Parallel Propane Tanks @ 0ºF for Dual Fuel Generator

[time2roll]

Don't need to be 90. 30 to 45 is plenty. I assume it shuts off at 90.

I would still keep 1 or 2 full cylinders as spares if conditions get difficult. Or fill 2 - 3 at a time if the roads are clear, easier for the effort.

 

[Bobert]

Use a heat pad powered from the generator and insulate your tanks after as long as you start with 2 full 40lb tanks you shouldn’t have any trouble. We had a situation years ago where we had to heat a space for 2 hours with a 60,000 btu furnace. In -20 Fahrenheit temperatures. I would set a 20 pound tank in an outside space heated by a diesel heater until the tank was 80 that worked.

 

[jimf909]

As I understand it, the freezing occurs in the tank when propane is removed faster than the tank can draw heat from the surrounding air, i.e. it's a surface area x flow problem and smaller tanks are more prone to freezing. I have a 500 gallon tank with a line that runs to an 11 WC" regulator outside the house. From there the black pipe runs 70' outside the house to a heater inside the house and there's enough pressure to operate the heater. A 3/4" 35' CSST line also runs from that regulator to a generator outside. I've had no propane issue down to temps below 0 degrees F (32 degrees below freezing). In my experience the freezing will only be an issue at your tank if the surface area is too low relative to the rate of propane flow.

But I think you had most of that figured out doing the research you did for your first post.

 

[green mountain boys]

Propane boil might be better than you think. Try it it with one and see how it goes?
(FWIW my propane heat was fine at -39*F)

buy one
Then plumb it from where they can be ~25’ of hose with direct burial copper and a brand new regulator.

They’ll charge you pretty expensively to fill it but probably not more per gallon than a refill station. I have a 100gal and I pay about 10-cents more per gallon than getting a 30lb cylinder refilled per gallon. But it lasts most if not all of the winter and I don’t have to bring a tank to refill. So it’s worth it.

I agree with 12voltinstalls. The OP may be trying to solve a problem that does not exist. Try it first the easy way, a single small tank, and see if you have a problem. If you do have a problem, then address it. Above ground propane tanks are very common around here and it get a whole lot colder than 0F on a regular basis. I have seen reduced propane flow at extreme temperatures, like -30sF, but it does not seem to be a big problem. Just give it a shot. If it works, great. If it does not work, what have you lost?

 

[JRH]

Just got a new inverter generator and want to run only on propane after initial break in. Worried about cold climate use of propane at 0ºF. Based on some power and propane evaporation tables at motor snorkel (ttps://motorsnorkel.com/propane-consumption-rate-2/), looks like I need the following:

5kw generator at 50% load uses: 50k BTU per hour

40# propane tank puts out 12.6K BTU per hour at 0ºF

50k/12.6k= 4 - 40# propane tanks in parallel

This will give me enough evaporation at 0ºF to run my 5kw generator at 2500kw for charging. Is this correct? If so where the hell do I get a 4 propane tank parallel connector..lol.

I would check to see if those numbers you post are accurate in real world use for a your exact device …. somthing sounds abit off …I have lived with propane in my RV for 10 years. the first 2 years I used a 20b tank and it gets colder than zero here …..they were mounted outside on the typical tongue mount….

near zero and below ,several times back then I have run my 30k (30,000 ) btuH ducted furnace plus the water heater ,plus cooked on the stove and the refer too Sometimes … I have purposly tried to turn everything on at the same time to test its ability…everything ran …
im not Gona get into the calculations as I don’t know all the numbers on all the devices I have as it never mattered to me because all the stuff worked when I turned it on…I have a standard 10.5 - 11 inch column RV regulator since new and that’s it…
the only thing that ran a majority of the time was the furnace and refer…and I did use electricity and propane sometimes for whatever reason..???
I may be wrong but my 20 lb tank put out a lot more than 12.6 kbtu per hour or I don’t think it could have properly run just the furnace…much less anything else ..something is wrong here.
…I’m not a propane whiz .. so I’m all ears…

im still using the same gear except I went to a 500 gallon tank…refill it once a year… love it.

 

[jimf909]

I've had a 20 lb propane tank freeze up running a 7.25kW generator at about 32*F, that's why I plumbed it to the 500 gallon tank. I'm sure there are a number of variables at play.

Regardless, the OP will need to discover what works for their temps and fuel draw.

 

[OzSolar]

I've had a 20 lb propane tank freeze up running a 7.25kW generator at about 32*F, that's why I plumbed it to the 500 gallon tank. I'm sure there are a number of variables at play.

Regardless, the OP will need to discover what works for their temps and fuel draw.

In my experience it's not that hard to freeze up portable propane tank when even a 8kW generator is running at anywhere near full load. We've been know to point the exhaust of the gennie at the tank to resolve this issue.

 

[ChrisG]

Thanks for all the feedback. The numbers I posted seem to correlate across multiple sites. Anyway probably am overthinking this but last time power was out for a few days the drive/road was not drivable and no sun. Just wanting to get better prepared.

