Propane!

No propane thread is complete without a little Hank Hill

jkwilson wrote:
It’s not pressure that’s the issue. It is vaporization rate that is the problem which essentially limits BTU/hour. At 0 degrees F, even a 100lb tank can’t supply anything close to enough to run a 100,000BTU/hr appliance.

I had no idea what you meant by that so I googled it and found this very interesting document:

http://www.regoproducts.com/pdfs/L-545_Servicemans_Manual.pdf

I am not a propane expert either, but I didn't realize that vaporization rate and temperature factored into tank size. Vaporization rate measured in BTUs drops dramatically with temperature and the amount of propane left in the tank. I guess someone determined that a 1,000 gallon tank would meet the needs of my home when it's cold out and as it's depleted. Both furnaces, fireplace, oven, etc. functioned without issue until the thing was nearly 100% empty.

Sorry for the diversion, but I thought jkwilson's point was interesting.

babock wrote:

jkwilson wrote:
I'm far from a propane expert, but my understanding has always been that a small cylinder can't produce vapor fast enough to supply gas to a big appliance like a household furnace.

It can easily supply it. The tank pressure no matter what size tank will be in the 140PSI region depending on temperature. The regulated pressure at the appliance is around 0.4PSI.

I have run my house on a 20lb BBQ tank when my 500 gallon tank has run out and I have a 190K BTU tankless water heater.

It’s not pressure that’s the issue. It is vaporization rate that is the problem which essentially limits BTU/hour. At 0 degrees F, even a 100lb tank can’t supply anything close to enough to run a 100,000BTU/hr appliance.

babock wrote:
It can easily supply it. The tank pressure no matter what size tank will be in the 140PSI region depending on temperature. The regulated pressure at the appliance is around 0.4PSI.

I have run my house on a 20lb BBQ tank when my 500 gallon tank has run out and I have a 190K BTU tankless water heater.

Good to know. Thanks! I got 200 gallons last Feb, which brought it up to 30% on the gauge (300 gallons). It's now down to 20% on the gauge. So between grilling and the HW heater, I'm using around 8 gallons a month (if the gauge is correct). I can get by with a cylinder while I wait for a refill if I need to. I figure I can wait until next year when prices dip again to top it off.

The HW heater is a 75-gallon high-efficiency unit and is very expensive to replace so I left it hooked up to the propane until it fails (it's only a few years old). When it kicks the bucket, I'll get a NG version of the same heater and be done with the propane except for grilling and zombie-apocalypse backup fuel for the generators.

jkwilson wrote:
I'm far from a propane expert, but my understanding has always been that a small cylinder can't produce vapor fast enough to supply gas to a big appliance like a household furnace.

It can easily supply it. The tank pressure no matter what size tank will be in the 140PSI region depending on temperature. The regulated pressure at the appliance is around 0.4PSI.

I have run my house on a 20lb BBQ tank when my 500 gallon tank has run out and I have a 190K BTU tankless water heater.

Farmboy666 wrote:

tinstartrvlr wrote:
FWIW, to save propane, I lower the thermostat down to 50 at night, just enough to keep the pipes and things from freezing.

I bought an electric mattress pad heated cover to stay warm, (one of the best things I ever bought I think) and then in the morning, fire up the furnace and electric heat to take the chill off.

If it's going to be a cold day, I just leave the electric heat on (not unattended), dress warmly, and use the propane only when necessary for heat.

I usually make it about 3 weeks before I need a refill (30# tank), and until I refill, I just switch to the other tank.

Sounds more like a contest to see how long you can make the propane last. I turn the thermostat to where I'm comfortable and when I need propane I get it refilled.

Who is winning? :B

tinstartrvlr wrote:
FWIW, to save propane, I lower the thermostat down to 50 at night, just enough to keep the pipes and things from freezing.

I bought an electric mattress pad heated cover to stay warm, (one of the best things I ever bought I think) and then in the morning, fire up the furnace and electric heat to take the chill off.

If it's going to be a cold day, I just leave the electric heat on (not unattended), dress warmly, and use the propane only when necessary for heat.

I usually make it about 3 weeks before I need a refill (30# tank), and until I refill, I just switch to the other tank.

Sounds more like a contest to see how long you can make the propane last. I turn the thermostat to where I'm comfortable and when I need propane I get it refilled.

What the bionic man said or take the auto change over valve out and toss it in the trash - or or maybe give it to me for a spare. :h

At 30 degrees I would be heating my unit solely on electric. Minus 30 and I'd be looking for propane.

With an automatic switch over, it works great to keep one bottle closed. Until you run out of propane on a cold night. And have to get up and manually change it because your furnace is blowing cold air.

I'd much rather leave both open, and have it work as it is designed to. Once you have the trailer for a while, you can better judge usage. Until then (and after), check every couple days, or once per week.