Home Generator / Liquid Propane

[Way Back Jack]

I understand that LP is usually expressed in lbs. The generator will use about 11.9 lbs. (2.8 gal.) per hour. We've had outages as long as

40 hours. What is the typical size of a LP tank? Thanx, Jack

[Edwin Pawlowski]

Define typical. The tanks used with grills are usually 20 pounds, but you can buy 40 pounds and 100 pounds easily. Your propane dealer can get much larger ones if you want one. Sounds like you need a couple of 100 pounders at a minimum, or a big humungous job for the full 40 hours.

IMO, the 100 pound tanks are a bit large to haul around in the mini van, plus probably illegal. There is a maximum you can transport in a vehicle with no placards and CDL license. IIRC, it is in the 100 pound range.

[m Ransley]

Do you own this unit, because in small amounts 20lb I pay maybe 16$ for propane. That is 8 $ an hour to run. It doesnt sount right, you would pay a fortune to run it. Propane tanks come in most any size you need. Load determines a major portion of usage. My 7500 -13500 uses 1/3 to 1 gph of gasolene depending on load. Do you have Ng

[Tom Lachance]

When we connect to gensets, we usually consider length of time power might be out, delivery difficulty, size of load. Vaporization has to be considered also.

[lp13-30]

What is this generator being used for-- a commercial building? It must be huge to comsume that much fuel. If you are correct about the consumption and want it to be able to run 40 hours, you will need 112 gallons.. The most common size tank in that range, with some to spare, is 250 gal. All propane tanks are only filled to 80% capacity, which would be 200. The main thing is that most propane companies will not deliver less than 100 gallons, and the few that do, charge so much extra per gallon that you will pay as much for 50 or 60 as you would for 100. Larry

[Stormin Mormon]

What the heck are you trying to run? I figured it out, for gasoline a galon provides about 2000 watts for an hour.

You trying to run a full 4000 watt load all that time? If so, you may wish to conisider turning off some of the load. Or perhaps cycling the fridge on for half an hour, and then the freezer for the other half of the hour. But not both full time.

[BobK207]

Cris-

I think your number might be off a factor of 10.

Some rough calcs gives me about 240,000 btu/r=hr (~12lbs/hr @ ~20,000 btu/lb)

That's about 70kw at 100% efficiency; ~15 to 20kw electric. That's a fair sized generator.

How many btu/hr (sustained energy supply rate) a propane can supply is a function of its size & the air temp. I couldn't find the data I was looking for but my guess is that you'd need a least a 100 lb cylinder to run this beast at all, even a faction of a day. For extended run times (24hrs/day for days) you'd need 100's of gallons.

cheers Bob

[lp13-30]

At the company I used to work for, I had a 94 Chevy pickup-- full sized

1/2 ton, V6, automatic-- that ran on propane. It got 15 mpg running down the road at 60 mph, which figures out to 4 gallons/hour. A generator that uses 70% as much fuel as a truck at 60 mph has to be huge. It has got me curious-- hopefully the OP will reply with more info. Larry