Propane Math

I'm getting closer to finishing "Bud" and should be ready to install the heater in a couple of days (I'm building a mounting rack for my LG), but I still wrestle with the propane vs diesel heater.

Here is my problem. I tend to clean commercial that is in excess of 10k sqft at a shot which takes me 7-8 hours of steady wand use. I need to be able to carry enough propane to finish that size of job, but I don't know where that number resides.

I know that when running full blast, the #4 LG would burn 2 gallons of propane per hour. That would tell me that I need like an 80 lb tank just to complete the one job based on 1 gallon of propane being equal to 5 lbs.

Now propane is cheap right now, but having to carry that big of tank AND needing to fill so often doesn't feel like a very good design. Maybe my understanding of these type of system is way off? Maybe the numbers are wrong?

What is the reality here, does it really take that much propane?

I'd be real surprised if you were able to burn 2 gal an hour with the #4.

I don't think I burn 1 gal an hr with the #3.

And I think you could make it threw the job with 12-14 gal. easily, prob more like 10, but I'm just erroring on the safe side.

#4 is .5 gal per hour approx

That sounds a whole lot better!!

I was going off an old furnace chart for 185k btu rating, but the real world numbers is what I needed.

I will finish the platform then and get this thing done!!

Now I remember where I got that 2 gph number....from our old board and Judson, but that was for both the #4 AND the motor on his all-propane system.

http://www.realcleaners.com/propane_turckmount.html

Yea, the eng alone will burn about 1 gph.

I think if you figured 1 gph used by LG #4, you would be really safe, and being overly conservative.

I'm almost pleased by this choice of heater, but I am still swimming through data about sources and costs.

In my area, the closest filling station is U-haul at 21 miles away. The Tractor Supply Stores fill as well and there is one 8 miles away, but the website doesn't list them as a filling station....might not be available.

The really sad part is that U-Haul quotes $3.43 per gallon of propane to fill the tank. I have a buddy that delivers propane to the farmers and it is like 40 cents per gallon right now. Diesel around here is $2.80 per gallon and literally 2 blocks away.

I could lease a large tank at the house and refill my tanks off of that, but then I will have a giant tank in the backyard which would not make the neighbors happy nor help my property re-sale any.

Decisions....decisions.

I think its 1.5 for kohler motor and .5 for LG but Im not completely sure, would have to ask Les again I dont really have a way of measuring it unless I were to run cold on a few jobs.

hard to say if propane is worth it then Mil, 21 miles is pretty far and 3.43 a gallon is a rip off

U haul here is 3.95 a gallon and right across the street its down to 2.19 now.


I think if your only running the one heater then its not worth getting a big tank at home, but I would check with delivery guy and see what the smallest tank size is that can still take delivery.


maybe they have like a 100gal, that would be easy to just put in the ground.


Like Les was saying in that post, compressed natural gas will be the future... lots of companies already running their trucks on it here. All our waste management trucks went NG.

you can get a fill station at your house for about 10grand if you already have NG service.

Thanks for the information AC, it really helps.

I spent the morning studying the Northstar heater....not going to be an option now. Ran it for about 10 minutes...awesome heat, but the diesel did smell and tossed up a soot cloud once. I don't want either in my truck. The salesman suggested I use kerosene, but that is just as big of a pita and expensive as the propane option.

So, propane is the winner. The 21 miles thing isn't going to cut it though, so I have to look for options. I might be able to just run 2-30 lb tanks mounted under the box and just take them off to refill local. Sure, kind of a pita to keep removing them, but it would be an option.

I think the smallest residential tank size was 250 gallons. That wouldn't be too bad and my buddy drives right buy me with his truck daily, so getting it filled when needed would be easy.

The downside would be that I would have to fill it from the alley behind the house which gets pretty packed with snow in the winter. Still, might be the best option right now.

What about mounting the north star on a slide out tray, so when running it, it wouldn't be making a mess in your truck?

I guess you would still have the problem with the Diesel odor possibility blowing into the job tho.

And for propane......
What about getting 6-8 or more, 5 gal BBQ type tanks, and just do the Rhino exchange deal, those places are everywhere now, at least around here, there's 6 or 8 places within 2-3 miles.....gas stations, liq stores, ace hardware, lowes, HD.  You could connect them with a hose and just draw from them, switch when needed, or transfer from them to your big tank on truck, but then you would prob need a pump.

