hours, more like 6 and only when I am in the high heat which will not be often. I'm glad I can vent the fridge through the roof, and I assume I'll find a range hood I can vent through the roof also. I am considering a Sun Frost fridge (3 month wait), but I may settle for an RV fridge and add the Tempshield Double Bubble and hope that helps.

This seems to me to mean that two 30 gallon propane tanks (both removable so if I can't get close enough to the filling station I can still fill up, will give me about a weeks worth of propane with realistic use in the summer. If it is really hot I'll just have to find an electric hookup camping place.

In my electric bus design I had 6 deepcyle batteries (I am cosidering the Optima Yellow top). Now I may only need two or three. They only need to power the kitchen appliances (coffee maker) lights and entertainment system. A smaller inverter will do as well.

OK I may even become enthusiastic about propane.

I'm leaning towards the Generac PrimePact 66 LP, which the dealer says was designed for propane not just a gas engine with a propane adapter. Is that likely to be true? Does it mean I don't have to mill the heads?

Thanks
John
Gary Stadler (Boogiethecat) (68.7.217.217)

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Posted on Saturday, April 06, 2002 - 11:02 pm:   

Hiya!
There's one little thing you ought to consider before taking two 30 gallon tanks on your bus- it is very likely illegal in many states- those "stationary" type of tanks are NOT approved by the DOT for "on the road" vehicle use. I believe you might be able to lash a couple of smaller tanks to the rear of your vehicle, but you need to check thoroughly with a local propane company to make sure what you can and cannot legally do, because as I remember 30 gallon non-vehicular tanks are too big for the rules of the road.
Vehicular tanks are availiable up to 100 gallons that are specially made with remote-venting capability and a few other considerations that make them less likely to go "boom" in case of an accident, and they are legal... but please check first because it could be a nasty ticket (and a nasty boom) !

Oh, and you certainly don't have to mill the heads when running a gas generator engine on propane...to do so might give you a little more power but it's not worth messing up a perfectly good engine. The dual fuel adapters are super simple and work very well. Easy to install too...
Cheers
Scott Whitney (24.205.239.4)

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Posted on Saturday, April 06, 2002 - 11:15 pm:   

Hi John,

From what I have heard from others, I would research long and hard before buying a Generac. I have heard a couple of people happy with them and quite a number of people report that the company is terrible to deal with on warrantee issues etc. My friend has a contractor model that seems to work fine though.

But take my negative comment with a grain of salt as I am only repeating what I hear.

My only complaint with Onan, is that they seem to hold an iron fist on the parts distribution system and charge a premium. (Yes, sir, we can have your part to you in six weeks. What? You want it sooner? Oh sure, no problem. Our warehouse can expidite it have it to you day after tomorrow. But that will cost you another $40. . .)

However, with only 88 hours on my unit, I haven't needed any parts except a side muffler kit. Apparently, you can cross refernce all your part numbers (filters etc) and buy OEM if you take the time to figure it all out.

Scott
Quest (198.29.191.148)

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Posted on Sunday, April 07, 2002 - 3:43 am:   

Forget the GENERAC!
You won't be happy with it, and they have a problem honoring the warrentee when you need help to repair it. It has specific operational requirements such as run time every month, even when stored. failure with cause a problem and, thats right boys and girls, GENERAC wont warrentee it because you did not follow the owners manual.
Look at anything else but GENERAC. NOW, if you have need for a boat anchor, GENERAC seems to fit the bill there. q
Don Peter (172.175.52.100)

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Posted on Sunday, April 07, 2002 - 12:08 pm:   

I replaced my 30+ year old Onan with a new Onan about a year and a half ago. At that time the dealer who carries both Onan and Generac recommended the Onan. He said that Generac made good generators that were fine for fixed location usage, but that the RV stuff was crap. While the Onan was more expensive than a comparable Generac, he also showed me that his profit on a Generac would be about the same as Onan.