I already have multiple 20lb tanks, going to get a manifold and parallel 2-3 of them and see how it goes in the next cold snap if we’re here. Next step would be 3 40# if first test doesn’t work.

 

[JRH]

In my experience it's not that hard to freeze up portable propane tank when even a 8kW generator is running at anywhere near full load. We've been know to point the exhaust of the gennie at the tank to resolve this issue.

Haaa , now that’s a good idea…

i Just bought my 3rd dual fuel and broke it in with propane.. it’s a 8500 watt … that is part of why I’m interested in what’s being said here about freezing…
“it seems” I have read that when a 20 lb tank is sorta low this can happen easier than when it’s full…if it’s really putting out fuel , I have seen the freeze line on the outside at or near the bottom of a 20 lb .”it’s seems“ to mean it’s getting ready to run out soon.
also “ it seems” that the faster / larger the release of fuel contributes to freezing…
( as in a large vs smaller gen set…) .

I did have some custom long lines and fittings made up this year for the 500 gallon tank with seperate shut off valves so I can draw from the big tank to run for extended periods… plus they Fit the bbq / fireplace quick connect fittings at the rear of the RV….

The champion 3500 has never given me problem freezing and I have never tried the 8500 champion in cold weather… but I will hopefully soon. I love propane gen sets …I hate gasoline ones…
I just havent had any real issues in my life using propane . That’s why I haven’t dived in deep to understand it better…
J.

 

[DIYrich]

If so where the hell do I get a 4 propane tank parallel connector..lol.

This joins 2. You can then daisy chain. Wouldn't do it long term, but emergency should be fine. Also, try a local RV dealer.

Lemfema Universal Y Type Splitter Propane Tank Converter Adapter Hose, Two Way Qcc1/Type1 Inlet & POL/QCC1 Exit Propane Hose to Connect 5-40lb Tank for Grill, Heater, Fire Pit, Fireplaces https://a.co/d/2JsXJJg

 

[12VoltInstalls]

They can't get their vehicles up the main road grade which is about 10-14 degrees, steeper up my drive to house which is around 12-20 degrees

Wimps. That’s not that uncommon here in Vermont.

@jimf909, just for example at moderate temperatures, if I run the regulator that came with the generator off a 40lb tank and through 40ish feet said the CSST or hard copper to the generator bellow using a quick connect or something, it would work? I’d have the required pressure?

The feet of drop will or may make too much pressure imho

 

[12VoltInstalls]

This joins 2. You can then daisy chain. Wouldn't do it long term, but emergency should be fine. Also, try a local RV dealer.

Think outside the box.

You can take cast iron nipples and Tees and make a manifold with gas shutoffs for each tank’s stub.

Everything does not come premade.

 

[jimf909]

Think outside the box.

You can take cast iron nipples and Tees and make a manifold with gas shutoffs for each tank’s stub.

Everything does not come premade.

- The premade hoses will start to run into some $ and may be a bit messy.
- If you know exactly what you want a propane or RV shop can build it with hoses and crimp all the fittings. This won't be easily changed if you want to do something different after a year or two (back to the shop for changes).
- The black pipe allows you to build something, test it and take it apart and build it differently. Position your 20# tanks where you want them sketch out a manifold design, go to a well stocked hardware store, buy the parts and assemble it. It's a fun puzzle to assemble.

There are many ways to put this together. Here's one:
- Propane tank to 3/8" flare fitting w/regulator
- 3/8" flare to 1/2" NPT (the black pipe)
- Black pipe nipples, tees, elbows to build the manifold
- You can put a valve at each tank or I think you could have just one valve at the start of the manifold.

Regarding measuring pressure, you can add a tee with a reducer and plug to allow easy checking of pressure at the top and bottom with a manometer. I believe that code requires an accessible port for this function. You can buy a gauge for $35-$50 but making a manometer is easy and fun.

Here's a homemade manometer that I made showing 8 water column inches:

Port to check pressure:


Manifold-ish

 

[Kremer]

I’d point the generator cooling air exhaust at the propane tank(s). Let the waste heat help you.

 

[ChrisG]

Found a simple kit to use with up to 3 20/30/40# tanks I’m going to buy. Here is the link: https://propanemanifold.com/

Warmed up today above 30 so just finished installing my generator inlet and interlock, all 10awg THHN. Needs to get warmer to silicone around the top and sides of inlet.

Sure people will ask what those ‘warts’ on my main panel are. They are Honeywell 24v heating relays for 240v electric baseboards. I have a Nest thermostats controlling upstairs and downstairs separately. Put these in before my mini-splits and are backup now.

 

[12VoltInstalls]

Found a simple kit to use with up to 3 20/30/40#

Those will do. $260 seems like a lot, imho. The two-tank automatic valve / regulator on my camper cost me ~$45 new at an RV place so $260 hurts my head

 

[ChrisG]

Those will do. $260 seems like a lot, imho. The two-tank automatic valve / regulator on my camper cost me ~$45 new at an RV place so $260 hurts my head

Yeah. I just want something that will allow me to have at least three. Still looking a building something like others mentioned.

 

[dopeassjackson]

Is there E0 fuel available near you?