Id go bbq tanks and just exchange them, you could also call Kacy with relia built and maybe order a pre heater

pre heater is really simple and saves a ton of propane on our express van set up, usually 2 bbq tanks a week is down to 1 tank lasting 1.5 weeks

actually if you went to home depot and got some tubing, not sure if copper is the best but they have other metals then coil it around your tnt exhaust and feed that to the LG youll get some pretty hot water going in.

Is that pre-heated water going threw your pump?......if so what temp is it?

Just an FYI, running hot water into pump will tear up the seals pretty quick.

I thought about the bbq tank idea as they are being exchanged everywhere around here as well, but carrying propane tanks inside the truck seems like a bad idea to me....even if secured well.

I guess it would still be an option....3 bbq tanks would last me the night, just irritating to have to change tanks a few times.

Now that I think about it, I could add a siphon valve to the belly tank and refill it with bbq tanks.....that may not be so bad.

As for the slide out and diesel heater....it weighs 300 lbs without fuel or water in the coils.

milspec6 wrote:I thought about the bbq tank idea as they are being exchanged everywhere around here as well, but carrying propane tanks inside the truck seems like a bad idea to me....even if secured well.

I guess it would still be an option....3 bbq tanks would last me the night, just irritating to have to change tanks a few times.

Now that I think about it, I could add a siphon valve to the belly tank and refill it with bbq tanks.....that may not be so bad.

You could always hook up 3-4 BBQ tanks in series, so you wouldn't have to stop and switch them, with the right hoses...or would that not work?

And have a special made bracket to secure them.

And using the BBQ tanks to refill the belly tank, is what I was also thinking, and mentioned above............just not sure if it would take a pump, of it it could be gravity fed?

I'm not sure if you could fill a larger tank with bbq tanks due to psi....vice versa yes, but maybe not small to large.

I've been told that you can use the valve adapter to add a bbq tank when the belly runs out as a back-up, but I don't know about filling one.

I guess I just need to make a few sales calls tomorrow to find out more details on what the retailers can offer. I know that the residential tanks are a contract lease around here, so it costs nothing to have set-up in the yard by the alley. I will just have to figure out if they have something smaller to avoid the negatives of having a big tank in the yard....like a 100 gallon maybe.

Then I would need to give the alley some attention in order to get close to the tank (Remove fencing and landscape) and the list never ends does it?

This might be one of those "other" mistakes in judgement that I have committed for this project build.....probably should have gone with the Sapphire Hx unit.

Too late now.....plowing forward.

I had this hose made, and bought this fitting to add in before my belly tank regulator from my Propane Wholesaler, that enables me to connect BBQ tank when the belly tank is empty.

So if I'm low and think I might run out at a job I'll bring a BBQ tank, but if I don't have one and I do run out, usually the customer will have one around that I have used and then given a few bucks off of bill to cover their gas I used.

Cool, that looks like a nice set-up.

I went back and watched some of Judson's videos and found one that covers the #4 LG heater.

For those interested in the numbers, using a 10 flow wand at 500 psi, usage is 0.9 gallons on commercial and 0.5 gallons on residential. I run a 12 flow wand on commercial, so it would be a little more.

I think I will just run it off a bbq tank for a couple of cleanings to verify that the heater works properly and that it fits my needs before I start looking for a permanent tank.

Thanks for all the help...my brain is less scrambled now.

Glad to hear you're feeling better about the heat situation now.

I still think those numbers that Les claims are high............but you'll soon find out if using a small tank, as it should be easy to track.

Caught a break today and discovered a small gas station in the neighboring town that will refill propane tanks.

I do a lot of work in that town and it is only 15 minutes away. He told me that he fills up to 30 lb tanks, but he might be willing to fill a larger belly tank as well for an "additional fee".

Right now, propane delivered is 85 cents in this area and U-Haul is adding a 400% mark-up, so this guy's "additional fee" can't be any worse and he is a lot closer.

Things are falling into place with "Bud" and I made some really good progress after having some time off last weekend. It is amazing how many little things go into a box truck build.

It will not be the prettiest build, but it looks like it will be a very durable build with everything being either SS or Aluminum...including all fasteners. There will never be any rust in this box.

I still am undecided on if I want to use the softener or not as I tied in my house softener to my hose bib. I also don't know what to do with the narrow compartments on either side of the box....well they aren't that small at 41" x 26" x 28" and stacked 3 high.