Small Scale Propane

[quicksandfarmer]

I have exactly one propane appliance, a cooktop, the oven is electric. When I bought the house there were two 100lb tanks out back, which were rented, and I just assumed the rental. The first few years the propane company would come out once a year, top up the tanks and inspect them. Because I use so little it was included in the service call, it would cost about $40/year. After a few years they said they wouldn't do that any more, they would only fill the tank when it was empty, I should call them.

A couple months ago I thought the cooktop was burning low, so I called them. It took them four days to come out! And when they came out it turned out the tanks weren't empty. They also said that from now on they aren't serving tanks below 250 lbs, and wanted to sell me a 250 lb tank. I feel like we're going in the wrong direction. I want smaller tanks, the ones I have now are big and ugly. I looked at my checkbook and the last time they were out was in 2014, so I figure we're using less than 20 lbs a year.

I'm thinking of just getting rid of the rented tanks and buying smaller tanks. A 20 or 30 lb tank would fit under the deck out of sight. It would also be something I could take to the hardware store to refill when it was empty rather than waiting four days for the propane company to come out. I'd probably get a pair so I always had a spare.

The cooktop has a rated capacity of 50,000 BTU if all burners are going. While we rarely/never use all the burners, I'd like to be able to supply it. Any special considerations for the regulator?

Thanks.

 

[Dftodd]

I had good luck with my 30lb tanks on my camper. Just running the hot water heater and fridge it would last quite a while. I had a diverter valve hooked to the tanks with a gauge. Gauge would start showing red when the tank was getting low.

Once 1 tank was empty, I would switch the valve to the other tank. I could then disconnect the empty tank and have it filled at my leisure.

Sorry, can't help with the regulators.

 

[Roadworthy]

It sounds like a practical solution to me.

 

[jaxs]

With only a 20 pound tank,you might have a problem on coldest days of winter running more than a couple of burners. That can be remedied by connecting 3 20 pounders together during cold weather. If 3 tanks are tied togeather by hose,2 can be isolated by simple turning tank valves off on 2. When cold days are expected,open all tanks until weather warm's. If primary tank has 5 pounds,spares have 13 each and 3 pounds is consumed while all valves are open,each tank will contribute near if not exactly 1 pound. That being true,you always empty one or two and still have one in reserve.

 

[RNeumann]

Typically a house has two regulars. One at the tank to drop the pressure to say 10psi and one at the house that drops it to say 1/2 psi. Sometimes the appliance has another. You should use a regulator at the house that will drop the pressure to the standard pressure for inside the house. Typically the regulator isn’t part of the rental. You should need anything more when switching from one tank size to another.

 

[3Ts]

Go with what K7LN said. An RV setup should work fine for you. Regulators have varrying BTU ratings, but since you are only doing 50k worst case, a small BBQ grill would work, but use an RV one instead! The 2 stage ones are more reliable and provide a better gas regulation.

LP Gas Regulators 11: How to Find or Replace a Gas Grill Regulator - The BBQ Depot

 

[widefat]

We run a cooktop with one 100lb tank. We are averaging 18-20 months; when empty, I run to the coop and have the 100lb tank refilled.
We own the tank, I think it was around 150 for a new tank.
I have also used a 20lb tank as a gapfiller.
Agree re the two stage regulator.

 

[CobyRupert]

With only a 20 pound tank,you might have a problem on coldest days of winter running more than a couple of burners. That can be remedied by connecting 3 20 pounders together during cold weather. If 3 tanks are tied togeather by hose,2 can be isolated by simple turning tank valves off on 2. When cold days are expected,open all tanks until weather warm's. If primary tank has 5 pounds,spares have 13 each and 3 pounds is consumed while all valves are open,each tank will contribute near if not exactly 1 pound. That being true,you always empty one or two and still have one in reserve.

I'm sure I won't explain this right, but the propane gas "boils" off the top of the liquid propane in the tank and gives it pressure. (LP boils at -44F). How much boils off is a function of the surface area of the liquid, that is, the shape of the tank, as well as the temperature. If the tank is tall and skinny, the rate of vaporization is less than a short and fat tank. However, if the tall and skinny tank is turned on its side, the liquid now has a lot more area to vaporize and your supply (pressure) is better, however the position of the valve is important as you don't want liquid exiting the valve or getting into the gas line and going to the end device (unless that device has a "vaporizer" and is rated to use actual "liquid propane" instead of LPG).

This can be demonstrated with a (butane) Bic lighter on a cold day.

 

[pmsmechanic]

I'm going to subscribe to this thread to learn something.

 

[dougtrr2]

Get two 20 pound cylinders and an RV type regulator. The tanks will switch over automatically, and you get a red flag that one has gone empty. This way you'll never get an interruption in the gas supply.