A couple of weeks ago, I stopped by the dealer for something else entirely and got to bsing with him. He still prefers Onan, but said Generac has made some changes and now he would feel comfortable intalling either in an RV.
John G Root Jr (Johnroot) (140.186.114.253)

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Posted on Sunday, April 07, 2002 - 9:05 pm:   

I'm glad I mentioned generac! I think, in the light of all the comments, I'll have the propane system professionally installed. I don't want to be responsible for the big boom. By the way, I was thinking of using the same tank as on a fork truck, but obviously there is more to it than that.
The nearest converter to me is RISCO in NJ, they advertise in Bus Conversions Magazine and I talked to them and they seem comfortable with installing a propane system.
Scott Whitney (24.205.239.4)

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Posted on Sunday, April 07, 2002 - 11:58 pm:   

Forklifts run on LP liquid and you will want LP Vapor. Maybe some of the forklift tanks have a dual withdrawl? I have not examined them closely. When I bought my permanent tank, I bought one that had both vapor and liquid withdrawl. I'll probably never need the liquid, but nice to know it is there if I want it.

What ever you do, don't do what I saw on a skoolie once. The liquid withdrawl tank was plumbed to a standard RV vapor regulator. If you pass liquid to an appliance that expects vapor, you have a problem. The situation on the skoolie was resolved by the new owner by plumbing the liquid from the first tank into a second tank where he then withdrew vapor off the top. Apparently it worked for him and he was able tok use the liquid tank with that method.

BTW, if you want to see many pics of my complete black iron propane system, let me know. I can attach the pics to an e-mail. The e-mail will be over a megabyte though, so it will take a while to retrieve depending on your connection speed.

Scott

scott @ dustyfoot . com
slc (4.17.253.211)

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Posted on Monday, April 08, 2002 - 1:28 am:   

Scott
I have an Onan Marquis 6.7, not installed yet. The manual says it uses liquid propane. Is this a misprint? I thought I saw some equipment on the genset to turn the liquid to gas before it goed into the engine.
Now ya got me running to the installation manual again. This hobbie is sure full of details. slc
Scott Whitney (24.205.239.4)

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Posted on Monday, April 08, 2002 - 2:03 am:   

My Onan Emerald can run on liquid too. If I remember right it requires an extra kit to be installed. It heats the liquid to vaporize it right before it enters the carb. I chose not to use that option since for an RV I needed vapor everywhere else anyway. (and saw no reason to install the extra kit) But it does have a secondary regulator in addition to using a standard RV regulator.

Sounds like your Marquis has the kit already installed - or maybe it comes from the factory that way? I think the problem with that is you will need to have liquid withdrawl for your genset and vapor withdrawl for everything else. You won't be able to put it all on the same pipe.

Having said that, I do have two seperate propane systems, but both are vapor. (one system for permanent tank and another for my portables)

But you might be able to just remove the vaporizor thing. I don't want to advise on the particulars - better check with Da Book.

Scott
George Myers (12.85.14.51)

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Posted on Monday, April 08, 2002 - 10:22 pm:   

Regarding an item above. The code NFPA1192 Article 2-2.1(a) permits up to three DOT approved, removable tanks of up to 45 pounds of LP each. These are the vertical tanks, and there are some horizontal ones, but they are hard to find.

NFPA1192 Article 2-2.1(b) permits one permanent tank of up to 200 gallons aprox. 712 lb

George Myers
Tom Caffrey (Pvcces) (12.146.33.144)

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Posted on Tuesday, April 09, 2002 - 10:28 pm:   

On Sunday, I talked to a propane distributer and he gave me some information on how to convert liquid and vapor propane numbers.

He said that 36.38 cubic feet of propane equals one gallon and that was equal to 91,500 btu. I asked him what pressure the vapor was on the conversion and he said that it is 11 inches of water column.

I didn't think to ask what the temperature was, but I would expect something like room temperature.

91,500 btu divided by 140,000 btu is .6536 and 4.25 lbs. divided by 7.17 lbs. is .5927. From these numbers, you can see that the energy available is pretty close to proportional to the weight of the fuel.

There is slightly more energy per pound (about 10%)in propane than there is in diesel. I expect that the higher percentage of hydrogen in the lighter fuel could be the reason.

Tom Caffrey PD4106-2576
Don Hughes (209.36.53.212)

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Posted on Wednesday, June 12, 2002 - 5:24 pm:   

I also run an Onan 6.5 with a 70 gallon ASME horizontal tank. I also equipped the tank with a product called "Extend-A-Stay" which is a length of hose that I can hook to a 5 gallon portable propane tank if the main one runs out. There were times last Winter in Oklahoma City that I could not get propane delivery due to bad weather so the portable tank came in very handy.

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