View attachment 625711

This looks like a good idea. But I would buy a third tank as back up. That way when I ignore the red flag and run both tanks empty I could still finish Thanksgiving dinner. On my grill I have two tanks. When I empty one I take it off the grill and set it by the garage door as a constant reminder I need to get it filled. You mentioned putting them under a deck and I think it would be easy to miss the flag popping up.

Doug in SW IA

 

[nyone]

100lb tanks with the multi fill valve that the propane truck can fill are $150 that may be your easiest option once you find a new propane supplier.

Are you sure your cook top is 50kbtu? If it is thats with all burners on and on high.

Fo arguement sake lets say your normal use isnt more than 25kbtu. A 20lb tank isnt enough in the winter still. Its hardly enough at 60*. Going upto a 30lb tank dosnt really help much. Also at the price of two new 20lb tanks your about $50 shy of just getting a 100lb tank that will vaporize in a way you need for your max of 50kbtu.

If you do get two smaller tanks get 20lb ones. The way i see it i buy them once and exchange when old to a newer one and the cycle starts again.

Take a look at this propane cylinder vaporization chart.

 

[quicksandfarmer]

100lb tanks with the multi fill valve that the propane truck can fill are $150 that may be your easiest option once you find a new propane supplier.

Are you sure your cook top is 50kbtu? If it is thats with all burners on and on high.

Fo arguement sake lets say your normal use isnt more than 25kbtu. A 20lb tank isnt enough in the winter still. Its hardly enough at 60*. Going upto a 30lb tank dosnt really help much. Also at the price of two new 20lb tanks your about $50 shy of just getting a 100lb tank that will vaporize in a way you need for your max of 50kbtu.

If you do get two smaller tanks get 20lb ones. The way i see it i buy them once and exchange when old to a newer one and the cycle starts again.

Take a look at this propane cylinder vaporization chart.

Thanks. This is incredibly helpful, really gets to the question I'm asking. So a bigger tank does give better performance.

Cooktop is 50K BTU -- five burners, one 16K, three 10K, one 4K.

 

[Diggin It]

I'd be looking at:

>>> A 100 pound tank if I had a way to move it safely to a refilling station. Looks like they make 50s and 60s also.

>>> Replacing the LP cooktop with electric.

 

[3Ts]

I have an RV with 2- 30# propane tanks and a 36k btu heater, in the winter in central Texas I go thru a tank in 2 to 3 days. That's a lot of area exposed to the cold with only 1.5" insulation. Since you're only running a cooktop off your tanks, they'll last a whole lot longer. The point being that you're not drawing much and will last awhile. The outside temperature and shape of tank is important for vaporization, there are charts that can tell you the BTU rate of vaporization for temperature and tank size. (The vaporization rate changes based on how full the tank is.)

It is theoretically possible to determine how long a gallon of propane will last when you run your cooktop. If we assume you run 2 of the 10k burners full on (not likely) for a half hour each day that's 10K BTUs per day. Propane has 91,502 BTUs per gallon, so you could run your cook top for 9 days on one gallon of LPG. A 20# tank (if it's properly filled) has 430,270 BTUs and would last 43 days.

 

[nyone]

I'd be looking at:

>>> A 100 pound tank if I had a way to move it safely to a refilling station. Looks like they make 50s and 60s also.

>>> Replacing the LP cooktop with electric.

With a 100lb tank thats got a multifill valve you own the tank, can take it some where to get filled but can also call the truck and have them do it.

 

[Diggin It]

They also said that from now on they aren't serving tanks below 250 lbs, and wanted to sell me a 250 lb tank.

once you find a new propane supplier.

but can also call the truck and have them do it.

Maybe. Maybe not. Suppliers tend not to want to come out to fill small tanks. Mine won't do less than 150 gallons and offers discounts for over 200.

 

[quicksandfarmer]

This looks like a good idea. But I would buy a third tank as back up. That way when I ignore the red flag and run both tanks empty I could still finish Thanksgiving dinner. On my grill I have two tanks. When I empty one I take it off the grill and set it by the garage door as a constant reminder I need to get it filled. You mentioned putting them under a deck and I think it would be easy to miss the flag popping up.

Doug in SW IA

I now understand something the propane guy said, which made absolutely no sense to me at the time. I've been running off of just one of the 100 lb tanks at a time, I figure that way I know when one runs out and switch over. He said I'd get more capacity running both at the same time. Now I get why.

 

[quicksandfarmer]

Maybe. Maybe not. Suppliers tend not to want to come out to fill small tanks. Mine won't do less than 150 gallons and offers discounts for over 200.

That's exactly the problem I have right now. I might use 20 lbs a year, I'm trying to figure out how to do it.

 

[nyone]

True. Finding a new supplier before you buy any tank would be key...or just going electric like someone else said.

Cast iron cooks alot nicer over gas than my current electric stove. When we go stove shopping it will be propane and our first propane appliance in our house. If i didnt enjoy cooking with cast iron i wouldnt own a gas stove.

 

[quicksandfarmer]

I think I know the answer, but would it be completely illegal for me to put a 20 lb tank in the basement?